Faster Wrapping of .mkv H.264 or MPEG-4 Part 10 to .mp4

[carlarogers]

One hour .mkv file. I need to convert it to .mp4. It is hammering cpu and taking forever. I looks to me like the encoding is the same in .mkv is the same as it will be in .mp4, this should be a fast process. I am blind to something here. Can you explain why this conversion is so much work for my computer?

ffmpeg -i input.mkv -vcodec h264 -acodec aac output.mp4









The conversion was successful but seemed like too much work for the computer.

[poisondeathray]

You're re-encoding the video and audio

It should be -vcodec copy , or -c:v copy for video

[davexnet]

It's re-encoding, that's why it's taking a while.
If you really want to remux use the command as specifed here:
https://forum.videohelp.com/threads/377229-Remux-mov-into-mkv-(with-ffmpeg-or-somethin...e)#post2434974

[carlarogers]

It's re-encoding, that's why it's taking a while.
If you really want to remux use the command as specifed here:
https://forum.videohelp.com/threads/377229-Remux-mov-into-mkv-(with-ffmpeg-or-somethin...e)#post2434974

I assume remuxing is what you do when you are trying to make changes or add effects. I just wanted a copy.

[davexnet]

To re-encode just the audio something like
ffmpeg -i input.mp4 -c:v copy -acodec aac output.mp4

[jagabo]

It's re-encoding, that's why it's taking a while.
If you really want to remux use the command as specifed here:
https://forum.videohelp.com/threads/377229-Remux-mov-into-mkv-(with-ffmpeg-or-somethin...e)#post2434974

I assume remuxing is what you do when you are trying to make changes or add effects. I just wanted a copy.

You have it backwards. Re-multiplexing (remuxing) is simply copying the compressed data from input to output. Re-encoding is the process of decompressing the source, optionally making changes to it, then compressing it again for the output.