OBS Audio Source plugin dev question...

[mediawiz]

I am developing an Audio Source plugin for OBS. I unfortunately can find very little documentation for doing this.

I think I'm pretty close to getting it working, but I am still trying to pin down what the values in the 'obs_source_audio' structure should be.

This is my current guess...

struct obs_source_audio   // from "obs.h" header file with my comments (guesses)
{
    const uint8_t *data[MAX_AV_PLANES];   

        // an array containing the pointers to 1 or more data blocks with audio data

            // My guess is that...

            //    - for "interleaved" PCM data, only the 1st pointer in the array should be used

            //    - for
    
    uint32_t frames;     // I am currently NOT SURE what this is supposed to contain???

    enum speaker_layout speakers;               

        // Number if input audio channels.   
        // Example:
        //    1 channel audio  = SPEAKERS_MONO,
        //    2 channel audio = SPEAKERS_STEREO,


    enum audio_format format;                       

        // Input audio format.   
        // Examples:
        //    Interleaved 16 bit audio = AUDIO_FORMAT_16BIT,
        //    Non-interleaved (planar) floating point audio  = AUDIO_FORMAT_FLOAT_PLANAR

    uint32_t samples_per_sec;                        // Number of audio samples to be played in 1 second

    uint64_t timestamp;                              //  I am not sure if this timestamp should start with zero, or with the current clock time???
                                                                        

};

I would be very grateful if someone could confirm correct values for these structure members.

 

[Lain]

frames is number of audio frames, i.e. number of audio samples. so if you had an array of 5 floating point mono audio samples, there'd be 5 floats in data[0], and the frames member would be 5.

timestamp represents the time value of the segment of audio, in nanoseconds. you can start from 0 if you want, but it's good that it be relatively seamless relative to the last segment.