Express route to transcode an audio file.

gistfile1.txt

//FIXME - investigate settings, etc.
function transcode(file) {
    var spawn = require('child_process').spawn

    var decode = spawn('flac', [
        '--decode',
        '--stdout',
        file
    ])

    var encode = spawn('lame', [
        '-V0',
        '-',
        '-'
    ])

    decode.stdout.pipe(encode.stdin)

    return encode
}

library.get('/play/:id', function(req, res, next) {
    console.log('stream');
    req.collection.findOne({ _id: req.params.id },
        function(e, result) {
            if(e) {
                console.log('error ', e)
                return next(e)
            }
            if(!result) {
                res.status(404).send('Sorry! Can\'t find it.');
            } else {
                console.log('play file ', result);
                var fs = require('fs')
                stat = fs.statSync(result.path);
                res.writeHead(200, {
                    'Content-Type': 'audio/mpeg',
                    'Content-Length': stat.size
                });
                var readStream;
                if(-1 === result.mime.indexOf('mpeg')) {
                    console.log('not an mpeg file, will transcode ', result);

                    readStream = transcode(result.path).stdout;
                } else {
                    readStream = fs.createReadStream(result.path);
                }
                readStream.pipe(res);
                readStream.on('end', function() {
                    console.log('readStream end');
                });
            }
        })
});