Webm/MKV file crashes on Machete edit-save and makes mess in Avidemux

[gumbygum]

I have a Webm file that plays fine in VLC and other players, but when I try to edit it with Machete, the program almost always crashes when I try to save the edit. It gets to a certain point in the save and then won’t go further, so I guess there are glitches in the file that prevent it from saving.

The first time I opened it in Machete, the program changed it to MKV and did save it, but I hadn’t done any edits.

When I try to edit the file in Avidemux, as either Webm or MKV, using Copy Video and Audio, Avidemux saves it but the result is terrible, the image is just a mass of pulsing pixelation throughout the video. I don’t know why.

This is a VP8 file in the Webm or MKV container.

I have also tried meteorite, orca, mkvtoolnix and some other programs I found that claim to fix mkv videos. They didn’t solve the problem.

Would converting this file to some other format, or putting it in an MP4 container, solve the problem and allow me to edit it? But I can’t find any info that says that MP4 container is compatible with VP8. I’d like to convert it without any quality loss or with imperceptible quality loss.

Any suggestions would be very appreciated.

[sneaker]

Did you try mkvtoolnix' cutting function?

[alex]

I've had similar experiences using machete thus I used a program called Solveig video splitter imported the video & removed any surplus audio streams inclusive of subtitles just retaining the original audio/video streams & subsequently this allowed me to save the file & edit with any other software conversion etc.

[gumbygum]

Did you try mkvtoolnix' cutting function?

Thanks for the suggestion, I was not aware it had any editing abilities. I don't just want to split the video into a few smaller parts. I want to edit it in hundreds of places by marking start and end keyframes, deleting them, and save without re-encoding. Can mkvtoolnix do this?

I installed mkvtoolnix just so I could try using Orca MKV Fix, which required it.

[gumbygum]

I've had similar experiences using machete thus I used a program called Solveig video splitter imported the video & removed any surplus audio streams inclusive of subtitles just retaining the original audio/video streams & subsequently this allowed me to save the file & edit with any other software conversion etc.

Thanks for the suggestion. I see that Solveig is rather expensive, though I'm sure it's a good program. Anyway, I don't think there are any subtitles in this video. There is just one VP8 video stream and one Vorbis audio stream with 2 channels.

i read somewhere that Virtualdub could edit MKVs with a plugin. Should I try that next?

I think I also read that avi container can contain VP8 and Vorbis. True? Maybe I could change the container to AVI...

[sneaker]

Thanks for the suggestion, I was not aware it had any editing abilities. I don't just want to split the video into a few smaller parts. I want to edit it in hundreds of places by marking start and end keyframes, deleting them, and save without re-encoding. Can mkvtoolnix do this?

It can edit without re-encoding but doesn't have a graphical preview to make this feasible.

[gumbygum]

I just installed Virtualdub Portable and the FFMPEG Input plugin. It was able to open the file, I made a few edits and when I tried to save it as AVI I got the error: "The source video stream uses a compression algorithm which is not compatible with AVI files. Direct stream copy cannot be used with this video stream."

Googling it I see this error is rather common.

According to https://en.wikipedia.org/wiki/Comparison_of_video_container_formats , AVI and MP4 both support VP8 video. As for Vorbis audio, it says that it is "not officially" supported by MP4 and AVI. So I guess it is unofficially supported?

I would love to be able to dump these streams into a different container and see it I can edit them in Machete. Is the Vorbis the main problem that would prevent me from changing containers? Can I convert the audio stream from Vorbis to something else that is more compatible? I don't mind if the audio loses quality a bit, I just want to keep the video lossless.