Mercurial > SDL_sound_CoreAudio

comparison decoders/libmpg123/layer1.c @ 562:7e08477b0fc1

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
MP3 decoder upgrade work. Ripped out SMPEG and mpglib support, replaced it with "mpg123.c" and libmpg123. libmpg123 is a much better version of mpglib, so it should solve all the problems about MP3's not seeking, or most modern MP3's not playing at all, etc. Since you no longer have to make a tradeoff with SMPEG for features, and SMPEG is basically rotting, I removed it from the project. There is still work to be done with libmpg123...there are MMX, 3DNow, SSE, Altivec, etc decoders which we don't have enabled at the moment, and the build system could use some work to make this compile more cleanly, etc. Still: huge win.
author Ryan C. Gordon <icculus@icculus.org>
date Fri, 30 Jan 2009 02:44:47 -0500
parents
children
comparison
equal deleted inserted replaced
561:f2985e08589c 562:7e08477b0fc1
1 /*
2 layer1.c: the layer 1 decoder
3
4 copyright 1995-2007 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 int i;
21 int jsbound = fr->jsbound;
22 for (i=0;i<jsbound;i++) {
23 *ba++ = getbits(fr, 4);
24 *ba++ = getbits(fr, 4);
25 }
26 for (i=jsbound;i<SBLIMIT;i++)
27 *ba++ = getbits(fr, 4);
28
29 ba = balloc;
30
31 for (i=0;i<jsbound;i++) {
32 if ((*ba++))
33 *sca++ = getbits(fr, 6);
34 if ((*ba++))
35 *sca++ = getbits(fr, 6);
36 }
37 for (i=jsbound;i<SBLIMIT;i++)
38 if ((*ba++)) {
39 *sca++ = getbits(fr, 6);
40 *sca++ = getbits(fr, 6);
41 }
42 }
43 else {
44 int i;
45 for (i=0;i<SBLIMIT;i++)
46 *ba++ = getbits(fr, 4);
47 ba = balloc;
48 for (i=0;i<SBLIMIT;i++)
49 if ((*ba++))
50 *sca++ = getbits(fr, 6);
51 }
52 }
53
54 void I_step_two(real fraction[2][SBLIMIT],unsigned int balloc[2*SBLIMIT],
55 unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr)
56 {
57 int i,n;
58 int smpb[2*SBLIMIT]; /* values: 0-65535 */
59 int *sample;
60 register unsigned int *ba;
61 register unsigned int *sca = (unsigned int *) scale_index;
62
63 if(fr->stereo == 2) {
64 int jsbound = fr->jsbound;
65 register real *f0 = fraction[0];
66 register real *f1 = fraction[1];
67 ba = balloc;
68 for (sample=smpb,i=0;i<jsbound;i++) {
69 if ((n = *ba++))
70 *sample++ = getbits(fr, n+1);
71 if ((n = *ba++))
72 *sample++ = getbits(fr, n+1);
73 }
74 for (i=jsbound;i<SBLIMIT;i++)
75 if ((n = *ba++))
76 *sample++ = getbits(fr, n+1);
77
78 ba = balloc;
79 for (sample=smpb,i=0;i<jsbound;i++) {
80 if((n=*ba++))
81 *f0++ = (real) ( ((-1)<<n) + (*sample++) + 1) * fr->muls[n+1][*sca++];
82 else
83 *f0++ = 0.0;
84 if((n=*ba++))
85 *f1++ = (real) ( ((-1)<<n) + (*sample++) + 1) * fr->muls[n+1][*sca++];
86 else
87 *f1++ = 0.0;
88 }
89 for (i=jsbound;i<SBLIMIT;i++) {
90 if ((n=*ba++)) {
91 real samp = ( ((-1)<<n) + (*sample++) + 1);
92 *f0++ = samp * fr->muls[n+1][*sca++];
93 *f1++ = samp * fr->muls[n+1][*sca++];
94 }
95 else
96 *f0++ = *f1++ = 0.0;
97 }
98 for(i=fr->down_sample_sblimit;i<32;i++)
99 fraction[0][i] = fraction[1][i] = 0.0;
100 }
101 else {
102 register real *f0 = fraction[0];
103 ba = balloc;
104 for (sample=smpb,i=0;i<SBLIMIT;i++)
105 if ((n = *ba++))
106 *sample++ = getbits(fr, n+1);
107 ba = balloc;
108 for (sample=smpb,i=0;i<SBLIMIT;i++) {
109 if((n=*ba++))
110 *f0++ = (real) ( ((-1)<<n) + (*sample++) + 1) * fr->muls[n+1][*sca++];
111 else
112 *f0++ = 0.0;
113 }
114 for(i=fr->down_sample_sblimit;i<32;i++)
115 fraction[0][i] = 0.0;
116 }
117 }
118
119 int do_layer1(mpg123_handle *fr)
120 {
121 int clip=0;
122 int i,stereo = fr->stereo;
123 unsigned int balloc[2*SBLIMIT];
124 unsigned int scale_index[2][SBLIMIT];
125 ALIGNED(16) real fraction[2][SBLIMIT];
126 int single = fr->single;
127
128 fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? (fr->mode_ext<<2)+4 : 32;
129
130 if(stereo == 1 || single == SINGLE_MIX) /* I don't see mixing handled here */
131 single = SINGLE_LEFT;
132
133 I_step_one(balloc,scale_index,fr);
134
135 for (i=0;i<SCALE_BLOCK;i++)
136 {
137 I_step_two(fraction,balloc,scale_index,fr);
138
139 if(single != SINGLE_STEREO)
140 {
141 clip += (fr->synth_mono)( (real *) fraction[single], fr);
142 }
143 else
144 {
145 clip += (fr->synth)( (real *) fraction[0], 0, fr, 0);
146 clip += (fr->synth)( (real *) fraction[1], 1, fr, 1);
147 }
148 }
149
150 return clip;
151 }
152
153