[FFmpeg-cvslog] ac3dec: Split coupling-specific code from decode_audio_block()
Luca Barbato
git at videolan.org
Wed Mar 15 22:57:11 EET 2017
ffmpeg | branch: master | Luca Barbato <lu_zero at gentoo.org> | Mon Jul 18 19:50:33 2016 +0200| [f0ccc65bc9ab9ddf1366066395564c71bcc825ee] | committer: Diego Biurrun
ac3dec: Split coupling-specific code from decode_audio_block()
Signed-off-by: Diego Biurrun <diego at biurrun.de>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=f0ccc65bc9ab9ddf1366066395564c71bcc825ee
---
libavcodec/ac3dec.c | 207 +++++++++++++++++++++++++++++-----------------------
1 file changed, 116 insertions(+), 91 deletions(-)
diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index 4de7475..f3e3da5 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -849,6 +849,118 @@ static inline void spx_coordinates(AC3DecodeContext *s)
}
}
+static inline int coupling_strategy(AC3DecodeContext *s, int blk,
+ uint8_t *bit_alloc_stages)
+{
+ GetBitContext *bc = &s->gbc;
+ int fbw_channels = s->fbw_channels;
+ int channel_mode = s->channel_mode;
+ int ch;
+
+ memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
+ if (!s->eac3)
+ s->cpl_in_use[blk] = get_bits1(bc);
+ if (s->cpl_in_use[blk]) {
+ /* coupling in use */
+ int cpl_start_subband, cpl_end_subband;
+
+ if (channel_mode < AC3_CHMODE_STEREO) {
+ av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ /* check for enhanced coupling */
+ if (s->eac3 && get_bits1(bc)) {
+ /* TODO: parse enhanced coupling strategy info */
+ avpriv_request_sample(s->avctx, "Enhanced coupling");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ /* determine which channels are coupled */
+ if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
+ s->channel_in_cpl[1] = 1;
+ s->channel_in_cpl[2] = 1;
+ } else {
+ for (ch = 1; ch <= fbw_channels; ch++)
+ s->channel_in_cpl[ch] = get_bits1(bc);
+ }
+
+ /* phase flags in use */
+ if (channel_mode == AC3_CHMODE_STEREO)
+ s->phase_flags_in_use = get_bits1(bc);
+
+ /* coupling frequency range */
+ cpl_start_subband = get_bits(bc, 4);
+ cpl_end_subband = s->spx_in_use ? (s->spx_src_start_freq - 37) / 12 :
+ get_bits(bc, 4) + 3;
+ 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 AVERROR_INVALIDDATA;
+ }
+ s->start_freq[CPL_CH] = cpl_start_subband * 12 + 37;
+ s->end_freq[CPL_CH] = cpl_end_subband * 12 + 37;
+
+ decode_band_structure(bc, 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++) {
+ s->channel_in_cpl[ch] = 0;
+ s->first_cpl_coords[ch] = 1;
+ }
+ s->first_cpl_leak = s->eac3;
+ s->phase_flags_in_use = 0;
+ }
+
+ return 0;
+}
+
+static inline int coupling_coordinates(AC3DecodeContext *s, int blk)
+{
+ GetBitContext *bc = &s->gbc;
+ int fbw_channels = s->fbw_channels;
+ int ch, bnd;
+ int cpl_coords_exist = 0;
+
+ for (ch = 1; ch <= fbw_channels; ch++) {
+ if (s->channel_in_cpl[ch]) {
+ if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(bc)) {
+ int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
+ s->first_cpl_coords[ch] = 0;
+ cpl_coords_exist = 1;
+ master_cpl_coord = 3 * get_bits(bc, 2);
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ cpl_coord_exp = get_bits(bc, 4);
+ cpl_coord_mant = get_bits(bc, 4);
+ if (cpl_coord_exp == 15)
+ s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
+ else
+ s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
+ s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
+ }
+ } else if (!blk) {
+ av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must "
+ "be present in block 0\n");
+ return AVERROR_INVALIDDATA;
+ }
+ } else {
+ /* channel not in coupling */
+ s->first_cpl_coords[ch] = 1;
+ }
+ }
+ /* phase flags */
+ if (s->channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
+ for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
+ s->phase_flags[bnd] = s->phase_flags_in_use ? get_bits1(bc) : 0;
+ }
+ }
+
+ return 0;
+}
+
/**
* Decode a single audio block from the AC-3 bitstream.
*/
@@ -916,63 +1028,8 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
/* coupling strategy */
if (s->eac3 ? s->cpl_strategy_exists[blk] : get_bits1(gbc)) {
- memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
- if (!s->eac3)
- s->cpl_in_use[blk] = get_bits1(gbc);
- if (s->cpl_in_use[blk]) {
- /* coupling in use */
- int cpl_start_subband, cpl_end_subband;
-
- if (channel_mode < AC3_CHMODE_STEREO) {
- av_log(s->avctx, AV_LOG_ERROR, "coupling not allowed in mono or dual-mono\n");
- return AVERROR_INVALIDDATA;
- }
-
- /* check for enhanced coupling */
- if (s->eac3 && get_bits1(gbc)) {
- /* TODO: parse enhanced coupling strategy info */
- avpriv_request_sample(s->avctx, "Enhanced coupling");
- return AVERROR_PATCHWELCOME;
- }
-
- /* determine which channels are coupled */
- if (s->eac3 && s->channel_mode == AC3_CHMODE_STEREO) {
- s->channel_in_cpl[1] = 1;
- s->channel_in_cpl[2] = 1;
- } else {
- for (ch = 1; ch <= fbw_channels; ch++)
- s->channel_in_cpl[ch] = get_bits1(gbc);
- }
-
- /* phase flags in use */
- if (channel_mode == AC3_CHMODE_STEREO)
- s->phase_flags_in_use = get_bits1(gbc);
-
- /* coupling frequency range */
- cpl_start_subband = get_bits(gbc, 4);
- cpl_end_subband = s->spx_in_use ? (s->spx_src_start_freq - 37) / 12 :
- get_bits(gbc, 4) + 3;
- 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 AVERROR_INVALIDDATA;
- }
- 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->num_cpl_bands, s->cpl_band_sizes);
- } else {
- /* coupling not in use */
- for (ch = 1; ch <= fbw_channels; ch++) {
- s->channel_in_cpl[ch] = 0;
- s->first_cpl_coords[ch] = 1;
- }
- s->first_cpl_leak = s->eac3;
- s->phase_flags_in_use = 0;
- }
+ if ((ret = coupling_strategy(s, blk, bit_alloc_stages)) < 0)
+ return ret;
} else if (!s->eac3) {
if (!blk) {
av_log(s->avctx, AV_LOG_ERROR, "new coupling strategy must "
@@ -986,40 +1043,8 @@ static int decode_audio_block(AC3DecodeContext *s, int blk)
/* coupling coordinates */
if (cpl_in_use) {
- int cpl_coords_exist = 0;
-
- for (ch = 1; ch <= fbw_channels; ch++) {
- if (s->channel_in_cpl[ch]) {
- if ((s->eac3 && s->first_cpl_coords[ch]) || get_bits1(gbc)) {
- int master_cpl_coord, cpl_coord_exp, cpl_coord_mant;
- s->first_cpl_coords[ch] = 0;
- cpl_coords_exist = 1;
- master_cpl_coord = 3 * get_bits(gbc, 2);
- for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
- cpl_coord_exp = get_bits(gbc, 4);
- cpl_coord_mant = get_bits(gbc, 4);
- if (cpl_coord_exp == 15)
- s->cpl_coords[ch][bnd] = cpl_coord_mant << 22;
- else
- s->cpl_coords[ch][bnd] = (cpl_coord_mant + 16) << 21;
- s->cpl_coords[ch][bnd] >>= (cpl_coord_exp + master_cpl_coord);
- }
- } else if (!blk) {
- av_log(s->avctx, AV_LOG_ERROR, "new coupling coordinates must "
- "be present in block 0\n");
- return AVERROR_INVALIDDATA;
- }
- } else {
- /* channel not in coupling */
- s->first_cpl_coords[ch] = 1;
- }
- }
- /* phase flags */
- if (channel_mode == AC3_CHMODE_STEREO && cpl_coords_exist) {
- for (bnd = 0; bnd < s->num_cpl_bands; bnd++) {
- s->phase_flags[bnd] = s->phase_flags_in_use? get_bits1(gbc) : 0;
- }
- }
+ if ((ret = coupling_coordinates(s, blk)) < 0)
+ return ret;
}
/* stereo rematrixing strategy and band structure */
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