text: #include "mov-internal.h"
  #include <assert.h>
  
  // ISO/IEC 14496-12:2012(E)
  // 8.3.2 Track Header Box (p31)
  // Box Type : 'tkhd' 
  // Container : Movie Box('trak') 
  // Mandatory : Yes 
  // Quantity : Exactly one
  
  /*
  aligned(8) class TrackHeaderBox extends FullBox('tkhd', version, flags){ 
  	if (version==1) { 
  		unsigned int(64) creation_time; 
  		unsigned int(64) modification_time; 
  		unsigned int(32) track_ID; 
  		const unsigned int(32) reserved = 0; 
  		unsigned int(64) duration; 
  	} else { // version==0 
  		unsigned int(32) creation_time; 
  		unsigned int(32) modification_time;
  		unsigned int(32) track_ID; 
  		const unsigned int(32) reserved = 0; 
  		unsigned int(32) duration; 
  	} 
  	const unsigned int(32)[2] reserved = 0; 
  	template int(16) layer = 0; 
  	template int(16) alternate_group = 0; 
  	template int(16) volume = {if track_is_audio 0x0100 else 0}; 
  	const unsigned int(16) reserved = 0; 
  	template int(32)[9] matrix= { 0x00010000,0,0,0,0x00010000,0,0,0,0x40000000 }; // unity matrix 
  	unsigned int(32) width; 
  	unsigned int(32) height; 
  }
  */
  int mov_read_tkhd(struct mov_t* mov, const struct mov_box_t* box)
  {
  	int i;
      uint8_t version;
      uint32_t flags;
      uint64_t creation_time;
      uint64_t modification_time;
      uint64_t duration;
      uint32_t track_ID;
  	struct mov_tkhd_t* tkhd;
      struct mov_track_t* track;
  
  	version = mov_buffer_r8(&mov->io);
  	flags = mov_buffer_r24(&mov->io);
  
  	if (1 == version)
  	{
  		creation_time = mov_buffer_r64(&mov->io);
  		modification_time = mov_buffer_r64(&mov->io);
  		track_ID = mov_buffer_r32(&mov->io);
  		/*reserved = */mov_buffer_r32(&mov->io);
  		duration = mov_buffer_r64(&mov->io);
  	}
  	else
  	{
  		assert(0 == version);
  		creation_time = mov_buffer_r32(&mov->io);
  		modification_time = mov_buffer_r32(&mov->io);
  		track_ID = mov_buffer_r32(&mov->io);
  		/*reserved = */mov_buffer_r32(&mov->io);
  		duration = mov_buffer_r32(&mov->io);
  	}
      mov_buffer_skip(&mov->io, 8); // const unsigned int(32)[2] reserved = 0;
  
      track = mov_fetch_track(mov, track_ID);
      if (NULL == track) return -1;
  
      mov->track = track;
      tkhd = &mov->track->tkhd;
  	tkhd->version = version;
      tkhd->flags = flags;
      tkhd->duration = duration;
      tkhd->creation_time = creation_time;
      tkhd->modification_time = modification_time;
  
  	tkhd->layer = (int16_t)mov_buffer_r16(&mov->io);
  	tkhd->alternate_group = (int16_t)mov_buffer_r16(&mov->io);
  	tkhd->volume = (int16_t)mov_buffer_r16(&mov->io);
  	mov_buffer_skip(&mov->io, 2); // const unsigned int(16) reserved = 0;
  	for (i = 0; i < 9; i++)
  		tkhd->matrix[i] = mov_buffer_r32(&mov->io);
  	tkhd->width = mov_buffer_r32(&mov->io);
  	tkhd->height = mov_buffer_r32(&mov->io);
  
  	(void)box;
  	return 0;
  }
  
  size_t mov_write_tkhd(const struct mov_t* mov)
  {
  //	int rotation = 0; // 90/180/270
  	uint16_t group = 0;
  	const struct mov_tkhd_t* tkhd = &mov->track->tkhd;
  
  	mov_buffer_w32(&mov->io, 92); /* size */
  	mov_buffer_write(&mov->io, "tkhd", 4);
  	mov_buffer_w8(&mov->io, 0); /* version */
  	mov_buffer_w24(&mov->io, tkhd->flags); /* flags */
  
  	mov_buffer_w32(&mov->io, (uint32_t)tkhd->creation_time); /* creation_time */
  	mov_buffer_w32(&mov->io, (uint32_t)tkhd->modification_time); /* modification_time */
  	mov_buffer_w32(&mov->io, tkhd->track_ID); /* track_ID */
  	mov_buffer_w32(&mov->io, 0); /* reserved */
  	mov_buffer_w32(&mov->io, (uint32_t)tkhd->duration); /* duration */
  
  	mov_buffer_w32(&mov->io, 0); /* reserved */
  	mov_buffer_w32(&mov->io, 0); /* reserved */
  	mov_buffer_w16(&mov->io, tkhd->layer); /* layer */
  	mov_buffer_w16(&mov->io, group); /* alternate_group */
  	//mov_buffer_w16(&mov->io, AVSTREAM_AUDIO == track->stream_type ? 0x0100 : 0); /* volume */
  	mov_buffer_w16(&mov->io, tkhd->volume); /* volume */
  	mov_buffer_w16(&mov->io, 0); /* reserved */
  
  	// matrix
  	//for (i = 0; i < 9; i++)
  	//	file_reader_rb32(mov->fp, tkhd->matrix[i]);
  	mov_buffer_w32(&mov->io, 0x00010000); /* u */
  	mov_buffer_w32(&mov->io, 0);
  	mov_buffer_w32(&mov->io, 0);
  	mov_buffer_w32(&mov->io, 0); /* v */
  	mov_buffer_w32(&mov->io, 0x00010000);
  	mov_buffer_w32(&mov->io, 0);
  	mov_buffer_w32(&mov->io, 0); /* w */
  	mov_buffer_w32(&mov->io, 0);
  	mov_buffer_w32(&mov->io, 0x40000000);
  
  	mov_buffer_w32(&mov->io, tkhd->width /*track->av.video.width * 0x10000U*/); /* width */
  	mov_buffer_w32(&mov->io, tkhd->height/*track->av.video.height * 0x10000U*/); /* height */
  	return 92;
  }
  