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avformat/matroskadec: Reuse AVIOContext 

When parsing EBML lacing, for every number read, a new AVIOContext has
been initialized (via ffio_init_context()) just for this number. This
has been changed: The context is kept now.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
Andreas Rheinhardt 2019-12-03 18:09:10 +01:00 committed by James Almer
parent dbe3be6744
commit d5274f86a8
1 changed files with 21 additions and 24 deletions
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45
libavformat/matroskadec.c
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@ -1024,28 +1024,17 @@ static int ebml_read_master(MatroskaDemuxContext *matroska,
}
/*
* Read signed/unsigned "EBML" numbers.
* Read a signed "EBML number"
* Return: number of bytes processed, < 0 on error
*/
static int matroska_ebmlnum_uint(MatroskaDemuxContext *matroska,
uint8_t *data, uint32_t size, uint64_t *num)
{
AVIOContext pb;
ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
return ebml_read_num(matroska, &pb, FFMIN(size, 8), num, 1);
}
/*
* Same as above, but signed.
*/
static int matroska_ebmlnum_sint(MatroskaDemuxContext *matroska,
uint8_t *data, uint32_t size, int64_t *num)
AVIOContext *pb, int64_t *num)
{
uint64_t unum;
int res;
/* read as unsigned number first */
if ((res = matroska_ebmlnum_uint(matroska, data, size, &unum)) < 0)
if ((res = ebml_read_num(matroska, pb, 8, &unum, 1)) < 0)
return res;
/* make signed (weird way) */
@ -2989,7 +2978,7 @@ static void matroska_clear_queue(MatroskaDemuxContext *matroska)
}
static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
int size, int type,
int size, int type, AVIOContext *pb,
uint32_t lace_size[256], int *laces)
{
int n;
@ -3047,27 +3036,33 @@ static int matroska_parse_laces(MatroskaDemuxContext *matroska, uint8_t **buf,
{
uint64_t num;
uint64_t total;
n = matroska_ebmlnum_uint(matroska, data, size, &num);
int offset;
avio_skip(pb, 4);
n = ebml_read_num(matroska, pb, 8, &num, 1);
if (n < 0)
return n;
if (num > INT_MAX)
return AVERROR_INVALIDDATA;
data += n;
size -= n;
total = lace_size[0] = num;
offset = n;
for (n = 1; n < *laces - 1; n++) {
int64_t snum;
int r;
r = matroska_ebmlnum_sint(matroska, data, size, &snum);
r = matroska_ebmlnum_sint(matroska, pb, &snum);
if (r < 0)
return r;
if (lace_size[n - 1] + snum > (uint64_t)INT_MAX)
return AVERROR_INVALIDDATA;
data += r;
size -= r;
lace_size[n] = lace_size[n - 1] + snum;
total += lace_size[n];
offset += r;
}
data += offset;
size -= offset;
if (size <= total) {
return AVERROR_INVALIDDATA;
}
@ -3510,6 +3505,7 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf
{
uint64_t timecode = AV_NOPTS_VALUE;
MatroskaTrack *track;
AVIOContext pb;
int res = 0;
AVStream *st;
int16_t block_time;
@ -3518,9 +3514,10 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf
uint64_t num;
int trust_default_duration = 1;
if ((n = matroska_ebmlnum_uint(matroska, data, size, &num)) < 0) {
ffio_init_context(&pb, data, size, 0, NULL, NULL, NULL, NULL);
if ((n = ebml_read_num(matroska, &pb, 8, &num, 1)) < 0)
return n;
}
data += n;
size -= n;
@ -3572,7 +3569,7 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf
}
res = matroska_parse_laces(matroska, &data, size, (flags & 0x06) >> 1,
lace_size, &laces);
&pb, lace_size, &laces);
if (res < 0) {
av_log(matroska->ctx, AV_LOG_ERROR, "Error parsing frame sizes.\n");
return res;