* Copyright (c) 2007-2008 Bartlomiej Wolowiec <bartek.wolowiec@gmail.com>
* Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
*
- * Portions of this code are derived from liba52
- * http://liba52.sourceforge.net
- * Copyright (C) 2000-2003 Michel Lespinasse <walken@zoy.org>
- * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
- *
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
+ * modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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.
+ * Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public
+ * You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
ac3_common_init();
ac3_tables_init();
- ff_mdct_init(&s->imdct_256, 8, 1);
- ff_mdct_init(&s->imdct_512, 9, 1);
+ ff_mdct_init(&s->imdct_256, 8, 1, 1.0);
+ ff_mdct_init(&s->imdct_512, 9, 1, 1.0);
ff_kbd_window_init(s->window, 5.0, 256);
dsputil_init(&s->dsp, avctx);
av_lfg_init(&s->dith_state, 0);
s->skip_syntax = 1;
memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));
return ac3_parse_header(s);
- } else {
+ } else if (CONFIG_EAC3_DECODER) {
s->eac3 = 1;
return ff_eac3_parse_header(s);
+ } else {
+ av_log(s->avctx, AV_LOG_ERROR, "E-AC-3 support not compiled in\n");
+ return -1;
}
}
*/
static void calc_transform_coeffs_cpl(AC3DecodeContext *s)
{
- int i, j, ch, bnd, subbnd;
+ int bin, band, ch;
- subbnd = -1;
- i = s->start_freq[CPL_CH];
- for(bnd=0; bnd<s->num_cpl_bands; bnd++) {
- do {
- subbnd++;
- for(j=0; j<12; j++) {
- for(ch=1; ch<=s->fbw_channels; ch++) {
- if(s->channel_in_cpl[ch]) {
- s->fixed_coeffs[ch][i] = ((int64_t)s->fixed_coeffs[CPL_CH][i] * (int64_t)s->cpl_coords[ch][bnd]) >> 23;
- if (ch == 2 && s->phase_flags[bnd])
- s->fixed_coeffs[ch][i] = -s->fixed_coeffs[ch][i];
- }
+ bin = s->start_freq[CPL_CH];
+ for (band = 0; band < s->num_cpl_bands; band++) {
+ int band_start = bin;
+ int band_end = bin + s->cpl_band_sizes[band];
+ for (ch = 1; ch <= s->fbw_channels; ch++) {
+ if (s->channel_in_cpl[ch]) {
+ int64_t cpl_coord = s->cpl_coords[ch][band];
+ for (bin = band_start; bin < band_end; bin++) {
+ s->fixed_coeffs[ch][bin] = ((int64_t)s->fixed_coeffs[CPL_CH][bin] *
+ cpl_coord) >> 23;
+ }
+ if (ch == 2 && s->phase_flags[band]) {
+ for (bin = band_start; bin < band_end; bin++)
+ s->fixed_coeffs[2][bin] = -s->fixed_coeffs[2][bin];
}
- i++;
}
- } while(s->cpl_band_struct[subbnd]);
+ }
+ bin = band_end;
}
}
* Grouped mantissas for 3-level 5-level and 11-level quantization
*/
typedef struct {
- int b1_mant[3];
- int b2_mant[3];
- int b4_mant[2];
- int b1ptr;
- int b2ptr;
- int b4ptr;
+ int b1_mant[2];
+ int b2_mant[2];
+ int b4_mant;
+ int b1;
+ int b2;
+ int b4;
} mant_groups;
/**
*/
static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, mant_groups *m)
{
+ int start_freq = s->start_freq[ch_index];
+ int end_freq = s->end_freq[ch_index];
+ uint8_t *baps = s->bap[ch_index];
+ int8_t *exps = s->dexps[ch_index];
+ int *coeffs = s->fixed_coeffs[ch_index];
+ int dither = (ch_index == CPL_CH) || s->dither_flag[ch_index];
GetBitContext *gbc = &s->gbc;
- int i, gcode, tbap, start, end;
- uint8_t *exps;
- uint8_t *bap;
- int *coeffs;
-
- exps = s->dexps[ch_index];
- bap = s->bap[ch_index];
- coeffs = s->fixed_coeffs[ch_index];
- start = s->start_freq[ch_index];
- end = s->end_freq[ch_index];
-
- for (i = start; i < end; i++) {
- tbap = bap[i];
- switch (tbap) {
+ int freq;
+
+ for(freq = start_freq; freq < end_freq; freq++){
+ int bap = baps[freq];
+ int mantissa;
+ switch(bap){
case 0:
- coeffs[i] = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
+ if (dither)
+ mantissa = (av_lfg_get(&s->dith_state) & 0x7FFFFF) - 0x400000;
+ else
+ mantissa = 0;
break;
-
case 1:
- if(m->b1ptr > 2) {
- gcode = get_bits(gbc, 5);
- m->b1_mant[0] = b1_mantissas[gcode][0];
- m->b1_mant[1] = b1_mantissas[gcode][1];
- m->b1_mant[2] = b1_mantissas[gcode][2];
- m->b1ptr = 0;
+ if(m->b1){
+ m->b1--;
+ mantissa = m->b1_mant[m->b1];
+ }
+ else{
+ int bits = get_bits(gbc, 5);
+ mantissa = b1_mantissas[bits][0];
+ m->b1_mant[1] = b1_mantissas[bits][1];
+ m->b1_mant[0] = b1_mantissas[bits][2];
+ m->b1 = 2;
}
- coeffs[i] = m->b1_mant[m->b1ptr++];
break;
-
case 2:
- if(m->b2ptr > 2) {
- gcode = get_bits(gbc, 7);
- m->b2_mant[0] = b2_mantissas[gcode][0];
- m->b2_mant[1] = b2_mantissas[gcode][1];
- m->b2_mant[2] = b2_mantissas[gcode][2];
- m->b2ptr = 0;
+ if(m->b2){
+ m->b2--;
+ mantissa = m->b2_mant[m->b2];
+ }
+ else{
+ int bits = get_bits(gbc, 7);
+ mantissa = b2_mantissas[bits][0];
+ m->b2_mant[1] = b2_mantissas[bits][1];
+ m->b2_mant[0] = b2_mantissas[bits][2];
+ m->b2 = 2;
}
- coeffs[i] = m->b2_mant[m->b2ptr++];
break;
-
case 3:
- coeffs[i] = b3_mantissas[get_bits(gbc, 3)];
+ mantissa = b3_mantissas[get_bits(gbc, 3)];
break;
-
case 4:
- if(m->b4ptr > 1) {
- gcode = get_bits(gbc, 7);
- m->b4_mant[0] = b4_mantissas[gcode][0];
- m->b4_mant[1] = b4_mantissas[gcode][1];
- m->b4ptr = 0;
+ if(m->b4){
+ m->b4 = 0;
+ mantissa = m->b4_mant;
+ }
+ else{
+ int bits = get_bits(gbc, 7);
+ mantissa = b4_mantissas[bits][0];
+ m->b4_mant = b4_mantissas[bits][1];
+ m->b4 = 1;
}
- coeffs[i] = m->b4_mant[m->b4ptr++];
break;
-
case 5:
- coeffs[i] = b5_mantissas[get_bits(gbc, 4)];
+ mantissa = b5_mantissas[get_bits(gbc, 4)];
break;
-
- default: {
- /* asymmetric dequantization */
- int qlevel = quantization_tab[tbap];
- coeffs[i] = get_sbits(gbc, qlevel) << (24 - qlevel);
+ default: /* 6 to 15 */
+ mantissa = get_bits(gbc, quantization_tab[bap]);
+ /* Shift mantissa and sign-extend it. */
+ mantissa = (mantissa << (32-quantization_tab[bap]))>>8;
break;
- }
}
- coeffs[i] >>= exps[i];
+ coeffs[freq] = mantissa >> exps[freq];
}
}
/**
- * Remove random dithering from coefficients with zero-bit mantissas
+ * Remove random dithering from coupling range coefficients with zero-bit
+ * mantissas for coupled channels which do not use dithering.
* reference: Section 7.3.4 Dither for Zero Bit Mantissas (bap=0)
*/
static void remove_dithering(AC3DecodeContext *s) {
int ch, i;
- int end=0;
- int *coeffs;
- uint8_t *bap;
for(ch=1; ch<=s->fbw_channels; ch++) {
- if(!s->dither_flag[ch]) {
- coeffs = s->fixed_coeffs[ch];
- bap = s->bap[ch];
- if(s->channel_in_cpl[ch])
- end = s->start_freq[CPL_CH];
- else
- end = s->end_freq[ch];
- for(i=0; i<end; i++) {
- if(!bap[i])
- coeffs[i] = 0;
- }
- if(s->channel_in_cpl[ch]) {
- bap = s->bap[CPL_CH];
- for(; i<s->end_freq[CPL_CH]; i++) {
- if(!bap[i])
- coeffs[i] = 0;
- }
+ if(!s->dither_flag[ch] && s->channel_in_cpl[ch]) {
+ for(i = s->start_freq[CPL_CH]; i<s->end_freq[CPL_CH]; i++) {
+ if(!s->bap[CPL_CH][i])
+ s->fixed_coeffs[ch][i] = 0;
}
}
}
/* if AHT is used, mantissas for all blocks are encoded in the first
block of the frame. */
int bin;
- if (!blk)
+ if (!blk && CONFIG_EAC3_DECODER)
ff_eac3_decode_transform_coeffs_aht_ch(s, ch);
for (bin = s->start_freq[ch]; bin < s->end_freq[ch]; bin++) {
s->fixed_coeffs[ch][bin] = s->pre_mantissa[ch][bin][blk] >> s->dexps[ch][bin];
int got_cplchan = 0;
mant_groups m;
- m.b1ptr = m.b2ptr = m.b4ptr = 3;
+ m.b1 = m.b2 = m.b4 = 0;
for (ch = 1; ch <= s->channels; ch++) {
/* transform coefficients for full-bandwidth channel */
{
int bnd, i;
int end, bndend;
- int tmp0, tmp1;
end = FFMIN(s->end_freq[1], s->end_freq[2]);
if(s->rematrixing_flags[bnd]) {
bndend = FFMIN(end, ff_ac3_rematrix_band_tab[bnd+1]);
for(i=ff_ac3_rematrix_band_tab[bnd]; i<bndend; i++) {
- tmp0 = s->fixed_coeffs[1][i];
- tmp1 = s->fixed_coeffs[2][i];
- s->fixed_coeffs[1][i] = tmp0 + tmp1;
- s->fixed_coeffs[2][i] = tmp0 - tmp1;
+ int tmp0 = s->fixed_coeffs[1][i];
+ s->fixed_coeffs[1][i] += s->fixed_coeffs[2][i];
+ s->fixed_coeffs[2][i] = tmp0 - s->fixed_coeffs[2][i];
}
}
}
/**
* Decode band structure for coupling, spectral extension, or enhanced coupling.
+ * The band structure defines how many subbands are in each band. For each
+ * subband in the range, 1 means it is combined with the previous band, and 0
+ * means that it starts a new band.
+ *
* @param[in] gbc bit reader context
* @param[in] blk block number
* @param[in] eac3 flag to indicate E-AC-3
* @param[in] start_subband subband number for start of range
* @param[in] end_subband subband number for end of range
* @param[in] default_band_struct default band structure table
- * @param[out] band_struct decoded band structure
- * @param[out] num_subbands number of subbands (optionally NULL)
* @param[out] num_bands number of bands (optionally NULL)
* @param[out] band_sizes array containing the number of bins in each band (optionally NULL)
*/
static void decode_band_structure(GetBitContext *gbc, int blk, int eac3,
int ecpl, int start_subband, int end_subband,
const uint8_t *default_band_struct,
- uint8_t *band_struct, int *num_subbands,
int *num_bands, uint8_t *band_sizes)
{
int subbnd, bnd, n_subbands, n_bands=0;
uint8_t bnd_sz[22];
+ uint8_t coded_band_struct[22];
+ const uint8_t *band_struct;
n_subbands = end_subband - start_subband;
/* decode band structure from bitstream or use default */
if (!eac3 || get_bits1(gbc)) {
for (subbnd = 0; subbnd < n_subbands - 1; subbnd++) {
- band_struct[subbnd] = get_bits1(gbc);
+ coded_band_struct[subbnd] = get_bits1(gbc);
}
+ band_struct = coded_band_struct;
} else if (!blk) {
- memcpy(band_struct,
- &default_band_struct[start_subband+1],
- n_subbands-1);
+ band_struct = &default_band_struct[start_subband+1];
+ } else {
+ /* no change in band structure */
+ return;
}
- band_struct[n_subbands-1] = 0;
/* calculate number of bands and band sizes based on band structure.
note that the first 4 subbands in enhanced coupling span only 6 bins
}
/* set optional output params */
- if (num_subbands)
- *num_subbands = n_subbands;
if (num_bands)
*num_bands = n_bands;
if (band_sizes)
/* spectral extension strategy */
if (s->eac3 && (!blk || get_bits1(gbc))) {
if (get_bits1(gbc)) {
- ff_log_missing_feature(s->avctx, "Spectral extension", 1);
+ av_log_missing_feature(s->avctx, "Spectral extension", 1);
return -1;
}
/* TODO: parse spectral extension strategy info */
/* check for enhanced coupling */
if (s->eac3 && get_bits1(gbc)) {
/* TODO: parse enhanced coupling strategy info */
- ff_log_missing_feature(s->avctx, "Enhanced coupling", 1);
+ av_log_missing_feature(s->avctx, "Enhanced coupling", 1);
return -1;
}
/* TODO: modify coupling end freq if spectral extension is used */
cpl_start_subband = get_bits(gbc, 4);
cpl_end_subband = get_bits(gbc, 4) + 3;
- s->num_cpl_subbands = cpl_end_subband - cpl_start_subband;
- if (s->num_cpl_subbands < 0) {
- av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d > %d)\n",
+ if (cpl_start_subband >= cpl_end_subband) {
+ av_log(s->avctx, AV_LOG_ERROR, "invalid coupling range (%d >= %d)\n",
cpl_start_subband, cpl_end_subband);
return -1;
}
s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
- decode_band_structure(gbc, blk, s->eac3, 0,
- cpl_start_subband, cpl_end_subband,
- ff_eac3_default_cpl_band_struct,
- s->cpl_band_struct, &s->num_cpl_subbands,
- &s->num_cpl_bands, NULL);
+ decode_band_structure(gbc, blk, s->eac3, 0, cpl_start_subband,
+ cpl_end_subband,
+ ff_eac3_default_cpl_band_struct,
+ &s->num_cpl_bands, s->cpl_band_sizes);
} else {
/* coupling not in use */
for (ch = 1; ch <= fbw_channels; ch++) {
for(bnd=0; bnd<s->num_rematrixing_bands; bnd++)
s->rematrixing_flags[bnd] = get_bits1(gbc);
} else if (!blk) {
- av_log(s->avctx, AV_LOG_ERROR, "new rematrixing strategy must be present in block 0\n");
- return -1;
+ av_log(s->avctx, AV_LOG_WARNING, "Warning: new rematrixing strategy not present in block 0\n");
+ s->num_rematrixing_bands = 0;
}
}
for(ch=1; ch<=s->channels; ch++) {
float gain = s->mul_bias / 4194304.0f;
if(s->channel_mode == AC3_CHMODE_DUALMONO) {
- gain *= s->dynamic_range[ch-1];
+ gain *= s->dynamic_range[2-ch];
} else {
gain *= s->dynamic_range[0];
}
int16_t *out_samples = (int16_t *)data;
int blk, ch, err;
const uint8_t *channel_map;
+ const float *output[AC3_MAX_CHANNELS];
/* initialize the GetBitContext with the start of valid AC-3 Frame */
if (s->input_buffer) {
/* decode the audio blocks */
channel_map = ff_ac3_dec_channel_map[s->output_mode & ~AC3_OUTPUT_LFEON][s->lfe_on];
+ for (ch = 0; ch < s->out_channels; ch++)
+ output[ch] = s->output[channel_map[ch]];
for (blk = 0; blk < s->num_blocks; blk++) {
- const float *output[s->out_channels];
if (!err && decode_audio_block(s, blk)) {
av_log(avctx, AV_LOG_ERROR, "error decoding the audio block\n");
err = 1;
}
- for (ch = 0; ch < s->out_channels; ch++)
- output[ch] = s->output[channel_map[ch]];
s->dsp.float_to_int16_interleave(out_samples, output, 256, s->out_channels);
out_samples += 256 * s->out_channels;
}
.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
};
+#if CONFIG_EAC3_DECODER
AVCodec eac3_decoder = {
.name = "eac3",
.type = CODEC_TYPE_AUDIO,
.decode = ac3_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52B (AC-3, E-AC-3)"),
};
+#endif
projects / ffmpeg / blobdiff