Go to most recent revision | Details | Last modification | View Log | RSS feed
Rev | Author | Line No. | Line |
---|---|---|---|
1905 | serge | 1 | /* |
2 | layer1.c: the layer 1 decoder |
||
3 | |||
4 | copyright 1995-2008 by the mpg123 project - free software under the terms of the LGPL 2.1 |
||
5 | see COPYING and AUTHORS files in distribution or http://mpg123.org |
||
6 | initially written by Michael Hipp |
||
7 | |||
8 | may have a few bugs after last optimization ... |
||
9 | */ |
||
10 | |||
11 | #include "mpg123lib_intern.h" |
||
12 | #include "getbits.h" |
||
13 | |||
14 | void I_step_one(unsigned int balloc[], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr) |
||
15 | { |
||
16 | unsigned int *ba=balloc; |
||
17 | unsigned int *sca = (unsigned int *) scale_index; |
||
18 | |||
19 | if(fr->stereo == 2) |
||
20 | { |
||
21 | int i; |
||
22 | int jsbound = fr->jsbound; |
||
23 | for(i=0;i |
||
24 | { |
||
25 | *ba++ = getbits(fr, 4); |
||
26 | *ba++ = getbits(fr, 4); |
||
27 | } |
||
28 | for(i=jsbound;i |
||
29 | |||
30 | ba = balloc; |
||
31 | |||
32 | for(i=0;i |
||
33 | { |
||
34 | if ((*ba++)) |
||
35 | *sca++ = getbits(fr, 6); |
||
36 | if ((*ba++)) |
||
37 | *sca++ = getbits(fr, 6); |
||
38 | } |
||
39 | for (i=jsbound;i |
||
40 | if((*ba++)) |
||
41 | { |
||
42 | *sca++ = getbits(fr, 6); |
||
43 | *sca++ = getbits(fr, 6); |
||
44 | } |
||
45 | } |
||
46 | else |
||
47 | { |
||
48 | int i; |
||
49 | for(i=0;i |
||
50 | |||
51 | ba = balloc; |
||
52 | for (i=0;i |
||
53 | if ((*ba++)) |
||
54 | *sca++ = getbits(fr, 6); |
||
55 | } |
||
56 | } |
||
57 | |||
58 | void I_step_two(real fraction[2][SBLIMIT],unsigned int balloc[2*SBLIMIT], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr) |
||
59 | { |
||
60 | int i,n; |
||
61 | int smpb[2*SBLIMIT]; /* values: 0-65535 */ |
||
62 | int *sample; |
||
63 | register unsigned int *ba; |
||
64 | register unsigned int *sca = (unsigned int *) scale_index; |
||
65 | |||
66 | if(fr->stereo == 2) |
||
67 | { |
||
68 | int jsbound = fr->jsbound; |
||
69 | register real *f0 = fraction[0]; |
||
70 | register real *f1 = fraction[1]; |
||
71 | ba = balloc; |
||
72 | for(sample=smpb,i=0;i |
||
73 | { |
||
74 | if((n = *ba++)) *sample++ = getbits(fr, n+1); |
||
75 | |||
76 | if((n = *ba++)) *sample++ = getbits(fr, n+1); |
||
77 | } |
||
78 | for(i=jsbound;i |
||
79 | if((n = *ba++)) |
||
80 | *sample++ = getbits(fr, n+1); |
||
81 | |||
82 | ba = balloc; |
||
83 | for(sample=smpb,i=0;i |
||
84 | { |
||
85 | if((n=*ba++)) |
||
86 | *f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)< |
||
87 | else *f0++ = DOUBLE_TO_REAL(0.0); |
||
88 | |||
89 | if((n=*ba++)) |
||
90 | *f1++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)< |
||
91 | else *f1++ = DOUBLE_TO_REAL(0.0); |
||
92 | } |
||
93 | for(i=jsbound;i |
||
94 | { |
||
95 | if((n=*ba++)) |
||
96 | { |
||
97 | real samp = DOUBLE_TO_REAL_15( ((-1)< |
||
98 | *f0++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]); |
||
99 | *f1++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]); |
||
100 | } |
||
101 | else *f0++ = *f1++ = DOUBLE_TO_REAL(0.0); |
||
102 | } |
||
103 | for(i=fr->down_sample_sblimit;i<32;i++) |
||
104 | fraction[0][i] = fraction[1][i] = 0.0; |
||
105 | } |
||
106 | else |
||
107 | { |
||
108 | register real *f0 = fraction[0]; |
||
109 | ba = balloc; |
||
110 | for(sample=smpb,i=0;i |
||
111 | if ((n = *ba++)) |
||
112 | *sample++ = getbits(fr, n+1); |
||
113 | |||
114 | ba = balloc; |
||
115 | for(sample=smpb,i=0;i |
||
116 | { |
||
117 | if((n=*ba++)) |
||
118 | *f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)< |
||
119 | else *f0++ = DOUBLE_TO_REAL(0.0); |
||
120 | } |
||
121 | for(i=fr->down_sample_sblimit;i<32;i++) |
||
122 | fraction[0][i] = DOUBLE_TO_REAL(0.0); |
||
123 | } |
||
124 | } |
||
125 | |||
126 | int do_layer1(mpg123_handle *fr) |
||
127 | { |
||
128 | int clip=0; |
||
129 | int i,stereo = fr->stereo; |
||
130 | unsigned int balloc[2*SBLIMIT]; |
||
131 | unsigned int scale_index[2][SBLIMIT]; |
||
132 | ALIGNED(16) real fraction[2][SBLIMIT]; |
||
133 | int single = fr->single; |
||
134 | |||
135 | fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? (fr->mode_ext<<2)+4 : 32; |
||
136 | |||
137 | if(stereo == 1 || single == SINGLE_MIX) /* I don't see mixing handled here */ |
||
138 | single = SINGLE_LEFT; |
||
139 | |||
140 | I_step_one(balloc,scale_index,fr); |
||
141 | |||
142 | for(i=0;i |
||
143 | { |
||
144 | I_step_two(fraction,balloc,scale_index,fr); |
||
145 | |||
146 | if(single != SINGLE_STEREO) |
||
147 | clip += (fr->synth_mono)(fraction[single], fr); |
||
148 | else |
||
149 | clip += (fr->synth_stereo)(fraction[0], fraction[1], fr); |
||
150 | } |
||
151 | |||
152 | return clip; |
||
153 | } |
||
154 | |||
155 |