video_stream.c

基于linux的DVD播放器程序

	  q_shmid = ev.gntpicbuf.q_shmid;
	  break;
	} else {
	  handle_events(msgq, &ev);
	}
      }
    }

    if(q_shmid >= 0) {
      if((q_shmaddr = shmat(q_shmid, NULL, SHM_SHARE_MMU)) == (void *)-1) {
	perror("**video_decode: attach_picq_buffer(), shmat()");
	return -1;
      }
      
      q_head = (q_head_t *)q_shmaddr;
      q_elems = (q_elem_t *)(q_shmaddr+sizeof(q_head_t));
      
    } else {
      ERROR("%s", "couldn't get qbuffer\n");
    }
    
  } else {
    ERROR("%s", "couldn't get buffer\n");
  }
  



  data_q->q_head = q_head;
  data_q->q_elems = q_elems;
  data_q->data_head = data_head;
  data_q->data_elems = data_elems;
  data_q->image_bufs = image_bufs;
    
#ifdef HAVE_MMX
  emms();
#endif
  
  /* this should not be here */
  DNOTE("horizontal_size: %d, vertical_size: %d\n",
	seq.horizontal_size, seq.vertical_size);
  DNOTE("padded_width: %d, padded_height: %d\n",
	padded_width, padded_height);
  
  DNOTE("%s", "frame rate: ");
  switch(seq.header.frame_rate_code) {
  case 0x0:
    break;
  case 0x1:
    DNOTEC("%s", "24000/1001 (23.976)\n");
    break;
  case 0x2:
    DNOTEC("%s", "24\n");
    break;
  case 0x3:
    DNOTEC("%s", "25\n");
    break;
  case 0x4:
    DNOTEC("%s", "30000/1001 (29.97)\n");
    break;
  case 0x5:
    DNOTEC("%s", "30\n");
    break;
  case 0x6:
    DNOTEC("%s", "50\n");
    break;
  case 0x7:
    DNOTEC("%s", "60000/1001 (59.94)\n");
    break;
  case 0x8:
    DNOTEC("%s", "60\n");
    break;
  default:
    DNOTEC("%f (computed)\n",
	   (double)(seq.header.frame_rate_code)*
	   ((double)(seq.ext.frame_rate_extension_n)+1.0)/
	   ((double)(seq.ext.frame_rate_extension_d)+1.0));
    break;
  }

  return 0;
}


/* 6.2.2.3 Sequence extension */
void sequence_extension(void) {
  long int frame_interval_pts = 0;
  uint32_t extension_start_code;
  
  extension_start_code = GETBITS(32, "extension_start_code");
  if(extension_start_code != MPEG2_VS_EXTENSION_START_CODE) {
    WARNING("wrong start_code extension_start_code: %08x\n",
	    extension_start_code);
  }

  DPRINTFI(1, "sequence_extension()\n");
  DINDENT(2);
  
  seq.ext.extension_start_code_identifier 
    = GETBITS(4, "extension_start_code_identifier");
  seq.ext.profile_and_level_indication 
    = GETBITS(8, "profile_and_level_indication");
  seq.ext.progressive_sequence = GETBITS(1, "progressive_sequence");
  seq.ext.chroma_format = GETBITS(2, "chroma_format");
  seq.ext.horizontal_size_extension = GETBITS(2, "horizontal_size_extension");
  seq.ext.vertical_size_extension = GETBITS(2, "vertical_size_extension");
  seq.ext.bit_rate_extension = GETBITS(12, "bit_rate_extension");
  marker_bit();
  seq.ext.vbv_buffer_size_extension = GETBITS(8, "vbv_buffer_size_extension");
  seq.ext.low_delay = GETBITS(1, "low_delay");
  seq.ext.frame_rate_extension_n = GETBITS(2, "frame_rate_extension_n");
  seq.ext.frame_rate_extension_d = GETBITS(5, "frame_rate_extension_d");
  next_start_code();

  seq.horizontal_size |= (seq.ext.horizontal_size_extension << 12);
  seq.vertical_size |= (seq.ext.vertical_size_extension << 12);

  seq.dpy_ext.display_horizontal_size = 0; //reset
  seq.dpy_ext.display_vertical_size = 0;
  
  //frame_centre_horizontal_offset = 0; // reset
  //frame_centre_vertical_offset = 0;

#ifdef DEBUG
	   
  DPRINTFI(2, "profile_and_level_indication: ");
  if(seq.ext.profile_and_level_indication & 0x80) {
    DPRINTF(2, "(reserved)\n");
  } else {
    DPRINTF(2, "Profile: ");
    switch((seq.ext.profile_and_level_indication & 0x70)>>4) {
    case 0x5:
      DPRINTF(2, "Simple");
      break;
    case 0x4:
      DPRINTF(2, "Main");
      break;
    case 0x3:
      DPRINTF(2, "SNR Scalable");
      break;
    case 0x2:
      DPRINTF(2, "Spatially Scalable");
      break;
    case 0x1:
      DPRINTF(2, "High");
      break;
    default:
      DPRINTF(2, "(reserved)");
      break;
    }

    DPRINTF(2, ", Level: ");
    switch(seq.ext.profile_and_level_indication & 0x0f) {
    case 0xA:
      DPRINTF(2, "Low");
      break;
    case 0x8:
      DPRINTF(2, "Main");
      break;
    case 0x6:
      DPRINTF(2, "High 1440");
      break;
    case 0x4:
      DPRINTF(2, "High");
      break;
    default:
      DPRINTF(2, "(reserved)");
      break;
    }
    DPRINTF(2, "\n");
  }
 
  DPRINTFI(2, "progressive seq: %01x\n", seq.ext.progressive_sequence);

  DPRINTFI(2, "chroma_format:(0x%01x) ", seq.ext.chroma_format);
  switch(seq.ext.chroma_format) {
  case 0x0:
    DPRINTF(2, "reserved\n");
    break;
  case 0x1:
    DPRINTF(2, "4:2:0\n");
    break;
  case 0x2:
    DPRINTF(2, "4:2:2\n");
    break;
  case 0x3:
    DPRINTF(2, "4:4:4\n");
    break;
  }
#endif

  DPRINTFI(2, "horizontal_size: %u\n", seq.horizontal_size);
  DPRINTFI(2, "vertical_size: %u\n", seq.vertical_size);

  DPRINTFI(2, "bit_rate: %d bits/second\n",
	  400 * ((seq.ext.bit_rate_extension << 12) 
		 | seq.header.bit_rate_value));

  DPRINTFI(2, "vbv_buffer_size: min %d bits\n",
	   16*1024*((seq.ext.vbv_buffer_size_extension << 10) |
		    seq.header.vbv_buffer_size_value));
  DPRINTFI(2, "low_delay: %01x\n", seq.ext.low_delay);
  
  DPRINTFI(2, "frame_rate: ");
  switch(seq.header.frame_rate_code) {
  case 0x0:
    DPRINTF(2, "forbidden\n");
    break;
  case 0x1:
    DPRINTF(2, "24000/1001 (23.976)\n");
    frame_interval_pts = 3754;
    break;
  case 0x2:
    DPRINTF(2, "24\n");
    frame_interval_pts = 3750;
    break;
  case 0x3:
    DPRINTF(2, "25\n");
    frame_interval_pts = 3600;
    break;
  case 0x4:
    DPRINTF(2, "30000/1001 (29.97)\n");
    if(last_gop_had_repeat_field_progressive_frame) {
      /* it's probably coded as 24 fps progressive */
      frame_interval_pts = 3754;
    } else {
      frame_interval_pts = 3003;
    }
    break;
  case 0x5:
    DPRINTF(2, "30\n");
    frame_interval_pts = 3000;
    break;
  case 0x6:
    DPRINTF(2, "50\n");
    frame_interval_pts = 1800;
    break;
  case 0x7:
    DPRINTF(2, "60000/1001 (59.94)\n");
    frame_interval_pts = 1502;
    break;
  case 0x8:
    DPRINTF(2, "60\n");
    frame_interval_pts = 1500;
    break;
  default:
    DPRINTF(2, "%f (computed)\n",
	    (double)(seq.header.frame_rate_code)*
	    ((double)(seq.ext.frame_rate_extension_n)+1.0)/
	    ((double)(seq.ext.frame_rate_extension_d)+1.0));
    //TODO: frame_interval_nsec = ?
    fprintf(stderr, "fixme computed framerate\n");
    break;
  }

  if(forced_frame_rate == -1) { /* No forced frame rate */
    //buf_ctrl_head->frame_interval = frame_interval_pts;
    frame_interval = frame_interval_pts;
  } else {
    if(forced_frame_rate == 0) {
      //buf_ctrl_head->frame_interval = 1;
      frame_interval = 1;
    } else {
      //buf_ctrl_head->frame_interval = PTS_BASE/forced_frame_rate;
      frame_interval = PTS_BASE/forced_frame_rate;
    }
  }
  DINDENT(-2);
}


/* 6.2.2.2 Extension and user data */
void extension_and_user_data(const unsigned int i) {
  
  DPRINTFI(1, "extension_and_user_data(%u)\n", i);
  DINDENT(2);
  while((nextbits(32) == MPEG2_VS_EXTENSION_START_CODE) ||
	(nextbits(32) == MPEG2_VS_USER_DATA_START_CODE)) {
    if(i != 1) {
      if(nextbits(32) == MPEG2_VS_EXTENSION_START_CODE) {
	extension_data(i);
      }
    }
    if(nextbits(32) == MPEG2_VS_USER_DATA_START_CODE) {
      user_data();
    }
  }
  DINDENT(-2);
}


/* 6.2.3.1 Picture coding extension */
int picture_coding_extension(void)
{
  uint32_t extension_start_code;
  unsigned int m,n;

  DPRINTFI(1, "picture_coding_extension()\n");
  DINDENT(2);
  extension_start_code = GETBITS(32, "extension_start_code");
  if(extension_start_code != MPEG2_VS_EXTENSION_START_CODE) {
    WARNING("wrong start_code extension_start_code: %08x\n",
	    extension_start_code);
    DINDENT(-2);
    return -1;
  }
  pic.coding_ext.extension_start_code_identifier 
    = GETBITS(4, "extension_start_code_identifier");

  pic.coding_ext.f_code[0][0] = GETBITS(4, "f_code[0][0]");
  pic.coding_ext.f_code[0][1] = GETBITS(4, "f_code[0][1]");
  pic.coding_ext.f_code[1][0] = GETBITS(4, "f_code[1][0]");
  pic.coding_ext.f_code[1][1] = GETBITS(4, "f_code[1][1]");
  
  /* FIXME: Workaround for faulty streams. */
  for(n = 0; n < 2; n++) {
    for(m = 0; m < 2; m++) {
      if(pic.coding_ext.f_code[n][m] == 0) {
	pic.coding_ext.f_code[n][m] = 1;
	WARNING("f_code[%d][%d] == ZERO\n", n, m);
      }
    }
  }
  pic.coding_ext.intra_dc_precision = GETBITS(2, "intra_dc_precision");

  /** opt4 **/
  switch(pic.coding_ext.intra_dc_precision) {
  case 0x0:
    mb.intra_dc_mult = 8;
    break;
  case 0x1:
    mb.intra_dc_mult = 4;
    break;
  case 0x2:
    mb.intra_dc_mult = 2;
    break;
  case 0x3:
    mb.intra_dc_mult = 1;
    break;
  }
  /**/
  pic.coding_ext.picture_structure = GETBITS(2, "picture_structure");
  
#ifdef DEBUG
  /* Table 6-14 Meaning of picture_structure */
  DPRINTFI(2, "picture_structure: ");
  switch(pic.coding_ext.picture_structure) {
  case PIC_STRUCT_RESERVED:
    DPRINTF(2, "reserved");
    break;
  case PIC_STRUCT_TOP_FIELD:
    DPRINTF(2, "Top Field");
    break;
  case PIC_STRUCT_BOTTOM_FIELD:
    DPRINTF(2, "Bottom Field");
    break;
  case PIC_STRUCT_FRAME_PICTURE:
    DPRINTF(2, "Frame Picture");
    break;
  }
  DPRINTF(2, "\n");
#endif
  
  /* FIXME: Workaround for faulty streams. */
  if(pic.coding_ext.picture_structure == PIC_STRUCT_RESERVED)
    pic.coding_ext.picture_structure = PIC_STRUCT_FRAME_PICTURE;

  pic.coding_ext.top_field_first = GETBITS(1, "top_field_first");
  pic.coding_ext.frame_pred_frame_dct = GETBITS(1, "frame_pred_frame_dct");
  pic.coding_ext.concealment_motion_vectors 
    = GETBITS(1, "concealment_motion_vectors");
  pic.coding_ext.q_scale_type = GETBITS(1, "q_scale_type");
  pic.coding_ext.intra_vlc_format = GETBITS(1, "intra_vlc_format");
  pic.coding_ext.alternate_scan = GETBITS(1, "alternate_scan");
  pic.coding_ext.repeat_first_field = GETBITS(1, "repeat_first_field");
  pic.coding_ext.chroma_420_type = GETBITS(1, "chroma_420_type");
  pic.coding_ext.progressive_frame = GETBITS(1, "progressive_frame");
  pic.coding_ext.composite_display_flag = GETBITS(1, "composite_display_flag");
  
  DPRINTFI(2, "top_field_first: %01x\n", pic.coding_ext.top_field_first);
  DPRINTFI(2, "frame_pred_frame_dct: %01x\n", pic.coding_ext.frame_pred_frame_dct);
  DPRINTFI(2, "intra_vlc_format: %01x\n", pic.coding_ext.intra_vlc_format);
  DPRINTFI(2, "alternate_scan: %01x\n", pic.coding_ext.alternate_scan);
  DPRINTFI(2, "repeat_first_field: %01x\n", pic.coding_ext.repeat_first_field);
  DPRINTFI(2, "progressive_frame: %01x\n", pic.coding_ext.progressive_frame);
  DPRINTFI(2, "composite_display_flag: %01x\n", pic.coding_ext.composite_display_flag);
  
  if(pic.coding_ext.composite_display_flag) {
    pic.coding_ext.v_axis = GETBITS(1, "v_axis");
    pic.coding_ext.field_sequence = GETBITS(3, "field_sequence");
    pic.coding_ext.sub_carrier = GETBITS(1, "sub_carrier");
    pic.coding_ext.burst_amplitude = GETBITS(7, "burst_amplitude");
    pic.coding_ext.sub_carrier_phase = GETBITS(8, "sub_carrier_phase");
  }
  
  if(pic.coding_ext.progressive_frame &&
     pic.coding_ext.repeat_first_field) {
    last_gop_had_repeat_field_progressive_frame++;
  }
  seq.mb_width = (seq.horizontal_size+15)/16;
  
  if(seq.ext.progressive_sequence) {
    seq.mb_height = (seq.vertical_size+15)/16;
  } else {
    if(pic.coding_ext.picture_structure == PIC_STRUCT_FRAME_PICTURE) {
      /* frame pic */
      seq.mb_height = 2*((seq.vertical_size+31)/32);
    } else {
      /* field_picture */
      seq.mb_height = ((seq.vertical_size+31)/32);
    }
  }
  DINDENT(-2);
  next_start_code();
  return 0;
}


/* 6.2.2.2.2 User data */
void user_data(void)
{
  uint32_t user_data_start_code;
  
  DPRINTFI(1, "user_data()\n");
  DINDENT(2);
  user_data_start_code = GETBITS(32, "user_data_start_code");
  /* It's safe, all callers have already tested for the correct start code */
  while(nextbits(24) != 0x000001) {
    GETBITS(8, "user_data");
  }
  DINDENT(-2);
  next_start_code();  
}


/* 6.2.2.6 Group of pictures header */
void group_of_pictures_header(void)
{
  uint32_t group_start_code;
  uint32_t time_code;
  uint8_t closed_gop;
  uint8_t broken_link;
  
  DPRINTFI(1, "group_of_pictures_header()\n");
  DINDENT(2);
  group_start_code = GETBITS(32, "group_start_code");

  if(group_start_code != MPEG2_VS_GROUP_START_CODE) {
    WARNING("wrong start_code group_start_code: %08x\n",
	    group_start_code);
  }
  /* TODO hack for progessive 24 */
  last_gop_had_repeat_field_progressive_frame = 0;

  time_code = GETBITS(25, "time_code");

  /* Table 6-11 --- time_code */
  DPRINTFI(2, "time_code: %02d:%02d.%02d'%02d\n",
	  (time_code & 0x00f80000)>>19,
	  (time_code & 0x0007e000)>>13,
	  (time_code & 0x00000fc0)>>6,
	  (time_code & 0x0000003f));
  
  /* These need to be in seq or some thing like that */
  closed_gop = GETBITS(1, "closed_gop");
  broken_link = GETBITS(1, "broken_link");

  last_temporal_ref_to_dpy = -1;
  prev_coded_temp_ref = -2;
  
  DINDENT(-2);
  next_start_code();
}


/* 6.2.3 Picture header */
int picture_header(void)
{
  uint32_t picture_start_code;

  DPRINTFI(1, "picture_header()\n");
  DINDENT(2);
  
  seq.mb_row = 0;
  picture_start_code = GETBITS(32, "picture_start_code");