3D block_lr or frame-packing to side-by-side format
I'm trying to convert a 3D mkv file from "stereo_mode: block_lr" or
"frame-packing 3d" to a mkv file that uses side-by-side (or top-bottom)
stereo3d instead - to be viewed using an Epson projector with active 3D
glasses (a setup that works well with side-by-side or top-bottom 3D files).
The input file has these characteristics:
Stream #0:0(eng): Video: h264 (High), yuv420p(tv, bt709, progressive),
1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc
stereo_mode : block_lr
Some of those options created files that show some 3D depths and seem
"OK" when the scenes are mostly static or have slow movements, but for
fast-moving scenes the results were not good and looked very "broken".
During the conversion, I see several error or warning messages repeated
[h264 @ 0x55a12faf1c40] SEI type 0 overread by 7 bits
[h264 @ 0x55a12faf1c40] SEI type 6 size 536 truncated at 40
[h264 @ 0x55a12fa4bc80] sps_id 1 out of range
[h264 @ 0x55a12fa4bc80] SEI type 37 size 1032 truncated at 1024
I've tried the ffmpeg available in Ubuntu 20.04 LTS (via apt), and I've
also tried purging the apt package and compiling ffmpeg from the
source-code (snapshot) - same results (and same error & warning messages).
Does anyone know how to convert 3D files from Blu-ray discs
(alternate-frame or block_lr or frame-packing 3d) into side-by-side or