Web Audio API onended事件不会触发

Question

I'm extremely new to the world of Node streaming, so pardon my lack of information.

I've got a simple Node server that receives a file stream (using BinaryJS), and then re-broadcasts it back to the client as an ArrayBuffer. In essence, assume that I'm getting an ArrayBuffer from the server, and I want to play it back. I'm currently decoding it as it comes in, creating a new source and scheduling playback every time. It all seems to work.

However, I want to trigger another function every time a chunk ends. The 'onended' event does not seem to be firing though. Can someone help? Thanks.

client.on('open', function() {
    var stream = client.send(file)
    client.on('stream', function(stream) {
        var nextTime = 0.01

        stream.on('data', function(data) {
            console.log('Receiving data from server')
            context.decodeAudioData(data, function(audioBuffer) {
                var source = context.createBufferSource()
                source.buffer = song[song.length-1]
                source.connect(context.destination);
                source.onended = function() {
                    console.log('Buffer depleted')
                }
                source.start(nextTime)
                nextTime += audioBuffer.duration - 0.01
            })
        })
        stream.on('end', function() {
            console.log('End of stream, ' + current)
        });
    })
})

Answer 1

After struggling for quite some time and looking at a lot of answers online, I figured that the reason my code didn't work was because I was constantly re-writing the 'source' variable. Since it was just an instance (a pointer for C++ folks), it pointed only to the latest source. Essentially, it was being overwritten before the event could fire.

I solved it by 'caching' all sources and buffers to arrays.

client.on('open', function() {
    var stream = client.send(file)
    client.on('stream', function(stream) {
        stream.on('data', function(data) {
            console.log('Receiving data from server')
            context.decodeAudioData(data, function(audioBuffer) {
                sources.push(context.createBufferSource())
                song.push(audioBuffer)
                sources[sources.length-1].buffer = song[song.length-1]
                sources[sources.length-1].connect(context.destination);
                sources[sources.length-1].onended = function() {
                    console.log('Buffer depleted')
                    current += 1;
                }
                sources[sources.length-1].start(nextTime)
                nextTime += audioBuffer.duration - 0.01
            })
        })
        stream.on('end', function() {
            console.log('End of stream, ' + current)
        });
    })
})

This time, I was actually pushing those values into the 'sources' array, and hence it wasn't overwritten and the event fired properly.

I'm not sure if this is the most efficient way (I hardly think it is), but it solves my problem for now.

If anyone has a better solution, do let me know :)