The VideoLAN Forums

Hi!

VLC allows to reduce or speed up the video playback speed. I adore that feature, but for me it lacks a central feature: Once playback speed is changed, the sound is lost.

Is there a chance to get sound playback when in "non-realtime" playback mode? I don't even need the proper sound pitching feature for that, simply double speed sound reduction would do the trick for me. The Windows Media Player for example has pitched low/highspeed sound playback, so I know that it's generally possible.

Best regards,
Garvin

There's some support for this in the nightly builds, it's not quite done yet I believe.

I just grabbed the latest build.

The speed selection is kind of coarse. It appears that it only will double and then double again. Also the pitch is not shifted.

If I could get a 1.5x selection in addition to 2x, and if the pitch would shift, I would be very very happy. How can I encourage this?


Thanks!

OK. I can see how to change the rate. Just need to modify Control() in input.c to move differently on reception of each INPUT_CONTROL_SET_RATE_FASTER/SLOWER.

However, I am at a loss as to how to go about shifting the pitch... I don't even know where to start... Can it be done in one place just before handing the waveform out to the audio hardware? I'm not really an audio wizard, but I'm pretty handy with C code. Does anyone out there have any clues for me?


Thanks!

I have added 1.5x and 3x speed position.
I plan to add audio pitch modification but it is not quite done yet (btw soundtouch is not suitable for our needs as it buffers too much audio when going slower and the current vlc audio output does not like that at all).

I think 1.25x would be also useful.
Anyway, on the next version interface for windows and linux, you have a slider to choose the speed control with a lot of precision ( from 0.3x to 3.0x)

That's excellent fenrir. If the pitch handling is good when going faster, then your solution is good enough for me. I only speed things up. When will I be able to see your code in a build?

I agree that 1.25x would be useful.

j-b, I have some questions:

• Which version are you speaking of, 0.9?
  Will the next version also adjust sound pitch?
  What are the barriers to adding this functionality to the Mac interface? (I'd rather run it on my Mac.)

This is all good news. Thanks!

Hi!

That's great news, I'm excited about the future builds. Many thanks for your replies, I'm happy to see I'm not the only one who'd enjoy this.

Best regards,
Garvin

@spambucket:
yes, 0.9.0,
about sound pitch, no idea, ask fenrir
mac, no idea yet, I'll discuss it wiht the mac os guys

Fenrir is there anything I can do to help you?

j-b, any word from the Mac guys? I haven't hacked Mac code since the 80's, but I'd be willing to put some time into this if it would help.


Thanks.

Thanks for getting the sound in with the playback (running the nightly build from 5-13-2008). I watch a lot of public meetings and faster than 1x is better.
How's the pitch shift coming along?
Thanks again.

The guy who worked on the pitched, we have no news since some time :'(