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-rwxr-xr-xsrc/libmpg123/layer2.c336
1 files changed, 336 insertions, 0 deletions
diff --git a/src/libmpg123/layer2.c b/src/libmpg123/layer2.c
new file mode 100755
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--- /dev/null
+++ b/src/libmpg123/layer2.c
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+
+/*
+ * Mpeg Layer-2 audio decoder
+ * --------------------------
+ * copyright (c) 1995 by Michael Hipp, All rights reserved. See also 'README'
+ *
+ */
+
+#include "mpg123.h"
+#include "l2tables.h"
+#include "getbits.h"
+
+static int grp_3tab[32 * 3] =
+{0,}; /* used: 27 */
+static int grp_5tab[128 * 3] =
+{0,}; /* used: 125 */
+static int grp_9tab[1024 * 3] =
+{0,}; /* used: 729 */
+
+real mpg123_muls[27][64]; /* also used by layer 1 */
+
+/* Used by the getbits macros */
+static unsigned long rval;
+
+void mpg123_init_layer2(void)
+{
+ static double mulmul[27] = {
+ 0.0, -2.0 / 3.0, 2.0 / 3.0, 2.0 / 7.0, 2.0 / 15.0,
+ 2.0 / 31.0, 2.0 / 63.0, 2.0 / 127.0, 2.0 / 255.0,
+ 2.0 / 511.0, 2.0 / 1023.0, 2.0 / 2047.0, 2.0 / 4095.0,
+ 2.0 / 8191.0, 2.0 / 16383.0, 2.0 / 32767.0, 2.0 / 65535.0,
+ -4.0 / 5.0, -2.0 / 5.0, 2.0 / 5.0, 4.0 / 5.0, -8.0 / 9.0,
+ -4.0 / 9.0, -2.0 / 9.0, 2.0 / 9.0, 4.0 / 9.0, 8.0 / 9.0 };
+ static int base[3][9] = {
+ {1, 0, 2,},
+ {17, 18, 0, 19, 20,},
+ {21, 1, 22, 23, 0, 24, 25, 2, 26}};
+ int i, j, k, l, len;
+ real *table;
+ static int tablen[3] = {3, 5, 9};
+ static int *itable, *tables[3] =
+ {grp_3tab, grp_5tab, grp_9tab};
+
+ for (i = 0; i < 3; i++)
+ {
+ itable = tables[i];
+ len = tablen[i];
+ for (j = 0; j < len; j++)
+ for (k = 0; k < len; k++)
+ for (l = 0; l < len; l++)
+ {
+ *itable++ = base[i][l];
+ *itable++ = base[i][k];
+ *itable++ = base[i][j];
+ }
+ }
+
+ for (k = 0; k < 27; k++)
+ {
+ double m = mulmul[k];
+
+ table = mpg123_muls[k];
+ for (j = 3, i = 0; i < 63; i++, j--)
+ *table++ = m * pow(2.0, (double) j / 3.0);
+ *table++ = 0.0;
+ }
+}
+
+void II_step_one(unsigned int *bit_alloc, int *scale, struct frame *fr)
+{
+ int stereo = fr->stereo - 1;
+ int sblimit = fr->II_sblimit;
+ int jsbound = fr->jsbound;
+ int sblimit2 = fr->II_sblimit << stereo;
+ struct al_table *alloc1 = fr->alloc;
+ int i;
+ static unsigned int scfsi_buf[64];
+ unsigned int *scfsi, *bita;
+ int sc, step;
+
+ bita = bit_alloc;
+ if (stereo)
+ {
+ for (i = jsbound; i > 0; i--, alloc1 += (1 << step))
+ {
+ *bita++ = (char) mpg123_getbits(step = alloc1->bits);
+ *bita++ = (char) mpg123_getbits(step);
+ }
+ for (i = sblimit - jsbound; i > 0; i--, alloc1 += (1 << step))
+ {
+ bita[0] = (char) mpg123_getbits(step = alloc1->bits);
+ bita[1] = bita[0];
+ bita += 2;
+ }
+ bita = bit_alloc;
+ scfsi = scfsi_buf;
+ for (i = sblimit2; i; i--)
+ if (*bita++)
+ *scfsi++ = (char) mpg123_getbits_fast(2);
+ }
+ else
+ /* mono */
+ {
+ for (i = sblimit; i; i--, alloc1 += (1 << step))
+ *bita++ = (char) mpg123_getbits(step = alloc1->bits);
+ bita = bit_alloc;
+ scfsi = scfsi_buf;
+ for (i = sblimit; i; i--)
+ if (*bita++)
+ *scfsi++ = (char) mpg123_getbits_fast(2);
+ }
+
+ bita = bit_alloc;
+ scfsi = scfsi_buf;
+ for (i = sblimit2; i; i--)
+ if (*bita++)
+ switch (*scfsi++)
+ {
+ case 0:
+ *scale++ = mpg123_getbits_fast(6);
+ *scale++ = mpg123_getbits_fast(6);
+ *scale++ = mpg123_getbits_fast(6);
+ break;
+ case 1:
+ *scale++ = sc = mpg123_getbits_fast(6);
+ *scale++ = sc;
+ *scale++ = mpg123_getbits_fast(6);
+ break;
+ case 2:
+ *scale++ = sc = mpg123_getbits_fast(6);
+ *scale++ = sc;
+ *scale++ = sc;
+ break;
+ default: /* case 3 */
+ *scale++ = mpg123_getbits_fast(6);
+ *scale++ = sc = mpg123_getbits_fast(6);
+ *scale++ = sc;
+ break;
+ }
+
+}
+
+void II_step_two(unsigned int *bit_alloc, real fraction[2][4][SBLIMIT], int *scale, struct frame *fr, int x1)
+{
+ int i, j, k, ba;
+ int stereo = fr->stereo;
+ int sblimit = fr->II_sblimit;
+ int jsbound = fr->jsbound;
+ struct al_table *alloc2, *alloc1 = fr->alloc;
+ unsigned int *bita = bit_alloc;
+ int d1, step;
+
+ for (i = 0; i < jsbound; i++, alloc1 += (1 << step))
+ {
+ step = alloc1->bits;
+ for (j = 0; j < stereo; j++)
+ {
+ if ((ba = *bita++))
+ {
+ k = (alloc2 = alloc1 + ba)->bits;
+ if ((d1 = alloc2->d) < 0)
+ {
+ real cm = mpg123_muls[k][scale[x1]];
+
+ fraction[j][0][i] = ((real) ((int) mpg123_getbits(k) + d1)) * cm;
+ fraction[j][1][i] = ((real) ((int) mpg123_getbits(k) + d1)) * cm;
+ fraction[j][2][i] = ((real) ((int) mpg123_getbits(k) + d1)) * cm;
+ }
+ else
+ {
+ static int *table[] =
+ {0, 0, 0, grp_3tab, 0, grp_5tab, 0, 0, 0, grp_9tab};
+ unsigned int idx, *tab, m = scale[x1];
+
+ idx = (unsigned int) mpg123_getbits(k);
+ tab = (unsigned int *) (table[d1] + idx + idx + idx);
+ fraction[j][0][i] = mpg123_muls[*tab++][m];
+ fraction[j][1][i] = mpg123_muls[*tab++][m];
+ fraction[j][2][i] = mpg123_muls[*tab][m];
+ }
+ scale += 3;
+ }
+ else
+ fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
+ }
+ }
+
+ for (i = jsbound; i < sblimit; i++, alloc1 += (1 << step))
+ {
+ step = alloc1->bits;
+ bita++; /* channel 1 and channel 2 bitalloc are the same */
+ if ((ba = *bita++))
+ {
+ k = (alloc2 = alloc1 + ba)->bits;
+ if ((d1 = alloc2->d) < 0)
+ {
+ real cm;
+
+ cm = mpg123_muls[k][scale[x1 + 3]];
+ fraction[1][0][i] = (fraction[0][0][i] = (real) ((int) mpg123_getbits(k) + d1)) * cm;
+ fraction[1][1][i] = (fraction[0][1][i] = (real) ((int) mpg123_getbits(k) + d1)) * cm;
+ fraction[1][2][i] = (fraction[0][2][i] = (real) ((int) mpg123_getbits(k) + d1)) * cm;
+ cm = mpg123_muls[k][scale[x1]];
+ fraction[0][0][i] *= cm;
+ fraction[0][1][i] *= cm;
+ fraction[0][2][i] *= cm;
+ }
+ else
+ {
+ static int *table[] =
+ {0, 0, 0, grp_3tab, 0, grp_5tab, 0, 0, 0, grp_9tab};
+ unsigned int idx, *tab, m1, m2;
+
+ m1 = scale[x1];
+ m2 = scale[x1 + 3];
+ idx = (unsigned int) mpg123_getbits(k);
+ tab = (unsigned int *) (table[d1] + idx + idx + idx);
+ fraction[0][0][i] = mpg123_muls[*tab][m1];
+ fraction[1][0][i] = mpg123_muls[*tab++][m2];
+ fraction[0][1][i] = mpg123_muls[*tab][m1];
+ fraction[1][1][i] = mpg123_muls[*tab++][m2];
+ fraction[0][2][i] = mpg123_muls[*tab][m1];
+ fraction[1][2][i] = mpg123_muls[*tab][m2];
+ }
+ scale += 6;
+ }
+ else
+ {
+ fraction[0][0][i] = fraction[0][1][i] = fraction[0][2][i] =
+ fraction[1][0][i] = fraction[1][1][i] = fraction[1][2][i] = 0.0;
+ }
+/*
+ should we use individual scalefac for channel 2 or
+ is the current way the right one , where we just copy channel 1 to
+ channel 2 ??
+ The current 'strange' thing is, that we throw away the scalefac
+ values for the second channel ...!!
+ -> changed .. now we use the scalefac values of channel one !!
+ */
+ }
+
+ if (sblimit > (fr->down_sample_sblimit))
+ sblimit = fr->down_sample_sblimit;
+
+ for (i = sblimit; i < SBLIMIT; i++)
+ for (j = 0; j < stereo; j++)
+ fraction[j][0][i] = fraction[j][1][i] = fraction[j][2][i] = 0.0;
+
+}
+
+static void II_select_table(struct frame *fr)
+{
+ static int translate[3][2][16] = {
+ {{0, 2, 2, 2, 2, 2, 2, 0, 0, 0, 1, 1, 1, 1, 1, 0},
+ {0, 2, 2, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0}},
+ {{0, 2, 2, 2, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+ {0, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}},
+ {{0, 3, 3, 3, 3, 3, 3, 0, 0, 0, 1, 1, 1, 1, 1, 0},
+ {0, 3, 3, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0}}
+ };
+
+ int table, sblim;
+ static struct al_table *tables[5] =
+ {alloc_0, alloc_1, alloc_2, alloc_3, alloc_4};
+ static int sblims[5] = { 27, 30, 8, 12, 30 };
+
+ if (fr->lsf)
+ table = 4;
+ else
+ table = translate[fr->sampling_frequency][2 - fr->stereo][fr->bitrate_index];
+ sblim = sblims[table];
+
+ fr->alloc = tables[table];
+ fr->II_sblimit = sblim;
+}
+
+
+int mpg123_do_layer2(struct frame *fr)
+{
+ int i, j;
+ int stereo = fr->stereo;
+ real fraction[2][4][SBLIMIT]; /* pick_table clears unused subbands */
+ unsigned int bit_alloc[64];
+ int scale[192];
+ int single = fr->single;
+
+ II_select_table(fr);
+ fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ?
+ (fr->mode_ext << 2) + 4 : fr->II_sblimit;
+ if (fr->jsbound > fr->II_sblimit)
+ fr->jsbound = fr->II_sblimit;
+
+ if (stereo == 1 || single == 3)
+ single = 0;
+
+ II_step_one(bit_alloc, scale, fr);
+
+ for (i = 0; i < SCALE_BLOCK; i++)
+ {
+ II_step_two(bit_alloc, fraction, scale, fr, i >> 2);
+ for (j = 0; j < 3; j++)
+ {
+ if (single >= 0)
+ {
+ (fr->synth_mono) (fraction[single][j], mpg123_pcm_sample, &mpg123_pcm_point);
+ }
+ else
+ {
+ int p1 = mpg123_pcm_point;
+
+ (fr->synth) (fraction[0][j], 0, mpg123_pcm_sample, &p1);
+ (fr->synth) (fraction[1][j], 1, mpg123_pcm_sample, &mpg123_pcm_point);
+ }
+
+ /* if(mpg123_pcm_point >= audiobufsize)
+ audio_flush(outmode,ai); */
+ }
+ }
+/***
+ if (mpg123_info->output_audio)
+ {
+
+ mpg123_ip.add_vis_pcm(mpg123_ip.output->written_time(), mpg123_cfg.resolution == 16 ? FMT_S16_NE : FMT_U8,
+ mpg123_cfg.channels == 2 ? fr->stereo : 1, mpg123_pcm_point, mpg123_pcm_sample);
+
+ while (mpg123_ip.output->buffer_free() < mpg123_pcm_point && mpg123_info->going && mpg123_info->jump_to_time == -1)
+ xmms_usleep(10000);
+ if (mpg123_info->going && mpg123_info->jump_to_time == -1)
+ mpg123_ip.output->write_audio(mpg123_pcm_sample, mpg123_pcm_point);
+
+ }
+***/
+ mpg123_pcm_point = 0;
+
+ return 1;
+}
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