| Message ID | 20190809162959.17924-12-velocityra@gmail.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Aug 09, 2019 at 07:29:57PM +0300, Nick Renieris wrote: > From: Nick Renieris <velocityra@gmail.com> > > Samples: > - Embedded JPEG images in the DNG images here: > https://www.photographyblog.com/previews/pentax_k1_photos > > Signed-off-by: Nick Renieris <velocityra@gmail.com> > --- > libavcodec/mjpegdec.c | 11 +++++++++-- > 1 file changed, 9 insertions(+), 2 deletions(-) > > diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c > index 0a920a7144..e7b273a363 100644 > --- a/libavcodec/mjpegdec.c > +++ b/libavcodec/mjpegdec.c > @@ -1807,8 +1807,15 @@ static int mjpeg_decode_app(MJpegDecodeContext *s) > int len, id, i; > > len = get_bits(&s->gb, 16); > - if (len < 6) > - return AVERROR_INVALIDDATA; > + if (len < 6) { > + if (s->bayer) { > + // Pentax K-1 (digital camera) JPEG images embedded in DNG images contain useless APP0 markers "useless" is a quite generic term, is it known what the contain why they are there ? thx [...]
The data the marker contains is only 2 bytes and they're 0x0000 in the samples above. I don't know what they're for. Στις Σάβ, 10 Αυγ 2019 στις 3:16 μ.μ., ο/η Michael Niedermayer <michael@niedermayer.cc> έγραψε: > > On Fri, Aug 09, 2019 at 07:29:57PM +0300, Nick Renieris wrote: > > From: Nick Renieris <velocityra@gmail.com> > > > > Samples: > > - Embedded JPEG images in the DNG images here: > > https://www.photographyblog.com/previews/pentax_k1_photos > > > > Signed-off-by: Nick Renieris <velocityra@gmail.com> > > --- > > libavcodec/mjpegdec.c | 11 +++++++++-- > > 1 file changed, 9 insertions(+), 2 deletions(-) > > > > diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c > > index 0a920a7144..e7b273a363 100644 > > --- a/libavcodec/mjpegdec.c > > +++ b/libavcodec/mjpegdec.c > > @@ -1807,8 +1807,15 @@ static int mjpeg_decode_app(MJpegDecodeContext *s) > > int len, id, i; > > > > len = get_bits(&s->gb, 16); > > - if (len < 6) > > - return AVERROR_INVALIDDATA; > > + if (len < 6) { > > + if (s->bayer) { > > + // Pentax K-1 (digital camera) JPEG images embedded in DNG images contain useless APP0 markers > > "useless" is a quite generic term, is it known what the contain why they > are there ? > > thx > > [...] > -- > Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB > > Asymptotically faster algorithms should always be preferred if you have > asymptotical amounts of data > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".
On Sat, Aug 10, 2019 at 04:52:10PM +0300, Nick Renieris wrote: > The data the marker contains is only 2 bytes and they're 0x0000 in the > samples above. I don't know what they're for. ok then please call them unknown and not useless in the comments thanks [...]
diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c index 0a920a7144..e7b273a363 100644 --- a/libavcodec/mjpegdec.c +++ b/libavcodec/mjpegdec.c @@ -1807,8 +1807,15 @@ static int mjpeg_decode_app(MJpegDecodeContext *s) int len, id, i; len = get_bits(&s->gb, 16); - if (len < 6) - return AVERROR_INVALIDDATA; + if (len < 6) { + if (s->bayer) { + // Pentax K-1 (digital camera) JPEG images embedded in DNG images contain useless APP0 markers + av_log(s->avctx, AV_LOG_WARNING, "skipping APPx (len=%"PRId32") for bayer-encoded image\n", len); + skip_bits(&s->gb, len); + return 0; + } else + return AVERROR_INVALIDDATA; + } if (8 * len > get_bits_left(&s->gb)) return AVERROR_INVALIDDATA;