ToolNix / Avidemux merging mp4, 2nd part grey video correct audio

[jfjfjf]

Original sources:
mp4 1-2
- Format: MPEG-4 at 676 kb/s
- Length: 273 MiB for 56 min 28s 840 ms
- Video #0 : AVC at 542 kb/s
- Aspect : 640 x 480 (1.333) at 25.000 fps
- Audio #0: AAC at 128 kb/s
- Infos: 2 Kanäle, 44,1 kHz
mp4 2-2
- Format: MPEG-4 at 833 kb/s
- Length: 334 MiB for 56 min 2s 600 ms
- Video #0: AVC at 700 kb/s
- Aspect: 640 x 480 (1.333) at 25.000 fps
- Audio #0: AAC at 128 kb/s
- Infos: 2 Kanäle, 44,1 kHz

Resulting video (both MKVToolNix and Avidemux) >>> MPC-HC displays 1st part all correct but 2nd part totally grey video with correct audio
- Format: Matroska at 750 kb/s
- Length: 603 MiB for 1 h 52 min 31s 440 ms
- Video #0: AVC at 619 kb/s
- Aspect: 640 x 480 (1.333) at 25.000 fps
- Audio #0: AAC at 128 kb/s
- Infos: 2 Kanäle, 44,1 kHz
- Language: it <<< it results the same even if the language is not determined

[Bernix]

Time to try different player.
But you can load merged video to Avidemux and see, if second part is really grey.

Edit: if totally grey not in greyscale, then something is really wrong. It happens sometimes, when second part doesn't start with Keyframe, but it recover itself when next keyframe is achieved. But if something is wrong, then check error in mkvtoolnix. I think it always get error when muxing two files, at least warning.

Bernix

[Bernix]

Actually seems also wrong 1st is 273 + 2nd 334 is equal to 607 your result is 603 MB I would expet less difference than 4 MB between mp4 vs mkv, but of course it is almost two hours, so probably o.k.

[sneaker]

Try ffmpeg concat demuxer instead of mkvtoolnix.

[jfjfjf]

The error occurs in the merge both using MKVToolNix and Avidemux
VLC player displays the video with the same error.

[jfjfjf]

[sneaker]! Unfortunately, I lack the knowledge to use this ffmpeg concat demuxer.
Anyway, I thank you very much and everyone who has dealt with my problem.