mpeg2enc/puthdr.c

   1 /* puthdr.c, generation of headers                                          */
   2
   3 /* Copyright (C) 1996, MPEG Software Simulation Group. All Rights Reserved. */
   4
   5 /*
   6  * Disclaimer of Warranty
   7  *
   8  * These software programs are available to the user without any license fee or
   9  * royalty on an "as is" basis.  The MPEG Software Simulation Group disclaims
  10  * any and all warranties, whether express, implied, or statuary, including any
  11  * implied warranties or merchantability or of fitness for a particular
  12  * purpose.  In no event shall the copyright-holder be liable for any
  13  * incidental, punitive, or consequential damages of any kind whatsoever
  14  * arising from the use of these programs.
  15  *
  16  * This disclaimer of warranty extends to the user of these programs and user's
  17  * customers, employees, agents, transferees, successors, and assigns.
  18  *
  19  * The MPEG Software Simulation Group does not represent or warrant that the
  20  * programs furnished hereunder are free of infringement of any third-party
  21  * patents.
  22  *
  23  * Commercial implementations of MPEG-1 and MPEG-2 video, including shareware,
  24  * are subject to royalty fees to patent holders.  Many of these patents are
  25  * general enough such that they are unavoidable regardless of implementation
  26  * design.
  27  *
  28  */
  29
  30 #include <stdio.h>
  31 #include <math.h>
  32 #include "config.h"
  33 #include "global.h"
  34
  35 /* private prototypes */
  36 static int frametotc _ANSI_ARGS_((int frame));
  37
  38 /* generate sequence header (6.2.2.1, 6.3.3)
  39  *
  40  * matrix download not implemented
  41  */
  42 void putseqhdr()
  43 {
  44   int i;
  45
  46   alignbits();
  47   mpeg2enc_putbits(SEQ_START_CODE,32); /* sequence_header_code */
  48   mpeg2enc_putbits(horizontal_size,12); /* horizontal_size_value */
  49   mpeg2enc_putbits(vertical_size,12); /* vertical_size_value */
  50   mpeg2enc_putbits(aspectratio,4); /* aspect_ratio_information */
  51   mpeg2enc_putbits(frame_rate_code,4); /* frame_rate_code */
  52   mpeg2enc_putbits((int)ceil(bit_rate/400.0),18); /* bit_rate_value */
  53   mpeg2enc_putbits(1,1); /* marker_bit */
  54   mpeg2enc_putbits(vbv_buffer_size,10); /* vbv_buffer_size_value */
  55   mpeg2enc_putbits(constrparms,1); /* constrained_parameters_flag */
  56
  57   mpeg2enc_putbits(load_iquant,1); /* load_intra_quantizer_matrix */
  58   if (load_iquant)
  59     for (i=0; i<64; i++)  /* matrices are always downloaded in zig-zag order */
  60       mpeg2enc_putbits(intra_q[mpeg2_zig_zag_scan[i]],8); /* intra_quantizer_matrix */
  61
  62   mpeg2enc_putbits(load_niquant,1); /* load_non_intra_quantizer_matrix */
  63   if (load_niquant)
  64     for (i=0; i<64; i++)
  65       mpeg2enc_putbits(inter_q[mpeg2_zig_zag_scan[i]],8); /* non_intra_quantizer_matrix */
  66         if (!mpeg1)
  67         {
  68                 putseqext();
  69                 putseqdispext();
  70         }
  71 }
  72
  73 /* generate sequence extension (6.2.2.3, 6.3.5) header (MPEG-2 only) */
  74 void putseqext()
  75 {
  76   alignbits();
  77   mpeg2enc_putbits(EXT_START_CODE,32); /* extension_start_code */
  78   mpeg2enc_putbits(SEQ_ID,4); /* extension_start_code_identifier */
  79   mpeg2enc_putbits((profile<<4)|level,8); /* profile_and_level_indication */
  80   mpeg2enc_putbits(prog_seq,1); /* progressive sequence */
  81   mpeg2enc_putbits(chroma_format,2); /* chroma_format */
  82   mpeg2enc_putbits(horizontal_size>>12,2); /* horizontal_size_extension */
  83   mpeg2enc_putbits(vertical_size>>12,2); /* vertical_size_extension */
  84   mpeg2enc_putbits(((int)ceil(bit_rate/400.0))>>18,12); /* bit_rate_extension */
  85   mpeg2enc_putbits(1,1); /* marker_bit */
  86   mpeg2enc_putbits(vbv_buffer_size>>10,8); /* vbv_buffer_size_extension */
  87   mpeg2enc_putbits(0,1); /* low_delay  -- currently not implemented */
  88   mpeg2enc_putbits(0,2); /* frame_rate_extension_n */
  89   mpeg2enc_putbits(0,5); /* frame_rate_extension_d */
  90 }
  91
  92 /* generate sequence display extension (6.2.2.4, 6.3.6)
  93  *
  94  * content not yet user setable
  95  */
  96 void putseqdispext()
  97 {
  98   alignbits();
  99   mpeg2enc_putbits(EXT_START_CODE,32); /* extension_start_code */
 100   mpeg2enc_putbits(DISP_ID,4); /* extension_start_code_identifier */
 101   mpeg2enc_putbits(video_format,3); /* video_format */
 102   mpeg2enc_putbits(1,1); /* colour_description */
 103   mpeg2enc_putbits(color_primaries,8); /* colour_primaries */
 104   mpeg2enc_putbits(transfer_characteristics,8); /* transfer_characteristics */
 105   mpeg2enc_putbits(matrix_coefficients,8); /* matrix_coefficients */
 106   mpeg2enc_putbits(display_horizontal_size,14); /* display_horizontal_size */
 107   mpeg2enc_putbits(1,1); /* marker_bit */
 108   mpeg2enc_putbits(display_vertical_size,14); /* display_vertical_size */
 109 }
 110
 111 /* output a zero terminated string as user data (6.2.2.2.2, 6.3.4.1)
 112  *
 113  * string must not emulate start codes
 114  */
 115 void putuserdata(userdata)
 116 char *userdata;
 117 {
 118   alignbits();
 119   mpeg2enc_putbits(USER_START_CODE,32); /* user_data_start_code */
 120   while (*userdata)
 121     mpeg2enc_putbits(*userdata++,8);
 122 }
 123
 124 /* generate group of pictures header (6.2.2.6, 6.3.9)
 125  *
 126  * uses tc0 (timecode of first frame) and frame0 (number of first frame)
 127  */
 128 void putgophdr(frame,closed_gop)
 129 int frame,closed_gop;
 130 {
 131   int tc;
 132
 133   alignbits();
 134   mpeg2enc_putbits(GOP_START_CODE,32); /* group_start_code */
 135   tc = frametotc(tc0+frame);
 136   mpeg2enc_putbits(tc,25); /* time_code */
 137   mpeg2enc_putbits(closed_gop,1); /* closed_gop */
 138   mpeg2enc_putbits(0,1); /* broken_link */
 139 }
 140
 141 /* convert frame number to time_code
 142  *
 143  * drop_frame not implemented
 144  */
 145 static int frametotc(frame)
 146 int frame;
 147 {
 148   int fps, pict, sec, minute, hour, tc;
 149
 150   fps = (int)(frame_rate+0.5);
 151   pict = frame%fps;
 152   frame = (frame-pict)/fps;
 153   sec = frame%60;
 154   frame = (frame-sec)/60;
 155   minute = frame%60;
 156   frame = (frame-minute)/60;
 157   hour = frame%24;
 158   tc = (hour<<19) | (minute<<13) | (1<<12) | (sec<<6) | pict;
 159
 160   return tc;
 161 }
 162
 163 /* generate picture header (6.2.3, 6.3.10) */
 164 void putpicthdr(pict_data_s *picture)
 165 {
 166   alignbits();
 167   mpeg2enc_putbits(PICTURE_START_CODE,32); /* picture_start_code */
 168   mpeg2enc_putbits(picture->temp_ref,10); /* temporal_reference */
 169   mpeg2enc_putbits(picture->pict_type,3); /* picture_coding_type */
 170   mpeg2enc_putbits(picture->vbv_delay,16); /* vbv_delay */
 171 //printf("putpicthdr %d %d %d\n", picture->temp_ref, picture->pict_type, picture->vbv_delay);
 172
 173   if (picture->pict_type==P_TYPE || picture->pict_type==B_TYPE)
 174   {
 175     mpeg2enc_putbits(0,1); /* full_pel_forward_vector */
 176     if (mpeg1)
 177       mpeg2enc_putbits(picture->forw_hor_f_code,3);
 178     else
 179       mpeg2enc_putbits(7,3); /* forward_f_code */
 180   }
 181
 182   if (picture->pict_type==B_TYPE)
 183   {
 184     mpeg2enc_putbits(0,1); /* full_pel_backward_vector */
 185     if (mpeg1)
 186       mpeg2enc_putbits(picture->back_hor_f_code,3);
 187     else
 188       mpeg2enc_putbits(7,3); /* backward_f_code */
 189   }
 190
 191   mpeg2enc_putbits(0,1); /* extra_bit_picture */
 192 }
 193
 194 /* generate picture coding extension (6.2.3.1, 6.3.11)
 195  *
 196  * composite display information (v_axis etc.) not implemented
 197  */
 198 void putpictcodext(pict_data_s *picture)
 199 {
 200   alignbits();
 201   mpeg2enc_putbits(EXT_START_CODE,32); /* extension_start_code */
 202   mpeg2enc_putbits(CODING_ID,4); /* extension_start_code_identifier */
 203   mpeg2enc_putbits(picture->forw_hor_f_code,4); /* forward_horizontal_f_code */
 204   mpeg2enc_putbits(picture->forw_vert_f_code,4); /* forward_vertical_f_code */
 205   mpeg2enc_putbits(picture->back_hor_f_code,4); /* backward_horizontal_f_code */
 206   mpeg2enc_putbits(picture->back_vert_f_code,4); /* backward_vertical_f_code */
 207   mpeg2enc_putbits(picture->dc_prec,2); /* intra_dc_precision */
 208   mpeg2enc_putbits(picture->pict_struct,2); /* picture_structure */
 209   mpeg2enc_putbits((picture->pict_struct==FRAME_PICTURE)?picture->topfirst:0,1); /* top_field_first */
 210   mpeg2enc_putbits(picture->frame_pred_dct,1); /* frame_pred_frame_dct */
 211   mpeg2enc_putbits(0,1); /* concealment_motion_vectors  -- currently not implemented */
 212   mpeg2enc_putbits(picture->q_scale_type,1); /* q_scale_type */
 213   mpeg2enc_putbits(picture->intravlc,1); /* intra_vlc_format */
 214   mpeg2enc_putbits(picture->altscan,1); /* alternate_scan */
 215   mpeg2enc_putbits(picture->repeatfirst,1); /* repeat_first_field */
 216   mpeg2enc_putbits(picture->prog_frame,1); /* chroma_420_type */
 217   mpeg2enc_putbits(picture->prog_frame,1); /* progressive_frame */
 218   mpeg2enc_putbits(0,1); /* composite_display_flag */
 219 }
 220
 221 /* generate sequence_end_code (6.2.2) */
 222 void putseqend()
 223 {
 224   alignbits();
 225   mpeg2enc_putbits(SEQ_END_CODE,32);
 226 }