Cannot play audio from persistent storage (Unity 2020.2.1f6)

We store audio (and textures) in the persistent storage.

In editor and for other build targets we play audio with:

   var sound = Path.Combine(Application.persistentDataPath, "test.mp3");

    using var webRequest = UnityWebRequestMultimedia.GetAudioClip(sound, AudioType.MPEG);

    yield return webRequest.SendWebRequest();

    var clip = ((DownloadHandlerAudioClip)webRequest.downloadHandler).audioClip;

    audioSrc.PlayOneShot(clip, 1);

But, on WebGl this yields this error:

    :49411/idbfs/6d977885fbd1c5ead313d73fe6d870bd/test.mp3:1 Failed to load resource: the server responded with a status of 404 (Not Found)

If I try to prefix it with "file://" we get an access error:

    Not allowed to load local resource: file:///idbfs/33ef7b0b7a8dd7d8c894e4046f92f4f3/test.mp3

I've tried many different paths, but none seems to work.

---

Observations:
- The sounds are there in the IndexedDB.
- I've tried Chrome, Firefox and Edge. No luck.
- Our textures are loaded from the same persistent storage without problems.

Any help would be greatly appreciated

Cheers,
Jesper

 

ps. I've also tried to play the sounds "directly" with a jslib "plugin".

But, I cannot get this to work either ... sigh

How do you play a sound when you have the object and not the url?

help ... pls

   PlaySound: function (pFile) {

        var file = Pointer_stringify(pFile);

        console.log('PlaySound: ' + file);



        // IndexedDB

        window.indexedDB = window.indexedDB || window.webkitIndexedDB ||

            window.mozIndexedDB || window.OIndexedDB ||

            window.msIndexedDB,

            IDBTransaction = window.IDBTransaction ||

            window.webkitIDBTransaction ||

            window.OIDBTransaction || window.msIDBTransaction,

            dbVersion = 1.0;



        var indexedDB = window.indexedDB;



        var request = indexedDB.open("/idbfs");



        request.onerror = function (event) {

            console.log("Failed to Open the indexedDB database");

        };





        request.onsuccess = function (event) {

            console.log("Succesfully opened the /idbfs db");

            db = request.result;

       

            // Open a transaction to the database

            var transaction = db.transaction(["FILE_DATA"], "readwrite");

       

            transaction.objectStore("FILE_DATA").get(file).onsuccess =

                function (event) {

                    console.log("Retrieved sound from db: " + event.target.result);

                    var audioFile = event.target.result;

       

                    var URL = window.URL || window.webkitURL;

                    var videoURL = URL.createObjectURL(audioFile);

       

                    var audio = new Audio();

                    audio.src = videoURL;

                    audio.play();

                };

        }

    }

 

For testing, I once placed the mp3 file in the StreamingAssets folder and saved it in indexedDB with the following code.
After that, I tried UnityWebRequestMultimedia.GetAudioClip() and was able to play the mp3 file.
Note: Your browser will not be able to autoplay audio without your permission (or your site has a low score).

Code (CSharp):

1.  
2.         var req = UnityWebRequest.Get(Path.Combine(Application.streamingAssetsPath, "test.mp3"));
3.         yield return req.SendWebRequest();
4.         var data = req.downloadHandler.data;
5.         var savePath = Path.Combine(Application.persistentDataPath, "test.mp3");
6.         File.WriteAllBytes(savePath, data);
7.