[FFmpeg-devel] [PATCH V2] avformat/mxf: fixed frame wrapping detection for J2K essence container

pal at sandflow.com pal at sandflow.com
Sun Jul 18 21:07:43 EEST 2021


From: Pierre-Anthony Lemieux <pal at sandflow.com>

Signed-off-by: Pierre-Anthony Lemieux <pal at sandflow.com>
---

Notes:
    For JPEG 2000 essence, the MXF input format module currently uses the value of byte 14 of the essence container UL to determine
    whether the J2K essence is clip- (byte 14 is 0x02) or frame-wrapped (byte 14 is 0x01). This approach does not work when
    byte 14 is larger than 0x02, e.g. when the essence container is MXFGCP1FrameWrappedPicture, in which case the
    essence is always frame-wrapped.

 libavformat/mxf.h    | 3 ++-
 libavformat/mxfdec.c | 6 +++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/libavformat/mxf.h b/libavformat/mxf.h
index b1b1fedac7..b9fe7fe7ef 100644
--- a/libavformat/mxf.h
+++ b/libavformat/mxf.h
@@ -75,7 +75,8 @@ typedef enum {
     NormalWrap = 0,
     D10D11Wrap,
     RawAWrap,
-    RawVWrap
+    RawVWrap,
+    J2KWrap
 } MXFWrappingIndicatorType;
 
 typedef struct MXFLocalTagPair {
diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index f813408b3d..88ff8001ff 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -1411,7 +1411,7 @@ static void *mxf_resolve_strong_ref(MXFContext *mxf, UID *strong_ref, enum MXFMe
 
 static const MXFCodecUL mxf_picture_essence_container_uls[] = {
     // video essence container uls
-    { { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x07,0x0d,0x01,0x03,0x01,0x02,0x0c,0x01,0x00 }, 14,   AV_CODEC_ID_JPEG2000, NULL, 14 },
+    { { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x07,0x0d,0x01,0x03,0x01,0x02,0x0c,0x01,0x00 }, 14,   AV_CODEC_ID_JPEG2000, NULL, 14, J2KWrap },
     { { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x02,0x0d,0x01,0x03,0x01,0x02,0x10,0x60,0x01 }, 14,       AV_CODEC_ID_H264, NULL, 15 }, /* H.264 */
     { { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x02,0x0d,0x01,0x03,0x01,0x02,0x11,0x01,0x00 }, 14,      AV_CODEC_ID_DNXHD, NULL, 14 }, /* VC-3 */
     { { 0x06,0x0e,0x2b,0x34,0x04,0x01,0x01,0x02,0x0d,0x01,0x03,0x01,0x02,0x12,0x01,0x00 }, 14,        AV_CODEC_ID_VC1, NULL, 14 }, /* VC-1 */
@@ -1495,6 +1495,10 @@ static MXFWrappingScheme mxf_get_wrapping_kind(UID *essence_container_ul)
             if (val == 0x02)
                 val = 0x01;
             break;
+        case J2KWrap:
+            if (val != 0x02)
+                val = 0x01;
+            break;
     }
     if (val == 0x01)
         return FrameWrapped;
-- 
2.17.1



More information about the ffmpeg-devel mailing list