[FFmpeg-cvslog] avformat/dhav: handle files missing data at start
Paul B Mahol
git at videolan.org
Sat Aug 24 22:35:08 EEST 2019
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sat Aug 24 18:03:46 2019 +0200| [45cefca1e79913f260743400274a0a7ff0fd3ecb] | committer: Kieran Kunhya
avformat/dhav: handle files missing data at start
Try to seek to end of file and if signature is found seek backwards until
last valid chunk is found.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=45cefca1e79913f260743400274a0a7ff0fd3ecb
---
libavformat/dhav.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/libavformat/dhav.c b/libavformat/dhav.c
index c80246c4e9..dac11df6c4 100644
--- a/libavformat/dhav.c
+++ b/libavformat/dhav.c
@@ -73,15 +73,30 @@ static int dhav_read_header(AVFormatContext *s)
ffio_ensure_seekback(s->pb, 5);
avio_read(s->pb, signature, sizeof(signature));
- if (!memcmp(signature, "DAHUA", 5))
+ if (!memcmp(signature, "DAHUA", 5)) {
avio_skip(s->pb, 0x400 - 5);
- else
- avio_seek(s->pb, -5, SEEK_CUR);
+ dhav->last_good_pos = avio_tell(s->pb);
+ } else {
+ if (!memcmp(signature, "DHAV", 4)) {
+ avio_seek(s->pb, -5, SEEK_CUR);
+ dhav->last_good_pos = avio_tell(s->pb);
+ } else if (s->pb->seekable) {
+ avio_seek(s->pb, avio_size(s->pb) - 8, SEEK_SET);
+ while (avio_rl32(s->pb) == MKTAG('d','h','a','v')) {
+ int seek_back;
+
+ seek_back = avio_rl32(s->pb) + 8;
+ dhav->last_good_pos = avio_tell(s->pb);
+ if (dhav->last_good_pos < seek_back)
+ break;
+ avio_seek(s->pb, -seek_back, SEEK_CUR);
+ }
+ }
+ }
s->ctx_flags |= AVFMTCTX_NOHEADER;
dhav->video_stream_index = -1;
dhav->audio_stream_index = -1;
- dhav->last_good_pos = avio_tell(s->pb);
return 0;
}
More information about the ffmpeg-cvslog
mailing list