95 lines
3.2 KiB
JavaScript
95 lines
3.2 KiB
JavaScript
"use strict";
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/**
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* Buffer Helper utils, providing methods dealing buffer length retrieval
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*/
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var BufferHelper = {
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isBuffered: function isBuffered(media, position) {
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if (media) {
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var buffered = media.buffered;
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for (var i = 0; i < buffered.length; i++) {
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if (position >= buffered.start(i) && position <= buffered.end(i)) {
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return true;
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}
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}
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}
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return false;
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},
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bufferInfo: function bufferInfo(media, pos, maxHoleDuration) {
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if (media) {
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var vbuffered = media.buffered,
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buffered = [],
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i;
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for (i = 0; i < vbuffered.length; i++) {
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buffered.push({ start: vbuffered.start(i), end: vbuffered.end(i) });
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}
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return this.bufferedInfo(buffered, pos, maxHoleDuration);
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} else {
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return { len: 0, start: pos, end: pos, nextStart: undefined };
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}
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},
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bufferedInfo: function bufferedInfo(buffered, pos, maxHoleDuration) {
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var buffered2 = [],
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// bufferStart and bufferEnd are buffer boundaries around current video position
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bufferLen,
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bufferStart,
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bufferEnd,
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bufferStartNext,
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i;
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// sort on buffer.start/smaller end (IE does not always return sorted buffered range)
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buffered.sort(function (a, b) {
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var diff = a.start - b.start;
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if (diff) {
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return diff;
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} else {
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return b.end - a.end;
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}
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});
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// there might be some small holes between buffer time range
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// consider that holes smaller than maxHoleDuration are irrelevant and build another
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// buffer time range representations that discards those holes
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for (i = 0; i < buffered.length; i++) {
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var buf2len = buffered2.length;
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if (buf2len) {
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var buf2end = buffered2[buf2len - 1].end;
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// if small hole (value between 0 or maxHoleDuration ) or overlapping (negative)
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if (buffered[i].start - buf2end < maxHoleDuration) {
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// merge overlapping time ranges
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// update lastRange.end only if smaller than item.end
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// e.g. [ 1, 15] with [ 2,8] => [ 1,15] (no need to modify lastRange.end)
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// whereas [ 1, 8] with [ 2,15] => [ 1,15] ( lastRange should switch from [1,8] to [1,15])
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if (buffered[i].end > buf2end) {
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buffered2[buf2len - 1].end = buffered[i].end;
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}
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} else {
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// big hole
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buffered2.push(buffered[i]);
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}
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} else {
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// first value
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buffered2.push(buffered[i]);
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}
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}
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for (i = 0, bufferLen = 0, bufferStart = bufferEnd = pos; i < buffered2.length; i++) {
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var start = buffered2[i].start,
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end = buffered2[i].end;
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//logger.log('buf start/end:' + buffered.start(i) + '/' + buffered.end(i));
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if (pos + maxHoleDuration >= start && pos < end) {
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// play position is inside this buffer TimeRange, retrieve end of buffer position and buffer length
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bufferStart = start;
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bufferEnd = end;
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bufferLen = bufferEnd - pos;
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} else if (pos + maxHoleDuration < start) {
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bufferStartNext = start;
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break;
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}
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}
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return { len: bufferLen, start: bufferStart, end: bufferEnd, nextStart: bufferStartNext };
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}
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};
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module.exports = BufferHelper; |