innocenat/gist:5c5a48365930b691c863 Secret

## gistfile1.html
<!DOCTYPE html>
<html>

<body>
</body>

<script>


// Load sound
var xhr = new XMLHttpRequest();

xhr.open('GET', '//localhost/file.wav', true);

xhr.onprogress = function (evt) {
    if (evt.lengthComputable) {
        console.log("Progress: " + evt.loaded + "/" + evt.total + " (" + (100*evt.loaded/evt.total) + "%)");
    } else {
        console.log("Progress: unavailable");
    }
};

var audCtx = new AudioContext();
window.data_bufSrc = undefined;

xhr.onload = function () {
    console.log("File loaded.");
    var d = new DataView(xhr.response);

    if (d.getUint32(0) != 0x52494646 || d.getUint32(8) != 0x57415645) {
        console.error('Not a .wav file!');
        return;
    }

    // Read metadata
    var data = {};
    var meta = false;
    var file_length = d.getUint32(4, true) + 8;

    console.log('Length: ' + file_length);

    var current_offset = 12;

    var audioBuffer;

    while (current_offset < xhr.response.byteLength) {
        // Chunk header
        var chunk_type = d.getUint32(current_offset);
        var chunk_size = d.getUint32(current_offset+4, true);
        current_offset += 8;

        console.log("Chunk: " + chunk_type + "; size=" + chunk_size);

        if (chunk_type == 0x666d7420) { // "fmt "
            if (chunk_size < 14) {
                console.error('Malformed wav file: invalid wav header size');
                return;
            }

            console.log('Found meta chunk!');
            data.format = d.getUint16(current_offset, true);
            data.num_chan = d.getUint16(current_offset+2, true);
            data.sample_rate = d.getUint32(current_offset+4, true);
            data.byte_rate = d.getUint32(current_offset+8, true);
            data.block_align = d.getUint16(current_offset+12, true);
            if (chunk_size >= 16)
                data.bps = d.getUint16(current_offset+14, true);
            else
                data.bps = 16; // FIXME not sure on this...
            if (chunk_size >= 18)
                data.extraSize = d.getUint16(current_offset+16, true);

            if (data.format == 0xFFFE) { // Wave Format Extensible
                if (!data.extraSize || data.extraSize < 22) {
                    console.error('WAVEEXT Format Error!');
                    return;
                }
                data.sample = d.getUint16(current_offset+18, true);
                data.channel_mask = d.getUint32(current_offset+20, true);
                data.guid = readByteArray(d, current_offset+24, 16);

                // GUID
                var intLPCM   = [0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71];
                var floatLPCM = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71];

                if (arraysEqual(data.guid, intLPCM)) {
                    console.log('Integer LPCM found.');
                } else if (arraysEqual(data.guid, floatLPCM)) {
                    console.log('Float LPCM found.');
                } else {
                    console.error("Invalid data format!");
                    return;
                }
            } else if (data.format == 1) { // Integer LPCM
                console.log('Integer LPCM found.');
            } else if (data.format == 3) {
                console.log('Float LPCM found.');
            } else {
                console.error("Invalid data format!");
                return;
            }

            meta = true;
            current_offset += chunk_size;
        } else if (chunk_type == 0x64617461) { // "data"
            if (!meta) {
                console.error('Malformed wav file: data chunk before fmt chunk');
                return;
            }
            console.log('Found data chunk!');

            // Calculate audio length
            var bytePerSample = data.num_chan * data.bps / 8;
            var bytePerSecond = bytePerSample * data.sample_rate;
            var second = chunk_size / bytePerSecond;
            var sampleCount = chunk_size / bytePerSample;

            console.log("File length: %d (%d:%d)", second, second/60, second%60);

            // Create AudioBuffer
            audioBuffer = audCtx.createBuffer(data.num_chan, sampleCount, data.sample_rate);

            var chanBuff = [];
            for (var i = 0; i < data.num_chan; i++) {
                chanBuff[i] = audioBuffer.getChannelData(i);
            }

            // Read data to AudioBuffer
            var ofst = current_offset;
            for (var sample = 0; sample < sampleCount; sample++) {
                for (var i = 0; i < data.num_chan; i++) {
                    switch (data.bps) { // Integer only for now
                        case 8:
                            var dat = d.getUint8(ofst);
                            chanBuff[i][sample] = (dat - 128) / 128;
                            break;
                        case 16:
                            var dat = d.getInt16(ofst, true);
                            chanBuff[i][sample] = dat / (1 << 15);
                            break;
                        case 32:
                            var dat = d.getInt32(ofst, true);
                            chanBuff[i][sample] = dat / (1 << 31);
                            break;
                    }
                    ofst += data.bps / 8;
                }
            }

            console.log("Demuxing complete.")

            current_offset += chunk_size;
            break; // stop processing
        } else { // we are skipping 'fact' chunk if present
            // Bypass chunk
            console.log("Skipping: " + chunk_type);
            current_offset += chunk_size;
        }
    }

    window.data_bufSrc = audCtx.createBufferSource();
    window.data_bufSrc.buffer = audioBuffer;
    window.data_bufSrc.connect(audCtx.destination);
    window.data_bufSrc.start(0);
    console.log("Done!");
}

function arraysEqual(a, b) {
    if (a === b) return true;
    if (a == null || b == null) return false;
    if (a.length != b.length) return false;

    for (var i = 0; i < a.length; i++) {
        if (a[i] !== b[i]) return false;
    }
    return true;
}

function readByteArray(d, o, s) {
    var r = [];
    for (var i = 0; i < s; i++) {
        r.push(d.getUint8(o+i));
    }
    return r;
}

xhr.responseType = "arraybuffer";
xhr.send();
console.log("Loading file...");


</script>

</html>
	<!DOCTYPE html>
	<html>

	<body>
	</body>

	<script>


	// Load sound
	var xhr = new XMLHttpRequest();

	xhr.open('GET', '//localhost/file.wav', true);

	xhr.onprogress = function (evt) {
	if (evt.lengthComputable) {
	console.log("Progress: " + evt.loaded + "/" + evt.total + " (" + (100*evt.loaded/evt.total) + "%)");
	} else {
	console.log("Progress: unavailable");
	}
	};

	var audCtx = new AudioContext();
	window.data_bufSrc = undefined;

	xhr.onload = function () {
	console.log("File loaded.");
	var d = new DataView(xhr.response);

	if (d.getUint32(0) != 0x52494646 \|\| d.getUint32(8) != 0x57415645) {
	console.error('Not a .wav file!');
	return;
	}

	// Read metadata
	var data = {};
	var meta = false;
	var file_length = d.getUint32(4, true) + 8;

	console.log('Length: ' + file_length);

	var current_offset = 12;

	var audioBuffer;

	while (current_offset < xhr.response.byteLength) {
	// Chunk header
	var chunk_type = d.getUint32(current_offset);
	var chunk_size = d.getUint32(current_offset+4, true);
	current_offset += 8;

	console.log("Chunk: " + chunk_type + "; size=" + chunk_size);

	if (chunk_type == 0x666d7420) { // "fmt "
	if (chunk_size < 14) {
	console.error('Malformed wav file: invalid wav header size');
	return;
	}

	console.log('Found meta chunk!');
	data.format = d.getUint16(current_offset, true);
	data.num_chan = d.getUint16(current_offset+2, true);
	data.sample_rate = d.getUint32(current_offset+4, true);
	data.byte_rate = d.getUint32(current_offset+8, true);
	data.block_align = d.getUint16(current_offset+12, true);
	if (chunk_size >= 16)
	data.bps = d.getUint16(current_offset+14, true);
	else
	data.bps = 16; // FIXME not sure on this...
	if (chunk_size >= 18)
	data.extraSize = d.getUint16(current_offset+16, true);

	if (data.format == 0xFFFE) { // Wave Format Extensible
	if (!data.extraSize \|\| data.extraSize < 22) {
	console.error('WAVEEXT Format Error!');
	return;
	}
	data.sample = d.getUint16(current_offset+18, true);
	data.channel_mask = d.getUint32(current_offset+20, true);
	data.guid = readByteArray(d, current_offset+24, 16);

	// GUID
	var intLPCM = [0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71];
	var floatLPCM = [0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x10, 0x00, 0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71];

	if (arraysEqual(data.guid, intLPCM)) {
	console.log('Integer LPCM found.');
	} else if (arraysEqual(data.guid, floatLPCM)) {
	console.log('Float LPCM found.');
	} else {
	console.error("Invalid data format!");
	return;
	}
	} else if (data.format == 1) { // Integer LPCM
	console.log('Integer LPCM found.');
	} else if (data.format == 3) {
	console.log('Float LPCM found.');
	} else {
	console.error("Invalid data format!");
	return;
	}

	meta = true;
	current_offset += chunk_size;
	} else if (chunk_type == 0x64617461) { // "data"
	if (!meta) {
	console.error('Malformed wav file: data chunk before fmt chunk');
	return;
	}
	console.log('Found data chunk!');

	// Calculate audio length
	var bytePerSample = data.num_chan * data.bps / 8;
	var bytePerSecond = bytePerSample * data.sample_rate;
	var second = chunk_size / bytePerSecond;
	var sampleCount = chunk_size / bytePerSample;

	console.log("File length: %d (%d:%d)", second, second/60, second%60);

	// Create AudioBuffer
	audioBuffer = audCtx.createBuffer(data.num_chan, sampleCount, data.sample_rate);

	var chanBuff = [];
	for (var i = 0; i < data.num_chan; i++) {
	chanBuff[i] = audioBuffer.getChannelData(i);
	}

	// Read data to AudioBuffer
	var ofst = current_offset;
	for (var sample = 0; sample < sampleCount; sample++) {
	for (var i = 0; i < data.num_chan; i++) {
	switch (data.bps) { // Integer only for now
	case 8:
	var dat = d.getUint8(ofst);
	chanBuff[i][sample] = (dat - 128) / 128;
	break;
	case 16:
	var dat = d.getInt16(ofst, true);
	chanBuff[i][sample] = dat / (1 << 15);
	break;
	case 32:
	var dat = d.getInt32(ofst, true);
	chanBuff[i][sample] = dat / (1 << 31);
	break;
	}
	ofst += data.bps / 8;
	}
	}

	console.log("Demuxing complete.")

	current_offset += chunk_size;
	break; // stop processing
	} else { // we are skipping 'fact' chunk if present
	// Bypass chunk
	console.log("Skipping: " + chunk_type);
	current_offset += chunk_size;
	}
	}

	window.data_bufSrc = audCtx.createBufferSource();
	window.data_bufSrc.buffer = audioBuffer;
	window.data_bufSrc.connect(audCtx.destination);
	window.data_bufSrc.start(0);
	console.log("Done!");
	}

	function arraysEqual(a, b) {
	if (a === b) return true;
	if (a == null \|\| b == null) return false;
	if (a.length != b.length) return false;

	for (var i = 0; i < a.length; i++) {
	if (a[i] !== b[i]) return false;
	}
	return true;
	}

	function readByteArray(d, o, s) {
	var r = [];
	for (var i = 0; i < s; i++) {
	r.push(d.getUint8(o+i));
	}
	return r;
	}

	xhr.responseType = "arraybuffer";
	xhr.send();
	console.log("Loading file...");


	</script>

	</html>