[FFmpeg-cvslog] lavc/mjpegdec: Skip unknown APPx marker on bayer images

[Nick Renieris]

ffmpeg | branch: master | Nick Renieris <velocityra at gmail.com> | Thu Aug 29 16:10:51 2019 +0300| [fcf0ebc4a95e837a8f104a9897d640912b034e39] | committer: Paul B Mahol

lavc/mjpegdec: Skip unknown APPx marker on bayer images

Samples:
- Embedded JPEG images in the DNG images here:
  https://www.photographyblog.com/previews/pentax_k1_photos

Signed-off-by: Nick Renieris <velocityra at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fcf0ebc4a95e837a8f104a9897d640912b034e39
---

 libavcodec/mjpegdec.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 0a920a7144..1f2fabe2df 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 unknown 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;