Cool_Tools/vgmstream
1
0
Fork 0
mirror of https://github.com/vgmstream/vgmstream.git synced 2025-01-18 07:44:43 +01:00
Code Issues Packages Projects Releases Wiki Activity

Improve init_seek: don't add existing index, find packet size (for M4A)

Browse Source
This commit is contained in:
bnnm 2016-12-03 01:56:27 +01:00
parent 8cdce2c196
commit 80c8791288
1 changed files with 36 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
src/meta/ffmpeg.c
View File

@ -373,43 +373,58 @@ fail:
*
* Fortunately seek_frame_generic can use an index to find the correct position. This function reads the
* first frame/packet and sets up index to timestamp 0. This ensures faulty demuxers will seek to 0 correctly.
* Some formats may not seek to 0 even with this though.
* Some formats may not seek to 0 even with this, though.
*/
static int init_seek(ffmpeg_codec_data * data) {
int ret, found = 0;
int ret, ts_index, found_first = 0;
int64_t ts = 0;
int64_t pos; /* offset */
int size; /* coded size */
int distance = 0; /* always? */
AVStream * stream;
AVPacket * pkt;
/* read_seek wouldn't use the index, but direct access to FFmpeg's internals is no good */
/* if (data->formatCtx->iformat->read_seek || data->formatCtx->iformat->read_seek2)
return; */
stream = data->formatCtx->streams[data->streamIndex];
pkt = data->lastReadPacket;
/* find the first packet */
while (!found) {
/* read_seek shouldn't need this index, but direct access to FFmpeg's internals is no good */
/* if (data->formatCtx->iformat->read_seek || data->formatCtx->iformat->read_seek2)
return 0; */
/* some formats already have a proper index (e.g. M4A) */
ts_index = av_index_search_timestamp(stream, ts, AVSEEK_FLAG_ANY);
if (ts_index>=0)
goto test_seek;
/* find the first + second packets to get pos/size */
while (1) {
av_packet_unref(pkt);
ret = av_read_frame(data->formatCtx, pkt);
if (ret < 0)
break;
goto fail;
if (pkt->stream_index != data->streamIndex)
continue; /* ignore non-selected streams */
found = 1;
if (!found_first) { /* first found */
found_first = 1;
pos = pkt->pos;
continue;
} else { /* second found */
size = pkt->pos - pos; /* coded, pkt->size is decoded size */
break;
}
}
if (!found)
return -1;
/* add index 0 */
stream = data->formatCtx->streams[data->streamIndex];
ret = av_add_index_entry(stream, pkt->pos, ts, pkt->size, 0, AVINDEX_KEYFRAME);
ret = av_add_index_entry(stream, pos, ts, size, distance, AVINDEX_KEYFRAME);
if ( ret < 0 )
return ret;
/* move back to beginning, since we just consumed packets */
test_seek:
/* seek to 0 test / move back to beginning, since we just consumed packets */
ret = avformat_seek_file(data->formatCtx, data->streamIndex, ts, ts, ts, AVSEEK_FLAG_ANY);
if ( ret < 0 )
return ret; /* we can't even reset_vgmstream the file */
@ -417,6 +432,10 @@ static int init_seek(ffmpeg_codec_data * data) {
avcodec_flush_buffers(data->codecCtx);
return 0;
fail:
return -1;
}