How to read wav file header with QFile

[kayakaan02]

I want to read a wav files header because I want to see the size located at the 40-44 bytes of 44 byte header as unsigned long.

Header data is like this:

    char                RIFF[4];
    unsigned long       ChunkSize;
    char                WAVE[4];
    char                fmt[4];
    unsigned long       Subchunk1Size;
    unsigned short      AudioFormat;
    unsigned short      NumOfChan;
    unsigned long       SamplesPerSec;
    unsigned long       bytesPerSec;
    unsigned short      blockAlign;
    unsigned short      bitsPerSample;
    char                Subchunk2ID[4];
    unsigned long       Subchunk2Size;

Subchunk2Size is where the data size is stored but I cannot access it with QFile and .read() etc.

How can I do it, I guess QDataStream can be useful but I don't know how.

Thanks in advance.

[jsulm]

@kayakaan02 Since you know at which position you need to read and how many bytes use https://doc.qt.io/qt-6/qiodevice.html#seek and https://doc.qt.io/qt-6/qiodevice.html#read to read it.

[JonB]

@kayakaan02 said in How to read wav file header with QFile:

Subchunk2Size is where the data size is stored but I cannot access it with QFile and .read() etc.

Yes you can! Follow @jsulm's links. You don't even have to seek() if you don't want to, you can just read the first 44 bytes and inspect the last 4.

I guess QDataStream can be useful but I don't know how.

QDataStream is useful where you exchange data between 2 Qt programs. It is not to be used where the format is produced by anything other than Qt using QDataStream, such as your .wav file format.