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libavcodec/flacdec: Implement decoding of 32 bit-per-sample PCM 

Add decoding of FLAC files coding for 32 bit-per-sample PCM to libavcodec.
This commit is contained in:
Martijn van Beurden 2022-10-11 19:24:35 +02:00 committed by Paul B Mahol
parent eeb280f351
commit 909cfdc205
4 changed files with 219 additions and 24 deletions
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4
libavcodec/flac.c
View File

@ -28,7 +28,7 @@
#include "flacdata.h"
#include "flac_parse.h"
static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 };
static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 32 };
static const AVChannelLayout flac_channel_layouts[8] = {
AV_CHANNEL_LAYOUT_MONO,
@ -82,7 +82,7 @@ int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb,
/* bits per sample */
bps_code = get_bits(gb, 3);
if (bps_code == 3 || bps_code == 7) {
if (bps_code == 3) {
av_log(avctx, AV_LOG_ERROR + log_level_offset,
"invalid sample size code (%d)\n",
bps_code);

218
libavcodec/flacdec.c
View File

@ -64,6 +64,9 @@ typedef struct FLACContext {
int32_t *decoded[FLAC_MAX_CHANNELS]; ///< decoded samples
uint8_t *decoded_buffer;
unsigned int decoded_buffer_size;
int64_t *decoded_33bps; ///< decoded samples for a 33 bps subframe
uint8_t *decoded_buffer_33bps;
unsigned int decoded_buffer_size_33bps;
int buggy_lpc; ///< use workaround for old lavc encoded files
FLACDSPContext dsp;
@ -154,6 +157,24 @@ static int allocate_buffers(FLACContext *s)
s->stream_info.channels,
s->stream_info.max_blocksize,
AV_SAMPLE_FMT_S32P, 0);
if (ret >= 0 && s->stream_info.bps == 32 && s->stream_info.channels == 2) {
buf_size = av_samples_get_buffer_size(NULL, 1,
s->stream_info.max_blocksize,
AV_SAMPLE_FMT_S64P, 0);
if (buf_size < 0)
return buf_size;
av_fast_malloc(&s->decoded_buffer_33bps, &s->decoded_buffer_size_33bps, buf_size);
if (!s->decoded_buffer_33bps)
return AVERROR(ENOMEM);
ret = av_samples_fill_arrays((uint8_t **)&s->decoded_33bps, NULL,
s->decoded_buffer_33bps,
1,
s->stream_info.max_blocksize,
AV_SAMPLE_FMT_S64P, 0);
}
return ret < 0 ? ret : 0;
}
@ -331,6 +352,62 @@ static int decode_subframe_fixed(FLACContext *s, int32_t *decoded,
return 0;
}
#define DECODER_SUBFRAME_FIXED_WIDE(residual) { \
const int blocksize = s->blocksize; \
int ret; \
\
if ((ret = decode_residuals(s, residual, pred_order)) < 0) \
return ret; \
\
switch (pred_order) { \
case 0: \
for (int i = pred_order; i < blocksize; i++) \
decoded[i] = residual[i]; \
break; \
case 1: \
for (int i = pred_order; i < blocksize; i++) \
decoded[i] = (int64_t)residual[i] + (int64_t)decoded[i-1];\
break; \
case 2: \
for (int i = pred_order; i < blocksize; i++) \
decoded[i] = (int64_t)residual[i] + 2*(int64_t)decoded[i-1] - (int64_t)decoded[i-2]; \
break; \
case 3: \
for (int i = pred_order; i < blocksize; i++) \
decoded[i] = (int64_t)residual[i] + 3*(int64_t)decoded[i-1] - 3*(int64_t)decoded[i-2] + (int64_t)decoded[i-3]; \
break; \
case 4: \
for (int i = pred_order; i < blocksize; i++) \
decoded[i] = (int64_t)residual[i] + 4*(int64_t)decoded[i-1] - 6*(int64_t)decoded[i-2] + 4*(int64_t)decoded[i-3] - (int64_t)decoded[i-4]; \
break; \
default: \
av_log(s->avctx, AV_LOG_ERROR, "illegal pred order %d\n", pred_order); \
return AVERROR_INVALIDDATA; \
} \
return 0; \
}
static int decode_subframe_fixed_wide(FLACContext *s, int32_t *decoded,
int pred_order, int bps)
{
/* warm up samples */
for (int i = 0; i < pred_order; i++) {
decoded[i] = get_sbits_long(&s->gb, bps);
}
DECODER_SUBFRAME_FIXED_WIDE(decoded);
}
static int decode_subframe_fixed_33bps(FLACContext *s, int64_t *decoded,
int32_t *residual, int pred_order)
{
/* warm up samples */ \
for (int i = 0; i < pred_order; i++) { \
decoded[i] = get_sbits64(&s->gb, 33); \
} \
DECODER_SUBFRAME_FIXED_WIDE(residual);
}
static void lpc_analyze_remodulate(SUINT32 *decoded, const int coeffs[32],
int order, int qlevel, int len, int bps)
{
@ -402,12 +479,53 @@ static int decode_subframe_lpc(FLACContext *s, int32_t *decoded, int pred_order,
return 0;
}
static int decode_subframe_lpc_33bps(FLACContext *s, int64_t *decoded,
int32_t *residual, int pred_order)
{
int i, j, ret;
int coeff_prec, qlevel;
int coeffs[32];
/* warm up samples */
for (i = 0; i < pred_order; i++) {
decoded[i] = get_sbits64(&s->gb, 33);
}
coeff_prec = get_bits(&s->gb, 4) + 1;
if (coeff_prec == 16) {
av_log(s->avctx, AV_LOG_ERROR, "invalid coeff precision\n");
return AVERROR_INVALIDDATA;
}
qlevel = get_sbits(&s->gb, 5);
if (qlevel < 0) {
av_log(s->avctx, AV_LOG_ERROR, "qlevel %d not supported, maybe buggy stream\n",
qlevel);
return AVERROR_INVALIDDATA;
}
for (i = 0; i < pred_order; i++) {
coeffs[pred_order - i - 1] = get_sbits(&s->gb, coeff_prec);
}
if ((ret = decode_residuals(s, residual, pred_order)) < 0)
return ret;
for (i = pred_order; i < s->blocksize; i++, decoded++) {
int64_t sum = 0;
for (j = 0; j < pred_order; j++)
sum += (int64_t)coeffs[j] * decoded[j];
decoded[j] = residual[i] + (sum >> qlevel);
}
return 0;
}
static inline int decode_subframe(FLACContext *s, int channel)
{
int32_t *decoded = s->decoded[channel];
int type, wasted = 0;
int bps = s->stream_info.bps;
int i, tmp, ret;
int i, ret;
if (channel == 0) {
if (s->ch_mode == FLAC_CHMODE_RIGHT_SIDE)
@ -427,7 +545,7 @@ static inline int decode_subframe(FLACContext *s, int channel)
int left = get_bits_left(&s->gb);
if ( left <= 0 ||
(left < bps && !show_bits_long(&s->gb, left)) ||
!show_bits_long(&s->gb, bps)) {
!show_bits_long(&s->gb, bps-1)) {
av_log(s->avctx, AV_LOG_ERROR,
"Invalid number of wasted bits > available bits (%d) - left=%d\n",
bps, left);
@ -436,34 +554,63 @@ static inline int decode_subframe(FLACContext *s, int channel)
wasted = 1 + get_unary(&s->gb, 1, get_bits_left(&s->gb));
bps -= wasted;
}
if (bps > 32) {
avpriv_report_missing_feature(s->avctx, "Decorrelated bit depth > 32");
return AVERROR_PATCHWELCOME;
}
//FIXME use av_log2 for types
if (type == 0) {
tmp = get_sbits_long(&s->gb, bps);
for (i = 0; i < s->blocksize; i++)
decoded[i] = tmp;
if (bps < 33) {
int32_t tmp = get_sbits_long(&s->gb, bps);
for (i = 0; i < s->blocksize; i++)
decoded[i] = tmp;
} else {
int64_t tmp = get_sbits64(&s->gb, 33);
for (i = 0; i < s->blocksize; i++)
s->decoded_33bps[i] = tmp;
}
} else if (type == 1) {
for (i = 0; i < s->blocksize; i++)
decoded[i] = get_sbits_long(&s->gb, bps);
if (bps < 33) {
for (i = 0; i < s->blocksize; i++)
decoded[i] = get_sbits_long(&s->gb, bps);
} else {
for (i = 0; i < s->blocksize; i++)
s->decoded_33bps[i] = get_sbits64(&s->gb, 33);
}
} else if ((type >= 8) && (type <= 12)) {
if ((ret = decode_subframe_fixed(s, decoded, type & ~0x8, bps)) < 0)
return ret;
int order = type & ~0x8;
if (bps < 33) {
if (bps + order <= 32) {
if ((ret = decode_subframe_fixed(s, decoded, order, bps)) < 0)
return ret;
} else {
if ((ret = decode_subframe_fixed_wide(s, decoded, order, bps)) < 0)
return ret;
}
} else {
if ((ret = decode_subframe_fixed_33bps(s, s->decoded_33bps, decoded, order)) < 0)
return ret;
}
} else if (type >= 32) {
if ((ret = decode_subframe_lpc(s, decoded, (type & ~0x20)+1, bps)) < 0)
return ret;
if (bps < 33) {
if ((ret = decode_subframe_lpc(s, decoded, (type & ~0x20)+1, bps)) < 0)
return ret;
} else {
if ((ret = decode_subframe_lpc_33bps(s, s->decoded_33bps, decoded, (type & ~0x20)+1)) < 0)
return ret;
}
} else {
av_log(s->avctx, AV_LOG_ERROR, "invalid coding type\n");
return AVERROR_INVALIDDATA;
}
if (wasted && wasted < 32) {
int i;
for (i = 0; i < s->blocksize; i++)
decoded[i] = (unsigned)decoded[i] << wasted;
if (wasted) {
if (wasted+bps == 33) {
int i;
for (i = 0; i < s->blocksize; i++)
s->decoded_33bps[i] = (uint64_t)decoded[i] << wasted;
} else if (wasted < 32) {
int i;
for (i = 0; i < s->blocksize; i++)
decoded[i] = (unsigned)decoded[i] << wasted;
}
}
return 0;
@ -554,6 +701,26 @@ static int decode_frame(FLACContext *s)
return 0;
}
static void decorrelate_33bps(int ch_mode, int32_t **decoded, int64_t *decoded_33bps, int len)
{
int i;
if (ch_mode == FLAC_CHMODE_LEFT_SIDE ) {
for (i = 0; i < len; i++)
decoded[1][i] = decoded[0][i] - decoded_33bps[i];
} else if (ch_mode == FLAC_CHMODE_RIGHT_SIDE ) {
for (i = 0; i < len; i++)
decoded[0][i] = decoded[1][i] + decoded_33bps[i];
} else if (ch_mode == FLAC_CHMODE_MID_SIDE ) {
for (i = 0; i < len; i++) {
uint64_t a = decoded[0][i];
int64_t b = decoded_33bps[i];
a -= b >> 1;
decoded[0][i] = (a + b);
decoded[1][i] = a;
}
}
}
static int flac_decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *avpkt)
{
@ -612,9 +779,15 @@ static int flac_decode_frame(AVCodecContext *avctx, AVFrame *frame,
if ((ret = ff_thread_get_buffer(avctx, frame, 0)) < 0)
return ret;
s->dsp.decorrelate[s->ch_mode](frame->data, s->decoded,
s->stream_info.channels,
s->blocksize, s->sample_shift);
if (s->stream_info.bps == 32 && s->ch_mode > 0) {
decorrelate_33bps(s->ch_mode, s->decoded, s->decoded_33bps, s->blocksize);
s->dsp.decorrelate[0](frame->data, s->decoded, s->stream_info.channels,
s->blocksize, s->sample_shift);
} else {
s->dsp.decorrelate[s->ch_mode](frame->data, s->decoded,
s->stream_info.channels,
s->blocksize, s->sample_shift);
}
if (bytes_read > buf_size) {
av_log(s->avctx, AV_LOG_ERROR, "overread: %d\n", bytes_read - buf_size);
@ -635,6 +808,7 @@ static av_cold int flac_decode_close(AVCodecContext *avctx)
FLACContext *s = avctx->priv_data;
av_freep(&s->decoded_buffer);
av_freep(&s->decoded_buffer_33bps);
return 0;
}

12
libavcodec/get_bits.h
View File

@ -596,6 +596,18 @@ static inline int get_sbits_long(GetBitContext *s, int n)
return sign_extend(get_bits_long(s, n), n);
}
/**
* Read 0-64 bits as a signed integer.
*/
static inline int64_t get_sbits64(GetBitContext *s, int n)
{
// sign_extend(x, 0) is undefined
if (!n)
return 0;
return sign_extend64(get_bits64(s, n), n);
}
/**
* Show 0-32 bits.
*/

9
libavcodec/mathops.h
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@ -138,6 +138,15 @@ static inline av_const int sign_extend(int val, unsigned bits)
}
#endif
#ifndef sign_extend64
static inline av_const int64_t sign_extend64(int64_t val, unsigned bits)
{
unsigned shift = 8 * sizeof(int64_t) - bits;
union { uint64_t u; int64_t s; } v = { (uint64_t) val << shift };
return v.s >> shift;
}
#endif
#ifndef zero_extend
static inline av_const unsigned zero_extend(unsigned val, unsigned bits)
{