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dca_parser: parse the sample rate and frame durations

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This commit is contained in:
Justin Ruggles
2012-02-27 13:58:01 -05:00
parent 85469f1c9e
commit 11ac796f7a
4 changed files with 120 additions and 46 deletions
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libavcodec/dca_parser.c
+79 -1
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@@ -24,6 +24,10 @@
#include "parser.h"
#include "dca.h"
#include "dcadata.h"
#include "dca_parser.h"
#include "get_bits.h"
#include "put_bits.h"
typedef struct DCAParseContext {
ParseContext pc;
@@ -100,6 +104,71 @@ static av_cold int dca_parse_init(AVCodecParserContext * s)
return 0;
}
int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
int max_size)
{
uint32_t mrk;
int i, tmp;
const uint16_t *ssrc = (const uint16_t *) src;
uint16_t *sdst = (uint16_t *) dst;
PutBitContext pb;
if ((unsigned) src_size > (unsigned) max_size)
src_size = max_size;
mrk = AV_RB32(src);
switch (mrk) {
case DCA_MARKER_RAW_BE:
memcpy(dst, src, src_size);
return src_size;
case DCA_MARKER_RAW_LE:
for (i = 0; i < (src_size + 1) >> 1; i++)
*sdst++ = av_bswap16(*ssrc++);
return src_size;
case DCA_MARKER_14B_BE:
case DCA_MARKER_14B_LE:
init_put_bits(&pb, dst, max_size);
for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
put_bits(&pb, 14, tmp);
}
flush_put_bits(&pb);
return (put_bits_count(&pb) + 7) >> 3;
default:
return AVERROR_INVALIDDATA;
}
}
static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
int *sample_rate)
{
GetBitContext gb;
uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
int ret, sample_blocks, sr_code;
if (buf_size < 12)
return AVERROR_INVALIDDATA;
if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
return ret;
init_get_bits(&gb, hdr, 96);
skip_bits_long(&gb, 39);
sample_blocks = get_bits(&gb, 7) + 1;
if (sample_blocks < 8)
return AVERROR_INVALIDDATA;
*duration = 256 * (sample_blocks / 8);
skip_bits(&gb, 20);
sr_code = get_bits(&gb, 4);
*sample_rate = dca_sample_rates[sr_code];
if (*sample_rate == 0)
return AVERROR_INVALIDDATA;
return 0;
}
static int dca_parse(AVCodecParserContext * s,
AVCodecContext * avctx,
const uint8_t ** poutbuf, int *poutbuf_size,
@@ -107,7 +176,7 @@ static int dca_parse(AVCodecParserContext * s,
{
DCAParseContext *pc1 = s->priv_data;
ParseContext *pc = &pc1->pc;
int next;
int next, duration, sample_rate;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
@@ -120,6 +189,15 @@ static int dca_parse(AVCodecParserContext * s,
return buf_size;
}
}
/* read the duration and sample rate from the frame header */
if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) {
s->duration = duration;
if (!avctx->sample_rate)
avctx->sample_rate = sample_rate;
} else
s->duration = 0;
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;