mp4box/src/writing/trun.js

JavaScript version of GPAC's MP4Box tool

BoxParser.trunBox.prototype.write = function(stream) {
	this.version = 0;
	this.size = 4;
	if (this.flags & BoxParser.TRUN_FLAGS_DATA_OFFSET) {
		this.size += 4;
	}
	if (this.flags & BoxParser.TRUN_FLAGS_FIRST_FLAG) {
		this.size += 4;
	}
	if (this.flags & BoxParser.TRUN_FLAGS_DURATION) {
		this.size += 4*this.sample_duration.length;
	}
	if (this.flags & BoxParser.TRUN_FLAGS_SIZE) {
		this.size += 4*this.sample_size.length;
	}
	if (this.flags & BoxParser.TRUN_FLAGS_FLAGS) {
		this.size += 4*this.sample_flags.length;
	}
	if (this.flags & BoxParser.TRUN_FLAGS_CTS_OFFSET) {
		this.size += 4*this.sample_composition_time_offset.length;
	}
	this.writeHeader(stream);
	stream.writeUint32(this.sample_count);
	if (this.flags & BoxParser.TRUN_FLAGS_DATA_OFFSET) {
		this.data_offset_position = stream.getPosition();
		stream.writeInt32(this.data_offset); //signed
	}
	if (this.flags & BoxParser.TRUN_FLAGS_FIRST_FLAG) {
		stream.writeUint32(this.first_sample_flags);
	}
	for (var i = 0; i < this.sample_count; i++) {
		if (this.flags & BoxParser.TRUN_FLAGS_DURATION) {
			stream.writeUint32(this.sample_duration[i]);
		}
		if (this.flags & BoxParser.TRUN_FLAGS_SIZE) {
			stream.writeUint32(this.sample_size[i]);
		}
		if (this.flags & BoxParser.TRUN_FLAGS_FLAGS) {
			stream.writeUint32(this.sample_flags[i]);
		}
		if (this.flags & BoxParser.TRUN_FLAGS_CTS_OFFSET) {
			if (this.version === 0) {
				stream.writeUint32(this.sample_composition_time_offset[i]);
			} else {
				stream.writeInt32(this.sample_composition_time_offset[i]); //signed
			}
		}
	}		
}