[bug] Pitch of audio maintained when adjusting speed

[chenlung]

1. Open video with PAL speedup.
2. Choose codec.
3. In Advanced features, Conform by speed 23.976.
4. Start function.

Expected result: Both video and audio are slowed to 23.976.
Actual result: Video is slowed to 23.976; audio is PAL-pitch and 23.976 tempo.

Using Shutter Encoder 14.6 - Mac 10.11.6.

[chenlung]

For some, this might be a feature; to others, it's a bug.

I don't know if there should be an additional option?

[paulpacifico]

This is not a bug, i decided to maintain audio pitch with conform by speed option.

[chenlung]

Okay.

Can we have an option to slow both video and audio down? I can personally only do this using Cinema Tools (Apple) on certain file types.

[paulpacifico]

Yes why not, i just need to think how to implement this, like a checkbox with "Maintain audio pitch"

[chenlung]

I think the default could be slowing both down, but you indeed have a checkbox option with 'Maintain audio pitch' (or 'Maintain pitch').

[paulpacifico]

For sure, it's a great idea.

[chenlung]

It might be ideal having an option to not resample the Hz if slowing or speeding video (like Cinema Tools).

48000 25fps > 46080 24fps / 46034 23.976

[paulpacifico]

After some research it seems the 'asetrate' filter of FFmpeg can do that easily!

[chenlung]

It doesn't just apply to video, it would seem.

I tried changing a WAV from 25 to 23.976; whilst the tempo was adjusted, the pitch was maintained.