Changing audio to NONE will switch video extension from .mp4 back to .m4v

nepenthe · 08-20-2022, 03:25 PM

Recently a handy change was made to Reaper on Mac which changed the file extension of videos rendered using the Format: MPEG-4 Video option from .m4v to .mp4.

However, if this format is selected and the Audio type is switched to NONE, the filename extension will revert back to .m4v unexpectedly. Expected behavior is for the file extension to remain as .mp4 as this is not contingent upon presence of audio.

nepenthe · 09-08-2022, 08:56 AM

edit: nvm

Dstruct · 10-11-2022, 12:21 PM

Not fully fixed in REAPER 6.68/x64.

When you enter filename without extension and set "Audio" to "NONE" the extension becomes "m4a" (Windows Media Encoder).

teeramusic · 10-14-2022, 01:54 PM

Reaper version 6.68/x64

On a PC, using FFMPEG encoder, now when video codec is set to H.264 and audio is set to 16-bit wav, the output file type is .mp4 but actually it should be .mov

Dstruct · 10-14-2022, 01:59 PM

Why should it be *.mov?

teeramusic · 10-15-2022, 10:52 AM

Technically FFmpeg doesn't even support creating .mp4 with LPCM (even though some players will play it back anyway), so I'm not sure how it came to be in the first place. Reaper used to default to .mov up until I'm not sure which version (I skipped a few versions updating to 6.68)

https://avidemux.org/smif/index.php?topic=19861.0

I did a little bit of research and found that while it used to be true that .mp4 didn't support LPCM, the spec has been revised and it does now. On the other hand, .mov has always allowed it and is widely supported.