Trying to get the waveform/envelope of an EventInstance but Sound.ReadData failing

Unity
,
1

Hi,

I would like to display the waveform (or envelope) of an fmod event before playing it, so that the user can see what sound it is beforehand.

Thanks to this Topic, I think I’m getting close: Trouble visualizing waveform from event without separate Sound object - Unity - FMOD Forums

Everything works fine except that Sound.ReadData() returns an ERR_UNSUPPORTED error.

Here is my code (most is copy pasted from the given topic, it’s just here for context):

public EventReference eventRef;
public void GetSound()
{
    eventInstance = RuntimeManager.CreateInstance(eventRef);
    //For now I'm starting it so that it loads, but I intend to either not start it or stop it right after as I don't want to play it now (I just need to readData)
    eventInstance.start();
    StartCoroutine(GetSoundFromInstance(eventInstance));
}

IEnumerator GetSoundFromInstance(EventInstance eventInstance)
{
    if (eventInstance.hasHandle() && !sound.hasHandle())
    {
        //Wait for the sound to load
        FMOD.Studio.PLAYBACK_STATE state;
        FMOD.RESULT result;
        do
        {
            result = eventInstance.getPlaybackState(out state);
            if (result == FMOD.RESULT.OK)
            {
                if (state == FMOD.Studio.PLAYBACK_STATE.PLAYING)
                {
                    if (eventInstance.getChannelGroup(out FMOD.ChannelGroup group) == FMOD.RESULT.OK)
                    {
                        sound = FindCurrentSound(group);
                        sound.getName(out string name, 256);
                        //This works fine for eg, as all others getSomething()
                        UnityEngine.Debug.Log($"Audio Name: {name}");

                        sound.getLength(out uint length, TIMEUNIT.RAWBYTES);
                        byte[] buffer = new byte[length];
                        //This seems correct as well
                        UnityEngine.Debug.Log($"Sound Length: {length}");

                        //================ISSUE IS HERE========================
                        FMOD.RESULT resultRead = sound.readData(buffer, out uint read);

                        if (resultRead != FMOD.RESULT.OK)
                        {
                            //This logs ERR_UNSUPPORTED
                            UnityEngine.Debug.Log($"Failed to retrieve data from sound: {resultRead }");
                        }

                        //Do things with buffer...
                    }
                }
            }
            //This is always waited once, as the sound seem to take a frame to start playing
            yield return null;
        } while (result != RESULT.OK || state != FMOD.Studio.PLAYBACK_STATE.PLAYING);
    }
}

//This is pasted from the above topic, seems to work fine
FMOD.Sound FindCurrentSound(FMOD.ChannelGroup channelGroup)
{
    FMOD.Sound sound = new FMOD.Sound();

    // Check if we are currently in the right channel group
    if (channelGroup.getNumChannels(out int numChannels) == FMOD.RESULT.OK && numChannels > 0)
    {
        if (numChannels > 1)
        {
            UnityEngine.Debug.Log("More than 1 channel");
        }
        else
        {
            if (channelGroup.getChannel(0, out FMOD.Channel channel) == FMOD.RESULT.OK)
            {
                if (channel.getCurrentSound(out sound) == FMOD.RESULT.OK)
                {
                    UnityEngine.Debug.Log("Found the correct Sound");
                }
                else
                {
                    UnityEngine.Debug.Log("Could not retrieve sound");
                    sound = new FMOD.Sound();
                }
            }
        }
    }

    // Check if the sound has been found
    if (!sound.hasHandle())
    {
        // If not, continue the recusion
        channelGroup.getName(out string name, 256);
        UnityEngine.Debug.Log(name);

        if (channelGroup.getNumGroups(out int numGroups) == FMOD.RESULT.OK && numGroups > 0)
        {
            if (numGroups > 1)
            {
                UnityEngine.Debug.Log("More than one Group");
            }
            else
            {
                if (channelGroup.getGroup(0, out FMOD.ChannelGroup child) == FMOD.RESULT.OK)
                {
                    sound = FindCurrentSound(child);
                }
            }
        }
    }
    // Else the sound has been found so return the sound
    // This will either be a real sound or not depending if it was found in the recussion.
    return sound;
}

I guess I’m missing a call to something but can’t figure what. Any idea?