We are converting a sequence of DPX images into an MP4 video:
ffmpeg -start_number 101 -i dpx/example.%04d.dpx ./example.mp4 # minimal conversion
ffmpeg -y -start_number 101 -i dpx/example.%04d.dpx -b12100k -minrate 12100k -maxrate 12100k -bufsize 12100k -vf colormatrix=bt601:bt709 -pix_fmt yuv420 ./example.mp4 # conversion with colour correction
However, when opening this MP4 in Adobe Premiere Pro, it appears to be missing the first two frames (first two frames not accessible, third frame is accessible, total frame count is 2 off). The same file does not have missing frames when opened in other applications (Quicktime Player and VLC). Other video files do not have missing frames when opened in Premiere.
ffmpeg -start_number 101 -i dpx/example.%04d.dpx -filter_complex " fps=fps=25" ./example.mp4 # force fps with filter_complex
ffmpeg -start_number 101 -i dpx/example.%%04d.dpx -timecode 00:00:00:01 ./example.mp4 # force timecode (tried drop and non-drop format)
The following conversion (inherited wholesale) does work. Why? Which argument is fixing the problem?
ffmpeg -start_number 101 -i dpx/example.%%04d.dpx -crf 15.0 -y -vcodec libx264 -b:a 128k -b:v 4000 -intra -s 1280x720 -r 25 -ar 48000 -ab 192000 -coder 1 -flags +loop -me_method hex -subq 6 -me_range 16 -g 1 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 1 -threads 0 ./example.mp4 # mystery meat
(Obviously we're tweaking the working one to match our other requirements.)