incorrect ULs when creating MXF with DNxHD

[Markus P Schumann]

Summary of the bug:

Use any audio/video file and transcode to MXF with DNxHD video.
Ffmpeg uses the incorrect ULs for the essence container and and essence element.

correct essence container = MXF-GC Frame-wrapped VC-3 Pictures:
06 0E 2B 34 04 01 01 0A 0D 01 03 01 02 11 01 00

incorrect by ffmpeg: essence container = wrong version number (byte 8):
06 0E 2B 34 04 01 01 01 0D 01 03 01 02 11 01 00

correct essence element = MXF_GC_VC3_FRAME_PICTURE_ELEMENT:
06 0E 2B 34 01 02 01 0A 0D 01 03 01 15 01 0C 00

incorrect ffmepg essence element = MXF_GC_MPEG_FRAME_PICTURE_ELEMENT:
06 0E 2B 34 01 02 01 01 0D 01 03 01 15 01 05 00

see SMPTE ST 2019-4:2016; 6.1 Essence Element Key; Table 1 – Key Value for the VC-3 Picture Element (page 6)

How to reproduce:

ffmpeg.exe -i any_a_v_file.mp4 -vcodec dnxhd -vf "scale=1280:720" -b:v 75M -ar 48000 ffmpeg_dnxhd_output.mxf


Y:\tools\ffmpeg-3.3>ffmpeg_g.exe -version
ffmpeg version N-85950-g8ef2c79 Copyright (c) 2000-2017 the FFmpeg developers
built with Microsoft (R) C/C++ Optimizing Compiler Version 18.00.40629 for x86
configuration: --optflags=-Od --disable-asm --disable-yasm --arch=i386 --disable-avdevice --disable-ffserver --disable-doc --enable-static --disable-bzlib --dis
able-libopenjpeg --disable-iconv --disable-zlib --prefix=/c/ffmpeg --toolchain=msvc
libavutil      55. 61.100 / 55. 61.100
libavcodec     57. 94.101 / 57. 94.101
libavformat    57. 72.101 / 57. 72.101
libavfilter     6. 88.100 /  6. 88.100
libswscale      4.  7.101 /  4.  7.101
libswresample   2.  8.100 /  2.  8.100

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Carl Eugen Hoyos]

Replying to go4shoe:

Use any audio/video file and transcode to MXF with DNxHD video.
Ffmpeg uses the incorrect ULs for the essence container and and essence element.

How can I reproduce this?
Which software fails for the produced files but succeeds if the values are changed?

correct essence container = MXF-GC Frame-wrapped VC-3 Pictures:
06 0E 2B 34 04 01 01 0A 0D 01 03 01 02 11 01 00

incorrect by ffmpeg: essence container = wrong version number (byte 8):
06 0E 2B 34 04 01 01 01 0D 01 03 01 02 11 01 00

Has this value ever changed?

Since I don't have access to the mentioned SMTP document, I suggest you send a patch made with git format-patch to the FFmpeg development mailing list.

[Elon Musk]

Looks like OP is not interested in fixing this issue.

[Balling]

Fixed in dd7c0bc4f981f7113d7bef267cc1eca8d9fb10f1.