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-rw-r--r--libavcodec/libac3/parse.c684
1 files changed, 684 insertions, 0 deletions
diff --git a/libavcodec/libac3/parse.c b/libavcodec/libac3/parse.c
new file mode 100644
index 0000000000..c6eae00ba5
--- /dev/null
+++ b/libavcodec/libac3/parse.c
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+/*
+ * parse.c
+ *
+ * Copyright (C) Aaron Holtzman - May 1999
+ *
+ * This file is part of ac3dec, a free Dolby AC-3 stream decoder.
+ *
+ * ac3dec is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * ac3dec is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Make; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ *
+ */
+
+#include <inttypes.h>
+#include <string.h>
+
+#include "ac3.h"
+#include "ac3_internal.h"
+
+#include "bitstream.h"
+#include "tables.h"
+
+extern stream_samples_t samples; // FIXME
+static float delay[6][256];
+
+void ac3_init (void)
+{
+ imdct_init ();
+}
+
+static uint8_t halfrate[12] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3};
+
+int ac3_syncinfo (uint8_t * buf, int * flags,
+ int * sample_rate, int * bit_rate)
+{
+ static int rate[] = { 32, 40, 48, 56, 64, 80, 96, 112,
+ 128, 160, 192, 224, 256, 320, 384, 448,
+ 512, 576, 640};
+ static uint8_t lfeon[8] = {0x10, 0x10, 0x04, 0x04, 0x04, 0x01, 0x04, 0x01};
+ int frmsizecod;
+ int bitrate;
+ int half;
+ int acmod;
+
+ if ((buf[0] != 0x0b) || (buf[1] != 0x77)) // syncword
+ return 0;
+
+ if (buf[5] >= 0x60) // bsid >= 12
+ return 0;
+ half = halfrate[buf[5] >> 3];
+
+ // acmod, dsurmod and lfeon
+ acmod = buf[6] >> 5;
+ *flags = (((buf[6] & 0xf8) == 0x50) ? AC3_DOLBY : acmod) |
+ ((buf[6] & lfeon[acmod]) ? AC3_LFE : 0);
+
+ frmsizecod = buf[4] & 63;
+ if (frmsizecod >= 38)
+ return 0;
+ bitrate = rate [frmsizecod >> 1];
+ *bit_rate = (bitrate * 1000) >> half;
+
+ switch (buf[4] & 0xc0) {
+ case 0: // 48 KHz
+ *sample_rate = 48000 >> half;
+ return 4 * bitrate;
+ case 0x40:
+ *sample_rate = 44100 >> half;
+ return 2 * (320 * bitrate / 147 + (frmsizecod & 1));
+ case 0x80:
+ *sample_rate = 32000 >> half;
+ return 6 * bitrate;
+ default:
+ return 0;
+ }
+}
+
+int ac3_frame (ac3_state_t * state, uint8_t * buf, int * flags, float * level,
+ float bias)
+{
+ static float clev[4] = {LEVEL_3DB, LEVEL_45DB, LEVEL_6DB, LEVEL_45DB};
+ static float slev[4] = {LEVEL_3DB, LEVEL_6DB, 0, LEVEL_6DB};
+ int chaninfo;
+ int acmod;
+
+ state->fscod = buf[4] >> 6;
+ state->halfrate = halfrate[buf[5] >> 3];
+ state->acmod = acmod = buf[6] >> 5;
+
+ bitstream_set_ptr (buf + 6);
+ bitstream_get (3); // skip acmod we already parsed
+
+ if ((acmod == 2) && (bitstream_get (2) == 2)) // dsurmod
+ acmod = AC3_DOLBY;
+
+ if ((acmod & 1) && (acmod != 1))
+ state->clev = clev[bitstream_get (2)]; // cmixlev
+
+ if (acmod & 4)
+ state->slev = slev[bitstream_get (2)]; // surmixlev
+
+ state->lfeon = bitstream_get (1);
+
+ state->output = downmix_init (acmod, *flags, level,
+ state->clev, state->slev);
+ if (state->output < 0)
+ return 1;
+ *flags = state->output;
+ state->level = *level;
+ state->bias = bias;
+
+ chaninfo = !acmod;
+ do {
+ bitstream_get (5); // dialnorm
+ if (bitstream_get (1)) // compre
+ bitstream_get (8); // compr
+ if (bitstream_get (1)) // langcode
+ bitstream_get (8); // langcod
+ if (bitstream_get (1)) // audprodie
+ bitstream_get (7); // mixlevel + roomtyp
+ } while (chaninfo--);
+
+ bitstream_get (2); // copyrightb + origbs
+
+ if (bitstream_get (1)) // timecod1e
+ bitstream_get (14); // timecod1
+ if (bitstream_get (1)) // timecod2e
+ bitstream_get (14); // timecod2
+
+ if (bitstream_get (1)) { // addbsie
+ int addbsil;
+
+ addbsil = bitstream_get (6);
+ do {
+ bitstream_get (8); // addbsi
+ } while (addbsil--);
+ }
+
+ return 0;
+}
+
+static int parse_exponents (int expstr, int ngrps, uint8_t exponent,
+ uint8_t * dest)
+{
+ int exps;
+
+ while (ngrps--) {
+ exps = bitstream_get (7);
+
+ exponent += exp_1[exps];
+ if (exponent > 24)
+ return 1;
+
+ switch (expstr) {
+ case EXP_D45:
+ *(dest++) = exponent;
+ *(dest++) = exponent;
+ case EXP_D25:
+ *(dest++) = exponent;
+ case EXP_D15:
+ *(dest++) = exponent;
+ }
+
+ exponent += exp_2[exps];
+ if (exponent > 24)
+ return 1;
+
+ switch (expstr) {
+ case EXP_D45:
+ *(dest++) = exponent;
+ *(dest++) = exponent;
+ case EXP_D25:
+ *(dest++) = exponent;
+ case EXP_D15:
+ *(dest++) = exponent;
+ }
+
+ exponent += exp_3[exps];
+ if (exponent > 24)
+ return 1;
+
+ switch (expstr) {
+ case EXP_D45:
+ *(dest++) = exponent;
+ *(dest++) = exponent;
+ case EXP_D25:
+ *(dest++) = exponent;
+ case EXP_D15:
+ *(dest++) = exponent;
+ }
+ }
+
+ return 0;
+}
+
+static int parse_deltba (int8_t * deltba)
+{
+ int deltnseg, deltlen, delta, j;
+
+ memset (deltba, 0, 50);
+
+ deltnseg = bitstream_get (3);
+ j = 0;
+ do {
+ j += bitstream_get (5);
+ deltlen = bitstream_get (4);
+ delta = bitstream_get (3);
+ delta -= (delta >= 4) ? 3 : 4;
+ if (!deltlen)
+ continue;
+ if (j + deltlen >= 50)
+ return 1;
+ while (deltlen--)
+ deltba[j++] = delta;
+ } while (deltnseg--);
+
+ return 0;
+}
+
+static inline int zero_snr_offsets (int nfchans, ac3_state_t * state)
+{
+ int i;
+
+ if ((state->csnroffst) || (state->cplinu && state->cplba.fsnroffst) ||
+ (state->lfeon && state->lfeba.fsnroffst))
+ return 0;
+ for (i = 0; i < nfchans; i++)
+ if (state->ba[i].fsnroffst)
+ return 0;
+ return 1;
+}
+
+static float q_1[2];
+static float q_2[2];
+static float q_4;
+static int q_1_pointer;
+static int q_2_pointer;
+static int q_4_pointer;
+
+#define GET_COEFF(COEFF,DITHER) \
+ switch (bap[i]) { \
+ case 0: \
+ DITHER (scale_factor[exp[i]]); \
+ \
+ case -1: \
+ if (q_1_pointer >= 0) { \
+ COEFF (q_1[q_1_pointer--] * scale_factor[exp[i]]); \
+ } else { \
+ int code; \
+ \
+ code = bitstream_get (5); \
+ \
+ q_1_pointer = 1; \
+ q_1[0] = q_1_2[code]; \
+ q_1[1] = q_1_1[code]; \
+ COEFF (q_1_0[code] * scale_factor[exp[i]]); \
+ } \
+ \
+ case -2: \
+ if (q_2_pointer >= 0) { \
+ COEFF (q_2[q_2_pointer--] * scale_factor[exp[i]]); \
+ } else { \
+ int code; \
+ \
+ code = bitstream_get (7); \
+ \
+ q_2_pointer = 1; \
+ q_2[0] = q_2_2[code]; \
+ q_2[1] = q_2_1[code]; \
+ COEFF (q_2_0[code] * scale_factor[exp[i]]); \
+ } \
+ \
+ case 3: \
+ COEFF (q_3[bitstream_get (3)] * scale_factor[exp[i]]); \
+ \
+ case -3: \
+ if (q_4_pointer == 0) { \
+ q_4_pointer = -1; \
+ COEFF (q_4 * scale_factor[exp[i]]); \
+ } else { \
+ int code; \
+ \
+ code = bitstream_get (7); \
+ \
+ q_4_pointer = 0; \
+ q_4 = q_4_1[code]; \
+ COEFF (q_4_0[code] * scale_factor[exp[i]]); \
+ } \
+ \
+ case 4: \
+ COEFF (q_5[bitstream_get (4)] * scale_factor[exp[i]]); \
+ \
+ default: \
+ COEFF (((int16_t)(bitstream_get(bap[i]) << (16 - bap[i]))) * \
+ scale_factor[exp[i]]); \
+ }
+
+#define CHANNEL_COEFF(val) \
+ coeff[i++] = val; \
+ continue;
+
+#define CHANNEL_DITHER(val) \
+ if (dither) { \
+ coeff[i++] = dither_gen () * val; \
+ continue; \
+ } else { \
+ coeff[i++] = 0; \
+ continue; \
+ }
+
+static uint16_t lfsr_state = 1;
+
+static inline int16_t dither_gen(void)
+{
+ int16_t state;
+
+ state = dither_lut[lfsr_state >> 8] ^ (lfsr_state << 8);
+
+ lfsr_state = (uint16_t) state;
+
+ return ((state * (int) (LEVEL_3DB * 256)) >> 8);
+}
+
+static void coeff_get (float * coeff, uint8_t * exp, int8_t * bap,
+ int dither, int end)
+{
+ int i;
+
+ i = 0;
+ while (i < end)
+ GET_COEFF (CHANNEL_COEFF, CHANNEL_DITHER);
+}
+
+#define COUPLING_COEFF(val) \
+ cplcoeff = val; \
+ break;
+
+#define COUPLING_DITHER(val) \
+ cplcoeff = val; \
+ for (ch = 0; ch < nfchans; ch++) \
+ if (state->chincpl[ch]) { \
+ if (dithflag[ch]) \
+ samples[ch][i] = \
+ state->cplco[ch][bnd] * dither_gen () * cplcoeff; \
+ else \
+ samples[ch][i] = 0; \
+ } \
+ i++; \
+ continue;
+
+int ac3_block (ac3_state_t * state)
+{
+ static const uint8_t nfchans_tbl[8] = {2, 1, 2, 3, 3, 4, 4, 5};
+ static int rematrix_band[4] = {25, 37, 61, 253};
+ int i, nfchans, chaninfo;
+ uint8_t cplexpstr, chexpstr[5], lfeexpstr, do_bit_alloc, done_cpl;
+ uint8_t blksw[5], dithflag[5];
+
+ nfchans = nfchans_tbl[state->acmod];
+
+ for (i = 0; i < nfchans; i++)
+ blksw[i] = bitstream_get (1);
+
+ for (i = 0; i < nfchans; i++)
+ dithflag[i] = bitstream_get (1);
+
+ chaninfo = !(state->acmod);
+ do {
+ if (bitstream_get (1)) // dynrnge
+ bitstream_get (8); // dynrng
+ } while (chaninfo--);
+
+ if (bitstream_get (1)) { // cplstre
+ state->cplinu = bitstream_get (1);
+ if (state->cplinu) {
+ static int bndtab[16] = {31, 35, 37, 39, 41, 42, 43, 44,
+ 45, 45, 46, 46, 47, 47, 48, 48};
+ int cplbegf;
+ int cplendf;
+ int ncplsubnd;
+
+ for (i = 0; i < nfchans; i++)
+ state->chincpl[i] = bitstream_get (1);
+ switch (state->acmod) {
+ case 0: case 1:
+ return 1;
+ case 2:
+ state->phsflginu = bitstream_get (1);
+ }
+ cplbegf = bitstream_get (4);
+ cplendf = bitstream_get (4);
+
+ if (cplendf + 3 - cplbegf < 0)
+ return 1;
+ state->ncplbnd = ncplsubnd = cplendf + 3 - cplbegf;
+ state->cplstrtbnd = bndtab[cplbegf];
+ state->cplstrtmant = cplbegf * 12 + 37;
+ state->cplendmant = cplendf * 12 + 73;
+
+ for (i = 0; i < ncplsubnd - 1; i++) {
+ state->cplbndstrc[i] = bitstream_get (1);
+ state->ncplbnd -= state->cplbndstrc[i];
+ }
+ state->cplbndstrc[i] = 0; // last value is a sentinel
+ }
+ }
+
+ if (state->cplinu) {
+ int j, cplcoe;
+
+ cplcoe = 0;
+ for (i = 0; i < nfchans; i++)
+ if (state->chincpl[i])
+ if (bitstream_get (1)) { // cplcoe
+ int mstrcplco, cplcoexp, cplcomant;
+
+ cplcoe = 1;
+ mstrcplco = 3 * bitstream_get (2);
+ for (j = 0; j < state->ncplbnd; j++) {
+ cplcoexp = bitstream_get (4);
+ cplcomant = bitstream_get (4);
+ if (cplcoexp == 15)
+ cplcomant <<= 14;
+ else
+ cplcomant = (cplcomant | 0x10) << 13;
+ state->cplco[i][j] =
+ cplcomant * scale_factor[cplcoexp + mstrcplco];
+ }
+ }
+ if ((state->acmod == 2) && state->phsflginu && cplcoe)
+ for (j = 0; j < state->ncplbnd; j++)
+ if (bitstream_get (1)) // phsflg
+ state->cplco[1][j] = -state->cplco[1][j];
+ }
+
+ if ((state->acmod == 2) && (bitstream_get (1))) { // rematstr
+ int end;
+
+ end = (state->cplinu) ? state->cplstrtmant : 253;
+ i = 0;
+ do
+ state->rematflg[i] = bitstream_get (1);
+ while (rematrix_band[i++] < end);
+ }
+
+ cplexpstr = EXP_REUSE;
+ lfeexpstr = EXP_REUSE;
+ if (state->cplinu)
+ cplexpstr = bitstream_get (2);
+ for (i = 0; i < nfchans; i++)
+ chexpstr[i] = bitstream_get (2);
+ if (state->lfeon)
+ lfeexpstr = bitstream_get (1);
+
+ for (i = 0; i < nfchans; i++)
+ if (chexpstr[i] != EXP_REUSE) {
+ if (state->cplinu && state->chincpl[i])
+ state->endmant[i] = state->cplstrtmant;
+ else {
+ int chbwcod;
+
+ chbwcod = bitstream_get (6);
+ if (chbwcod > 60)
+ return 1;
+ state->endmant[i] = chbwcod * 3 + 73;
+ }
+ }
+
+ do_bit_alloc = 0;
+
+ if (cplexpstr != EXP_REUSE) {
+ int cplabsexp, ncplgrps;
+
+ do_bit_alloc = 1;
+ ncplgrps = ((state->cplendmant - state->cplstrtmant) /
+ (3 << (cplexpstr - 1)));
+ cplabsexp = bitstream_get (4) << 1;
+ if (parse_exponents (cplexpstr, ncplgrps, cplabsexp,
+ state->cpl_exp + state->cplstrtmant))
+ return 1;
+ }
+ for (i = 0; i < nfchans; i++)
+ if (chexpstr[i] != EXP_REUSE) {
+ int grp_size, nchgrps;
+
+ do_bit_alloc = 1;
+ grp_size = 3 << (chexpstr[i] - 1);
+ nchgrps = (state->endmant[i] + grp_size - 4) / grp_size;
+ state->fbw_exp[i][0] = bitstream_get (4);
+ if (parse_exponents (chexpstr[i], nchgrps, state->fbw_exp[i][0],
+ state->fbw_exp[i] + 1))
+ return 1;
+ bitstream_get (2); // gainrng
+ }
+ if (lfeexpstr != EXP_REUSE) {
+ do_bit_alloc = 1;
+ state->lfe_exp[0] = bitstream_get (4);
+ if (parse_exponents (lfeexpstr, 2, state->lfe_exp[0],
+ state->lfe_exp + 1))
+ return 1;
+ }
+
+ if (bitstream_get (1)) { // baie
+ do_bit_alloc = 1;
+ state->sdcycod = bitstream_get (2);
+ state->fdcycod = bitstream_get (2);
+ state->sgaincod = bitstream_get (2);
+ state->dbpbcod = bitstream_get (2);
+ state->floorcod = bitstream_get (3);
+ }
+ if (bitstream_get (1)) { //snroffste
+ do_bit_alloc = 1;
+ state->csnroffst = bitstream_get (6);
+ if (state->cplinu) {
+ state->cplba.fsnroffst = bitstream_get (4);
+ state->cplba.fgaincod = bitstream_get (3);
+ }
+ for (i = 0; i < nfchans; i++) {
+ state->ba[i].fsnroffst = bitstream_get (4);
+ state->ba[i].fgaincod = bitstream_get (3);
+ }
+ if (state->lfeon) {
+ state->lfeba.fsnroffst = bitstream_get (4);
+ state->lfeba.fgaincod = bitstream_get (3);
+ }
+ }
+ if ((state->cplinu) && (bitstream_get (1))) { // cplleake
+ do_bit_alloc = 1;
+ state->cplfleak = 2304 - (bitstream_get (3) << 8);
+ state->cplsleak = 2304 - (bitstream_get (3) << 8);
+ }
+
+ if (bitstream_get (1)) { // deltbaie
+ do_bit_alloc = 1;
+ if (state->cplinu)
+ state->cplba.deltbae = bitstream_get (2);
+ for (i = 0; i < nfchans; i++)
+ state->ba[i].deltbae = bitstream_get (2);
+ if (state->cplinu && (state->cplba.deltbae == DELTA_BIT_NEW) &&
+ parse_deltba (state->cplba.deltba))
+ return 1;
+ for (i = 0; i < nfchans; i++)
+ if ((state->ba[i].deltbae == DELTA_BIT_NEW) &&
+ parse_deltba (state->ba[i].deltba))
+ return 1;
+ }
+
+ if (do_bit_alloc) {
+ if (zero_snr_offsets (nfchans, state)) {
+ memset (state->cpl_bap, 0, sizeof (state->cpl_bap));
+ memset (state->fbw_bap, 0, sizeof (state->fbw_bap));
+ memset (state->lfe_bap, 0, sizeof (state->lfe_bap));
+ } else {
+ if (state->cplinu)
+ bit_allocate (state, &state->cplba, state->cplstrtbnd,
+ state->cplstrtmant, state->cplendmant,
+ state->cplfleak, state->cplsleak,
+ state->cpl_exp, state->cpl_bap);
+ for (i = 0; i < nfchans; i++)
+ bit_allocate (state, state->ba + i, 0, 0, state->endmant[i],
+ 0, 0, state->fbw_exp[i], state->fbw_bap[i]);
+ if (state->lfeon) {
+ state->lfeba.deltbae = DELTA_BIT_NONE;
+ bit_allocate (state, &state->lfeba, 0, 0, 7, 0, 0,
+ state->lfe_exp, state->lfe_bap);
+ }
+ }
+ }
+
+ if (bitstream_get (1)) { // skiple
+ i = bitstream_get (9); // skipl
+ while (i--)
+ bitstream_get (8);
+ }
+
+ q_1_pointer = q_2_pointer = q_4_pointer = -1;
+ done_cpl = 0;
+
+ for (i = 0; i < nfchans; i++) {
+ int j;
+
+ coeff_get (samples[i], state->fbw_exp[i], state->fbw_bap[i],
+ dithflag[i], state->endmant[i]);
+
+ if (state->cplinu && state->chincpl[i]) {
+ if (!done_cpl) {
+ int i, i_end, bnd, sub_bnd, ch;
+ float cplcoeff;
+
+ done_cpl = 1;
+
+#define bap state->cpl_bap
+#define exp state->cpl_exp
+
+ sub_bnd = bnd = 0;
+ i = state->cplstrtmant;
+ while (i < state->cplendmant) {
+ i_end = i + 12;
+ while (state->cplbndstrc[sub_bnd++])
+ i_end += 12;
+
+ while (i < i_end) {
+ GET_COEFF (COUPLING_COEFF, COUPLING_DITHER);
+ for (ch = 0; ch < nfchans; ch++)
+ if (state->chincpl[ch])
+ samples[ch][i] =
+ state->cplco[ch][bnd] * cplcoeff;
+ i++;
+ }
+ bnd++;
+ }
+
+#undef bap
+#undef exp
+ }
+ j = state->cplendmant;
+ } else
+ j = state->endmant[i];
+ for (; j < 256; j++)
+ samples[i][j] = 0;
+ }
+
+ if (state->acmod == 2) {
+ int j, end, band;
+
+ end = ((state->endmant[0] < state->endmant[1]) ?
+ state->endmant[0] : state->endmant[1]);
+
+ i = 0;
+ j = 13;
+ do {
+ if (!state->rematflg[i]) {
+ j = rematrix_band[i++];
+ continue;
+ }
+ band = rematrix_band[i++];
+ if (band > end)
+ band = end;
+ do {
+ float tmp0, tmp1;
+
+ tmp0 = samples[0][j];
+ tmp1 = samples[1][j];
+ samples[0][j] = tmp0 + tmp1;
+ samples[1][j] = tmp0 - tmp1;
+ } while (++j < band);
+ } while (j < end);
+ }
+
+ if (state->lfeon) {
+ coeff_get (samples[5], state->lfe_exp, state->lfe_bap, 0, 7);
+#if 0
+ for (i = 7; i < 256; i++)
+ samples[5][i] = 0;
+#endif
+ }
+
+ for (i = 0; i < nfchans; i++)
+ if (blksw[i])
+ imdct_256 (samples[i], delay[i]);
+ else
+ imdct_512 (samples[i], delay[i]);
+
+#if 0
+ if (state->lfeon)
+ imdct_512 (samples[5], delay[5]);
+#endif
+
+ downmix (*samples, state->acmod, state->output, state->level, state->bias,
+ state->clev, state->slev);
+
+ return 0;
+}
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