Platform is Linux, CLI tools is needed.
There are two files: one for left eye another for right eye. I search a way to compose it into single 3D MKV (or any other container) with alternate frame format.
I tried FFmpeg filter
framepack and MKV metadata
ffmpeg -i input_l.mkv -i input_r.mkv -filter_complex framepack=frameseq -metadata stereo_mode=block_lr -y out.mkv
But result is short, not all frames repacked/remuxed: input files contains 500 frames, out.mkv contains only 32 one and has doubled FPS.
I expect, that output file will contain 1000 frames.
Any tools are welcomed.
Another related question: is it possible to do such muxing without frame re-encoding? Input files already well-coded and I want just repack them into 3D video format.
PS FFmpeg version 4.2.1