Stereo >sf not giving correct output file

[mathiasbredholt]

Minimal example

Working - 1 channel

sapf> 800 0 sinosc 1 T "sine" >sfo
wrote file '[...]/sine.wav'  1 channels  1 secs

Gives correct sound file of 1 secs length.

Not working - 2 channels

sapf> 800 2X 0 sinosc 1 T "sine" >sfo
wrote file '[...]/sine.wav'  2 channels  1 secs

Gives sound file of 0.5 secs length. Sounds like every second sample is skipped.

Running v0.1.21 on macOS 15.2.

[lfnoise]

Problem is here:

@@ -386,7 +386,7 @@ void sfwrite(Thread& th, V& v, Arg filename, bool openIt)
                        minn = std::min(n, minn);
                }
 
-               abl.mBuffers[0].mDataByteSize = minn * sizeof(float);
+               abl.mBuffers[0].mDataByteSize = numChannels * minn * sizeof(float);
                OSStatus err = ExtAudioFileWrite(xaf, minn, &abl);
                if (err) {
                        post("ExtAudioFileWrite failed %d\n", (int)err);

This incorrect code worked for years. My former co-workers at Apple must have fixed a bug and now ExtAudioFile obeys the buffer byte size instead of the number of frames requested in the ExtAudioFileWrite call. I'd think ExtAudioFileWrite should return an error rather than silently write a buffer with a mismatched size.

[mathiasbredholt]

Yeah that is strange. Works on my side though, after the change.