WebSVN – Kolibri OS – Blame – /programs/media/ac97snd/mpg/readers.c

Rev	Author	Line No.	Line
646	serge	1	#include "mpg123.h"
		2	#include "..\kolibri.h"
		3
		4	#define MAXFRAMESIZE 3456
		5
		6	static int fsizeold=0,ssize;
		7	static unsigned char bsspace[2][MAXFRAMESIZE+512]; /* MAXFRAMESIZE */
		8	static unsigned char bsbuf=bsspace[1],bsbufold;
		9	static int bsnum=0;
		10
		11	static unsigned long oldhead = 0;
		12	unsigned long firsthead=0;
		13
		14	struct bitstream_info bsi;
		15
		16	int tabsel_123[2][3][16] = {
		17	{ {0,32,64,96,128,160,192,224,256,288,320,352,384,416,448,},
		18	{0,32,48,56, 64, 80, 96,112,128,160,192,224,256,320,384,},
		19	{0,32,40,48, 56, 64, 80, 96,112,128,160,192,224,256,320,} },
		20
		21	{ {0,32,48,56,64,80,96,112,128,144,160,176,192,224,256,},
		22	{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,},
		23	{0,8,16,24,32,40,48,56,64,80,96,112,128,144,160,} }
		24	};
		25
		26	int freqs[9] = { 44100, 48000, 32000, 22050, 24000, 16000 , 11025 , 12000 , 8000 };
		27
		28	int stream_head_read(struct reader rd,unsigned long newhead);
		29	int stream_read_raw(struct reader rd,unsigned char buf, int size);
		30
		31	void set_synth_functions(struct frame *fr)
		32	{
		33	#ifdef USE_3DNOW
		34	static func_dct36 funcs_dct36[2] = {dct36 , dct36_3dnow};
		35	#endif
		36
		37	fr->synth = synth_1to1;
		38	fr->synth_mono = synth_1to1_mono2stereo;;
		39
		40	/* TODO: make autodetection for _all_ x86 optimizations (maybe just for i586+ and keep separate 486 build?) */
		41	#ifdef USE_3DNOW
		42	/* check cpuflags bit 31 (3DNow!) and 23 (MMX) */
		43	if((param.stat_3dnow < 2) &&
		44	((param.stat_3dnow == 1) \|\|
		45	(getcpuflags() & 0x80800000) == 0x80800000))
		46	{
		47	fr->synth = funcs[2][ds]; /* 3DNow! optimized synth_1to1() */
		48	fr->dct36 = funcs_dct36[1]; /* 3DNow! optimized dct36() */
		49	}
		50	else
		51	{
		52	fr->dct36 = funcs_dct36[0];
		53	}
		54	#endif
		55	}
		56
		57	int __stdcall create_reader(struct reader rd,byte buffer, int buffsize)
		58	{ rd->head_read = stream_head_read;
		59	rd->read_frame_body = stream_read_raw;
		60
		61	rd->buffer = buffer;
		62	rd->stream = buffer;
		63	rd->strpos = 0;
		64
		65	rd->strremain = 0;
		66	rd->filepos = 0;
		67	return 1;
		68	};
		69
		70	int __stdcall init_reader(struct reader rd, char file)
		71	{ FILEINFO fileinfo;
		72	int retval;
		73	int bytes;
		74
		75	rd->hFile = file;
576	serge	76	get_fileinfo(file, &fileinfo);
		77
646	serge	78	rd->filelen = fileinfo.size;
		79	rd->strpos = 0;
576	serge	80	retval=read_file (file,rd->buffer,0,0x10000,&bytes);
646	serge	81
		82	if( (retval==0)\|\|(retval==6))
		83	{
		84	rd->strremain=bytes;
		85	rd->filepos=bytes;
		86	rd->strpos = 0;
		87	return 1;
		88	};
		89	return 0;
		90	};
		91
		92	static int fill_reader(struct reader *rd)
		93	{ int retval;
		94	int bytes;
		95
		96	if(rd->strremain > 0)
		97	mem_cpy(rd->buffer,rd->stream,rd->strremain);
		98
		99	rd->stream = rd->buffer;
		100	retval=read_file (rd->hFile,rd->buffer+rd->strremain,rd->filepos,
		101	0x10000-rd->strremain,&bytes);
		102	if( (retval==0)\|\|(retval==6))
		103	{
		104	rd->strremain+=bytes;
		105	rd->filepos+=bytes;
		106	rd->strpos = 0;
		107	return bytes;
		108	};
		109	return 0;
		110	};
		111
		112	int __stdcall set_reader(struct reader *rd, unsigned int filepos)
		113	{ int retval;
		114	unsigned int bytes;
		115	retval=read_file (rd->hFile,rd->buffer,filepos,0x10000,&bytes);
		116	if( (retval==0)\|\|(retval==6))
		117	{
		118	rd->stream = rd->buffer;
		119	rd->strremain=bytes;
		120	rd->filepos=filepos+bytes;
		121	rd->strpos = 0;
		122
		123	fsizeold=0;
		124	firsthead=0;
		125	bsbufold = 0;
		126	bsbuf = bsspace[1];
		127	bsnum = 0;
		128	ssize=0;
		129	oldhead=0;
		130	memset(bsspace,0,sizeof(bsspace));
		131	return 1;
		132	};
		133	return 0;
		134	};
		135
		136	static int stream_head_read(struct reader rd,unsigned long newhead)
		137	{
		138	if(rd->strremain < 4)
		139	if( !fill_reader(rd))
		140	return 0;
		141	*newhead = (rd->stream[0]<<24)\|(rd->stream[1] << 16)\|
		142	(rd->stream[2] << 8)\| rd->stream[3];
		143	rd->strpos+=4;
		144	rd->stream+=4;
		145	rd->strremain-=4;
		146	return TRUE;
		147	};
		148
		149	int stream_read_raw(struct reader rd,unsigned char buf, int size)
		150	{
		151
		152	if(rd->strremain < size) fill_reader(rd);
		153
		154	if(size > rd->strremain) size=rd->strremain;
		155
		156	if(size>0)
		157	{
		158	mem_cpy(buf,rd->stream,size);
		159	rd->strpos+=size;
		160	rd->stream+=size;
		161	rd->strremain-=size;
		162	return size;
		163	};
		164	return 0;
		165	};
		166
		167	void set_pointer(long backstep)
		168	{
		169	bsi.wordpointer = bsbuf + ssize - backstep;
		170	if (backstep)
		171	mem_cpy(bsi.wordpointer,bsbufold+fsizeold-backstep,backstep);
		172	bsi.bitindex = 0;
		173	}
		174
		175	int head_check(unsigned long head)
		176	{ if
		177	(
		178	/* first 11 bits are set to 1 for frame sync */
		179	((head & 0xffe00000) != 0xffe00000)
		180	\|\|
		181	/* layer: 01,10,11 is 1,2,3; 00 is reserved */
		182	(!((head>>17)&3))
		183	\|\|
		184	/* 1111 means bad bitrate */
		185	(((head>>12)&0xf) == 0xf)
		186	\|\|
		187	/* 0000 means free format... */
		188	(((head>>12)&0xf) == 0x0)
		189	\|\|
		190	/* sampling freq: 11 is reserved */
		191	(((head>>10)&0x3) == 0x3 )
		192	/* here used to be a mpeg 2.5 check... re-enabled 2.5 decoding due to lack of evidence that it is really not good */
		193	)
		194	{
		195	return FALSE;
		196	}
		197	/* if no check failed, the header is valid (hopefully)*/
		198	else
		199	{
		200	return TRUE;
		201	}
		202	}
		203
		204	int __stdcall decode_header(struct frame *fr,unsigned long newhead)
		205	{
		206	if(!head_check(newhead))
		207	return 0;
		208	if( newhead & (1<<20) )
		209	{ fr->lsf = (newhead & (1<<19)) ? 0x0 : 0x1;
		210	fr->mpeg25 = 0;
		211	}
		212	else
		213	{ fr->lsf = 1;
		214	fr->mpeg25 = 1;
		215	};
		216
		217	fr->lay = 4-((newhead>>17)&3);
		218	if(fr->mpeg25)
		219	fr->sampling_frequency = 6 + ((newhead>>10)&0x3);
		220	else
		221	fr->sampling_frequency = ((newhead>>10)&0x3) + (fr->lsf*3);
		222	fr->error_protection = ((newhead>>16)&0x1)^0x1;
		223
		224	fr->bitrate_index = ((newhead>>12)&0xf);
		225	fr->padding = ((newhead>>9)&0x1);
		226	fr->extension = ((newhead>>8)&0x1);
		227	fr->mode = ((newhead>>6)&0x3);
		228	fr->mode_ext = ((newhead>>4)&0x3);
		229	fr->copyright = ((newhead>>3)&0x1);
		230	fr->original = ((newhead>>2)&0x1);
		231	fr->emphasis = newhead & 0x3;
		232
		233	fr->stereo = (fr->mode == MPG_MD_MONO) ? 1 : 2;
		234
		235	oldhead = newhead;
		236
		237	if(!fr->bitrate_index)
		238	return (0);
		239
		240	switch(fr->lay)
		241	{ case 1:
		242	fr->do_layer = do_layer1;
		243	#ifdef VARMODESUPPORT
		244	if (varmode) {
		245	error("Sorry, layer-1 not supported in varmode.");
		246	return (0);
		247	}
		248	#endif
		249	fr->framesize = (long) tabsel_123[fr->lsf][0][fr->bitrate_index] * 12000;
		250	fr->framesize /= freqs[fr->sampling_frequency];
		251	fr->framesize = ((fr->framesize+fr->padding)<<2)-4;
		252	break;
		253	case 2:
		254	fr->do_layer = do_layer2;
		255	#ifdef VARMODESUPPORT
		256	if (varmode) {
		257	error("Sorry, layer-2 not supported in varmode.");
		258	return (0);
		259	}
		260	#endif
		261	fr->framesize = (long) tabsel_123[fr->lsf][1][fr->bitrate_index] * 144000;
		262	fr->framesize /= freqs[fr->sampling_frequency];
		263	fr->framesize += fr->padding - 4;
		264	break;
		265	case 3:
		266	fr->do_layer = do_layer3;
		267	if(fr->lsf)
		268	ssize = (fr->stereo == 1) ? 9 : 17;
		269	else
		270	ssize = (fr->stereo == 1) ? 17 : 32;
		271	if(fr->error_protection)
		272	ssize += 2;
		273	fr->framesize = (long) tabsel_123[fr->lsf][2][fr->bitrate_index] * 144000;
		274	fr->framesize /= freqs[fr->sampling_frequency]<<(fr->lsf);
		275	fr->framesize = fr->framesize + fr->padding - 4;
		276	break;
		277	default:
		278	return (0);
		279	}
		280	if (fr->framesize > MAXFRAMESIZE)
		281	return (0);
		282	return 1;
		283	}
		284
		285
		286	int read_frame(struct reader rd, struct frame fr)
		287	{ unsigned long newhead;
		288	static unsigned char ssave[34];
		289	//off_t framepos;
		290	fsizeold=fr->framesize; /* for Layer3 */
		291
		292	read_again:
		293
		294	if(!rd->head_read(rd,&newhead))
		295	return FALSE;
		296
		297	if(!decode_header(fr,newhead))
		298	{
		299	if((newhead & 0xffffff00) == 0x49443300)
		300	{
		301	int id3length = 0;
		302	id3length = parse_new_id3(rd, newhead);
		303	goto read_again;
		304	};
		305	rd->strpos-=3;
		306	rd->stream-=3;
		307	rd->strremain+=3;
		308	goto read_again;
		309	};
		310
		311	#if 0
		312	if(1 \|\| oldhead != newhead \|\| !oldhead)
		313	{
		314
		315	init_resync:
		316
		317	#ifdef SKIP_JUNK
		318	/* watch out for junk/tags on beginning of stream by invalid header */
		319	if(!firsthead && !head_check(newhead) && !free_format_header(newhead)) {
		320	int i;
		321
		322	/* check for id3v2; first three bytes (of 4) are "ID3" */
		323	if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300)
		324	{
		325	int id3length = 0;
		326	id3length = parse_new_id3(newhead, rd);
		327	goto read_again;
		328	}
		329	else if(param.verbose > 1) fprintf(stderr,"Note: Junk at the beginning (0x%08lx)\n",newhead);
		330
		331	/* I even saw RIFF headers at the beginning of MPEG streams ;( */
		332	if(newhead == ('R'<<24)+('I'<<16)+('F'<<8)+'F') {
		333	if(param.verbose > 1) fprintf(stderr, "Note: Looks like a RIFF header.\n");
		334	if(!rd->head_read(rd,&newhead))
		335	return 0;
		336	while(newhead != ('d'<<24)+('a'<<16)+('t'<<8)+'a') {
		337	if(!rd->head_shift(rd,&newhead))
		338	return 0;
		339	}
		340	if(!rd->head_read(rd,&newhead))
		341	return 0;
		342	if(param.verbose > 1) fprintf(stderr,"Note: Skipped RIFF header!\n");
		343	goto read_again;
		344	}
		345	/* unhandled junk... just continue search for a header */
		346	/* step in byte steps through next 64K */
		347	for(i=0;i<65536;i++) {
		348	if(!rd->head_shift(rd,&newhead))
		349	return 0;
		350	/* if(head_check(newhead)) */
		351	if(head_check(newhead) && decode_header(fr, newhead))
		352	break;
		353	}
		354	if(i == 65536) {
		355	if(!param.quiet) error("Giving up searching valid MPEG header after 64K of junk.");
		356	return 0;
		357	}
		358	/*
		359	* should we additionaly check, whether a new frame starts at
		360	* the next expected position? (some kind of read ahead)
		361	* We could implement this easily, at least for files.
		362	*/
		363	}
		364	#endif
		365
		366	/* first attempt of read ahead check to find the real first header; cannot believe what junk is out there! */
		367	/* for now, a spurious first free format header screws up here; need free format support for detecting false free format headers... */
		368	if(!firsthead && rd->flags & READER_SEEKABLE && head_check(newhead) && decode_header(fr, newhead))
		369	{
		370	unsigned long nexthead = 0;
		371	int hd = 0;
		372	off_t start = rd->tell(rd);
		373	debug1("doing ahead check with BPF %d", fr->framesize+4);
		374	/* step framesize bytes forward and read next possible header*/
		375	if(rd->back_bytes(rd, -fr->framesize))
		376	{
		377	error("cannot seek!");
		378	return 0;
		379	}
		380	hd = rd->head_read(rd,&nexthead);
		381	if(rd->back_bytes(rd, rd->tell(rd)-start))
		382	{
		383	error("cannot seek!");
		384	return 0;
		385	}
		386	if(!hd)
		387	{
		388	warning("cannot read next header, a one-frame stream? Duh...");
		389	}
		390	else
		391	{
		392	debug2("does next header 0x%08lx match first 0x%08lx?", nexthead, newhead);
		393	/* not allowing free format yet */
		394	if(!head_check(nexthead) \|\| (nexthead & HDRCMPMASK) != (newhead & HDRCMPMASK))
		395	{
		396	debug("No, the header was not valid, start from beginning...");
		397	/* try next byte for valid header */
		398	if(rd->back_bytes(rd, 3))
		399	{
		400	error("cannot seek!");
		401	return 0;
		402	}
		403	goto read_again;
		404	}
		405	}
		406	}
		407
		408	/* why has this head check been avoided here before? */
		409	if(!head_check(newhead))
		410	{
		411	if(!firsthead && free_format_header(newhead))
		412	{
		413	error1("Header 0x%08lx seems to indicate a free format stream; I do not handle that yet", newhead);
		414	goto read_again;
		415	return 0;
		416	}
		417	/* and those ugly ID3 tags */
		418	if((newhead & 0xffffff00) == ('T'<<24)+('A'<<16)+('G'<<8)) {
		419	rd->skip_bytes(rd,124);
		420	if (param.verbose > 1) fprintf(stderr,"Note: Skipped ID3 Tag!\n");
		421	goto read_again;
		422	}
		423	/* duplicated code from above! */
		424	/* check for id3v2; first three bytes (of 4) are "ID3" */
		425	if((newhead & (unsigned long) 0xffffff00) == (unsigned long) 0x49443300)
		426	{
		427	int id3length = 0;
		428	id3length = parse_new_id3(newhead, rd);
		429	goto read_again;
		430	}
		431	else if (give_note)
		432	{
		433	fprintf(stderr,"Note: Illegal Audio-MPEG-Header 0x%08lx at offset 0x%lx.\n", newhead,rd->tell(rd)-4);
		434	}
		435
		436	if(give_note && (newhead & 0xffffff00) == ('b'<<24)+('m'<<16)+('p'<<8)) fprintf(stderr,"Note: Could be a BMP album art.\n");
		437	if (param.tryresync \|\| do_recover) {
		438	int try = 0;
		439	/* TODO: make this more robust, I'd like to cat two mp3 fragments together (in a dirty way) and still have mpg123 beign able to decode all it somehow. */
		440	if(give_note) fprintf(stderr, "Note: Trying to resync...\n");
		441	/* Read more bytes until we find something that looks
		442	reasonably like a valid header. This is not a
		443	perfect strategy, but it should get us back on the
		444	track within a short time (and hopefully without
		445	too much distortion in the audio output). */
		446	do {
		447	if(!rd->head_shift(rd,&newhead))
		448	return 0;
		449	/* debug2("resync try %i, got newhead 0x%08lx", try, newhead); */
		450	if (!oldhead)
		451	{
		452	debug("going to init_resync...");
		453	goto init_resync; /* "considered harmful", eh? */
		454	}
		455	/* we should perhaps collect a list of valid headers that occured in file... there can be more */
		456	/* Michael's new resync routine seems to work better with the one frame readahead (and some input buffering?) */
		457	} while
		458	(
		459	++try < RESYNC_LIMIT
		460	&& (newhead & HDRCMPMASK) != (oldhead & HDRCMPMASK)
		461	&& (newhead & HDRCMPMASK) != (firsthead & HDRCMPMASK)
		462	);
		463	/* too many false positives
		464	}while (!(head_check(newhead) && decode_header(fr, newhead))); */
		465	if(try == RESYNC_LIMIT)
		466	{
		467	error("giving up resync - your stream is not nice... perhaps an improved routine could catch up");
		468	return 0;
		469	}
		470
		471	if (give_note)
		472	fprintf (stderr, "Note: Skipped %d bytes in input.\n", try);
		473	}
		474	else
		475	{
		476	error("not attempting to resync...");
		477	return (0);
		478	}
		479	}
		480
		481	if (!firsthead) {
		482	if(!decode_header(fr,newhead))
		483	{
		484	error("decode header failed before first valid one, going to read again");
		485	goto read_again;
		486	}
		487	}
		488	else
		489	if(!decode_header(fr,newhead))
		490	{
		491	error("decode header failed - goto resync");
		492	/* return 0; */
		493	goto init_resync;
		494	}
		495	}
		496	else
		497	fr->header_change = 0;
		498	#endif
		499
		500	bsbufold = bsbuf;
		501	bsbuf = bsspace[bsnum]+512;
		502	bsnum = (bsnum + 1) & 1;
		503	/* if filepos is invalid, so is framepos */
		504	//framepos = rd->filepos - 4;
		505	/* read main data into memory */
		506	/* 0 is error! */
		507
		508	if(rd->read_frame_body(rd,bsbuf,fr->framesize) < fr->framesize)
		509	return 0;
		510
		511	#if 0
		512	if(!firsthead)
		513	{
		514	/* following stuff is actually layer3 specific (in practice, not in theory) */
		515	if(fr->lay == 3)
		516	{
		517	/*
		518	going to look for Xing or Info at some position after the header
		519	MPEG 1 MPEG 2/2.5 (LSF)
		520	Stereo, Joint Stereo, Dual Channel 32 17
		521	Mono 17 9
		522
		523	Also, how to avoid false positives? I guess I should interpret more of the header to rule that out(?).
		524	I hope that ensuring all zeros until tag start is enough.
		525	*/
		526	size_t lame_offset = (fr->stereo == 2) ? (fr->lsf ? 17 : 32 ) : (fr->lsf ? 9 : 17);
		527	if(fr->framesize >= 120+lame_offset) /* traditional Xing header is 120 bytes */
		528	{
		529	size_t i;
		530	int lame_type = 0;
		531	/* only search for tag when all zero before it (apart from checksum) */
		532	for(i=2; i < lame_offset; ++i) if(bsbuf[i] != 0) break;
		533	if(i == lame_offset)
		534	{
		535	if
		536	(
		537	(bsbuf[lame_offset] == 'I')
		538	&& (bsbuf[lame_offset+1] == 'n')
		539	&& (bsbuf[lame_offset+2] == 'f')
		540	&& (bsbuf[lame_offset+3] == 'o')
		541	)
		542	{
		543	lame_type = 1; /* We still have to see what there is */
		544	}
		545	else if
		546	(
		547	(bsbuf[lame_offset] == 'X')
		548	&& (bsbuf[lame_offset+1] == 'i')
		549	&& (bsbuf[lame_offset+2] == 'n')
		550	&& (bsbuf[lame_offset+3] == 'g')
		551	)
		552	{
		553	lame_type = 2;
		554	vbr = VBR; /* Xing header means always VBR */
		555	}
		556	if(lame_type)
		557	{
		558	unsigned long xing_flags;
		559
		560	/* we have one of these headers... */
		561	if(param.verbose > 1) fprintf(stderr, "Note: Xing/Lame/Info header detected\n");
		562	/* now interpret the Xing part, I have 120 bytes total for sure */
		563	/* there are 4 bytes for flags, but only the last byte contains known ones */
		564	lame_offset += 4; /* now first byte after Xing/Name */
		565	/* 4 bytes dword for flags */
		566	#define make_long(a, o) ((((unsigned long) a[o]) << 24) \| (((unsigned long) a[o+1]) << 16) \| (((unsigned long) a[o+2]) << 8) \| ((unsigned long) a[o+3]))
		567	/* 16 bit */
		568	#define make_short(a,o) ((((unsigned short) a[o]) << 8) \| ((unsigned short) a[o+1]))
		569	xing_flags = make_long(bsbuf, lame_offset);
		570	lame_offset += 4;
		571	debug1("Xing: flags 0x%08lx", xing_flags);
		572	if(xing_flags & 1) /* frames */
		573	{
		574	/*
		575	In theory, one should use that value for skipping...
		576	When I know the exact number of samples I could simply count in audio_flush,
		577	but that's problematic with seeking and such.
		578	I still miss the real solution for detecting the end.
		579	*/
		580	track_frames = make_long(bsbuf, lame_offset);
		581	if(track_frames > TRACK_MAX_FRAMES) track_frames = 0; /* endless stream? */
		582	#ifdef GAPLESS
		583	/* if no further info there, remove/add at least the decoder delay */
		584	if(param.gapless)
		585	{
		586	unsigned long length = track_frames * spf(fr);
		587	if(length > 1)
		588	layer3_gapless_init(DECODER_DELAY+GAP_SHIFT, length+DECODER_DELAY+GAP_SHIFT);
		589	}
		590	#endif
		591	debug1("Xing: %lu frames", track_frames);
		592	lame_offset += 4;
		593	}
		594	if(xing_flags & 0x2) /* bytes */
		595	{
		596	#ifdef DEBUG
		597	unsigned long xing_bytes = make_long(bsbuf, lame_offset);
		598	debug1("Xing: %lu bytes", xing_bytes);
		599	#endif
		600	lame_offset += 4;
		601	}
		602	if(xing_flags & 0x4) /* TOC */
		603	{
		604	lame_offset += 100; /* just skip */
		605	}
		606	if(xing_flags & 0x8) /* VBR quality */
		607	{
		608	#ifdef DEBUG
		609	unsigned long xing_quality = make_long(bsbuf, lame_offset);
		610	debug1("Xing: quality = %lu", xing_quality);
		611	#endif
		612	lame_offset += 4;
		613	}
		614	/* I guess that either 0 or LAME extra data follows */
		615	/* there may this crc16 be floating around... (?) */
		616	if(bsbuf[lame_offset] != 0)
		617	{
		618	unsigned char lame_vbr;
		619	float replay_gain[2] = {0,0};
		620	float peak = 0;
		621	float gain_offset = 0; /* going to be +6 for old lame that used 83dB */
		622	char nb[10];
		623	memcpy(nb, bsbuf+lame_offset, 9);
		624	nb[9] = 0;
		625	debug1("Info: Encoder: %s", nb);
		626	if(!strncmp("LAME", nb, 4))
		627	{
		628	gain_offset = 6;
		629	debug("TODO: finish lame detetcion...");
		630	}
		631	lame_offset += 9;
		632	/* the 4 big bits are tag revision, the small bits vbr method */
		633	lame_vbr = bsbuf[lame_offset] & 15;
		634	debug1("Info: rev %u", bsbuf[lame_offset] >> 4);
		635	debug1("Info: vbr mode %u", lame_vbr);
		636	lame_offset += 1;
		637	switch(lame_vbr)
		638	{
		639	/* from rev1 proposal... not sure if all good in practice */
		640	case 1:
		641	case 8: vbr = CBR; break;
		642	case 2:
		643	case 9: vbr = ABR; break;
		644	default: vbr = VBR; /* 00==unknown is taken as VBR */
		645	}
		646	/* skipping: lowpass filter value */
		647	lame_offset += 1;
		648	/* replaygain */
		649	/* 32bit float: peak amplitude -- why did I parse it as int before??*/
		650	/* Ah, yes, lame seems to store it as int since some day in 2003; I've only seen zeros anyway until now, bah! */
		651	if
		652	(
		653	(bsbuf[lame_offset] != 0)
		654	\|\| (bsbuf[lame_offset+1] != 0)
		655	\|\| (bsbuf[lame_offset+2] != 0)
		656	\|\| (bsbuf[lame_offset+3] != 0)
		657	)
		658	{
		659	debug("Wow! Is there _really_ a non-zero peak value? Now is it stored as float or int - how should I know?");
		660	peak = (float) (bsbuf+lame_offset);
		661	}
		662	debug1("Info: peak = %f (I won't use this)", peak);
		663	peak = 0; /* until better times arrived */
		664	lame_offset += 4;
		665	/*
		666	ReplayGain values - lame only writes radio mode gain...
		667	16bit gain, 3 bits name, 3 bits originator, sign (1=-, 0=+), dB value*10 in 9 bits (fixed point)
		668	ignore the setting if name or originator == 000!
		669	radio 0 0 1 0 1 1 1 0 0 1 1 1 1 1 0 1
		670	audiophile 0 1 0 0 1 0 0 0 0 0 0 1 0 1 0 0
		671	*/
		672
		673	for(i =0; i < 2; ++i)
		674	{
		675	unsigned char origin = (bsbuf[lame_offset] >> 2) & 0x7; /* the 3 bits after that... */
		676	if(origin != 0)
		677	{
		678	unsigned char gt = bsbuf[lame_offset] >> 5; /* only first 3 bits */
		679	if(gt == 1) gt = 0; /* radio */
		680	else if(gt == 2) gt = 1; /* audiophile */
		681	else continue;
		682	/* get the 9 bits into a number, divide by 10, multiply sign... happy bit banging */
		683	replay_gain[0] = ((bsbuf[lame_offset] & 0x2) ? -0.1 : 0.1) * (make_short(bsbuf, lame_offset) & 0x1f);
		684	}
		685	lame_offset += 2;
		686	}
		687	debug1("Info: Radio Gain = %03.1fdB", replay_gain[0]);
		688	debug1("Info: Audiophile Gain = %03.1fdB", replay_gain[1]);
		689	for(i=0; i < 2; ++i)
		690	{
		691	if(rva_level[i] <= 0)
		692	{
		693	rva_peak[i] = 0; /* at some time the parsed peak should be used */
		694	rva_gain[i] = replay_gain[i];
		695	rva_level[i] = 0;
		696	}
		697	}
		698	lame_offset += 1; /* skipping encoding flags byte */
		699	if(vbr == ABR)
		700	{
		701	abr_rate = bsbuf[lame_offset];
		702	debug1("Info: ABR rate = %u", abr_rate);
		703	}
		704	lame_offset += 1;
		705	/* encoder delay and padding, two 12 bit values... lame does write them from int ...*/
		706	#ifdef GAPLESS
		707	if(param.gapless)
		708	{
		709	/*
		710	Temporary hack that doesn't work with seeking and also is not waterproof but works most of the time;
		711	in future the lame delay/padding and frame number info should be passed to layer3.c and the junk samples avoided at the source.
		712	*/
		713	unsigned long length = track_frames * spf(fr);
		714	unsigned long skipbegin = DECODER_DELAY + ((((int) bsbuf[lame_offset]) << 4) \| (((int) bsbuf[lame_offset+1]) >> 4));
		715	unsigned long skipend = -DECODER_DELAY + (((((int) bsbuf[lame_offset+1]) << 8) \| (((int) bsbuf[lame_offset+2]))) & 0xfff);
		716	debug3("preparing gapless mode for layer3: length %lu, skipbegin %lu, skipend %lu", length, skipbegin, skipend);
		717	if(length > 1)
		718	layer3_gapless_init(skipbegin+GAP_SHIFT, (skipend < length) ? length-skipend+GAP_SHIFT : length+GAP_SHIFT);
		719	}
		720	#endif
		721	}
		722	/* switch buffer back ... */
		723	bsbuf = bsspace[bsnum]+512;
		724	bsnum = (bsnum + 1) & 1;
		725	goto read_again;
		726	}
		727	}
		728	}
		729	} /* end block for Xing/Lame/Info tag */
		730	firsthead = newhead; /* _now_ it's time to store it... the first real header */
		731	debug1("firsthead: %08lx", firsthead);
		732	/* now adjust volume */
		733	do_rva();
		734	/* and print id3 info */
		735	if(!param.quiet) print_id3_tag(rd->flags & READER_ID3TAG ? rd->id3buf : NULL);
		736	}
		737	#endif
		738
		739	bsi.bitindex = 0;
		740	bsi.wordpointer = (unsigned char *) bsbuf;
		741	set_synth_functions(fr);
		742	if (fr->error_protection)
		743	getbits(16);
		744	return 1;
		745	}
		746
		747
		748	#if 0
		749
		750	static int stream_back_bytes(struct reader *rds, off_t bytes)
		751	{
		752	if(stream_lseek(rds,-bytes,SEEK_CUR) < 0)
		753	return -1;
		754	/* you sure you want the buffer to resync here? */
		755	if(param.usebuffer)
		756	buffer_resync();
		757	return 0;
		758	}
		759
		760
		761	/* this function strangely is define to seek num frames _back_ (and is called with -offset - duh!) */
		762	/* also... let that int be a long in future! */
		763	static int stream_back_frame(struct reader rds,struct frame fr,long num)
		764	{
		765	if(rds->flags & READER_SEEKABLE)
		766	{
		767	unsigned long newframe, preframe;
		768	if(num > 0) /* back! */
		769	{
		770	if(num > fr->num) newframe = 0;
		771	else newframe = fr->num-num;
		772	}
		773	else newframe = fr->num-num;
		774
		775	/* two leading frames? hm, doesn't seem to be really needed... */
		776	/*if(newframe > 1) newframe -= 2;
		777	else newframe = 0;*/
		778
		779	/* now seek to nearest leading index position and read from there until newframe is reached */
		780	if(stream_lseek(rds,frame_index_find(newframe, &preframe),SEEK_SET) < 0)
		781	return -1;
		782
		783	debug2("going to %lu; just got %lu", newframe, preframe);
		784
		785	fr->num = preframe;
		786
		787	while(fr->num < newframe)
		788	{
		789	/* try to be non-fatal now... frameNum only gets advanced on success anyway */
		790	if(!read_frame(fr)) break;
		791	}
		792
		793	/* this is not needed at last? */
		794	/*read_frame(fr);
		795	read_frame(fr);*/
		796
		797	if(fr->lay == 3) {
		798	set_pointer(512);
		799	}
		800
		801	debug1("arrived at %lu", fr->num);
		802
		803	if(param.usebuffer)
		804	buffer_resync();
		805
		806	return 0;
		807
		808	}
		809	else return -1; /* invalid, no seek happened */
		810	}
		811
		812	static int stream_head_read(struct reader rds,unsigned long newhead)
		813	{
		814	unsigned char hbuf[4];
		815
		816	if(fullread(rds,hbuf,4) != 4)
		817	return FALSE;
576	serge	818
646	serge	819	*newhead = ((unsigned long) hbuf[0] << 24) \|
		820	((unsigned long) hbuf[1] << 16) \|
		821	((unsigned long) hbuf[2] << 8) \|
		822	(unsigned long) hbuf[3];
		823
		824	return TRUE;
		825	}
		826
		827	static int stream_head_shift(struct reader rds,unsigned long head)
		828	{
		829	unsigned char hbuf;
		830
		831	if(fullread(rds,&hbuf,1) != 1)
		832	return 0;
		833	*head <<= 8;
		834	*head \|= hbuf;
		835	*head &= 0xffffffff;
		836	return 1;
		837	}
		838
		839	static off_t stream_skip_bytes(struct reader *rds,off_t len)
		840	{
		841	if (rds->filelen >= 0) {
		842	off_t ret = stream_lseek(rds, len, SEEK_CUR);
		843	if (param.usebuffer)
		844	buffer_resync();
		845	return ret;
		846	} else if (len >= 0) {
		847	unsigned char buf[1024]; /* ThOr: Compaq cxx complained and it makes sense to me... or should one do a cast? What for? */
		848	off_t ret;
		849	while (len > 0) {
		850	off_t num = len < sizeof(buf) ? len : sizeof(buf);
		851	ret = fullread(rds, buf, num);
		852	if (ret < 0)
		853	return ret;
		854	len -= ret;
		855	}
		856	return rds->filepos;
		857	} else
		858	return -1;
		859	}
		860
		861	static int stream_read_frame_body(struct reader rds,unsigned char buf,
		862	int size)
		863	{
		864	long l;
		865
		866	if( (l=fullread(rds,buf,size)) != size)
		867	{
		868	if(l <= 0)
		869	return 0;
		870	memset(buf+l,0,size-l);
		871	}
		872
		873	return 1;
		874	}
		875
		876	static off_t stream_tell(struct reader *rds)
		877	{
		878	return rds->filepos;
		879	}
		880
		881	static void stream_rewind(struct reader *rds)
		882	{
		883	stream_lseek(rds,0,SEEK_SET);
		884	if(param.usebuffer)
		885	buffer_resync();
		886	}
		887
		888	static off_t get_fileinfo(struct reader rds,char buf)
		889	{
		890	off_t len;
		891
		892	if((len=lseek(rds->filept,0,SEEK_END)) < 0) {
		893	return -1;
		894	}
		895	if(lseek(rds->filept,-128,SEEK_END) < 0)
		896	return -1;
		897	if(fullread(rds,(unsigned char *)buf,128) != 128) {
		898	return -1;
		899	}
		900	if(!strncmp(buf,"TAG",3)) {
		901	len -= 128;
		902	}
		903	if(lseek(rds->filept,0,SEEK_SET) < 0)
		904	return -1;
		905	if(len <= 0)
		906	return -1;
		907	return len;
		908	}
		909
		910	#endif
		911
		912	#define syncsafe_to_long(buf,res) \
		913	( \
		914	(((buf)[0]\|(buf)[1]\|(buf)[2]\|(buf)[3]) & 0x80) ? 0 : \
		915	(res = (((unsigned long) (buf)[0]) << 27) \
		916	\| (((unsigned long) (buf)[1]) << 14) \
		917	\| (((unsigned long) (buf)[2]) << 7) \
		918	\| ((unsigned long) (buf)[3]) \
		919	,1) \
		920	)
		921
576	serge	922	int parse_new_id3(struct reader *rd, unsigned long header)
		923	{
646	serge	924	#define UNSYNC_FLAG 128
		925	#define EXTHEAD_FLAG 64
		926	#define EXP_FLAG 32
		927	#define FOOTER_FLAG 16
		928	#define UNKNOWN_FLAGS 15 /* 00001111*/
		929	unsigned char buf[6];
		930	unsigned long length=0;
		931	unsigned char flags = 0;
		932	int ret = 1;
		933	unsigned char* tagdata = NULL;
		934	unsigned char major = header & 0xff;
576	serge	935
646	serge	936	if(major == 0xff) return -1;
		937
		938	if (rd->read_frame_body(rd,buf,6)<6)
		939	return 0;
		940	if(buf[0] == 0xff) /* major version, will never be 0xff */
		941	return -1;
		942
		943	/* second new byte are some nice flags, if these are invalid skip the whole thing */
		944	flags = buf[1];
		945	/* use 4 bytes from buf to construct 28bit uint value and return 1; return 0 if bytes are not syncsafe */
		946
		947	if(!syncsafe_to_long(buf+2,length))
		948	return -1;
		949
		950
		951	rd->strpos+=length;
		952	rd->stream+=length;
		953	rd->strremain-=length;
		954
		955	#if 0
		956	/* skip if unknown version/scary flags, parse otherwise */
		957	if((flags & UNKNOWN_FLAGS) \|\| (major > 4))
		958	{
		959	/* going to skip because there are unknown flags set */
		960	if(!rds->skip_bytes(rds,length)) /* will not store data in backbuff! */
		961
		962	rd->strpos+=length;
		963	rd->stream+=length;
		964	rd->strremain-=length;
		965	ret = 0;
		966	};
		967	#endif
576	serge	968	return length;
		969	};

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(root)/programs/media/ac97snd/mpg/readers.c – Rev 646