/* puthdr.c, 產生頭信息*/

#include <stdio.h>#include <math.h>#include "global.h"/* 函數聲明 */static int frametotc(int frame);/* 產生序列頭 * */void putseqhdr(){  int i;  alignbits();  putbits(SEQ_START_CODE,32);   putbits(horizontal_size,12);   putbits(vertical_size,12);   putbits(aspectratio,4);   putbits(frame_rate_code,4);   putbits((int)ceil(bit_rate/400.0),18);   putbits(1,1);   putbits(vbv_buffer_size,10);   putbits(constrparms,1);   putbits(load_iquant,1);   if (load_iquant)    for (i=0; i<64; i++)  /*矩陣以之形順序下載 */      putbits(intra_q[zig_zag_scan[i]],8); 1  putbits(load_niquant,1);   if (load_niquant)    for (i=0; i<64; i++)      putbits(inter_q[zig_zag_scan[i]],8); }/* 產生序列的擴展頭*/void putseqext(){  alignbits();  putbits(EXT_START_CODE,32);   putbits(SEQ_ID,4);   putbits((profile<<4)|level,8);   putbits(prog_seq,1);   putbits(chroma_format,2);   putbits(horizontal_size>>12,2);   putbits(vertical_size>>12,2);   putbits(((int)ceil(bit_rate/400.0))>>18,12); /  putbits(1,1);   putbits(vbv_buffer_size>>10,8);   putbits(0,1);   putbits(0,2);   putbits(0,5); }/* 產生序列顯示的擴展頭信息 * */void putseqdispext(){  alignbits();  putbits(EXT_START_CODE,32);   putbits(DISP_ID,4);   putbits(video_format,3);   putbits(1,1);   putbits(color_primaries,8);   putbits(transfer_characteristics,8);   putbits(matrix_coefficients,8);   putbits(display_horizontal_size,14);   putbits(1,1);   putbits(display_vertical_size,14); }void putuserdata(userdata)char *userdata;{  alignbits();  putbits(USER_START_CODE,32);   while (*userdata)    putbits(*userdata++,8);}/* 產生組圖像的頭信息 * */void putgophdr(frame,closed_gop)int frame,closed_gop;{  int tc;  alignbits();  putbits(GOP_START_CODE,32); /* group_start_code */  tc = frametotc(tc0+frame);  putbits(tc,25); /* time_code */  putbits(closed_gop,1); /* closed_gop */  putbits(0,1); /* broken_link */}static int frametotc(frame)int frame;{  int fps, pict, sec, minute, hour, tc;  fps = (int)(frame_rate+0.5);  pict = frame%fps;  frame = (frame-pict)/fps;  sec = frame%60;  frame = (frame-sec)/60;  minute = frame%60;  frame = (frame-minute)/60;  hour = frame%24;  tc = (hour<<19) | (minute<<13) | (1<<12) | (sec<<6) | pict;  return tc;}void putpicthdr(){  alignbits();  putbits(PICTURE_START_CODE,32);   calc_vbv_delay();  putbits(temp_ref,10);   putbits(pict_type,3);   putbits(vbv_delay,16);   if (pict_type==P_TYPE || pict_type==B_TYPE)  {    putbits(0,1);       putbits(forw_hor_f_code,3);  }  if (pict_type==B_TYPE)  {    putbits(0,1);       putbits(back_hor_f_code,3);  }  putbits(0,1);}/* 產生圖像編碼擴展 * */void putpictcodext(){  alignbits();  putbits(EXT_START_CODE,32);   putbits(CODING_ID,4);   putbits(forw_hor_f_code,4);   putbits(forw_vert_f_code,4);   putbits(back_hor_f_code,4);   putbits(back_vert_f_code,4);   putbits(dc_prec,2);   putbits(pict_struct,2);   putbits((pict_struct==FRAME_PICTURE)?topfirst:0,1);   putbits(frame_pred_dct,1);   putbits(0,1);   putbits(q_scale_type,1);   putbits(intravlc,1);   putbits(altscan,1);   putbits(repeatfirst,1);   putbits(prog_frame,1);   putbits(prog_frame,1);   putbits(0,1); }/* 產生序列結束字節*/void putseqend(){  alignbits();  putbits(SEQ_END_CODE,32);}