[FFmpeg-user] Strange TC on 50 FPS clips

[Bouke / VideoToolShed]

Hi all,
Getting strange TC readings on 50 FPS clips.
FFmpeg reports      timecode        : 11:26:32:42
(And that corresponds with the frame counter in the start of the mdat atom.)

Premiere  reports  				22:53:05:34
 QT 7 and Avid (older version)	22:53:05:17

Now Avid and QT have the habit of stepping trough the video by two frames if fps > 30, so that might be a hint.
(If I take FFmpegs TC to frames, (2059642) multiply that by 2 I’m at the ‘correct’ frame number, converted back to TC it gives 22:53:05:34)

Now, is this a bug or am I missing something?

(Setting TC with FFmpeg has no issues as far as I’ve seen.)

If interested, the clip can be found here:
Download link 
https://we.tl/t-CP6GlfQIeG <https://we.tl/t-CP6GlfQIeG>
(Turn your volume down if you want to play it, it has loud LTC on the right channel.)

Bouke

bouke at Boukes-iMac ~ % /Applications/ffmpeg -i /Volumes/Samsung\ 2TB\ SSD\ -\ Data/Guilliamme\ 50fps/tokyoprod-e8655b/CAMC3472.MOV 
ffmpeg version git-2020-02-03-1c15111 Copyright (c) 2000-2020 the FFmpeg developers
  built with Apple clang version 11.0.0 (clang-1100.0.33.8)
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-appkit --enable-avfoundation --enable-coreimage --enable-audiotoolbox
  libavutil      56. 38.100 / 56. 38.100
  libavcodec     58. 67.100 / 58. 67.100
  libavformat    58. 37.100 / 58. 37.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 73.100 /  7. 73.100
  libswscale      5.  6.100 /  5.  6.100
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/Volumes/Samsung 2TB SSD - Data/clp/tokyoprod-e8655b/CAMC3472.MOV':
  Metadata:
    major_brand     : qt  
    minor_version   : 538247680
    compatible_brands: qt  CAEP
    com.apple.quicktime.make: Canon
    com.apple.quicktime.model: Canon EOS-1D X Mark II
    com.apple.quicktime.rating.user: 0.000000
    com.apple.quicktime.copyright: XXXX
    com.apple.quicktime.author: XXXX
    creation_time   : 2020-02-01T15:52:40.000000Z
  Duration: 00:00:09.68, start: 0.000000, bitrate: 843798 kb/s
    Stream #0:0(eng): Video: mjpeg (Baseline) (jpeg / 0x6765706A), yuvj422p(pc, bt470bg/bt709/bt709), 4096x2160, 841993 kb/s, 50 fps, 50 tbr, 50k tbn, 50k tbc (default)
    Metadata:
      creation_time   : 2020-02-01T15:52:40.000000Z
      encoder         : Photo - JPEG
      timecode        : 11:26:32:42
    Stream #0:1(eng): Audio: pcm_s16le (sowt / 0x74776F73), 48000 Hz, stereo, s16, 1536 kb/s (default)
    Metadata:
      creation_time   : 2020-02-01T15:52:40.000000Z
      timecode        : 11:26:32:42
    Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 1 kb/s (default)
    Metadata:
      creation_time   : 2020-02-01T15:52:40.000000Z
      timecode        : 11:26:32:42
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