Am Mi., 1. Apr. 2020 um 18:01 Uhr schrieb Matthieu Bouron <matthieu.bou...@gmail.com>: > > Fixes probing of JPEG files containing MPF metadata appended at the end > of the file. > > The MPF metadata chunk can contains multiple JPEG images (thumbnails) > which makes the jpeg_probe fails (return 0) because it finds a SOI > marker after EOI. > --- > > This patch fixes probing of JPEG files containing MPF metadata [1] appended > at the end of the file. > > Such files can be produced by GoPro camera (which produces JPEG files > with MPF metadata). > > You can find a sample here: > https://0x5c.me/gopro_jpg_mpf_probe_fail > > To reproduce the issue using ffmpeg master: > wget https://0x5c.me/gopro_jpg_mpf_probe_fail > ./ffmpeg -formatprobesize 5000000 -i gopro_jpg_mpf_probe_fail > > I removed intentionally the jpeg extension from the filename so the > image2 demuxer is not used. > > Current ffmpeg master won't still be able to decode this file because of a > "regression" introduced by ec3d8a0e6945fe015d16cd98a1e7dbb4be815c15 on > the mjpeg_parser. > The jpeg_pipe demuxer outputs partial chunks of the jpeg file that the > mjpeg decoder can't handle (it needs the whole data). Before > ec3d8a0e6945fe015d16cd98a1e7dbb4be815c15, the mjpeg_parser was > outputting a complete frame. > > If the parser is correct as is, another way to fix this issue whould be > to add AVSTREAM_PARSE_HEADERS to the need_parsing flags from the > jpeg_pipe demuxer, ie: > > --- a/libavformat/img2dec.c > +++ b/libavformat/img2dec.c > @@ -209,7 +209,7 @@ int ff_img_read_header(AVFormatContext *s1) > s->is_pipe = 0; > else { > s->is_pipe = 1; > - st->need_parsing = AVSTREAM_PARSE_FULL; > + st->need_parsing = AVSTREAM_PARSE_FULL | AVSTREAM_PARSE_HEADERS; > > Settings AVSTREAM_PARSE_HEADERS makes avformat requests complete frames > from the parser in libavformat/utils.c > > What do you think ?
Why is your sample not detected by the mjpeg demuxer? I suspect your patch breaks the mjpeg demuxer. > [1] https://exiftool.org/TagNames/MPF.html > > --- > libavformat/img2dec.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c > index 93cd51c1932..decd8023e02 100644 > --- a/libavformat/img2dec.c > +++ b/libavformat/img2dec.c > @@ -773,9 +773,7 @@ static int jpeg_probe(const AVProbeData *p) > case EOI: > if (state != SOS) > return 0; > - state = EOI; > - break; > - case DHT: > + return AVPROBE_SCORE_EXTENSION + 1; I don't think this is correct. > case DQT: > case APP0: > case APP1: > @@ -803,8 +801,6 @@ static int jpeg_probe(const AVProbeData *p) > } > } > > - if (state == EOI) > - return AVPROBE_SCORE_EXTENSION + 1; > if (state == SOS) > return AVPROBE_SCORE_EXTENSION / 2; > return AVPROBE_SCORE_EXTENSION / 8; Carl Eugen _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
