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avcodec/dca_parser: skip initial padding

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Padding before the first sync word can be very large for DTS-in-WAV
streams. There is no reason to include this padding in parsed packet.

Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
foo86 2016-05-31 14:46:14 +03:00 committed by James Almer
parent 1f7b67a1ca
commit 214e63f851
1 changed files with 28 additions and 13 deletions
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41
libavcodec/dca_parser.c
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@ -33,6 +33,7 @@ typedef struct DCAParseContext {
uint32_t lastmarker; uint32_t lastmarker;
int size; int size;
int framesize; int framesize;
unsigned int startpos;
DCAExssParser exss; DCAExssParser exss;
unsigned int sr_code; unsigned int sr_code;
} DCAParseContext; } DCAParseContext;
@ -75,20 +76,27 @@ static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
i = 0; i = 0;
if (!start_found) { if (!start_found) {
for (i = 0; i < buf_size; i++) { for (; i < buf_size; i++) {
size++;
state = (state << 8) | buf[i]; state = (state << 8) | buf[i];
if (IS_MARKER(state)) {
if (!pc1->lastmarker || if (IS_MARKER(state) &&
pc1->lastmarker == CORE_MARKER(state) || (!pc1->lastmarker ||
pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM) { pc1->lastmarker == CORE_MARKER(state) ||
start_found = 1; pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
if (IS_EXSS_MARKER(state)) if (!pc1->lastmarker)
pc1->lastmarker = EXSS_MARKER(state); pc1->startpos = IS_EXSS_MARKER(state) ? size - 4 : size - 6;
else
pc1->lastmarker = CORE_MARKER(state); if (IS_EXSS_MARKER(state))
i++; pc1->lastmarker = EXSS_MARKER(state);
break; else
} pc1->lastmarker = CORE_MARKER(state);
start_found = 1;
size = 0;
i++;
break;
} }
} }
} }
@ -284,6 +292,13 @@ static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
*poutbuf_size = 0; *poutbuf_size = 0;
return buf_size; return buf_size;
} }
/* skip initial padding */
if (buf_size > pc1->startpos) {
buf += pc1->startpos;
buf_size -= pc1->startpos;
}
pc1->startpos = 0;
} }
/* read the duration and sample rate from the frame header */ /* read the duration and sample rate from the frame header */