source: gs3-extensions/audioDB/trunk/src/interface/js/similarity-matrix-play.js.checkpt1@ 26291

// Audio objects
var baseSong;
var leftSong;
var rightSong;

var pannedPlayback = new Audio();

var leftBuffers = [];
var rightBuffers = [];

var leftStartTimeSecs  = 0.0;
var rightStartTimeSecs = 0.0;
var leftStartTimeOffset  = 0;
var rightStartTimeOffset = 0;

var totalFullBufferSize = 0;

function resetAudioBuffers()
{
    console.log("Panned audio playback buffers initialized/reset");

    pannedPlayback = new Audio();

    leftBuffers = [];
    rightBuffers = [];

    leftStartTimeSecs  = 0.0;
    rightStartTimeSecs = 0.0;
    leftStartTimeOffset  = 0;
    rightStartTimeOffset = 0;
    
    totalFullBufferSize = 0;
}

function dualPlay(evt) 
{
    //var target = evt.target;
    //console.log("target = " + target);

    var img_x = $("#selfSimImgId").offset().left;
    var img_y = $("#selfSimImgId").offset().top;

    var mouse_x = evt.clientX;
    var mouse_y = evt.clientY;
    
    var x_org = mouse_x - img_x;
    var y_org = mouse_y - img_y;
    
    //console.log("mouse (x y) = (" + mouse_x + "," + mouse_y + ")");
    //console.log("(x y) = (" + x_org + "," + y_org + ")");

    var mysong = document.getElementById("mysong");
    var barWidth = mysong.getElementWidth();

    var baseSongSrc="sites/localsite/collect/" + collect +"/import/"+source;

    leftStartTimeSecs  = duration * x_org / barWidth;
    rightStartTimeSecs = duration * y_org / barWidth;

    var sampleMult = * baseSong.mozSampleRate * baseSong.mozChannels;
    leftStartTimeOffset  = leftStartTimeSecs * sampleMult;
    rightStartTimeOffset = rightStartTimeSecs * sampleMult;

    leftSong.src  = baseSongSrc;
    rightSong.src = baseSongSrc;

    resetAudioBuffer();
}

function svgInitSimilarityPlay() 
{
    var mysong = document.getElementById("mysong");
    var barWidth = mysong.getElementWidth();

    var baseSongSrc="sites/localsite/collect/" + collect +"/import/"+source;

    baseSong = new Audio();
    baseSong.src = baseSongSrc;
    baseSong.control = "control";

    baseSong.addEventListener('MozAudioAvailable', audioAvailable, false);
    baseSong.addEventListener('loadedmetadata', loadedMetadata, false);

    leftSong = new Audio();
    leftSong.addEventListener('MozAudioAvailable', audioAvailableLeft, false);
    leftSong.addEventListener('loadedmetadata', loadedMetadataLeft, false);

    rightSong = new Audio();
    rightSong.addEventListener('MozAudioAvailable', audioAvailableRight, false);
    rightSong.addEventListener('loadedmetadata', loadedMetadataRight, false);


    // Set up self similarity image

    var selfSimImgSrc="sites/localsite/collect/" + collect +"/bordered/"+self_sim_png;
    console.log("self sim img = " + selfSimImgSrc);

    var simPlayLine = document.getElementById("simPlayLineGroup");

    var selfSimImg = document.createElementNS(SVG_NS,"image");
    selfSimImg.setAttributeNS(XLINK_NS, "xlink:href", selfSimImgSrc);

    var selfSimImgHeight = barWidth * (815.0 / 776.0);

    selfSimImg.setAttribute("x",0);
    selfSimImg.setAttribute("y",30);
    selfSimImg.setAttribute("id","selfSimImgId");
    selfSimImg.setAttribute("width",barWidth);
    selfSimImg.setAttribute("height",selfSimImgHeight);
    selfSimImg.setAttribute("onclick","dualPlay(evt)");

    simPlayLine.appendChild(selfSimImg);
    /*

                var searchImgElem = document.createElementNS(SVG_NS,'image');
        searchImgElem.setAttributeNS(XLINK_NS, "xlink:href", 
                                   "ext/audioDB/icons/search20.png");
        searchImgElem.setAttribute("x","544");
            searchImgElem.setAttribute("y","42");
            searchImgElem.setAttribute("width","20");
            searchImgElem.setAttribute("height","20");
        //var onclickSearch ="searchSubmit(100)";
        var onclickSearch ="dualPlay(evt)";
            searchImgElem.setAttribute("onclick",onclickSearch);
        simPlayLine.appendChild(searchImgElem);
    */


    var svgSimilarityPlay = document.getElementById("svgSimilarityPlay");
    svgSimilarityPlay.setAttribute("height",30 + selfSimImgHeight);


}




function loadedMetadata() {
    // Mute baseSong audio.
    baseSong.volume = 0;

    // Set up a pannedPlayback for baseSong to routed through
    console.log("num channels = " + baseSong.mozChannels);

    pannedPlayback.mozSetup(2, baseSong.mozSampleRate);

}


function loadedMetadataLeft() {
    // Mute baseSong audio.
    leftSong.volume = 0;

    leftSong.currentTime = leftStartTimeSecs;
    leftSong.play();
}


function loadedMetadataRigh() {
    // Mute baseSong audio.
    rightSong.volume = 0;

    rightSong.currentTime = rightStartTimeSecs;
    rightSong.play();
}

function audioAvailable(event) {
    // Write the current framebuffer
    alert("audioAvailable() should no longer be called");
    var frameBuffer = event.frameBuffer; // frameBuffer is Float32Array
    //writeAudio(frameBuffer);
}

function audioAvailableLeft(event) 
{
    // Write the current framebuffer
    var frameBuffer = event.frameBuffer; 
    writeAudio(frameBuffer,"left");
}

function audioAvailableRight(event) 
{
    // Write the current framebuffer
    var frameBuffer = event.frameBuffer; 
    writeAudio(frameBuffer,"right");
}




function activeAudioBuffer(audioBuffer,currentFullBufferSize,startTime) 
{
    var buffer;
    if (currentFullBufferSize < startTime) {
    // active audio starts at offset within this segment of audioBuffer

    var position = startTime - currentFullBufferSize;
    buffer = audioBuffer.subarray(position);
    }
    else {
    buffer = audioBuffer;
    }
    return buffer;
}

function panLeftEffect(buffer,s,panned_buffer,d) 
{
    panned_buffer[d] = buffer[s];
    if ((d+1) < panned_buffer.length) {
    panned_buffer[d+1] = 0;
    }
}

function panRightEffect(buffer,s,panned_buffer,d) 
{
    panned_buffer[d] = 0;
    if ((d+1) < panned_buffer.length) {
    panned_buffer[d+1] = buffer[s];
    }
}

function panAudioBuffersHead(buffer,position,panEffect)
{
    var remaining_len = buffer.length - position;
    var panned_buffer;
    if (baseSong.mozChannels == 1) {
    panned_buffer = new Float32Array(remaining_len * 2);

    var d=0;
    for (var s=position; s < buffer.length; s++) {
        panEffect(buffer,s,panned_buffer,d);
        d += 2;
    }
    }
    else {
    // assume stereo
    panned_buffer = new Float32Array(remaining_len);
      
    var d=0;
    for (var s=position; s < buffer.length; s+=2) {
        panEffect(buffer,s,panned_buffer,d);
        d += 2;
    }
    }

    return panned_buffer;
}

function mergeLeftAndRightPan(leftPannedBuffer,rightPannedBuffer)
{
    // left and right buffers guaranteed to be stereo samples

    var leftLen  = leftPannedBuffer.length;
    var rightLen = rightPannedBuffer.length;
    var maxLen = Math.max(leftLen,rightLen);

    var pannedBuffer = new Float32Array(maxLen);

    for (i=0; i < maxLen; i+=2) {

        if (i < leftLen) {
        pannedBuffer[i] = leftPannedBuffer[i];
    }
    else {
        pannedBuffer[i] = 0;
    }

        if (i < leftLen) {
        pannedBuffer[i+1] = rightPannedBuffer[i+1];
    }
    else {
        pannedBuffer[i+1] = 0;
    }
    }

    return pannedBuffer;

}

function writeAudio(audioBuffer,channel) {

    // audioBuffer is Float32Array
    var audioBufferLen = audioBuffer.length; 

    if ((totalFullBufferSize + audioBufferLen) > leftStartTimeOffset) {
        var leftBuffer = activeAudioBuffer(audioBuffer,totalFullBufferSize,leftStartTime);
    leftBuffers.push({buffer: leftBuffer, position: 0});
    }

    if ((totalFullBufferSize + audioBufferLen) > rightStartTimeOffset) {
        var rightBuffer = activeAudioBuffer(audioBuffer,totalFullBufferSize,rightStartTime);
    rightBuffers.push({buffer: rightBuffer, position: 0});
    }

    totalFullBufferSize += audioBufferLen;


    // If there's buffered data in both left and right buffers,
    // then it's time to play something 

    while((leftBuffers.length > 0) && (rightBuffers.length > 0)) {

        var leftBuffer = leftBuffers[0].buffer;
    var leftBufferPos = leftBuffers[0].position;
        var leftPannedBuffer  = panAudioBuffersHead(leftBuffer,leftBufferPos,panLeftEffect);

        var rightBuffer = rightBuffers[0].buffer;
    var rightBufferPos = rightBuffers[0].position;
        var rightPannedBuffer = panAudioBuffersHead(rightBuffer,rightBufferPos,panRightEffect);

        var pannedBuffer = mergeLeftAndRightPan(leftPannedBuffer,rightPannedBuffer);

    //var written = pannedPlayback.mozWriteAudio(buffer.subarray(position));
    var written = pannedPlayback.mozWriteAudio(pannedBuffer);

    // // If all data wasn't written, keep it in the buffers:
    var doBreak = false;

    if (leftBufferPos + written < leftBuffer.length) {
        leftBuffers[0].position = leftBufferPos + written;
        doBreak = true;
    }
    else {
        leftBuffers.shift();
        }

    if (rightBufferPos + written < rightBuffer.length) {
        rightBuffers[0].position = rightBufferPos + written;
        doBreak = true;
    }
    else {
        rightBuffers.shift();
        }

    if (doBreak) {
        break;
    }
    }
}