Vimeo DASH stream downloader

vimeo-dash.js

/***
 * This will create 2 separate files:
 *   - Vimeo Rip.mp4    - The video file
 *   - Vimeo Rip.mp4a   - The associated audio
 *
 * This is by Vimeo's design. These files simply need to be merged.
 * The following ffmpeg command may be used:
 *
 *   ffmpeg -i ".\Vimeo Rip.mp4" -i ".\Vimeo Rip.mp4a" -c copy output.mp4
 */


(function() {
    var url = playerConfig.request.files.dash.cdns[playerConfig.request.files.dash.default_cdn].url;

    console.info("Ripping DASH stream from VIMEO. This may take some time...");

    // First we load the stream manifest
    var xhr = new XMLHttpRequest
    xhr.onreadystatechange = function() {
        if (xhr.readyState == 4) {
            if (xhr.status == 200) {
                handleStream(xhr.responseText);
            } else {
                console.error("STATUS: " + xhr.status);
            }
        }
    };
    xhr.open("GET", url);
    xhr.send();

    function handleStream(streamData) {
        // Now we pick the highest bitrate stream
        var stream = JSON.parse(streamData);

        var base_url = new URL(stream.base_url, url);

        stream.video.sort(function(x,y) {
            if (x.width > y.width) return -1;
            if (x.width < y.width) return +1;
            return 0;
        });

        stream.audio.sort(function(a, b) {
            if (a.bitrate > b.bitrate) return -1;
            if (a.bitrate < b.bitrate) return +1;
            return 0;
        });

        audioRip(videoRip);

        function videoRip(cb) {
            var videoStream = stream.video.filter(v => v.hasOwnProperty('index_segment'))[0];
            var videoUrl = base_url + videoStream.base_url;
    
            // Now we start gluing the stream together... We need to figure out how many bytes this file is.
            //  We can do this by looking at the end range of the last segment.
            var lastByte = videoStream.segments.at(-1).url.split('-')[1];
    
            // Now we can forge our URL range to begin at byte 0 and finish at lastByte
            var forgedBasePath = videoStream.index_segment.split('range=')[0] + 'range=0-' + lastByte;
    
            console.info('Picking ' + videoStream.height + 'p stream');
            console.debug('Video file size ' + lastByte + 'B. Beginning download now.');
    
            (function() {
                let x = new XMLHttpRequest();
                x.responseType = "blob";
                x.onreadystatechange = function() {
                    if (x.readyState == 4 && x.status == 200) {
                        saveData(x.response, "Vimeo Rip.mp4");
                        if (cb) {
                            cb();
                        }
                    }
                };
                x.open("GET", videoUrl + forgedBasePath);
                x.send();
            })();
        }

        function audioRip(cb) {
            var audioStream = stream.audio.filter(a => a.hasOwnProperty('index_segment'))[0];
            var audioUrl = base_url + audioStream.base_url;
    
            var lastByte = audioStream.segments.at(-1).url.split('-')[1];
            var forgedBasePath = audioStream.index_segment.split('range=')[0] + 'range=0-' + lastByte;
    
            console.info('Picking ' + audioStream.bitrate + ' bitrate ' + audioStream.codecs + ' stream');
            console.debug('Audio file size ' + lastByte + 'B. Beginning download now.');
    
            (function() {
                let x = new XMLHttpRequest();
                x.responseType = "blob";
                x.onreadystatechange = function() {
                    if (x.readyState == 4 && x.status == 200) {
                        saveData(x.response, "Vimeo Rip.mp4a");
                        if (cb) {
                            cb();
                        }
                    }
                };
                x.open("GET", audioUrl + forgedBasePath);
                x.send();
            })();
        }
    }

    function saveData(data, name) {
        var a = document.createElement("a");
        document.body.appendChild(a);
        a.style = "display: none";
        url = window.URL.createObjectURL(data);
        a.href = url;
        a.download = name;
        a.click();
        window.URL.revokeObjectURL(url);
    }
})();