I am currently working on a small project where I want to split an mp3 into frames, send them to a client (browser) through a websocket and then play them back using WebAudio (webkitAudioContext). My server is running nodejs and to transfer the data as binary, I use binaryJS. The browser I am testing with is Chrome 25.0.1354.0 dev, running on Ubuntu 12.04.
I have gotten as far as successfully splitting the mp3 into frames, or, at least, based on my tests, it seems to work. If I write the frames back into a file, mplayer has no problem playing back the file and also parses the header correctly. Each frame is stored in a nodejs Buffer of the correct size and the last byte of the buffer is always the first byte before the next sync word.
As an initial test, I am only sending the first MP3 frame. The client receives the frame successfully (stored in an ArrayBuffer), and the buffer contains the correct data. However, when I call decode, I get the following message:
Uncaught Error: SyntaxError: DOM Exception 12
My function, where I call decodeAudio, looks like this:
streamDone = ->
bArray = new Uint8Array(arr[0].byteLength)
console.log "Stream is done, bytes", bArray.length
context.decodeAudioData bArray, playAudio, err
The initial frame that I am trying to deocde, can be found here.
I have been banging my head in the wall for a couple of days now trying to solve this. Has anyone managed to solve this and sucessfully decoded mp3 frames, and see what I do wrong? I have found two related question on StackOverflow, but the answers did not help me solve my problem. However, according to the accepted answer here, my frame should qualify as a valid mp3 chunk and, thus, be decoded.
Thanks in advance for any help!
Turns out that a break and some fresh eyes can work wonders, a general code cleanup solved the issue. If anyone is interested in the code, I published it here.