MP4Box.js crashes with uncompressed audio.

[louderspace]

MP4Box attempts to create a javascript per audio sample when it references uncompressed PCM sample data. This is also quite common with Quicktime .mov files.

To reproduce the problem:

1. Download this file: https://www.dropbox.com/scl/fi/2n9ewhxeo4r1h813abn59/500x500_30FPS_600s_HEVC_PCM.mp4?rlkey=9vyzx3s80ydsiwvbypgzrk0i6&dl=0
2. Using the test page, https://gpac.github.io/mp4box.js/test/filereader.html hit the "Choose File" button, select the downloaded file, and when uploading finishes, select the "Load" button.
3. If it doesn't crash the tab, just hit "Load" again and again.

Result: In Chrome: "Aw Snap!" Error code 5.

This is due to the buildTrakSampleLists creating a javascript object for each audio sample! MP4Box.js should detect uncompressed audio formats and allow the client to access those samples, without allocating excessive javascript memory.