I have a bunch of files I've "shrunk" with Handbrake using a custom preset I've built after reading what each of the advanced options of the x264 encoder, at least those listed under "Advanced" tab, does.
When I encoded these files, originally MP4 I don't have anymore, for some reason I don't remember I chose the M4V over MKV.
Then today I was uploading one of the files and got an error that M4V wasn't supported. Thinking I could do a "lossless" conversion with FFMPEG I ran:
ffmpeg -i "path/to/file.m4v" -c:v copy -c:a copy "path/to/file.mkv"
And all files were converted without problems, at least none FFMPEG could relate with:
ffmpeg.exe -v error -i "path/to/file.mkv"
But then again I'm no video expert, not even close to that.
Do I have any sort of loss doing that? I would like to know so I could delete the M4V that as I read it more proprietary in favour of the open-source and more acceptable MKV