Empty .wav file from writeFromAudioSource()

[dhng22]

I’m trying to write a file from my AudioSource class implementation, which has an inner AudioTransportSource as its source of data. Here’s my code:

The output file has 0 second of length, but still has a size about 70Mb.
Values of the above variables:
samplePerBlockExpected: 1920
processSpec->sampleRate: 48000
readerSource->getAudioFormatReader()->lengthInSamples: 9482112
readerSource->getAudioFormatReader()->bitsPerSample: 32

Thanks for any help.

[xenakios]

The writer returned by format.createWriter is a raw pointer and needs to be deleted after writing the data, which also finalizes the file as a proper wav file. Didn’t you get a Juce memory leak warning about that?

[dhng22]

And i get this error:

[xenakios]

There must be some deletion order problem happening, I’d need to check what’s the correct way to do it in your code since you deal a bit differently with the file output stream object.

This is how I am doing it :

juce::File outfile(path);
    outfile.deleteFile();
    auto ostream = outfile.createOutputStream();
    WavAudioFormat wav;
    auto writer = wav.createWriterFor(ostream.release(), sr, 2, 32, {}, 0);
    // my processing loop...
    delete writer;

[dhng22]

Hey, it works! You’re always my saviour Xenakios

[dhng22]

The audio now has the time length of 3:17. But the original audio is 3:35 and it’s silence, i can not hear anything, here’s my getNextAudioBlock():

When performing playback, the transportSource.getNextReadPosition() give incremental numbers. But when writing the audio, it just gave 0 all the times

[xenakios]

Difficult to say without seeing all of the code…You might need to start the transport source, seek it to the beginning etc before doing the offline render.

[dhng22]

Here’s the rest of it:

It’s a simple code to test writing the same file out by buffer

[dhng22]

@dhng22

@xenakios

You might need to start the transport source, seek it to the beginning

Yes i did call stop and seek it to 0
Oh so i need to call start again?

[dhng22]

@dhng22

Yes it has sound now but it cut like 20 last seconds of the audio,
is the value returned by readerSource->getAudioFormatReader()->lengthInSamples not correct?

P/s: The input is a .mp3 file