var spawn = require("child_process").spawn, stream = require("stream"); // Forked from https://github.com/jhurliman/node-pcm module.exports = function(filename, options) { var sampleStream = new stream.Stream(), channels = 2, output = "", channel = 0, oddByte; sampleStream.readable = true; if (options && options.channels) channels = options.channels; var args = ["-i", filename, "-f", "s16le", "-ac", channels, "-acodec", "pcm_s16le"]; if (options && options.sampleRate) { args.push("-ar", options.sampleRate); } args.push("-y", "pipe:1"); var spawned = spawn("ffmpeg", args); spawned.stdout.on("data", function(data) { var len = data.length; if (oddByte != null) { sampleStream.emit("data", ((data.readInt8(i++, true) << 8) | oddByte) / 32767.0, channel); channel = ++channel % channels; } for (var i = 0; i < len; i += 2) { sampleStream.emit("data", data.readInt16LE(i, true) / 32767.0, channel); channel = ++channel % channels; } oddByte = (i < len) ? data.readUInt8(i, true) : null; }); spawned.stderr.on("data", function(data) { output += data.toString(); }); spawned.stderr.on("end", function() { sampleStream.emit(oddByte !== undefined ? "end" : "error", output); }); return sampleStream; };