Time Strech and SDL

SDL Development
1

I need acelerate the sound, change your speed. For this, I’m using pitch code, that i found in GitHub… Ok, it’s possible, but, when the sound acelerate, it becomes more acute, and it’s my problem… I need change the speed, but keeping your característics… Someone could give me some tip about this?
Thanks…

I’m using this code

2

It’s a real shame that SDL_mixer can’t do this! I use:

alSourcef(sourceID, AL_PITCH, fPitch);

on my native iOS apps, but for the SDL port of my WW2 game I ended up using Audacity to alter the pitch of the tank engine sound and created about 20 differently pitched .wav files which I switch between to get the same effect.

3

Thanks, Sean. It’s difficult to me. For some reasons I need use SDL… Maybe to be impossible. I Will search more…

4

what you’re trying to do is much more difficult than just squeezing the sound (and rising the pitch), by several orders of magnitude :wink:
It’s not surprising that a simple mixer like SDL_mixer does not offer this. Even audacity does not offer to do this in real-time.

Real-time is possible if you’re not too picky about quality of sound. For best quality, doing it beforehand (like @SeanOConnor suggest) is probably the way to go.

5

It’s not necessary real time… really not necessary…

6

Unless you have a strong scientific background, it’s almost impossible to program this yourself. You need instead to use an specific library, like rubber-band https://breakfastquay.com/rubberband/index.html

7

this one looks nice too: http://www.surina.net/soundtouch/README.html

8

Big Thanks, Sanette… really big thanks… this step is very important to me… for the finish my application… Do you know one free library that can do it?

9

both libraries: soundtouch and rubberband that I mentioned above can be used freely in opensource applications. For more specific needs you need to have a look a their license.

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