50 lines
932 B
JavaScript
50 lines
932 B
JavaScript
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DataView.prototype.getString = function(offset, length) {
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text = '';
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let end = offset + length;
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for (let i = offset; i < end; i++) {
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text += String.fromCharCode(this.getUint8(i));
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}
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return text;
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}
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class MP4Tree {
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constructor(data) {
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this.data = new DataView(data);
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this.codecs = [];
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this.idx = 0;
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this.parse_codecs();
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}
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parse_codecs() {
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this.parse_until('moov');
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console.log(this.idx);
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}
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get_mime() {
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return 'video/mp4; codecs="' + this.get_codec_string() + '"';
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}
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get_codec_string() {
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return this.codecs.join(', ');
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}
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parse_until(name) {
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let curr_head = null;
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while (this.idx < this.data.byteLength) {
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curr_head = this.read_next_head();
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console.log(curr_head);
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if (curr_head.name == name) {
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break;
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} else {
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this.idx += curr_head.len;
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}
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}
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}
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read_next_head() {
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return {"len": this.data.getUint32(this.idx), "name": this.data.getString(this.idx + 4, 4)};
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}
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}
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