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avformat/matroskadec: use refcounted buffers in EbmlBin

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Data in EbmlBin objects is never changed after being read from the
input file (save for two specific cases with encoded CodePrivate), so
using AVBufferRef we can prevent unnecessary copy of data by instead
creating new references to said constant data.

Signed-off-by: James Almer <jamrial@gmail.com>
This commit is contained in:
James Almer 2018-04-04 14:12:54 -03:00
parent 647fd4b829
commit a61886650b
1 changed files with 31 additions and 13 deletions
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44
libavformat/matroskadec.c
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@ -104,6 +104,7 @@ typedef struct EbmlList {
typedef struct EbmlBin {
int size;
AVBufferRef *buf;
uint8_t *data;
int64_t pos;
} EbmlBin;
@ -962,14 +963,19 @@ static int ebml_read_ascii(AVIOContext *pb, int size, char **str)
*/
static int ebml_read_binary(AVIOContext *pb, int length, EbmlBin *bin)
{
av_fast_padded_malloc(&bin->data, &bin->size, length);
if (!bin->data)
return AVERROR(ENOMEM);
int ret;
ret = av_buffer_realloc(&bin->buf, length + AV_INPUT_BUFFER_PADDING_SIZE);
if (ret < 0)
return ret;
memset(bin->buf->data + length, 0, AV_INPUT_BUFFER_PADDING_SIZE);
bin->data = bin->buf->data;
bin->size = length;
bin->pos = avio_tell(pb);
if (avio_read(pb, bin->data, length) != length) {
av_freep(&bin->data);
av_buffer_unref(&bin->buf);
bin->data = NULL;
bin->size = 0;
return AVERROR(EIO);
}
@ -1252,7 +1258,7 @@ static void ebml_free(EbmlSyntax *syntax, void *data)
av_freep(data_off);
break;
case EBML_BIN:
av_freep(&((EbmlBin *) data_off)->data);
av_buffer_unref(&((EbmlBin *) data_off)->buf);
break;
case EBML_LEVEL1:
case EBML_NEST:
@ -2036,12 +2042,13 @@ static int get_qt_codec(MatroskaTrack *track, uint32_t *fourcc, enum AVCodecID *
* by expanding/shifting the data by 4 bytes and storing the data
* size at the start. */
if (ff_codec_get_id(codec_tags, AV_RL32(track->codec_priv.data))) {
uint8_t *p = av_realloc(track->codec_priv.data,
track->codec_priv.size + 4);
if (!p)
return AVERROR(ENOMEM);
memmove(p + 4, p, track->codec_priv.size);
track->codec_priv.data = p;
int ret = av_buffer_realloc(&track->codec_priv.buf,
track->codec_priv.size + 4 + AV_INPUT_BUFFER_PADDING_SIZE);
if (ret < 0)
return ret;
track->codec_priv.data = track->codec_priv.buf->data;
memmove(track->codec_priv.data + 4, track->codec_priv.data, track->codec_priv.size);
track->codec_priv.size += 4;
AV_WB32(track->codec_priv.data, track->codec_priv.size);
}
@ -2162,8 +2169,19 @@ static int matroska_parse_tracks(AVFormatContext *s)
"Failed to decode codec private data\n");
}
if (codec_priv != track->codec_priv.data)
av_free(codec_priv);
if (codec_priv != track->codec_priv.data) {
av_buffer_unref(&track->codec_priv.buf);
if (track->codec_priv.data) {
track->codec_priv.buf = av_buffer_create(track->codec_priv.data,
track->codec_priv.size + AV_INPUT_BUFFER_PADDING_SIZE,
NULL, NULL, 0);
if (!track->codec_priv.buf) {
av_freep(&track->codec_priv.data);
track->codec_priv.size = 0;
return AVERROR(ENOMEM);
}
}
}
}
}