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Failure to Append .mp4 files

Started by SandSmudge, January 02, 2022, 03:47:20 PM

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eumagga0x2a

Quote from: SandSmudge on January 02, 2022, 09:27:57 PMI've gotten the vob files loaded and appended in the proper order, and I can play the entire film in Avidemux with just a slight black screen delay between vob strings.

It would be helpful to see the admlog.txt from %localappdata%\avidemux\ from the above operation to assess the situation.

Quote from: SandSmudge on January 02, 2022, 09:27:57 PMI have the "Output Format" set to Mp4 Muxer.

Yes, this is the right muxer if you would like to re-encode the video from MPEG-2 e.g. to H.264 using the x264 encoder plugin to be able to watch it on mobile devices (H.264 is decoded in hardware while MPEG-2 while much less complex is decoded in software, greatly increasing battery drain). As you probably know, H.264 is a lossy codec, so the quality will always* degrade when you re-encode.

If you would like just to merge both streams in one single stream to be watched either on a computer or on a TV set capable of reading from mass storage devices, you might leave both video and audio at copy and export using MpegPS muxer.

Quote from: SandSmudge on January 02, 2022, 09:27:57 PMI tried "Saving" the file, but got an error that "video was too short". The error occurs at the end of the first batch of vob files.

admlog.txt might provide sligntly more insights, but generally this error when saving to MP4 happens when decode timestamps are missing or collide (they absolutely must increase from one frame to the next one). The MpegPS and MpegTS muxers which like the MP4 one are just shells around the libavformat library also need decode timestamps to be sane, so depending on the particular problem it might not work in this case either.

Re-encoding the stream instead of copying can help though.

*) Setting quantizer to zero should produce lossless output at cost of a huge file size and slow operation.

SandSmudge

Thanks very much! I was playing with the Video/Audio Outputs (Mpeg4/AAC worked), and played with A & B markers and cuts to remove "black space" between vob batches.

WORKED!!!!! Now have 1 contiguous mp4 file that streams seamlessly.

You are awesome, and this tool is great! will play with other vids as well ! Great help, and great many thanks!

Regards,

eumagga0x2a

Glad it worked :-)

Quote from: SandSmudge on January 02, 2022, 11:24:40 PMMpeg4/AAC worked

"Mpeg4" includes a big family of different codecs, most of them obsolete except of the widely used H.264 output by the "Mpeg4 AVC (x264)" software encoder and depending on your hardware eventually also by the "Nvidia H264" hardware encoder in Avidemux.

Forget about the remaining Mpeg4 encoders, they are legacy/obsolete nowadays.