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- "use strict";
- var tfhd = function tfhd(data) {
- var view = new DataView(data.buffer, data.byteOffset, data.byteLength),
- result = {
- version: data[0],
- flags: new Uint8Array(data.subarray(1, 4)),
- trackId: view.getUint32(4)
- },
- baseDataOffsetPresent = result.flags[2] & 0x01,
- sampleDescriptionIndexPresent = result.flags[2] & 0x02,
- defaultSampleDurationPresent = result.flags[2] & 0x08,
- defaultSampleSizePresent = result.flags[2] & 0x10,
- defaultSampleFlagsPresent = result.flags[2] & 0x20,
- durationIsEmpty = result.flags[0] & 0x010000,
- defaultBaseIsMoof = result.flags[0] & 0x020000,
- i;
- i = 8;
- if (baseDataOffsetPresent) {
- i += 4; // truncate top 4 bytes
- // FIXME: should we read the full 64 bits?
- result.baseDataOffset = view.getUint32(12);
- i += 4;
- }
- if (sampleDescriptionIndexPresent) {
- result.sampleDescriptionIndex = view.getUint32(i);
- i += 4;
- }
- if (defaultSampleDurationPresent) {
- result.defaultSampleDuration = view.getUint32(i);
- i += 4;
- }
- if (defaultSampleSizePresent) {
- result.defaultSampleSize = view.getUint32(i);
- i += 4;
- }
- if (defaultSampleFlagsPresent) {
- result.defaultSampleFlags = view.getUint32(i);
- }
- if (durationIsEmpty) {
- result.durationIsEmpty = true;
- }
- if (!baseDataOffsetPresent && defaultBaseIsMoof) {
- result.baseDataOffsetIsMoof = true;
- }
- return result;
- };
- module.exports = tfhd;
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