WebSVN – Kolibri OS – Blame – /contrib/sdk/sources/ffmpeg/doc/ffmpeg-codecs.pod

Rev	Author	Line No.	Line
4349	Serge	1	=head1 NAME
		2
		3	ffmpeg-codecs - FFmpeg codecs
		4
		5	=head1 DESCRIPTION
		6
		7
		8	This document describes the codecs (decoders and encoders) provided by
		9	the libavcodec library.
		10
		11
		12
		13
		14	=head1 CODEC OPTIONS
		15
		16
		17	libavcodec provides some generic global options, which can be set on
		18	all the encoders and decoders. In addition each codec may support
		19	so-called private options, which are specific for a given codec.
		20
		21	Sometimes, a global option may only affect a specific kind of codec,
		22	and may be unsensical or ignored by another, so you need to be aware
		23	of the meaning of the specified options. Also some options are
		24	meant only for decoding or encoding.
		25
		26	Options may be set by specifying -I
		27	FFmpeg tools, or by setting the value explicitly in the
		28	C options or using the F API
		29	for programmatic use.
		30
		31	The list of supported options follow:
		32
		33
		34	=over 4
		35
		36
		37	=item B I B<(>IB<)>
		38
		39	Set bitrate in bits/s. Default value is 200K.
		40
		41
		42	=item B I B<(>IB<)>
		43
		44	Set audio bitrate (in bits/s). Default value is 128K.
		45
		46
		47	=item B I B<(>IB<)>
		48
		49	Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
		50	tolerance specifies how far ratecontrol is willing to deviate from the
		51	target average bitrate value. This is not related to min/max
		52	bitrate. Lowering tolerance too much has an adverse effect on quality.
		53
		54
		55	=item B I B<(>IB<)>
		56
		57	Set generic flags.
		58
		59	Possible values:
		60
		61	=over 4
		62
		63
		64	=item B
		65
		66	Use four motion vector by macroblock (mpeg4).
		67
		68	=item B
		69
		70	Use 1/4 pel motion compensation.
		71
		72	=item B
		73
		74	Use loop filter.
		75
		76	=item B
		77
		78	Use fixed qscale.
		79
		80	=item B
		81
		82	Use gmc.
		83
		84	=item B
		85
		86	Always try a mb with mv=E0,0E.
		87
		88	=item B
		89
		90
		91
		92	=item B
		93
		94	Use internal 2pass ratecontrol in first pass mode.
		95
		96	=item B
		97
		98	Use internal 2pass ratecontrol in second pass mode.
		99
		100	=item B
		101
		102	Only decode/encode grayscale.
		103
		104	=item B
		105
		106	Do not draw edges.
		107
		108	=item B
		109
		110	Set error[?] variables during encoding.
		111
		112	=item B
		113
		114
		115
		116	=item B
		117
		118	Normalize adaptive quantization.
		119
		120	=item B
		121
		122	Use interlaced DCT.
		123
		124	=item B
		125
		126	Force low delay.
		127
		128	=item B
		129
		130	Place global headers in extradata instead of every keyframe.
		131
		132	=item B
		133
		134	Use only bitexact stuff (except (I)DCT).
		135
		136	=item B
		137
		138	Apply H263 advanced intra coding / mpeg4 ac prediction.
		139
		140	=item B
		141
		142	Deprecated, use mpegvideo private options instead.
		143
		144	=item B
		145
		146	Deprecated, use mpegvideo private options instead.
		147
		148	=item B
		149
		150	Apply interlaced motion estimation.
		151
		152	=item B
		153
		154	Use closed gop.
		155
		156	=back
		157
		158
		159
		160	=item B I B<(>IB<)>
		161
		162	Set motion estimation method.
		163
		164	Possible values:
		165
		166	=over 4
		167
		168
		169	=item B
		170
		171	zero motion estimation (fastest)
		172
		173	=item B
		174
		175	full motion estimation (slowest)
		176
		177	=item B
		178
		179	EPZS motion estimation (default)
		180
		181	=item B
		182
		183	esa motion estimation (alias for full)
		184
		185	=item B
		186
		187	tesa motion estimation
		188
		189	=item B
		190
		191	dia motion estimation (alias for epzs)
		192
		193	=item B
		194
		195	log motion estimation
		196
		197	=item B
		198
		199	phods motion estimation
		200
		201	=item B
		202
		203	X1 motion estimation
		204
		205	=item B
		206
		207	hex motion estimation
		208
		209	=item B
		210
		211	umh motion estimation
		212
		213	=item B
		214
		215	iter motion estimation
		216
		217	=back
		218
		219
		220
		221	=item B I
		222
		223	Set extradata size.
		224
		225
		226	=item B I
		227
		228	Set codec time base.
		229
		230	It is the fundamental unit of time (in seconds) in terms of which
		231	frame timestamps are represented. For fixed-fps content, timebase
		232	should be C<1 / frame_rate> and timestamp increments should be
		233	identically 1.
		234
		235
		236	=item B I B<(>IB<)>
		237
		238	Set the group of picture size. Default value is 12.
		239
		240
		241	=item B I B<(>IB<)>
		242
		243	Set audio sampling rate (in Hz).
		244
		245
		246	=item B I B<(>IB<)>
		247
		248	Set number of audio channels.
		249
		250
		251	=item B I B<(>IB<)>
		252
		253	Set cutoff bandwidth.
		254
		255
		256	=item B I B<(>IB<)>
		257
		258	Set audio frame size.
		259
		260	Each submitted frame except the last must contain exactly frame_size
		261	samples per channel. May be 0 when the codec has
		262	CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
		263	restricted. It is set by some decoders to indicate constant frame
		264	size.
		265
		266
		267	=item B I
		268
		269	Set the frame number.
		270
		271
		272	=item B I
		273
		274
		275
		276	=item B I B<(>IB<)>
		277
		278	Set video quantizer scale compression (VBR). It is used as a constant
		279	in the ratecontrol equation. Recommended range for default rc_eq:
		280	0.0-1.0.
		281
		282
		283	=item B I B<(>IB<)>
		284
		285	Set video quantizer scale blur (VBR).
		286
		287
		288	=item B I B<(>IB<)>
		289
		290	Set min video quantizer scale (VBR). Must be included between -1 and
		291	69, default value is 2.
		292
		293
		294	=item B I B<(>IB<)>
		295
		296	Set max video quantizer scale (VBR). Must be included between -1 and
		297	1024, default value is 31.
		298
		299
		300	=item B I B<(>IB<)>
		301
		302	Set max difference between the quantizer scale (VBR).
		303
		304
		305	=item B I B<(>IB<)>
		306
		307	Set max number of B frames.
		308
		309
		310	=item B I B<(>IB<)>
		311
		312	Set qp factor between P and B frames.
		313
		314
		315	=item B I B<(>IB<)>
		316
		317	Set ratecontrol method.
		318
		319
		320	=item B I B<(>IB<)>
		321
		322	Set strategy to choose between I/P/B-frames.
		323
		324
		325	=item B I B<(>IB<)>
		326
		327	Set RTP payload size in bytes.
		328
		329
		330	=item B I
		331
		332
		333	=item B I
		334
		335
		336	=item B I
		337
		338
		339	=item B I
		340
		341
		342	=item B I
		343
		344
		345	=item B I
		346
		347
		348	=item B I
		349
		350
		351	=item B I
		352
		353
		354	=item B I
		355
		356
		357	=item B I
		358
		359
		360	=item B I B<(>IB<)>
		361
		362	Workaround not auto detected encoder bugs.
		363
		364	Possible values:
		365
		366	=over 4
		367
		368
		369	=item B
		370
		371
		372
		373	=item B
		374
		375	some old lavc generated msmpeg4v3 files (no autodetection)
		376
		377	=item B
		378
		379	Xvid interlacing bug (autodetected if fourcc==XVIX)
		380
		381	=item B
		382
		383	(autodetected if fourcc==UMP4)
		384
		385	=item B
		386
		387	padding bug (autodetected)
		388
		389	=item B
		390
		391
		392
		393	=item B
		394
		395	illegal vlc bug (autodetected per fourcc)
		396
		397	=item B
		398
		399
		400
		401	=item B
		402
		403	old standard qpel (autodetected per fourcc/version)
		404
		405	=item B
		406
		407
		408
		409	=item B
		410
		411	direct-qpel-blocksize bug (autodetected per fourcc/version)
		412
		413	=item B
		414
		415	edge padding bug (autodetected per fourcc/version)
		416
		417	=item B
		418
		419
		420
		421	=item B
		422
		423
		424
		425	=item B
		426
		427	Workaround various bugs in microsoft broken decoders.
		428
		429	=item B
		430
		431	trancated frames
		432
		433	=back
		434
		435
		436
		437	=item B I B<(>IB<)>
		438
		439	Set single coefficient elimination threshold for luminance (negative
		440	values also consider DC coefficient).
		441
		442
		443	=item B I B<(>IB<)>
		444
		445	Set single coefficient elimination threshold for chrominance (negative
		446	values also consider dc coefficient)
		447
		448
		449	=item B I B<(>IB<)>
		450
		451	Specify how strictly to follow the standards.
		452
		453	Possible values:
		454
		455	=over 4
		456
		457
		458	=item B
		459
		460	strictly conform to a older more strict version of the spec or reference software
		461
		462	=item B
		463
		464	strictly conform to all the things in the spec no matter what consequences
		465
		466	=item B
		467
		468
		469
		470	=item B
		471
		472	allow unofficial extensions
		473
		474	=item B
		475
		476	allow non standardized experimental things, experimental
		477	(unfinished/work in progress/not well tested) decoders and encoders.
		478	Note: experimental decoders can pose a security risk, do not use this for
		479	decoding untrusted input.
		480
		481	=back
		482
		483
		484
		485	=item B I B<(>IB<)>
		486
		487	Set QP offset between P and B frames.
		488
		489
		490	=item B I B<(>IB<)>
		491
		492	Set error detection flags.
		493
		494	Possible values:
		495
		496	=over 4
		497
		498
		499	=item B
		500
		501	verify embedded CRCs
		502
		503	=item B
		504
		505	detect bitstream specification deviations
		506
		507	=item B
		508
		509	detect improper bitstream length
		510
		511	=item B
		512
		513	abort decoding on minor error detection
		514
		515	=item B
		516
		517	consider things that violate the spec and have not been seen in the wild as errors
		518
		519	=item B
		520
		521	consider all spec non compliancies as errors
		522
		523	=item B
		524
		525	consider things that a sane encoder should not do as an error
		526
		527	=back
		528
		529
		530
		531	=item B I
		532
		533
		534
		535	=item B I
		536
		537
		538
		539	=item B I B<(>IB<)>
		540
		541	Use MPEG quantizers instead of H.263.
		542
		543
		544	=item B I B<(>IB<)>
		545
		546	How to keep quantizer between qmin and qmax (0 = clip, 1 = use
		547	differentiable function).
		548
		549
		550	=item B I B<(>IB<)>
		551
		552	Set experimental quantizer modulation.
		553
		554
		555	=item B I B<(>IB<)>
		556
		557	Set experimental quantizer modulation.
		558
		559
		560	=item B I
		561
		562
		563
		564	=item B I B<(>IB<)>
		565
		566	Set rate control equation. When computing the expression, besides the
		567	standard functions defined in the section 'Expression Evaluation', the
		568	following functions are available: bits2qp(bits), qp2bits(qp). Also
		569	the following constants are available: iTex pTex tex mv fCode iCount
		570	mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
		571	avgTex.
		572
		573
		574	=item B I B<(>IB<)>
		575
		576	Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
		577
		578
		579	=item B I B<(>IB<)>
		580
		581	Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
		582	encode. It is of little use elsewise.
		583
		584
		585	=item B I B<(>IB<)>
		586
		587	Set ratecontrol buffer size (in bits).
		588
		589
		590	=item B I B<(>IB<)>
		591
		592	Currently useless.
		593
		594
		595	=item B I B<(>IB<)>
		596
		597	Set QP factor between P and I frames.
		598
		599
		600	=item B I B<(>IB<)>
		601
		602	Set QP offset between P and I frames.
		603
		604
		605	=item B I B<(>IB<)>
		606
		607	Set initial complexity for 1-pass encoding.
		608
		609
		610	=item B I B<(>IB<)>
		611
		612	Set DCT algorithm.
		613
		614	Possible values:
		615
		616	=over 4
		617
		618
		619	=item B
		620
		621	autoselect a good one (default)
		622
		623	=item B
		624
		625	fast integer
		626
		627	=item B
		628
		629	accurate integer
		630
		631	=item B
		632
		633
		634
		635	=item B
		636
		637
		638
		639	=item B
		640
		641	floating point AAN DCT
		642
		643	=back
		644
		645
		646
		647	=item B I B<(>IB<)>
		648
		649	Compress bright areas stronger than medium ones.
		650
		651
		652	=item B I B<(>IB<)>
		653
		654	Set temporal complexity masking.
		655
		656
		657	=item B I B<(>IB<)>
		658
		659	Set spatial complexity masking.
		660
		661
		662	=item B I B<(>IB<)>
		663
		664	Set inter masking.
		665
		666
		667	=item B I B<(>IB<)>
		668
		669	Compress dark areas stronger than medium ones.
		670
		671
		672	=item B I B<(>IB<)>
		673
		674	Select IDCT implementation.
		675
		676	Possible values:
		677
		678	=over 4
		679
		680
		681	=item B
		682
		683
		684
		685	=item B
		686
		687
		688
		689	=item B
		690
		691
		692
		693	=item B
		694
		695
		696
		697	=item B
		698
		699
		700
		701	=item B
		702
		703
		704
		705	=item B
		706
		707
		708
		709	=item B
		710
		711
		712
		713	=item B
		714
		715
		716
		717	=item B
		718
		719
		720
		721	=item B
		722
		723
		724
		725	=item B
		726
		727
		728
		729	=item B
		730
		731
		732
		733	=item B
		734
		735
		736
		737	=item B
		738
		739	floating point AAN IDCT
		740
		741	=back
		742
		743
		744
		745	=item B I
		746
		747
		748
		749	=item B I B<(>IB<)>
		750
		751	Set error concealment strategy.
		752
		753	Possible values:
		754
		755	=over 4
		756
		757
		758	=item B
		759
		760	iterative motion vector (MV) search (slow)
		761
		762	=item B
		763
		764	use strong deblock filter for damaged MBs
		765
		766	=back
		767
		768
		769
		770	=item B I
		771
		772
		773
		774	=item B I B<(>IB<)>
		775
		776	Set prediction method.
		777
		778	Possible values:
		779
		780	=over 4
		781
		782
		783	=item B
		784
		785
		786
		787	=item B
		788
		789
		790
		791	=item B
		792
		793
		794
		795	=back
		796
		797
		798
		799	=item B I B<(>IB<)>
		800
		801	Set sample aspect ratio.
		802
		803
		804	=item B I B<(>IB<)>
		805
		806	Print specific debug info.
		807
		808	Possible values:
		809
		810	=over 4
		811
		812
		813	=item B
		814
		815	picture info
		816
		817	=item B
		818
		819	rate control
		820
		821	=item B
		822
		823
		824
		825	=item B
		826
		827	macroblock (MB) type
		828
		829	=item B
		830
		831	per-block quantization parameter (QP)
		832
		833	=item B
		834
		835	motion vector
		836
		837	=item B
		838
		839
		840
		841	=item B
		842
		843
		844
		845	=item B
		846
		847
		848
		849	=item B
		850
		851
		852
		853	=item B
		854
		855	error recognition
		856
		857	=item B
		858
		859	memory management control operations (H.264)
		860
		861	=item B
		862
		863
		864
		865	=item B
		866
		867	visualize quantization parameter (QP), lower QP are tinted greener
		868
		869	=item B
		870
		871	visualize block types
		872
		873	=item B
		874
		875	picture buffer allocations
		876
		877	=item B
		878
		879	threading operations
		880
		881	=back
		882
		883
		884
		885	=item B I B<(>IB<)>
		886
		887	Visualize motion vectors (MVs).
		888
		889	Possible values:
		890
		891	=over 4
		892
		893
		894	=item B
		895
		896	forward predicted MVs of P-frames
		897
		898	=item B
		899
		900	forward predicted MVs of B-frames
		901
		902	=item B
		903
		904	backward predicted MVs of B-frames
		905
		906	=back
		907
		908
		909
		910	=item B I B<(>IB<)>
		911
		912	Set full pel me compare function.
		913
		914	Possible values:
		915
		916	=over 4
		917
		918
		919	=item B
		920
		921	sum of absolute differences, fast (default)
		922
		923	=item B
		924
		925	sum of squared errors
		926
		927	=item B
		928
		929	sum of absolute Hadamard transformed differences
		930
		931	=item B
		932
		933	sum of absolute DCT transformed differences
		934
		935	=item B
		936
		937	sum of squared quantization errors (avoid, low quality)
		938
		939	=item B
		940
		941	number of bits needed for the block
		942
		943	=item B
		944
		945	rate distortion optimal, slow
		946
		947	=item B
		948
		949
		950
		951	=item B
		952
		953	sum of absolute vertical differences
		954
		955	=item B
		956
		957	sum of squared vertical differences
		958
		959	=item B
		960
		961	noise preserving sum of squared differences
		962
		963	=item B
		964
		965	5/3 wavelet, only used in snow
		966
		967	=item B
		968
		969	9/7 wavelet, only used in snow
		970
		971	=item B
		972
		973
		974
		975	=item B
		976
		977
		978
		979	=back
		980
		981
		982
		983	=item B I B<(>IB<)>
		984
		985	Set sub pel me compare function.
		986
		987	Possible values:
		988
		989	=over 4
		990
		991
		992	=item B
		993
		994	sum of absolute differences, fast (default)
		995
		996	=item B
		997
		998	sum of squared errors
		999
		1000	=item B
		1001
		1002	sum of absolute Hadamard transformed differences
		1003
		1004	=item B
		1005
		1006	sum of absolute DCT transformed differences
		1007
		1008	=item B
		1009
		1010	sum of squared quantization errors (avoid, low quality)
		1011
		1012	=item B
		1013
		1014	number of bits needed for the block
		1015
		1016	=item B
		1017
		1018	rate distortion optimal, slow
		1019
		1020	=item B
		1021
		1022
		1023
		1024	=item B
		1025
		1026	sum of absolute vertical differences
		1027
		1028	=item B
		1029
		1030	sum of squared vertical differences
		1031
		1032	=item B
		1033
		1034	noise preserving sum of squared differences
		1035
		1036	=item B
		1037
		1038	5/3 wavelet, only used in snow
		1039
		1040	=item B
		1041
		1042	9/7 wavelet, only used in snow
		1043
		1044	=item B
		1045
		1046
		1047
		1048	=item B
		1049
		1050
		1051
		1052	=back
		1053
		1054
		1055
		1056	=item B I B<(>IB<)>
		1057
		1058	Set macroblock compare function.
		1059
		1060	Possible values:
		1061
		1062	=over 4
		1063
		1064
		1065	=item B
		1066
		1067	sum of absolute differences, fast (default)
		1068
		1069	=item B
		1070
		1071	sum of squared errors
		1072
		1073	=item B
		1074
		1075	sum of absolute Hadamard transformed differences
		1076
		1077	=item B
		1078
		1079	sum of absolute DCT transformed differences
		1080
		1081	=item B
		1082
		1083	sum of squared quantization errors (avoid, low quality)
		1084
		1085	=item B
		1086
		1087	number of bits needed for the block
		1088
		1089	=item B
		1090
		1091	rate distortion optimal, slow
		1092
		1093	=item B
		1094
		1095
		1096
		1097	=item B
		1098
		1099	sum of absolute vertical differences
		1100
		1101	=item B
		1102
		1103	sum of squared vertical differences
		1104
		1105	=item B
		1106
		1107	noise preserving sum of squared differences
		1108
		1109	=item B
		1110
		1111	5/3 wavelet, only used in snow
		1112
		1113	=item B
		1114
		1115	9/7 wavelet, only used in snow
		1116
		1117	=item B
		1118
		1119
		1120
		1121	=item B
		1122
		1123
		1124
		1125	=back
		1126
		1127
		1128
		1129	=item B I B<(>IB<)>
		1130
		1131	Set interlaced dct compare function.
		1132
		1133	Possible values:
		1134
		1135	=over 4
		1136
		1137
		1138	=item B
		1139
		1140	sum of absolute differences, fast (default)
		1141
		1142	=item B
		1143
		1144	sum of squared errors
		1145
		1146	=item B
		1147
		1148	sum of absolute Hadamard transformed differences
		1149
		1150	=item B
		1151
		1152	sum of absolute DCT transformed differences
		1153
		1154	=item B
		1155
		1156	sum of squared quantization errors (avoid, low quality)
		1157
		1158	=item B
		1159
		1160	number of bits needed for the block
		1161
		1162	=item B
		1163
		1164	rate distortion optimal, slow
		1165
		1166	=item B
		1167
		1168
		1169
		1170	=item B
		1171
		1172	sum of absolute vertical differences
		1173
		1174	=item B
		1175
		1176	sum of squared vertical differences
		1177
		1178	=item B
		1179
		1180	noise preserving sum of squared differences
		1181
		1182	=item B
		1183
		1184	5/3 wavelet, only used in snow
		1185
		1186	=item B
		1187
		1188	9/7 wavelet, only used in snow
		1189
		1190	=item B
		1191
		1192
		1193
		1194	=item B
		1195
		1196
		1197
		1198	=back
		1199
		1200
		1201
		1202	=item B I B<(>IB<)>
		1203
		1204	Set diamond type & size for motion estimation.
		1205
		1206
		1207	=item B I B<(>IB<)>
		1208
		1209	Set amount of motion predictors from the previous frame.
		1210
		1211
		1212	=item B I B<(>IB<)>
		1213
		1214	Set pre motion estimation.
		1215
		1216
		1217	=item B I B<(>IB<)>
		1218
		1219	Set pre motion estimation compare function.
		1220
		1221	Possible values:
		1222
		1223	=over 4
		1224
		1225
		1226	=item B
		1227
		1228	sum of absolute differences, fast (default)
		1229
		1230	=item B
		1231
		1232	sum of squared errors
		1233
		1234	=item B
		1235
		1236	sum of absolute Hadamard transformed differences
		1237
		1238	=item B
		1239
		1240	sum of absolute DCT transformed differences
		1241
		1242	=item B
		1243
		1244	sum of squared quantization errors (avoid, low quality)
		1245
		1246	=item B
		1247
		1248	number of bits needed for the block
		1249
		1250	=item B
		1251
		1252	rate distortion optimal, slow
		1253
		1254	=item B
		1255
		1256
		1257
		1258	=item B
		1259
		1260	sum of absolute vertical differences
		1261
		1262	=item B
		1263
		1264	sum of squared vertical differences
		1265
		1266	=item B
		1267
		1268	noise preserving sum of squared differences
		1269
		1270	=item B
		1271
		1272	5/3 wavelet, only used in snow
		1273
		1274	=item B
		1275
		1276	9/7 wavelet, only used in snow
		1277
		1278	=item B
		1279
		1280
		1281
		1282	=item B
		1283
		1284
		1285
		1286	=back
		1287
		1288
		1289
		1290	=item B I B<(>IB<)>
		1291
		1292	Set diamond type & size for motion estimation pre-pass.
		1293
		1294
		1295	=item B I B<(>IB<)>
		1296
		1297	Set sub pel motion estimation quality.
		1298
		1299
		1300	=item B I
		1301
		1302
		1303
		1304	=item B I B<(>IB<)>
		1305
		1306	Set limit motion vectors range (1023 for DivX player).
		1307
		1308
		1309	=item B I B<(>IB<)>
		1310
		1311	Set intra quant bias.
		1312
		1313
		1314	=item B I B<(>IB<)>
		1315
		1316	Set inter quant bias.
		1317
		1318
		1319	=item B I
		1320
		1321
		1322
		1323	=item B I B<(>IB<)>
		1324
		1325
		1326
		1327	=item B I B<(>IB<)>
		1328
		1329
		1330	Possible values:
		1331
		1332	=over 4
		1333
		1334
		1335	=item B
		1336
		1337	variable length coder / huffman coder
		1338
		1339	=item B
		1340
		1341	arithmetic coder
		1342
		1343	=item B
		1344
		1345	raw (no encoding)
		1346
		1347	=item B
		1348
		1349	run-length coder
		1350
		1351	=item B
		1352
		1353	deflate-based coder
		1354
		1355	=back
		1356
		1357
		1358
		1359	=item B I B<(>IB<)>
		1360
		1361	Set context model.
		1362
		1363
		1364	=item B I
		1365
		1366
		1367
		1368	=item B I
		1369
		1370
		1371
		1372	=item B I B<(>IB<)>
		1373
		1374	Set macroblock decision algorithm (high quality mode).
		1375
		1376	Possible values:
		1377
		1378	=over 4
		1379
		1380
		1381	=item B
		1382
		1383	use mbcmp (default)
		1384
		1385	=item B
		1386
		1387	use fewest bits
		1388
		1389	=item B
		1390
		1391	use best rate distortion
		1392
		1393	=back
		1394
		1395
		1396
		1397	=item B I
		1398
		1399
		1400
		1401	=item B I B<(>IB<)>
		1402
		1403	Set scene change threshold.
		1404
		1405
		1406	=item B I B<(>IB<)>
		1407
		1408	Set min lagrange factor (VBR).
		1409
		1410
		1411	=item B I B<(>IB<)>
		1412
		1413	Set max lagrange factor (VBR).
		1414
		1415
		1416	=item B I B<(>IB<)>
		1417
		1418	Set noise reduction.
		1419
		1420
		1421	=item B I B<(>IB<)>
		1422
		1423	Set number of bits which should be loaded into the rc buffer before
		1424	decoding starts.
		1425
		1426
		1427	=item B I B<(>IB<)>
		1428
		1429
		1430	Possible values:
		1431
		1432	=over 4
		1433
		1434
		1435	=item B
		1436
		1437	Allow non spec compliant speedup tricks.
		1438
		1439	=item B
		1440
		1441	Deprecated, use mpegvideo private options instead.
		1442
		1443	=item B
		1444
		1445	Skip bitstream encoding.
		1446
		1447	=item B
		1448
		1449	Ignore cropping information from sps.
		1450
		1451	=item B
		1452
		1453	Place global headers at every keyframe instead of in extradata.
		1454
		1455	=item B
		1456
		1457	Frame data might be split into multiple chunks.
		1458
		1459	=item B
		1460
		1461	Show all frames before the first keyframe.
		1462
		1463	=item B
		1464
		1465	Deprecated, use mpegvideo private options instead.
		1466
		1467	=back
		1468
		1469
		1470
		1471	=item B I B<(>IB<)>
		1472
		1473
		1474
		1475	=item B I B<(>IB<)>
		1476
		1477	Deprecated, use mpegvideo private options instead.
		1478
		1479
		1480	=item B I B<(>IB<)>
		1481
		1482
		1483	Possible values:
		1484
		1485	=over 4
		1486
		1487
		1488	=item B
		1489
		1490	detect a good number of threads
		1491
		1492	=back
		1493
		1494
		1495
		1496	=item B I B<(>IB<)>
		1497
		1498	Set motion estimation threshold.
		1499
		1500
		1501	=item B I B<(>IB<)>
		1502
		1503	Set macroblock threshold.
		1504
		1505
		1506	=item B I B<(>IB<)>
		1507
		1508	Set intra_dc_precision.
		1509
		1510
		1511	=item B I B<(>IB<)>
		1512
		1513	Set nsse weight.
		1514
		1515
		1516	=item B I B<(>IB<)>
		1517
		1518	Set number of macroblock rows at the top which are skipped.
		1519
		1520
		1521	=item B I B<(>IB<)>
		1522
		1523	Set number of macroblock rows at the bottom which are skipped.
		1524
		1525
		1526	=item B I B<(>IB<)>
		1527
		1528
		1529	Possible values:
		1530
		1531	=over 4
		1532
		1533
		1534	=item B
		1535
		1536
		1537
		1538	=item B
		1539
		1540
		1541
		1542	=item B
		1543
		1544
		1545
		1546	=item B
		1547
		1548
		1549
		1550	=item B
		1551
		1552
		1553
		1554	=item B
		1555
		1556
		1557
		1558	=item B
		1559
		1560
		1561
		1562	=item B
		1563
		1564
		1565
		1566	=item B
		1567
		1568
		1569
		1570	=item B
		1571
		1572
		1573
		1574	=item B
		1575
		1576
		1577
		1578	=item B
		1579
		1580
		1581
		1582	=item B
		1583
		1584
		1585
		1586	=item B
		1587
		1588
		1589
		1590	=item B
		1591
		1592
		1593
		1594	=item B
		1595
		1596
		1597
		1598	=back
		1599
		1600
		1601
		1602	=item B I B<(>IB<)>
		1603
		1604
		1605	Possible values:
		1606
		1607	=over 4
		1608
		1609
		1610	=item B
		1611
		1612
		1613
		1614	=back
		1615
		1616
		1617
		1618	=item B I B<(>IB<)>
		1619
		1620	Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
		1621
		1622
		1623	=item B I B<(>IB<)>
		1624
		1625	Set frame skip threshold.
		1626
		1627
		1628	=item B I B<(>IB<)>
		1629
		1630	Set frame skip factor.
		1631
		1632
		1633	=item B I B<(>IB<)>
		1634
		1635	Set frame skip exponent.
		1636
		1637
		1638	=item B I B<(>IB<)>
		1639
		1640	Set frame skip compare function.
		1641
		1642	Possible values:
		1643
		1644	=over 4
		1645
		1646
		1647	=item B
		1648
		1649	sum of absolute differences, fast (default)
		1650
		1651	=item B
		1652
		1653	sum of squared errors
		1654
		1655	=item B
		1656
		1657	sum of absolute Hadamard transformed differences
		1658
		1659	=item B
		1660
		1661	sum of absolute DCT transformed differences
		1662
		1663	=item B
		1664
		1665	sum of squared quantization errors (avoid, low quality)
		1666
		1667	=item B
		1668
		1669	number of bits needed for the block
		1670
		1671	=item B
		1672
		1673	rate distortion optimal, slow
		1674
		1675	=item B
		1676
		1677
		1678
		1679	=item B
		1680
		1681	sum of absolute vertical differences
		1682
		1683	=item B
		1684
		1685	sum of squared vertical differences
		1686
		1687	=item B
		1688
		1689	noise preserving sum of squared differences
		1690
		1691	=item B
		1692
		1693	5/3 wavelet, only used in snow
		1694
		1695	=item B
		1696
		1697	9/7 wavelet, only used in snow
		1698
		1699	=item B
		1700
		1701
		1702
		1703	=item B
		1704
		1705
		1706
		1707	=back
		1708
		1709
		1710
		1711	=item B I B<(>IB<)>
		1712
		1713	Increase the quantizer for macroblocks close to borders.
		1714
		1715
		1716	=item B I B<(>IB<)>
		1717
		1718	Set min macroblock lagrange factor (VBR).
		1719
		1720
		1721	=item B I B<(>IB<)>
		1722
		1723	Set max macroblock lagrange factor (VBR).
		1724
		1725
		1726	=item B I B<(>IB<)>
		1727
		1728	Set motion estimation bitrate penalty compensation (1.0 = 256).
		1729
		1730
		1731	=item B I B<(>IB<)>
		1732
		1733
		1734	=item B I B<(>IB<)>
		1735
		1736
		1737	=item B I B<(>IB<)>
		1738
		1739
		1740	Make decoder discard processing depending on the frame type selected
		1741	by the option value.
		1742
		1743	B skips frame loop filtering, B
		1744	skips frame IDCT/dequantization, B skips decoding.
		1745
		1746	Possible values:
		1747
		1748	=over 4
		1749
		1750
		1751	=item B
		1752
		1753	Discard no frame.
		1754
		1755
		1756	=item B
		1757
		1758	Discard useless frames like 0-sized frames.
		1759
		1760
		1761	=item B
		1762
		1763	Discard all non-reference frames.
		1764
		1765
		1766	=item B
		1767
		1768	Discard all bidirectional frames.
		1769
		1770
		1771	=item B
		1772
		1773	Discard all frames excepts keyframes.
		1774
		1775
		1776	=item B
		1777
		1778	Discard all frames.
		1779
		1780	=back
		1781
		1782
		1783	Default value is B.
		1784
		1785
		1786	=item B I B<(>IB<)>
		1787
		1788	Refine the two motion vectors used in bidirectional macroblocks.
		1789
		1790
		1791	=item B I B<(>IB<)>
		1792
		1793	Downscale frames for dynamic B-frame decision.
		1794
		1795
		1796	=item B I B<(>IB<)>
		1797
		1798	Set minimum interval between IDR-frames.
		1799
		1800
		1801	=item B I B<(>IB<)>
		1802
		1803	Set reference frames to consider for motion compensation.
		1804
		1805
		1806	=item B I B<(>IB<)>
		1807
		1808	Set chroma qp offset from luma.
		1809
		1810
		1811	=item B I B<(>IB<)>
		1812
		1813	Set rate-distortion optimal quantization.
		1814
		1815
		1816	=item B I B<(>IB<)>
		1817
		1818	Set value multiplied by qscale for each frame and added to
		1819	scene_change_score.
		1820
		1821
		1822	=item B I B<(>IB<)>
		1823
		1824
		1825	=item B I B<(>IB<)>
		1826
		1827	Adjust sensitivity of b_frame_strategy 1.
		1828
		1829
		1830	=item B I B<(>IB<)>
		1831
		1832
		1833	=item B I B<(>IB<)>
		1834
		1835
		1836	=item B I B<(>IB<)>
		1837
		1838
		1839	=item B I B<(>IB<)>
		1840
		1841	Set GOP timecode frame start number, in non drop frame format.
		1842
		1843
		1844	=item B I B<(>IB<)>
		1845
		1846	Set desired number of audio channels.
		1847
		1848
		1849	=item B I
		1850
		1851
		1852	=item B I B<(>IB<)>
		1853
		1854
		1855	Possible values:
		1856
		1857	=over 4
		1858
		1859
		1860	=back
		1861
		1862
		1863	=item B I B<(>IB<)>
		1864
		1865
		1866	Possible values:
		1867
		1868	=over 4
		1869
		1870
		1871	=back
		1872
		1873
		1874	=item B I B<(>IB<)>
		1875
		1876
		1877	=item B I B<(>IB<)>
		1878
		1879
		1880	=item B I B<(>IB<)>
		1881
		1882
		1883	=item B I B<(>IB<)>
		1884
		1885
		1886	=item B I B<(>IB<)>
		1887
		1888
		1889	=item B I B<(>IB<)>
		1890
		1891
		1892	=item B I B<(>IB<)>
		1893
		1894
		1895	=item B I B<(>IB<)>
		1896
		1897
		1898
		1899	=item B I
		1900
		1901	Set the log level offset.
		1902
		1903
		1904	=item B I B<(>IB<)>
		1905
		1906	Number of slices, used in parallelized encoding.
		1907
		1908
		1909	=item B I B<(>IB<)>
		1910
		1911	Select multithreading type.
		1912
		1913	Possible values:
		1914
		1915	=over 4
		1916
		1917
		1918	=item B
		1919
		1920
		1921
		1922	=item B
		1923
		1924
		1925
		1926	=back
		1927
		1928
		1929	=item B I B<(>IB<)>
		1930
		1931	Set audio service type.
		1932
		1933	Possible values:
		1934
		1935	=over 4
		1936
		1937
		1938	=item B
		1939
		1940	Main Audio Service
		1941
		1942	=item B
		1943
		1944	Effects
		1945
		1946	=item B
		1947
		1948	Visually Impaired
		1949
		1950	=item B
		1951
		1952	Hearing Impaired
		1953
		1954	=item B
		1955
		1956	Dialogue
		1957
		1958	=item B
		1959
		1960	Commentary
		1961
		1962	=item B
		1963
		1964	Emergency
		1965
		1966	=item B
		1967
		1968	Voice Over
		1969
		1970	=item B
		1971
		1972	Karaoke
		1973
		1974	=back
		1975
		1976
		1977
		1978	=item B I B<(>IB<)>
		1979
		1980	Set sample format audio decoders should prefer. Default value is
		1981	C.
		1982
		1983
		1984	=item B I
		1985
		1986
		1987
		1988	=item B I B<(>IB<)>
		1989
		1990	Set the input subtitles character encoding.
		1991
		1992
		1993	=item B I B<(>I
		1994
		1995	Set/override the field order of the video.
		1996	Possible values:
		1997
		1998	=over 4
		1999
		2000
		2001	=item B
		2002
		2003	Progressive video
		2004
		2005	=item B
		2006
		2007	Interlaced video, top field coded and displayed first
		2008
		2009	=item B
		2010
		2011	Interlaced video, bottom field coded and displayed first
		2012
		2013	=item B
		2014
		2015	Interlaced video, top coded first, bottom displayed first
		2016
		2017	=item B
		2018
		2019	Interlaced video, bottom coded first, top displayed first
		2020
		2021	=back
		2022
		2023
		2024
		2025	=item B I B<(>IB<)>
		2026
		2027	Set to 1 to disable processing alpha (transparency). This works like the
		2028	B flag in the B option which skips chroma information
		2029	instead of alpha. Default is 0.
		2030
		2031	=back
		2032
		2033
		2034
		2035
		2036	=head1 DECODERS
		2037
		2038
		2039	Decoders are configured elements in FFmpeg which allow the decoding of
		2040	multimedia streams.
		2041
		2042	When you configure your FFmpeg build, all the supported native decoders
		2043	are enabled by default. Decoders requiring an external library must be enabled
		2044	manually via the corresponding C<--enable-lib> option. You can list all
		2045	available decoders using the configure option C<--list-decoders>.
		2046
		2047	You can disable all the decoders with the configure option
		2048	C<--disable-decoders> and selectively enable / disable single decoders
		2049	with the options C<--enable-decoder=I> /
		2050	C<--disable-decoder=I>.
		2051
		2052	The option C<-codecs> of the ff* tools will display the list of
		2053	enabled decoders.
		2054
		2055
		2056
		2057	=head1 VIDEO DECODERS
		2058
		2059
		2060	A description of some of the currently available video decoders
		2061	follows.
		2062
		2063
		2064	=head2 rawvideo
		2065
		2066
		2067	Raw video decoder.
		2068
		2069	This decoder decodes rawvideo streams.
		2070
		2071
		2072	=head3 Options
		2073
		2074
		2075
		2076	=over 4
		2077
		2078
		2079	=item B I
		2080
		2081	Specify the assumed field type of the input video.
		2082
		2083	=over 4
		2084
		2085
		2086	=item B<-1>
		2087
		2088	the video is assumed to be progressive (default)
		2089
		2090	=item B<0>
		2091
		2092	bottom-field-first is assumed
		2093
		2094	=item B<1>
		2095
		2096	top-field-first is assumed
		2097
		2098	=back
		2099
		2100
		2101
		2102	=back
		2103
		2104
		2105
		2106
		2107	=head1 AUDIO DECODERS
		2108
		2109
		2110
		2111	=head2 ffwavesynth
		2112
		2113
		2114	Internal wave synthetizer.
		2115
		2116	This decoder generates wave patterns according to predefined sequences. Its
		2117	use is purely internal and the format of the data it accepts is not publicly
		2118	documented.
		2119
		2120
		2121	=head2 libcelt
		2122
		2123
		2124	libcelt decoder wrapper.
		2125
		2126	libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
		2127	Requires the presence of the libcelt headers and library during configuration.
		2128	You need to explicitly configure the build with C<--enable-libcelt>.
		2129
		2130
		2131	=head2 libgsm
		2132
		2133
		2134	libgsm decoder wrapper.
		2135
		2136	libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
		2137	the presence of the libgsm headers and library during configuration. You need
		2138	to explicitly configure the build with C<--enable-libgsm>.
		2139
		2140	This decoder supports both the ordinary GSM and the Microsoft variant.
		2141
		2142
		2143	=head2 libilbc
		2144
		2145
		2146	libilbc decoder wrapper.
		2147
		2148	libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
		2149	audio codec. Requires the presence of the libilbc headers and library during
		2150	configuration. You need to explicitly configure the build with
		2151	C<--enable-libilbc>.
		2152
		2153
		2154	=head3 Options
		2155
		2156
		2157	The following option is supported by the libilbc wrapper.
		2158
		2159
		2160	=over 4
		2161
		2162
		2163	=item B
		2164
		2165
		2166	Enable the enhancement of the decoded audio when set to 1. The default
		2167	value is 0 (disabled).
		2168
		2169
		2170	=back
		2171
		2172
		2173
		2174	=head2 libopencore-amrnb
		2175
		2176
		2177	libopencore-amrnb decoder wrapper.
		2178
		2179	libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
		2180	Narrowband audio codec. Using it requires the presence of the
		2181	libopencore-amrnb headers and library during configuration. You need to
		2182	explicitly configure the build with C<--enable-libopencore-amrnb>.
		2183
		2184	An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
		2185	without this library.
		2186
		2187
		2188	=head2 libopencore-amrwb
		2189
		2190
		2191	libopencore-amrwb decoder wrapper.
		2192
		2193	libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
		2194	Wideband audio codec. Using it requires the presence of the
		2195	libopencore-amrwb headers and library during configuration. You need to
		2196	explicitly configure the build with C<--enable-libopencore-amrwb>.
		2197
		2198	An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
		2199	without this library.
		2200
		2201
		2202	=head2 libopus
		2203
		2204
		2205	libopus decoder wrapper.
		2206
		2207	libopus allows libavcodec to decode the Opus Interactive Audio Codec.
		2208	Requires the presence of the libopus headers and library during
		2209	configuration. You need to explicitly configure the build with
		2210	C<--enable-libopus>.
		2211
		2212
		2213
		2214	=head1 SUBTITLES DECODERS
		2215
		2216
		2217
		2218	=head2 dvdsub
		2219
		2220
		2221	This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
		2222	also be found in VobSub file pairs and in some Matroska files.
		2223
		2224
		2225	=head3 Options
		2226
		2227
		2228
		2229	=over 4
		2230
		2231
		2232	=item B
		2233
		2234	Specify the global palette used by the bitmaps. When stored in VobSub, the
		2235	palette is normally specified in the index file; in Matroska, the palette is
		2236	stored in the codec extra-data in the same format as in VobSub. In DVDs, the
		2237	palette is stored in the IFO file, and therefore not available when reading
		2238	from dumped VOB files.
		2239
		2240	The format for this option is a string containing 16 24-bits hexadecimal
		2241	numbers (without 0x prefix) separated by comas, for example C<0d00ee,
		2242	ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
		2243	7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b>.
		2244
		2245	=back
		2246
		2247
		2248
		2249	=head2 libzvbi-teletext
		2250
		2251
		2252	Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
		2253	subtitles. Requires the presence of the libzvbi headers and library during
		2254	configuration. You need to explicitly configure the build with
		2255	C<--enable-libzvbi>.
		2256
		2257
		2258	=head3 Options
		2259
		2260
		2261
		2262	=over 4
		2263
		2264
		2265	=item B
		2266
		2267	List of teletext page numbers to decode. You may use the special * string to
		2268	match all pages. Pages that do not match the specified list are dropped.
		2269	Default value is *.
		2270
		2271	=item B
		2272
		2273	Discards the top teletext line. Default value is 1.
		2274
		2275	=item B
		2276
		2277	Specifies the format of the decoded subtitles. The teletext decoder is capable
		2278	of decoding the teletext pages to bitmaps or to simple text, you should use
		2279	"bitmap" for teletext pages, because certain graphics and colors cannot be
		2280	expressed in simple text. You might use "text" for teletext based subtitles if
		2281	your application can handle simple text based subtitles. Default value is
		2282	bitmap.
		2283
		2284	=item B
		2285
		2286	X offset of generated bitmaps, default is 0.
		2287
		2288	=item B
		2289
		2290	Y offset of generated bitmaps, default is 0.
		2291
		2292	=item B
		2293
		2294	Chops leading and trailing spaces and removes empty lines from the generated
		2295	text. This option is useful for teletext based subtitles where empty spaces may
		2296	be present at the start or at the end of the lines or empty lines may be
		2297	present between the subtitle lines because of double-sized teletext charactes.
		2298	Default value is 1.
		2299
		2300	=item B
		2301
		2302	Sets the display duration of the decoded teletext pages or subtitles in
		2303	miliseconds. Default value is 30000 which is 30 seconds.
		2304
		2305	=item B
		2306
		2307	Force transparent background of the generated teletext bitmaps. Default value
		2308	is 0 which means an opaque (black) background.
		2309
		2310	=back
		2311
		2312
		2313
		2314	=head1 ENCODERS
		2315
		2316
		2317	Encoders are configured elements in FFmpeg which allow the encoding of
		2318	multimedia streams.
		2319
		2320	When you configure your FFmpeg build, all the supported native encoders
		2321	are enabled by default. Encoders requiring an external library must be enabled
		2322	manually via the corresponding C<--enable-lib> option. You can list all
		2323	available encoders using the configure option C<--list-encoders>.
		2324
		2325	You can disable all the encoders with the configure option
		2326	C<--disable-encoders> and selectively enable / disable single encoders
		2327	with the options C<--enable-encoder=I> /
		2328	C<--disable-encoder=I>.
		2329
		2330	The option C<-codecs> of the ff* tools will display the list of
		2331	enabled encoders.
		2332
		2333
		2334
		2335	=head1 AUDIO ENCODERS
		2336
		2337
		2338	A description of some of the currently available audio encoders
		2339	follows.
		2340
		2341
		2342
		2343	=head2 aac
		2344
		2345
		2346	Advanced Audio Coding (AAC) encoder.
		2347
		2348	This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
		2349	low complexity (AAC-LC) profile is supported. To use this encoder, you must set
		2350	B option to B or lower.
		2351
		2352	As this encoder is experimental, unexpected behavior may exist from time to
		2353	time. For a more stable AAC encoder, see libvo-aacenc. However, be warned
		2354	that it has a worse quality reported by some users.
		2355
		2356
		2357
		2358	=head3 Options
		2359
		2360
		2361
		2362	=over 4
		2363
		2364
		2365	=item B
		2366
		2367	Set bit rate in bits/s. Setting this automatically activates constant bit rate
		2368	(CBR) mode.
		2369
		2370
		2371	=item B
		2372
		2373	Set quality for variable bit rate (VBR) mode. This option is valid only using
		2374	the B command-line tool. For library interface users, use
		2375	B.
		2376
		2377
		2378	=item B
		2379
		2380	Set stereo encoding mode. Possible values:
		2381
		2382
		2383	=over 4
		2384
		2385
		2386	=item B
		2387
		2388	Automatically selected by the encoder.
		2389
		2390
		2391	=item B
		2392
		2393	Disable middle/side encoding. This is the default.
		2394
		2395
		2396	=item B
		2397
		2398	Force middle/side encoding.
		2399
		2400	=back
		2401
		2402
		2403
		2404	=item B
		2405
		2406	Set AAC encoder coding method. Possible values:
		2407
		2408
		2409	=over 4
		2410
		2411
		2412	=item B
		2413
		2414	FAAC-inspired method.
		2415
		2416	This method is a simplified reimplementation of the method used in FAAC, which
		2417	sets thresholds proportional to the band energies, and then decreases all the
		2418	thresholds with quantizer steps to find the appropriate quantization with
		2419	distortion below threshold band by band.
		2420
		2421	The quality of this method is comparable to the two loop searching method
		2422	descibed below, but somewhat a little better and slower.
		2423
		2424
		2425	=item B
		2426
		2427	Average noise to mask ratio (ANMR) trellis-based solution.
		2428
		2429	This has a theoretic best quality out of all the coding methods, but at the
		2430	cost of the slowest speed.
		2431
		2432
		2433	=item B
		2434
		2435	Two loop searching (TLS) method.
		2436
		2437	This method first sets quantizers depending on band thresholds and then tries
		2438	to find an optimal combination by adding or subtracting a specific value from
		2439	all quantizers and adjusting some individual quantizer a little.
		2440
		2441	This method produces similar quality with the FAAC method and is the default.
		2442
		2443
		2444	=item B
		2445
		2446	Constant quantizer method.
		2447
		2448	This method sets a constant quantizer for all bands. This is the fastest of all
		2449	the methods, yet produces the worst quality.
		2450
		2451
		2452	=back
		2453
		2454
		2455
		2456	=back
		2457
		2458
		2459
		2460	=head2 ac3 and ac3_fixed
		2461
		2462
		2463	AC-3 audio encoders.
		2464
		2465	These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
		2466	the undocumented RealAudio 3 (a.k.a. dnet).
		2467
		2468	The I encoder uses floating-point math, while the I
		2469	encoder only uses fixed-point integer math. This does not mean that one is
		2470	always faster, just that one or the other may be better suited to a
		2471	particular system. The floating-point encoder will generally produce better
		2472	quality audio for a given bitrate. The I encoder is not the
		2473	default codec for any of the output formats, so it must be specified explicitly
		2474	using the option C<-acodec ac3_fixed> in order to use it.
		2475
		2476
		2477	=head3 AC-3 Metadata
		2478
		2479
		2480	The AC-3 metadata options are used to set parameters that describe the audio,
		2481	but in most cases do not affect the audio encoding itself. Some of the options
		2482	do directly affect or influence the decoding and playback of the resulting
		2483	bitstream, while others are just for informational purposes. A few of the
		2484	options will add bits to the output stream that could otherwise be used for
		2485	audio data, and will thus affect the quality of the output. Those will be
		2486	indicated accordingly with a note in the option list below.
		2487
		2488	These parameters are described in detail in several publicly-available
		2489	documents.
		2490
		2491	=over 4
		2492
		2493
		2494	=item *BE>
		2495
		2496
		2497	=item *BE>
		2498
		2499
		2500	=item *BE>
		2501
		2502
		2503	=item *BE>
		2504
		2505
		2506	=back
		2507
		2508
		2509
		2510	=head4 Metadata Control Options
		2511
		2512
		2513
		2514	=over 4
		2515
		2516
		2517
		2518	=item B<-per_frame_metadata> I
		2519
		2520	Allow Per-Frame Metadata. Specifies if the encoder should check for changing
		2521	metadata for each frame.
		2522
		2523	=over 4
		2524
		2525
		2526	=item B<0>
		2527
		2528	The metadata values set at initialization will be used for every frame in the
		2529	stream. (default)
		2530
		2531	=item B<1>
		2532
		2533	Metadata values can be changed before encoding each frame.
		2534
		2535	=back
		2536
		2537
		2538
		2539	=back
		2540
		2541
		2542
		2543	=head4 Downmix Levels
		2544
		2545
		2546
		2547	=over 4
		2548
		2549
		2550
		2551	=item B<-center_mixlev> I
		2552
		2553	Center Mix Level. The amount of gain the decoder should apply to the center
		2554	channel when downmixing to stereo. This field will only be written to the
		2555	bitstream if a center channel is present. The value is specified as a scale
		2556	factor. There are 3 valid values:
		2557
		2558	=over 4
		2559
		2560
		2561	=item B<0.707>
		2562
		2563	Apply -3dB gain
		2564
		2565	=item B<0.595>
		2566
		2567	Apply -4.5dB gain (default)
		2568
		2569	=item B<0.500>
		2570
		2571	Apply -6dB gain
		2572
		2573	=back
		2574
		2575
		2576
		2577	=item B<-surround_mixlev> I
		2578
		2579	Surround Mix Level. The amount of gain the decoder should apply to the surround
		2580	channel(s) when downmixing to stereo. This field will only be written to the
		2581	bitstream if one or more surround channels are present. The value is specified
		2582	as a scale factor. There are 3 valid values:
		2583
		2584	=over 4
		2585
		2586
		2587	=item B<0.707>
		2588
		2589	Apply -3dB gain
		2590
		2591	=item B<0.500>
		2592
		2593	Apply -6dB gain (default)
		2594
		2595	=item B<0.000>
		2596
		2597	Silence Surround Channel(s)
		2598
		2599	=back
		2600
		2601
		2602
		2603	=back
		2604
		2605
		2606
		2607	=head4 Audio Production Information
		2608
		2609	Audio Production Information is optional information describing the mixing
		2610	environment. Either none or both of the fields are written to the bitstream.
		2611
		2612
		2613	=over 4
		2614
		2615
		2616
		2617	=item B<-mixing_level> I
		2618
		2619	Mixing Level. Specifies peak sound pressure level (SPL) in the production
		2620	environment when the mix was mastered. Valid values are 80 to 111, or -1 for
		2621	unknown or not indicated. The default value is -1, but that value cannot be
		2622	used if the Audio Production Information is written to the bitstream. Therefore,
		2623	if the C option is not the default value, the C
		2624	option must not be -1.
		2625
		2626
		2627	=item B<-room_type> I
		2628
		2629	Room Type. Describes the equalization used during the final mixing session at
		2630	the studio or on the dubbing stage. A large room is a dubbing stage with the
		2631	industry standard X-curve equalization; a small room has flat equalization.
		2632	This field will not be written to the bitstream if both the C
		2633	option and the C option have the default values.
		2634
		2635	=over 4
		2636
		2637
		2638	=item B<0>
		2639
		2640
		2641	=item B
		2642
		2643	Not Indicated (default)
		2644
		2645	=item B<1>
		2646
		2647
		2648	=item B
		2649
		2650	Large Room
		2651
		2652	=item B<2>
		2653
		2654
		2655	=item B
		2656
		2657	Small Room
		2658
		2659	=back
		2660
		2661
		2662
		2663	=back
		2664
		2665
		2666
		2667	=head4 Other Metadata Options
		2668
		2669
		2670
		2671	=over 4
		2672
		2673
		2674
		2675	=item B<-copyright> I
		2676
		2677	Copyright Indicator. Specifies whether a copyright exists for this audio.
		2678
		2679	=over 4
		2680
		2681
		2682	=item B<0>
		2683
		2684
		2685	=item B
		2686
		2687	No Copyright Exists (default)
		2688
		2689	=item B<1>
		2690
		2691
		2692	=item B
		2693
		2694	Copyright Exists
		2695
		2696	=back
		2697
		2698
		2699
		2700	=item B<-dialnorm> I
		2701
		2702	Dialogue Normalization. Indicates how far the average dialogue level of the
		2703	program is below digital 100% full scale (0 dBFS). This parameter determines a
		2704	level shift during audio reproduction that sets the average volume of the
		2705	dialogue to a preset level. The goal is to match volume level between program
		2706	sources. A value of -31dB will result in no volume level change, relative to
		2707	the source volume, during audio reproduction. Valid values are whole numbers in
		2708	the range -31 to -1, with -31 being the default.
		2709
		2710
		2711	=item B<-dsur_mode> I
		2712
		2713	Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
		2714	(Pro Logic). This field will only be written to the bitstream if the audio
		2715	stream is stereo. Using this option does B mean the encoder will actually
		2716	apply Dolby Surround processing.
		2717
		2718	=over 4
		2719
		2720
		2721	=item B<0>
		2722
		2723
		2724	=item B
		2725
		2726	Not Indicated (default)
		2727
		2728	=item B<1>
		2729
		2730
		2731	=item B
		2732
		2733	Not Dolby Surround Encoded
		2734
		2735	=item B<2>
		2736
		2737
		2738	=item B
		2739
		2740	Dolby Surround Encoded
		2741
		2742	=back
		2743
		2744
		2745
		2746	=item B<-original> I
		2747
		2748	Original Bit Stream Indicator. Specifies whether this audio is from the
		2749	original source and not a copy.
		2750
		2751	=over 4
		2752
		2753
		2754	=item B<0>
		2755
		2756
		2757	=item B
		2758
		2759	Not Original Source
		2760
		2761	=item B<1>
		2762
		2763
		2764	=item B
		2765
		2766	Original Source (default)
		2767
		2768	=back
		2769
		2770
		2771
		2772	=back
		2773
		2774
		2775
		2776	=head3 Extended Bitstream Information
		2777
		2778	The extended bitstream options are part of the Alternate Bit Stream Syntax as
		2779	specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
		2780	If any one parameter in a group is specified, all values in that group will be
		2781	written to the bitstream. Default values are used for those that are written
		2782	but have not been specified. If the mixing levels are written, the decoder
		2783	will use these values instead of the ones specified in the C
		2784	and C options if it supports the Alternate Bit Stream
		2785	Syntax.
		2786
		2787
		2788	=head4 Extended Bitstream Information - Part 1
		2789
		2790
		2791
		2792	=over 4
		2793
		2794
		2795
		2796	=item B<-dmix_mode> I
		2797
		2798	Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
		2799	(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
		2800
		2801	=over 4
		2802
		2803
		2804	=item B<0>
		2805
		2806
		2807	=item B
		2808
		2809	Not Indicated (default)
		2810
		2811	=item B<1>
		2812
		2813
		2814	=item B
		2815
		2816	Lt/Rt Downmix Preferred
		2817
		2818	=item B<2>
		2819
		2820
		2821	=item B
		2822
		2823	Lo/Ro Downmix Preferred
		2824
		2825	=back
		2826
		2827
		2828
		2829	=item B<-ltrt_cmixlev> I
		2830
		2831	Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
		2832	center channel when downmixing to stereo in Lt/Rt mode.
		2833
		2834	=over 4
		2835
		2836
		2837	=item B<1.414>
		2838
		2839	Apply +3dB gain
		2840
		2841	=item B<1.189>
		2842
		2843	Apply +1.5dB gain
		2844
		2845	=item B<1.000>
		2846
		2847	Apply 0dB gain
		2848
		2849	=item B<0.841>
		2850
		2851	Apply -1.5dB gain
		2852
		2853	=item B<0.707>
		2854
		2855	Apply -3.0dB gain
		2856
		2857	=item B<0.595>
		2858
		2859	Apply -4.5dB gain (default)
		2860
		2861	=item B<0.500>
		2862
		2863	Apply -6.0dB gain
		2864
		2865	=item B<0.000>
		2866
		2867	Silence Center Channel
		2868
		2869	=back
		2870
		2871
		2872
		2873	=item B<-ltrt_surmixlev> I
		2874
		2875	Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
		2876	surround channel(s) when downmixing to stereo in Lt/Rt mode.
		2877
		2878	=over 4
		2879
		2880
		2881	=item B<0.841>
		2882
		2883	Apply -1.5dB gain
		2884
		2885	=item B<0.707>
		2886
		2887	Apply -3.0dB gain
		2888
		2889	=item B<0.595>
		2890
		2891	Apply -4.5dB gain
		2892
		2893	=item B<0.500>
		2894
		2895	Apply -6.0dB gain (default)
		2896
		2897	=item B<0.000>
		2898
		2899	Silence Surround Channel(s)
		2900
		2901	=back
		2902
		2903
		2904
		2905	=item B<-loro_cmixlev> I
		2906
		2907	Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
		2908	center channel when downmixing to stereo in Lo/Ro mode.
		2909
		2910	=over 4
		2911
		2912
		2913	=item B<1.414>
		2914
		2915	Apply +3dB gain
		2916
		2917	=item B<1.189>
		2918
		2919	Apply +1.5dB gain
		2920
		2921	=item B<1.000>
		2922
		2923	Apply 0dB gain
		2924
		2925	=item B<0.841>
		2926
		2927	Apply -1.5dB gain
		2928
		2929	=item B<0.707>
		2930
		2931	Apply -3.0dB gain
		2932
		2933	=item B<0.595>
		2934
		2935	Apply -4.5dB gain (default)
		2936
		2937	=item B<0.500>
		2938
		2939	Apply -6.0dB gain
		2940
		2941	=item B<0.000>
		2942
		2943	Silence Center Channel
		2944
		2945	=back
		2946
		2947
		2948
		2949	=item B<-loro_surmixlev> I
		2950
		2951	Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
		2952	surround channel(s) when downmixing to stereo in Lo/Ro mode.
		2953
		2954	=over 4
		2955
		2956
		2957	=item B<0.841>
		2958
		2959	Apply -1.5dB gain
		2960
		2961	=item B<0.707>
		2962
		2963	Apply -3.0dB gain
		2964
		2965	=item B<0.595>
		2966
		2967	Apply -4.5dB gain
		2968
		2969	=item B<0.500>
		2970
		2971	Apply -6.0dB gain (default)
		2972
		2973	=item B<0.000>
		2974
		2975	Silence Surround Channel(s)
		2976
		2977	=back
		2978
		2979
		2980
		2981	=back
		2982
		2983
		2984
		2985	=head4 Extended Bitstream Information - Part 2
		2986
		2987
		2988
		2989	=over 4
		2990
		2991
		2992
		2993	=item B<-dsurex_mode> I
		2994
		2995	Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
		2996	(7.1 matrixed to 5.1). Using this option does B mean the encoder will actually
		2997	apply Dolby Surround EX processing.
		2998
		2999	=over 4
		3000
		3001
		3002	=item B<0>
		3003
		3004
		3005	=item B
		3006
		3007	Not Indicated (default)
		3008
		3009	=item B<1>
		3010
		3011
		3012	=item B
		3013
		3014	Dolby Surround EX Off
		3015
		3016	=item B<2>
		3017
		3018
		3019	=item B
		3020
		3021	Dolby Surround EX On
		3022
		3023	=back
		3024
		3025
		3026
		3027	=item B<-dheadphone_mode> I
		3028
		3029	Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
		3030	encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
		3031	option does B mean the encoder will actually apply Dolby Headphone
		3032	processing.
		3033
		3034	=over 4
		3035
		3036
		3037	=item B<0>
		3038
		3039
		3040	=item B
		3041
		3042	Not Indicated (default)
		3043
		3044	=item B<1>
		3045
		3046
		3047	=item B
		3048
		3049	Dolby Headphone Off
		3050
		3051	=item B<2>
		3052
		3053
		3054	=item B
		3055
		3056	Dolby Headphone On
		3057
		3058	=back
		3059
		3060
		3061
		3062	=item B<-ad_conv_type> I
		3063
		3064	A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
		3065	conversion.
		3066
		3067	=over 4
		3068
		3069
		3070	=item B<0>
		3071
		3072
		3073	=item B
		3074
		3075	Standard A/D Converter (default)
		3076
		3077	=item B<1>
		3078
		3079
		3080	=item B
		3081
		3082	HDCD A/D Converter
		3083
		3084	=back
		3085
		3086
		3087
		3088	=back
		3089
		3090
		3091
		3092	=head3 Other AC-3 Encoding Options
		3093
		3094
		3095
		3096	=over 4
		3097
		3098
		3099
		3100	=item B<-stereo_rematrixing> I
		3101
		3102	Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
		3103	is an optional AC-3 feature that increases quality by selectively encoding
		3104	the left/right channels as mid/side. This option is enabled by default, and it
		3105	is highly recommended that it be left as enabled except for testing purposes.
		3106
		3107
		3108	=back
		3109
		3110
		3111
		3112	=head3 Floating-Point-Only AC-3 Encoding Options
		3113
		3114
		3115	These options are only valid for the floating-point encoder and do not exist
		3116	for the fixed-point encoder due to the corresponding features not being
		3117	implemented in fixed-point.
		3118
		3119
		3120	=over 4
		3121
		3122
		3123
		3124	=item B<-channel_coupling> I
		3125
		3126	Enables/Disables use of channel coupling, which is an optional AC-3 feature
		3127	that increases quality by combining high frequency information from multiple
		3128	channels into a single channel. The per-channel high frequency information is
		3129	sent with less accuracy in both the frequency and time domains. This allows
		3130	more bits to be used for lower frequencies while preserving enough information
		3131	to reconstruct the high frequencies. This option is enabled by default for the
		3132	floating-point encoder and should generally be left as enabled except for
		3133	testing purposes or to increase encoding speed.
		3134
		3135	=over 4
		3136
		3137
		3138	=item B<-1>
		3139
		3140
		3141	=item B
		3142
		3143	Selected by Encoder (default)
		3144
		3145	=item B<0>
		3146
		3147
		3148	=item B
		3149
		3150	Disable Channel Coupling
		3151
		3152	=item B<1>
		3153
		3154
		3155	=item B
		3156
		3157	Enable Channel Coupling
		3158
		3159	=back
		3160
		3161
		3162
		3163	=item B<-cpl_start_band> I
		3164
		3165	Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
		3166	value higher than the bandwidth is used, it will be reduced to 1 less than the
		3167	coupling end band. If I is used, the start band will be determined by
		3168	the encoder based on the bit rate, sample rate, and channel layout. This option
		3169	has no effect if channel coupling is disabled.
		3170
		3171	=over 4
		3172
		3173
		3174	=item B<-1>
		3175
		3176
		3177	=item B
		3178
		3179	Selected by Encoder (default)
		3180
		3181	=back
		3182
		3183
		3184
		3185	=back
		3186
		3187
		3188
		3189
		3190	=head2 libmp3lame
		3191
		3192
		3193	LAME (Lame Ain't an MP3 Encoder) MP3 encoder wrapper.
		3194
		3195	Requires the presence of the libmp3lame headers and library during
		3196	configuration. You need to explicitly configure the build with
		3197	C<--enable-libmp3lame>.
		3198
		3199	See libshine for a fixed-point MP3 encoder, although with a
		3200	lower quality.
		3201
		3202
		3203	=head3 Options
		3204
		3205
		3206	The following options are supported by the libmp3lame wrapper. The
		3207	B-equivalent of the options are listed in parentheses.
		3208
		3209
		3210	=over 4
		3211
		3212
		3213	=item BI<-b>B<)>
		3214
		3215	Set bitrate expressed in bits/s for CBR. LAME C is
		3216	expressed in kilobits/s.
		3217
		3218
		3219	=item BI<-V>B<)>
		3220
		3221	Set constant quality setting for VBR. This option is valid only
		3222	using the B command-line tool. For library interface
		3223	users, use B.
		3224
		3225
		3226	=item BI<-q>B<)>
		3227
		3228	Set algorithm quality. Valid arguments are integers in the 0-9 range,
		3229	with 0 meaning highest quality but slowest, and 9 meaning fastest
		3230	while producing the worst quality.
		3231
		3232
		3233	=item B
		3234
		3235	Enable use of bit reservoir when set to 1. Default value is 1. LAME
		3236	has this enabled by default, but can be overriden by use
		3237	B<--nores> option.
		3238
		3239
		3240	=item BI<-m j>B<)>
		3241
		3242	Enable the encoder to use (on a frame by frame basis) either L/R
		3243	stereo or mid/side stereo. Default value is 1.
		3244
		3245
		3246	=back
		3247
		3248
		3249
		3250	=head2 libopencore-amrnb
		3251
		3252
		3253	OpenCORE Adaptive Multi-Rate Narrowband encoder.
		3254
		3255	Requires the presence of the libopencore-amrnb headers and library during
		3256	configuration. You need to explicitly configure the build with
		3257	C<--enable-libopencore-amrnb --enable-version3>.
		3258
		3259	This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
		3260	but you can override it by setting B to B or
		3261	lower.
		3262
		3263
		3264	=head3 Options
		3265
		3266
		3267
		3268	=over 4
		3269
		3270
		3271
		3272	=item B
		3273
		3274	Set bitrate in bits per second. Only the following bitrates are supported,
		3275	otherwise libavcodec will round to the nearest valid bitrate.
		3276
		3277
		3278	=over 4
		3279
		3280
		3281	=item B<4750>
		3282
		3283
		3284	=item B<5150>
		3285
		3286
		3287	=item B<5900>
		3288
		3289
		3290	=item B<6700>
		3291
		3292
		3293	=item B<7400>
		3294
		3295
		3296	=item B<7950>
		3297
		3298
		3299	=item B<10200>
		3300
		3301
		3302	=item B<12200>
		3303
		3304
		3305	=back
		3306
		3307
		3308
		3309	=item B
		3310
		3311	Allow discontinuous transmission (generate comfort noise) when set to 1. The
		3312	default value is 0 (disabled).
		3313
		3314
		3315	=back
		3316
		3317
		3318
		3319
		3320	=head2 libshine
		3321
		3322
		3323	Shine Fixed-Point MP3 encoder wrapper.
		3324
		3325	Shine is a fixed-point MP3 encoder. It has a far better performance on
		3326	platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
		3327	However, as it is more targeted on performance than quality, it is not on par
		3328	with LAME and other production-grade encoders quality-wise. Also, according to
		3329	the project's homepage, this encoder may not be free of bugs as the code was
		3330	written a long time ago and the project was dead for at least 5 years.
		3331
		3332	This encoder only supports stereo and mono input. This is also CBR-only.
		3333
		3334	The original project (last updated in early 2007) is at
		3335	EBE. We only support the
		3336	updated fork by the Savonet/Liquidsoap project at EBE.
		3337
		3338	Requires the presence of the libshine headers and library during
		3339	configuration. You need to explicitly configure the build with
		3340	C<--enable-libshine>.
		3341
		3342	See also libmp3lame.
		3343
		3344
		3345	=head3 Options
		3346
		3347
		3348	The following options are supported by the libshine wrapper. The
		3349	B-equivalent of the options are listed in parentheses.
		3350
		3351
		3352	=over 4
		3353
		3354
		3355	=item BI<-b>B<)>
		3356
		3357	Set bitrate expressed in bits/s for CBR. B B<-b> option
		3358	is expressed in kilobits/s.
		3359
		3360
		3361	=back
		3362
		3363
		3364
		3365	=head2 libtwolame
		3366
		3367
		3368	TwoLAME MP2 encoder wrapper.
		3369
		3370	Requires the presence of the libtwolame headers and library during
		3371	configuration. You need to explicitly configure the build with
		3372	C<--enable-libtwolame>.
		3373
		3374
		3375	=head3 Options
		3376
		3377
		3378	The following options are supported by the libtwolame wrapper. The
		3379	B-equivalent options follow the FFmpeg ones and are in
		3380	parentheses.
		3381
		3382
		3383	=over 4
		3384
		3385
		3386	=item BI<-b>B<)>
		3387
		3388	Set bitrate expressed in bits/s for CBR. B B
		3389	option is expressed in kilobits/s. Default value is 128k.
		3390
		3391
		3392	=item BI<-V>B<)>
		3393
		3394	Set quality for experimental VBR support. Maximum value range is
		3395	from -50 to 50, useful range is from -10 to 10. The higher the
		3396	value, the better the quality. This option is valid only using the
		3397	B command-line tool. For library interface users,
		3398	use B.
		3399
		3400
		3401	=item BI<--mode>B<)>
		3402
		3403	Set the mode of the resulting audio. Possible values:
		3404
		3405
		3406	=over 4
		3407
		3408
		3409	=item B
		3410
		3411	Choose mode automatically based on the input. This is the default.
		3412
		3413	=item B
		3414
		3415	Stereo
		3416
		3417	=item B
		3418
		3419	Joint stereo
		3420
		3421	=item B
		3422
		3423	Dual channel
		3424
		3425	=item B
		3426
		3427	Mono
		3428
		3429	=back
		3430
		3431
		3432
		3433	=item BI<--psyc-mode>B<)>
		3434
		3435	Set psychoacoustic model to use in encoding. The argument must be
		3436	an integer between -1 and 4, inclusive. The higher the value, the
		3437	better the quality. The default value is 3.
		3438
		3439
		3440	=item BI<--energy>B<)>
		3441
		3442	Enable energy levels extensions when set to 1. The default value is
		3443
		3444
		3445
		3446	=item BI<--protect>B<)>
		3447
		3448	Enable CRC error protection when set to 1. The default value is 0
		3449	(disabled).
		3450
		3451
		3452	=item BI<--copyright>B<)>
		3453
		3454	Set MPEG audio copyright flag when set to 1. The default value is 0
		3455	(disabled).
		3456
		3457
		3458	=item BI<--original>B<)>
		3459
		3460	Set MPEG audio original flag when set to 1. The default value is 0
		3461	(disabled).
		3462
		3463
		3464	=back
		3465
		3466
		3467
		3468
		3469	=head2 libvo-aacenc
		3470
		3471
		3472	VisualOn AAC encoder.
		3473
		3474	Requires the presence of the libvo-aacenc headers and library during
		3475	configuration. You need to explicitly configure the build with
		3476	C<--enable-libvo-aacenc --enable-version3>.
		3477
		3478	This encoder is considered to be worse than the
		3479	native experimental FFmpeg AAC encoder, according to
		3480	multiple sources.
		3481
		3482
		3483	=head3 Options
		3484
		3485
		3486	The VisualOn AAC encoder only support encoding AAC-LC and up to 2
		3487	channels. It is also CBR-only.
		3488
		3489
		3490	=over 4
		3491
		3492
		3493
		3494	=item B
		3495
		3496	Set bit rate in bits/s.
		3497
		3498
		3499	=back
		3500
		3501
		3502
		3503	=head2 libvo-amrwbenc
		3504
		3505
		3506	VisualOn Adaptive Multi-Rate Wideband encoder.
		3507
		3508	Requires the presence of the libvo-amrwbenc headers and library during
		3509	configuration. You need to explicitly configure the build with
		3510	C<--enable-libvo-amrwbenc --enable-version3>.
		3511
		3512	This is a mono-only encoder. Officially it only supports 16000Hz sample
		3513	rate, but you can override it by setting B to
		3514	B or lower.
		3515
		3516
		3517	=head3 Options
		3518
		3519
		3520
		3521	=over 4
		3522
		3523
		3524
		3525	=item B
		3526
		3527	Set bitrate in bits/s. Only the following bitrates are supported, otherwise
		3528	libavcodec will round to the nearest valid bitrate.
		3529
		3530
		3531	=over 4
		3532
		3533
		3534	=item B<6600>
		3535
		3536
		3537	=item B<8850>
		3538
		3539
		3540	=item B<12650>
		3541
		3542
		3543	=item B<14250>
		3544
		3545
		3546	=item B<15850>
		3547
		3548
		3549	=item B<18250>
		3550
		3551
		3552	=item B<19850>
		3553
		3554
		3555	=item B<23050>
		3556
		3557
		3558	=item B<23850>
		3559
		3560
		3561	=back
		3562
		3563
		3564
		3565	=item B
		3566
		3567	Allow discontinuous transmission (generate comfort noise) when set to 1. The
		3568	default value is 0 (disabled).
		3569
		3570
		3571	=back
		3572
		3573
		3574
		3575	=head2 libopus
		3576
		3577
		3578	libopus Opus Interactive Audio Codec encoder wrapper.
		3579
		3580	Requires the presence of the libopus headers and library during
		3581	configuration. You need to explicitly configure the build with
		3582	C<--enable-libopus>.
		3583
		3584
		3585	=head3 Option Mapping
		3586
		3587
		3588	Most libopus options are modeled after the B utility from
		3589	opus-tools. The following is an option mapping chart describing options
		3590	supported by the libopus wrapper, and their B-equivalent
		3591	in parentheses.
		3592
		3593
		3594	=over 4
		3595
		3596
		3597
		3598	=item BIB<)>
		3599
		3600	Set the bit rate in bits/s. FFmpeg's B option is
		3601	expressed in bits/s, while B's B in
		3602	kilobits/s.
		3603
		3604
		3605	=item BIB<,> IB<, and> IB<)>
		3606
		3607	Set VBR mode. The FFmpeg B option has the following
		3608	valid arguments, with the their B equivalent options
		3609	in parentheses:
		3610
		3611
		3612	=over 4
		3613
		3614
		3615	=item BIB<)>
		3616
		3617	Use constant bit rate encoding.
		3618
		3619
		3620	=item BIB<)>
		3621
		3622	Use variable bit rate encoding (the default).
		3623
		3624
		3625	=item BIB<)>
		3626
		3627	Use constrained variable bit rate encoding.
		3628
		3629	=back
		3630
		3631
		3632
		3633	=item BIB<)>
		3634
		3635	Set encoding algorithm complexity. Valid options are integers in
		3636	the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
		3637	gives the highest quality but slowest encoding. The default is 10.
		3638
		3639
		3640	=item BIB<)>
		3641
		3642	Set maximum frame size, or duration of a frame in milliseconds. The
		3643	argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
		3644	frame sizes achieve lower latency but less quality at a given bitrate.
		3645	Sizes greater than 20ms are only interesting at fairly low bitrates.
		3646	The default of FFmpeg is 10ms, but is 20ms in B.
		3647
		3648
		3649	=item BIB<)>
		3650
		3651	Set expected packet loss percentage. The default is 0.
		3652
		3653
		3654	=item B
		3655
		3656	Set intended application type. Valid options are listed below:
		3657
		3658
		3659	=over 4
		3660
		3661
		3662	=item B
		3663
		3664	Favor improved speech intelligibility.
		3665
		3666	=item B
		3667
		3668	Favor faithfulness to the input (the default).
		3669
		3670	=item B
		3671
		3672	Restrict to only the lowest delay modes.
		3673
		3674	=back
		3675
		3676
		3677
		3678	=item B
		3679
		3680	Set cutoff bandwidth in Hz. The argument must be exactly one of the
		3681	following: 4000, 6000, 8000, 12000, or 20000, corresponding to
		3682	narrowband, mediumband, wideband, super wideband, and fullband
		3683	respectively. The default is 0 (cutoff disabled).
		3684
		3685
		3686	=back
		3687
		3688
		3689
		3690	=head2 libvorbis
		3691
		3692
		3693	libvorbis encoder wrapper.
		3694
		3695	Requires the presence of the libvorbisenc headers and library during
		3696	configuration. You need to explicitly configure the build with
		3697	C<--enable-libvorbis>.
		3698
		3699
		3700	=head3 Options
		3701
		3702
		3703	The following options are supported by the libvorbis wrapper. The
		3704	B-equivalent of the options are listed in parentheses.
		3705
		3706	To get a more accurate and extensive documentation of the libvorbis
		3707	options, consult the libvorbisenc's and B's documentations.
		3708	See EBE,
		3709	EBE, and oggenc(1).
		3710
		3711
		3712	=over 4
		3713
		3714
		3715	=item BI<-b>B<)>
		3716
		3717	Set bitrate expressed in bits/s for ABR. B B<-b> is
		3718	expressed in kilobits/s.
		3719
		3720
		3721	=item BI<-q>B<)>
		3722
		3723	Set constant quality setting for VBR. The value should be a float
		3724	number in the range of -1.0 to 10.0. The higher the value, the better
		3725	the quality. The default value is B<3.0>.
		3726
		3727	This option is valid only using the B command-line tool.
		3728	For library interface users, use B.
		3729
		3730
		3731	=item BI<--advanced-encode-option lowpass_frequency=N>B<)>
		3732
		3733	Set cutoff bandwidth in Hz, a value of 0 disables cutoff. B's
		3734	related option is expressed in kHz. The default value is B<0> (cutoff
		3735	disabled).
		3736
		3737
		3738	=item BI<-m>B<)>
		3739
		3740	Set minimum bitrate expressed in bits/s. B B<-m> is
		3741	expressed in kilobits/s.
		3742
		3743
		3744	=item BI<-M>B<)>
		3745
		3746	Set maximum bitrate expressed in bits/s. B B<-M> is
		3747	expressed in kilobits/s. This only has effect on ABR mode.
		3748
		3749
		3750	=item BI<--advanced-encode-option impulse_noisetune=N>B<)>
		3751
		3752	Set noise floor bias for impulse blocks. The value is a float number from
		3753	-15.0 to 0.0. A negative bias instructs the encoder to pay special attention
		3754	to the crispness of transients in the encoded audio. The tradeoff for better
		3755	transient response is a higher bitrate.
		3756
		3757
		3758	=back
		3759
		3760
		3761
		3762	=head2 libwavpack
		3763
		3764
		3765	A wrapper providing WavPack encoding through libwavpack.
		3766
		3767	Only lossless mode using 32-bit integer samples is supported currently.
		3768	The B option can be used to control speed vs.
		3769	compression tradeoff, with the values mapped to libwavpack as follows:
		3770
		3771
		3772	=over 4
		3773
		3774
		3775
		3776	=item B<0>
		3777
		3778	Fast mode - corresponding to the wavpack B<-f> option.
		3779
		3780
		3781	=item B<1>
		3782
		3783	Normal (default) settings.
		3784
		3785
		3786	=item B<2>
		3787
		3788	High quality - corresponding to the wavpack B<-h> option.
		3789
		3790
		3791	=item B<3>
		3792
		3793	Very high quality - corresponding to the wavpack B<-hh> option.
		3794
		3795
		3796	=item B<4-8>
		3797
		3798	Same as 3, but with extra processing enabled - corresponding to the wavpack
		3799	B<-x> option. I.e. 4 is the same as B<-x2> and 8 is the same as
		3800	B<-x6>.
		3801
		3802
		3803	=back
		3804
		3805
		3806
		3807
		3808	=head1 VIDEO ENCODERS
		3809
		3810
		3811	A description of some of the currently available video encoders
		3812	follows.
		3813
		3814
		3815	=head2 libtheora
		3816
		3817
		3818	Theora format supported through libtheora.
		3819
		3820	Requires the presence of the libtheora headers and library during
		3821	configuration. You need to explicitly configure the build with
		3822	C<--enable-libtheora>.
		3823
		3824
		3825	=head3 Options
		3826
		3827
		3828	The following global options are mapped to internal libtheora options
		3829	which affect the quality and the bitrate of the encoded stream.
		3830
		3831
		3832	=over 4
		3833
		3834
		3835	=item B
		3836
		3837	Set the video bitrate, only works if the C flag in
		3838	B is not enabled.
		3839
		3840
		3841	=item B
		3842
		3843	Used to enable constant quality mode encoding through the
		3844	B flag, and to enable the C and C
		3845	modes.
		3846
		3847
		3848	=item B
		3849
		3850	Set the GOP size.
		3851
		3852
		3853	=item B
		3854
		3855	Set the global quality in lambda units, only works if the
		3856	C flag in B is enabled. The value is clipped
		3857	in the [0 - 10*C] range, and then multiplied for 6.3
		3858	to get a value in the native libtheora range [0-63]. A higher value
		3859	corresponds to a higher quality.
		3860
		3861	For example, to set maximum constant quality encoding with
		3862	B:
		3863
		3864	ffmpeg -i INPUT -flags:v qscale -global_quality:v "10*QP2LAMBDA" -codec:v libtheora OUTPUT.ogg
		3865
		3866
		3867	=back
		3868
		3869
		3870
		3871	=head2 libvpx
		3872
		3873
		3874	VP8 format supported through libvpx.
		3875
		3876	Requires the presence of the libvpx headers and library during configuration.
		3877	You need to explicitly configure the build with C<--enable-libvpx>.
		3878
		3879
		3880	=head3 Options
		3881
		3882
		3883	Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
		3884
		3885
		3886	=over 4
		3887
		3888
		3889
		3890	=item B
		3891
		3892	g_threads
		3893
		3894
		3895	=item B
		3896
		3897	g_profile
		3898
		3899
		3900	=item B
		3901
		3902	rc_target_bitrate
		3903
		3904
		3905	=item B
		3906
		3907	kf_max_dist
		3908
		3909
		3910	=item B
		3911
		3912	kf_min_dist
		3913
		3914
		3915	=item B
		3916
		3917	rc_min_quantizer
		3918
		3919
		3920	=item B
		3921
		3922	rc_max_quantizer
		3923
		3924
		3925	=item B
		3926
		3927	rc_buf_sz
		3928	C<(bufsize * 1000 / vb)>
		3929
		3930	rc_buf_optimal_sz
		3931	C<(bufsize * 1000 / vb * 5 / 6)>
		3932
		3933
		3934	=item B
		3935
		3936	rc_buf_initial_sz
		3937	C<(rc_init_occupancy * 1000 / vb)>
		3938
		3939
		3940	=item B
		3941
		3942	rc_undershoot_pct
		3943
		3944
		3945	=item B
		3946
		3947	rc_dropframe_thresh
		3948
		3949
		3950	=item B
		3951
		3952	rc_2pass_vbr_bias_pct
		3953
		3954
		3955	=item B
		3956
		3957	rc_2pass_vbr_maxsection_pct
		3958	C<(maxrate * 100 / vb)>
		3959
		3960
		3961	=item B
		3962
		3963	rc_2pass_vbr_minsection_pct
		3964	C<(minrate * 100 / vb)>
		3965
		3966
		3967	=item B
		3968
		3969	C
		3970	C<(minrate == maxrate == vb)>
		3971
		3972
		3973	=item B
		3974
		3975	C, C
		3976
		3977
		3978	=item B
		3979
		3980
		3981	=over 4
		3982
		3983
		3984	=item I
		3985
		3986	C
		3987
		3988	=item I
		3989
		3990	C
		3991
		3992	=item I
		3993
		3994	C
		3995
		3996	=back
		3997
		3998
		3999
		4000	=item B
		4001
		4002	C
		4003
		4004
		4005	=item B
		4006
		4007	C
		4008
		4009
		4010	=item B
		4011
		4012	C
		4013
		4014
		4015	=item B
		4016
		4017	C
		4018
		4019
		4020	=item B
		4021
		4022	C
		4023
		4024
		4025	=item B
		4026
		4027	C
		4028
		4029
		4030	=item B
		4031
		4032
		4033	=over 4
		4034
		4035
		4036	=item B
		4037
		4038	C
		4039
		4040	=item I
		4041
		4042	C
		4043
		4044	=item I
		4045
		4046	C
		4047
		4048	=item I
		4049
		4050	C
		4051
		4052	=item I
		4053
		4054	g_lag_in_frames
		4055
		4056	=back
		4057
		4058
		4059
		4060	=item B
		4061
		4062	g_error_resilient
		4063
		4064
		4065	=back
		4066
		4067
		4068	For more information about libvpx see:
		4069	EBE
		4070
		4071
		4072	=head2 libx264
		4073
		4074
		4075	x264 H.264/MPEG-4 AVC encoder wrapper.
		4076
		4077	This encoder requires the presence of the libx264 headers and library
		4078	during configuration. You need to explicitly configure the build with
		4079	C<--enable-libx264>.
		4080
		4081	libx264 supports an impressive number of features, including 8x8 and
		4082	4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
		4083	entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
		4084	for detail retention (adaptive quantization, psy-RD, psy-trellis).
		4085
		4086	Many libx264 encoder options are mapped to FFmpeg global codec
		4087	options, while unique encoder options are provided through private
		4088	options. Additionally the B and B
		4089	private options allows to pass a list of key=value tuples as accepted
		4090	by the libx264 C function.
		4091
		4092	The x264 project website is at
		4093	EBE.
		4094
		4095
		4096	=head3 Options
		4097
		4098
		4099	The following options are supported by the libx264 wrapper. The
		4100	B-equivalent options or values are listed in parentheses
		4101	for easy migration.
		4102
		4103	To reduce the duplication of documentation, only the private options
		4104	and some others requiring special attention are documented here. For
		4105	the documentation of the undocumented generic options, see
		4106	the Codec Options chapter.
		4107
		4108	To get a more accurate and extensive documentation of the libx264
		4109	options, invoke the command B or consult
		4110	the libx264 documentation.
		4111
		4112
		4113	=over 4
		4114
		4115
		4116	=item BIB<)>
		4117
		4118	Set bitrate in bits/s. Note that FFmpeg's B option is
		4119	expressed in bits/s, while B's B is in
		4120	kilobits/s.
		4121
		4122
		4123	=item BIB<)>
		4124
		4125
		4126
		4127	=item BIB<)>
		4128
		4129
		4130
		4131	=item BIB<)>
		4132
		4133
		4134
		4135	=item BIB<)>
		4136
		4137
		4138
		4139	=item BIB<)>
		4140
		4141
		4142
		4143	=item BIB<)>
		4144
		4145
		4146
		4147	=item BIB<)>
		4148
		4149
		4150
		4151	=item BIB<)>
		4152
		4153
		4154
		4155	=item BIB<)>
		4156
		4157
		4158
		4159	=item BIB<)>
		4160
		4161
		4162
		4163	=item BIB<)>
		4164
		4165
		4166
		4167	=item BIB<)>
		4168
		4169
		4170
		4171	=item BIB<)>
		4172
		4173	Set motion estimation method. Possible values in the decreasing order
		4174	of speed:
		4175
		4176
		4177	=over 4
		4178
		4179
		4180	=item BIB<)>
		4181
		4182
		4183	=item BIB<)>
		4184
		4185	Diamond search with radius 1 (fastest). B is an alias for
		4186	B.
		4187
		4188	=item BIB<)>
		4189
		4190	Hexagonal search with radius 2.
		4191
		4192	=item BIB<)>
		4193
		4194	Uneven multi-hexagon search.
		4195
		4196	=item BIB<)>
		4197
		4198	Exhaustive search.
		4199
		4200	=item BIB<)>
		4201
		4202	Hadamard exhaustive search (slowest).
		4203
		4204	=back
		4205
		4206
		4207
		4208	=item BIB<)>
		4209
		4210
		4211
		4212	=item BIB<)>
		4213
		4214
		4215
		4216	=item BIB<)>
		4217
		4218
		4219
		4220	=item B
		4221
		4222	Set entropy encoder. Possible values:
		4223
		4224
		4225	=over 4
		4226
		4227
		4228	=item B
		4229
		4230	Enable CABAC.
		4231
		4232
		4233	=item B
		4234
		4235	Enable CAVLC and disable CABAC. It generates the same effect as
		4236	B's B<--no-cabac> option.
		4237
		4238	=back
		4239
		4240
		4241
		4242	=item B
		4243
		4244	Set full pixel motion estimation comparation algorithm. Possible values:
		4245
		4246
		4247	=over 4
		4248
		4249
		4250	=item B
		4251
		4252	Enable chroma in motion estimation.
		4253
		4254
		4255	=item B
		4256
		4257	Ignore chroma in motion estimation. It generates the same effect as
		4258	B's B<--no-chroma-me> option.
		4259
		4260	=back
		4261
		4262
		4263
		4264	=item BIB<)>
		4265
		4266
		4267
		4268	=item B
		4269
		4270	Set multithreading technique. Possible values:
		4271
		4272
		4273	=over 4
		4274
		4275
		4276	=item B
		4277
		4278	Slice-based multithreading. It generates the same effect as
		4279	B's B<--sliced-threads> option.
		4280
		4281	=item B
		4282
		4283	Frame-based multithreading.
		4284
		4285	=back
		4286
		4287
		4288
		4289	=item B
		4290
		4291	Set encoding flags. It can be used to disable closed GOP and enable
		4292	open GOP by setting it to C<-cgop>. The result is similar to
		4293	the behavior of B's B<--open-gop> option.
		4294
		4295
		4296	=item BIB<)>
		4297
		4298
		4299
		4300	=item BIB<)>
		4301
		4302	Set the encoding preset.
		4303
		4304
		4305	=item BIB<)>
		4306
		4307	Set tuning of the encoding params.
		4308
		4309
		4310	=item BIB<)>
		4311
		4312	Set profile restrictions.
		4313
		4314
		4315	=item B
		4316
		4317	Enable fast settings when encoding first pass, when set to 1. When set
		4318	to 0, it has the same effect of B's
		4319	B<--slow-firstpass> option.
		4320
		4321
		4322	=item BIB<)>
		4323
		4324	Set the quality for constant quality mode.
		4325
		4326
		4327	=item BIB<)>
		4328
		4329	In CRF mode, prevents VBV from lowering quality beyond this point.
		4330
		4331
		4332	=item BIB<)>
		4333
		4334	Set constant quantization rate control method parameter.
		4335
		4336
		4337	=item BIB<)>
		4338
		4339	Set AQ method. Possible values:
		4340
		4341
		4342	=over 4
		4343
		4344
		4345	=item BI<0>B<)>
		4346
		4347	Disabled.
		4348
		4349
		4350	=item BI<1>B<)>
		4351
		4352	Variance AQ (complexity mask).
		4353
		4354
		4355	=item BI<2>B<)>
		4356
		4357	Auto-variance AQ (experimental).
		4358
		4359	=back
		4360
		4361
		4362
		4363	=item BIB<)>
		4364
		4365	Set AQ strength, reduce blocking and blurring in flat and textured areas.
		4366
		4367
		4368	=item B
		4369
		4370	Use psychovisual optimizations when set to 1. When set to 0, it has the
		4371	same effect as B's B<--no-psy> option.
		4372
		4373
		4374	=item BIB<)>
		4375
		4376	Set strength of psychovisual optimization, in
		4377	I:I format.
		4378
		4379
		4380	=item BIB<)>
		4381
		4382	Set number of frames to look ahead for frametype and ratecontrol.
		4383
		4384
		4385	=item B
		4386
		4387	Enable weighted prediction for B-frames when set to 1. When set to 0,
		4388	it has the same effect as B's B<--no-weightb> option.
		4389
		4390
		4391	=item BIB<)>
		4392
		4393	Set weighted prediction method for P-frames. Possible values:
		4394
		4395
		4396	=over 4
		4397
		4398
		4399	=item BI<0>B<)>
		4400
		4401	Disabled
		4402
		4403	=item BI<1>B<)>
		4404
		4405	Enable only weighted refs
		4406
		4407	=item BI<2>B<)>
		4408
		4409	Enable both weighted refs and duplicates
		4410
		4411	=back
		4412
		4413
		4414
		4415	=item BIB<)>
		4416
		4417	Enable calculation and printing SSIM stats after the encoding.
		4418
		4419
		4420	=item BIB<)>
		4421
		4422	Enable the use of Periodic Intra Refresh instead of IDR frames when set
		4423	to 1.
		4424
		4425
		4426	=item BIB<)>
		4427
		4428	Configure the encoder to be compatible with the bluray standard.
		4429	It is a shorthand for setting "bluray-compat=1 force-cfr=1".
		4430
		4431
		4432	=item BIB<)>
		4433
		4434	Set the influence on how often B-frames are used.
		4435
		4436
		4437	=item BIB<)>
		4438
		4439	Set method for keeping of some B-frames as references. Possible values:
		4440
		4441
		4442	=over 4
		4443
		4444
		4445	=item BIB<)>
		4446
		4447	Disabled.
		4448
		4449	=item BIB<)>
		4450
		4451	Strictly hierarchical pyramid.
		4452
		4453	=item BIB<)>
		4454
		4455	Non-strict (not Blu-ray compatible).
		4456
		4457	=back
		4458
		4459
		4460
		4461	=item B
		4462
		4463	Enable the use of one reference per partition, as opposed to one
		4464	reference per macroblock when set to 1. When set to 0, it has the
		4465	same effect as B's B<--no-mixed-refs> option.
		4466
		4467
		4468	=item B<8x8dct>
		4469
		4470	Enable adaptive spatial transform (high profile 8x8 transform)
		4471	when set to 1. When set to 0, it has the same effect as
		4472	B's B<--no-8x8dct> option.
		4473
		4474
		4475	=item B
		4476
		4477	Enable early SKIP detection on P-frames when set to 1. When set
		4478	to 0, it has the same effect as B's
		4479	B<--no-fast-pskip> option.
		4480
		4481
		4482	=item BIB<)>
		4483
		4484	Enable use of access unit delimiters when set to 1.
		4485
		4486
		4487	=item B
		4488
		4489	Enable use macroblock tree ratecontrol when set to 1. When set
		4490	to 0, it has the same effect as B's
		4491	B<--no-mbtree> option.
		4492
		4493
		4494	=item BIB<)>
		4495
		4496	Set loop filter parameters, in I:I form.
		4497
		4498
		4499	=item BIB<)>
		4500
		4501	Set fluctuations reduction in QP (before curve compression).
		4502
		4503
		4504	=item BIB<)>
		4505
		4506	Set partitions to consider as a comma-separated list of. Possible
		4507	values in the list:
		4508
		4509
		4510	=over 4
		4511
		4512
		4513	=item B
		4514
		4515	8x8 P-frame partition.
		4516
		4517	=item B
		4518
		4519	4x4 P-frame partition.
		4520
		4521	=item B
		4522
		4523	4x4 B-frame partition.
		4524
		4525	=item B
		4526
		4527	8x8 I-frame partition.
		4528
		4529	=item B
		4530
		4531	4x4 I-frame partition.
		4532	(Enabling B requires B to be enabled. Enabling
		4533	B requires adaptive spatial transform (B<8x8dct>
		4534	option) to be enabled.)
		4535
		4536	=item BIB<)>
		4537
		4538	Do not consider any partitions.
		4539
		4540	=item BIB<)>
		4541
		4542	Consider every partition.
		4543
		4544	=back
		4545
		4546
		4547
		4548	=item BIB<)>
		4549
		4550	Set direct MV prediction mode. Possible values:
		4551
		4552
		4553	=over 4
		4554
		4555
		4556	=item BIB<)>
		4557
		4558	Disable MV prediction.
		4559
		4560	=item BIB<)>
		4561
		4562	Enable spatial predicting.
		4563
		4564	=item BIB<)>
		4565
		4566	Enable temporal predicting.
		4567
		4568	=item BIB<)>
		4569
		4570	Automatically decided.
		4571
		4572	=back
		4573
		4574
		4575
		4576	=item BIB<)>
		4577
		4578	Set the limit of the size of each slice in bytes. If not specified
		4579	but RTP payload size (B) is specified, that is used.
		4580
		4581
		4582	=item BIB<)>
		4583
		4584	Set the file name for multi-pass stats.
		4585
		4586
		4587	=item BIB<)>
		4588
		4589	Set signal HRD information (requires B to be set).
		4590	Possible values:
		4591
		4592
		4593	=over 4
		4594
		4595
		4596	=item BIB<)>
		4597
		4598	Disable HRD information signaling.
		4599
		4600	=item BIB<)>
		4601
		4602	Variable bit rate.
		4603
		4604	=item BIB<)>
		4605
		4606	Constant bit rate (not allowed in MP4 container).
		4607
		4608	=back
		4609
		4610
		4611
		4612	=item B
		4613
		4614	Set any x264 option, see B for a list.
		4615
		4616	Argument is a list of I=I couples separated by
		4617	":". In I and I options that use ":" as a separator
		4618	themselves, use "," instead. They accept it as well since long ago but this
		4619	is kept undocumented for some reason.
		4620
		4621	For example to specify libx264 encoding options with B:
		4622
		4623	ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
		4624
		4625
		4626
		4627	=item B
		4628
		4629	Override the x264 configuration using a :-separated list of key=value
		4630	parameters.
		4631
		4632	This option is functionally the same as the B, but is
		4633	duplicated for compability with the Libav fork.
		4634
		4635	For example to specify libx264 encoding options with B:
		4636
		4637	ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
		4638	cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
		4639	no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
		4640
		4641
		4642	=back
		4643
		4644
		4645	Encoding ffpresets for common usages are provided so they can be used with the
		4646	general presets system (e.g. passing the B option).
		4647
		4648
		4649	=head2 libxvid
		4650
		4651
		4652	Xvid MPEG-4 Part 2 encoder wrapper.
		4653
		4654	This encoder requires the presence of the libxvidcore headers and library
		4655	during configuration. You need to explicitly configure the build with
		4656	C<--enable-libxvid --enable-gpl>.
		4657
		4658	The native C encoder supports the MPEG-4 Part 2 format, so
		4659	users can encode to this format without this library.
		4660
		4661
		4662	=head3 Options
		4663
		4664
		4665	The following options are supported by the libxvid wrapper. Some of
		4666	the following options are listed but are not documented, and
		4667	correspond to shared codec options. See the Codec
		4668	Options chapter for their documentation. The other shared options
		4669	which are not listed have no effect for the libxvid encoder.
		4670
		4671
		4672	=over 4
		4673
		4674
		4675	=item B
		4676
		4677
		4678
		4679	=item B
		4680
		4681
		4682
		4683	=item B
		4684
		4685
		4686
		4687	=item B
		4688
		4689
		4690
		4691	=item B
		4692
		4693
		4694
		4695	=item B
		4696
		4697
		4698
		4699	=item B
		4700
		4701
		4702
		4703	=item B
		4704
		4705
		4706
		4707	=item B
		4708
		4709
		4710
		4711	=item B
		4712
		4713	Set specific encoding flags. Possible values:
		4714
		4715
		4716	=over 4
		4717
		4718
		4719
		4720	=item B
		4721
		4722	Use four motion vector by macroblock.
		4723
		4724
		4725	=item B
		4726
		4727	Enable high quality AC prediction.
		4728
		4729
		4730	=item B
		4731
		4732	Only encode grayscale.
		4733
		4734
		4735	=item B
		4736
		4737	Enable the use of global motion compensation (GMC).
		4738
		4739
		4740	=item B
		4741
		4742	Enable quarter-pixel motion compensation.
		4743
		4744
		4745	=item B
		4746
		4747	Enable closed GOP.
		4748
		4749
		4750	=item B
		4751
		4752	Place global headers in extradata instead of every keyframe.
		4753
		4754
		4755	=back
		4756
		4757
		4758
		4759	=item B
		4760
		4761
		4762
		4763	=item B
		4764
		4765	Set motion estimation method. Possible values in decreasing order of
		4766	speed and increasing order of quality:
		4767
		4768
		4769	=over 4
		4770
		4771
		4772	=item B
		4773
		4774	Use no motion estimation (default).
		4775
		4776
		4777	=item B
		4778
		4779
		4780	=item B
		4781
		4782
		4783	=item B
		4784
		4785	Enable advanced diamond zonal search for 16x16 blocks and half-pixel
		4786	refinement for 16x16 blocks. B and B are aliases for
		4787	B.
		4788
		4789
		4790	=item B
		4791
		4792	Enable all of the things described above, plus advanced diamond zonal
		4793	search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
		4794	estimation on chroma planes.
		4795
		4796
		4797	=item B
		4798
		4799	Enable all of the things described above, plus extended 16x16 and 8x8
		4800	blocks search.
		4801
		4802	=back
		4803
		4804
		4805
		4806	=item B
		4807
		4808	Set macroblock decision algorithm. Possible values in the increasing
		4809	order of quality:
		4810
		4811
		4812	=over 4
		4813
		4814
		4815	=item B
		4816
		4817	Use macroblock comparing function algorithm (default).
		4818
		4819
		4820	=item B
		4821
		4822	Enable rate distortion-based half pixel and quarter pixel refinement for
		4823	16x16 blocks.
		4824
		4825
		4826	=item B
		4827
		4828	Enable all of the things described above, plus rate distortion-based
		4829	half pixel and quarter pixel refinement for 8x8 blocks, and rate
		4830	distortion-based search using square pattern.
		4831
		4832	=back
		4833
		4834
		4835
		4836	=item B
		4837
		4838	Enable lumi masking adaptive quantization when set to 1. Default is 0
		4839	(disabled).
		4840
		4841
		4842	=item B
		4843
		4844	Enable variance adaptive quantization when set to 1. Default is 0
		4845	(disabled).
		4846
		4847	When combined with B, the resulting quality will not
		4848	be better than any of the two specified individually. In other
		4849	words, the resulting quality will be the worse one of the two
		4850	effects.
		4851
		4852
		4853	=item B
		4854
		4855	Set structural similarity (SSIM) displaying method. Possible values:
		4856
		4857
		4858	=over 4
		4859
		4860
		4861	=item B
		4862
		4863	Disable displaying of SSIM information.
		4864
		4865
		4866	=item B
		4867
		4868	Output average SSIM at the end of encoding to stdout. The format of
		4869	showing the average SSIM is:
		4870
		4871
		4872	Average SSIM: %f
		4873
		4874
		4875	For users who are not familiar with C, %f means a float number, or
		4876	a decimal (e.g. 0.939232).
		4877
		4878
		4879	=item B
		4880
		4881	Output both per-frame SSIM data during encoding and average SSIM at
		4882	the end of encoding to stdout. The format of per-frame information
		4883	is:
		4884
		4885
		4886	SSIM: avg: %1.3f min: %1.3f max: %1.3f
		4887
		4888
		4889	For users who are not familiar with C, %1.3f means a float number
		4890	rounded to 3 digits after the dot (e.g. 0.932).
		4891
		4892
		4893	=back
		4894
		4895
		4896
		4897	=item B
		4898
		4899	Set SSIM accuracy. Valid options are integers within the range of
		4900	0-4, while 0 gives the most accurate result and 4 computes the
		4901	fastest.
		4902
		4903
		4904	=back
		4905
		4906
		4907
		4908	=head2 png
		4909
		4910
		4911	PNG image encoder.
		4912
		4913
		4914	=head3 Private options
		4915
		4916
		4917
		4918	=over 4
		4919
		4920
		4921	=item B I
		4922
		4923	Set physical density of pixels, in dots per inch, unset by default
		4924
		4925	=item B I
		4926
		4927	Set physical density of pixels, in dots per meter, unset by default
		4928
		4929	=back
		4930
		4931
		4932
		4933	=head2 ProRes
		4934
		4935
		4936	Apple ProRes encoder.
		4937
		4938	FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
		4939	The used encoder can be choosen with the C<-vcodec> option.
		4940
		4941
		4942	=head3 Private Options for prores-ks
		4943
		4944
		4945
		4946	=over 4
		4947
		4948
		4949	=item B I
		4950
		4951	Select the ProRes profile to encode
		4952
		4953	=over 4
		4954
		4955
		4956	=item B
		4957
		4958
		4959	=item B
		4960
		4961
		4962	=item B
		4963
		4964
		4965	=item B
		4966
		4967
		4968	=item B<4444>
		4969
		4970
		4971	=back
		4972
		4973
		4974
		4975	=item B I
		4976
		4977	Select quantization matrix.
		4978
		4979	=over 4
		4980
		4981
		4982	=item B
		4983
		4984
		4985	=item B
		4986
		4987
		4988	=item B
		4989
		4990
		4991	=item B
		4992
		4993
		4994	=item B
		4995
		4996
		4997	=item B
		4998
		4999
		5000	=back
		5001
		5002	If set to I, the matrix matching the profile will be picked.
		5003	If not set, the matrix providing the highest quality, I, will be
		5004	picked.
		5005
		5006
		5007	=item B I
		5008
		5009	How many bits to allot for coding one macroblock. Different profiles use
		5010	between 200 and 2400 bits per macroblock, the maximum is 8000.
		5011
		5012
		5013	=item B I
		5014
		5015	Number of macroblocks in each slice (1-8); the default value (8)
		5016	should be good in almost all situations.
		5017
		5018
		5019	=item B I
		5020
		5021	Override the 4-byte vendor ID.
		5022	A custom vendor ID like I would claim the stream was produced by
		5023	the Apple encoder.
		5024
		5025
		5026	=item B I
		5027
		5028	Specify number of bits for alpha component.
		5029	Possible values are I<0>, I<8> and I<16>.
		5030	Use I<0> to disable alpha plane coding.
		5031
		5032
		5033	=back
		5034
		5035
		5036
		5037	=head3 Speed considerations
		5038
		5039
		5040	In the default mode of operation the encoder has to honor frame constraints
		5041	(i.e. not produc frames with size bigger than requested) while still making
		5042	output picture as good as possible.
		5043	A frame containing a lot of small details is harder to compress and the encoder
		5044	would spend more time searching for appropriate quantizers for each slice.
		5045
		5046	Setting a higher B limit will improve the speed.
		5047
		5048	For the fastest encoding speed set the B parameter (4 is the
		5049	recommended value) and do not set a size constraint.
		5050
		5051
		5052
		5053	=head1 SEE ALSO
		5054
		5055
		5056
		5057	ffmpeg(1), ffplay(1), ffprobe(1), ffserver(1), libavcodec(3)
		5058
		5059
		5060	=head1 AUTHORS
		5061
		5062
		5063	The FFmpeg developers.
		5064
		5065	For details about the authorship, see the Git history of the project
		5066	(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
		5067	B in the FFmpeg source directory, or browsing the
		5068	online repository at EBE.
		5069
		5070	Maintainers for the specific components are listed in the file
		5071	F in the source code tree.
		5072
		5073

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(root)/contrib/sdk/sources/ffmpeg/doc/ffmpeg-codecs.pod @ 4349 – Rev