audio.cpp

完整的RTP RTSP代码库

#include "mpeg4ip.h"
#include "mp4v2/mp4.h"
#include <mpeg4ip_bitstream.h>

void CheckProgramConfigElement (CBitstream *bs) {
  uint32_t temp, i, num_front_channel_elements, num_side_channel_elements, num_back_channel_elements;
  uint32_t num_lfe_channel_elements, num_assoc_data_elements, num_valid_cc_elements;
  
  printf("  Program Config Element\n");
  temp = bs->GetBits(4);
  printf("    element_instance_tag - 0x%x\n", temp);

  temp = bs->GetBits(2);
  printf("    object_type - 0x%x\n", temp);

  temp = bs->GetBits(4);
  printf("    sampling_frequency_index - 0x%x\n", temp);

  num_front_channel_elements = bs->GetBits(4);
  printf("    num_front_channel_elements - 0x%x\n", num_front_channel_elements);

  num_side_channel_elements = bs->GetBits(4);
  printf("    num_side_channel_elements - 0x%x\n", num_side_channel_elements);

  num_back_channel_elements = bs->GetBits(4);
  printf("    num_back_channel_elements - 0x%x\n", num_back_channel_elements);

  num_lfe_channel_elements = bs->GetBits(2);
  printf("    num_lfe_channel_elements - 0x%x\n", num_lfe_channel_elements);

  num_assoc_data_elements = bs->GetBits(3);
  printf("    num_assoc_data_elements - 0x%x\n", num_assoc_data_elements);

  num_valid_cc_elements = bs->GetBits(4);
  printf("    num_valid_cc_elements - 0x%x\n", num_valid_cc_elements);

  temp = bs->GetBits(1);
  printf("    mono_mixdown_present - 0x%x\n", temp);
  if(temp) {
    temp = bs->GetBits(4);
    printf("      mono_mixdown_element_number - 0x%x\n", temp);
  }

  temp = bs->GetBits(1);
  printf("    stereo_mixdown_present - 0x%x\n", temp);
  if(temp) {
    temp = bs->GetBits(4);
    printf("      stereo_mixdown_element_number - 0x%x\n", temp);
  }

  temp = bs->GetBits(1);
  printf("    matrix_mixdown_idx_present - 0x%x\n", temp);
  if(temp) {
    temp = bs->GetBits(2);
    printf("      matrix_mixdown_idx - 0x%x\n", temp);

    temp = bs->GetBits(1);
    printf("      pseudo_surround_enable - 0x%x\n", temp);
  }

  for (i = 0; i < num_front_channel_elements; i++) {
    printf("    front_channel_element - %i\n", i);
    temp = bs->GetBits(1);
    printf("      front_element_is_cpei? - 0x%x\n", temp);
    temp = bs->GetBits(4);
    printf("      front_element_tag_selecti? - 0x%x\n", temp);
  }

  for (i = 0; i < num_side_channel_elements; i++) {  
    printf("    side_channel_element - %i\n", i);
    temp = bs->GetBits(1);
    printf("      side_element_is_cpei? - 0x%x\n", temp);
    temp = bs->GetBits(4);
    printf("      side_element_tag_selecti? - 0x%x\n", temp);
  }

  for (i = 0; i < num_back_channel_elements; i++) {  
    printf("    back_channel_element - %i\n", i);
    temp = bs->GetBits(1);
    printf("      back_element_is_cpei? - 0x%x\n", temp);
    temp = bs->GetBits(4);
    printf("      back_element_tag_selecti? - 0x%x\n", temp);
  } 

  for (i = 0; i < num_lfe_channel_elements; i++) {
    printf("    lfe_channel_element - %i\n", i);
    temp = bs->GetBits(4);
    printf("      lfe_element_tag_selecti? - 0x%x\n", temp);
  }
  
  for (i = 0; i < num_assoc_data_elements; i++) {
    printf("    assoc_data_element - %i\n", i);
    temp = bs->GetBits(4);
    printf("      assoc_data_element_tag_selecti? - 0x%x\n", temp);
  }
  
  for (i = 0; i < num_valid_cc_elements; i++) {  
    printf("    valid_cc__element - %i\n", i);
    temp = bs->GetBits(1);
    printf("      cc_element_is_ind_swi? - 0x%x\n", temp);
    temp = bs->GetBits(4);
    printf("      valid_cc_element_tag_selecti? - 0x%x\n", temp);
  }

  bs->byte_align();
  uint32_t comment_field_bytes = bs->GetBits(8);
  printf("    comment_field_bytes - 0x%x\n", comment_field_bytes);
  if(comment_field_bytes > 0) {
    char *comment_field = (char *)malloc(comment_field_bytes+1);
    printf("    comment_field: (0x");
    for (i = 0; i < comment_field_bytes; i++) {
      temp = bs->GetBits(8);
      printf("%x", temp);
      comment_field[i] = temp;
    }
    comment_field[comment_field_bytes] = '\0';
    printf(") %s\n", comment_field);
    free(comment_field);
  }

  printf("  End of Program Config Element\n");
}

// See ISO  14496-3:2001 section 1.6.2
void CheckAudioSpecificConfig (CBitstream *bs) {

  uint32_t temp;
	uint32_t audioObjectType, channelConfiguration, extensionFlag;
  uint32_t i, j;

  printf("AudioSpecificConfig\n");

  // Audio Object Type
  audioObjectType = bs->GetBits(5);
  printf("Audio object type (5 bit) - 0x%x - ", audioObjectType);
  switch(audioObjectType) {
    case 0:
      printf("null\n");
      break;
    case 1:
      printf("AAC Main\n");
      break;
    case 2:
      printf("AAC LC\n");
      break;
    case 3:
      printf("AAC SSR\n");
      break;
    case 4:
      printf("AAC LTP\n");
      break;
    case 5:
      printf("reserved\n");
      break;
    case 6:
      printf("AAC Scalable\n");
      break;
    case 7:
      printf("TwinVQ\n");
      break;
    case 8:
      printf("CELP\n");
      break;
    case 9:
      printf("HVXC\n");
      break;
    case 10:
      printf("reserved\n");
      break;
    case 11:
      printf("reserved\n");
      break;
    case 12:
      printf("TTSI\n");
      break;
    case 13:
      printf("Main synthetic\n");
      break;
    case 14:
      printf("Wavetable synthesis\n");
      break;
    case 15:
      printf("General MIDI\n");
      break;
    case 16:
      printf("Algorithmic Syntesis and Audio FX\n");
      break;
    case 17:
      printf("ER AAC LC\n");
      break;
    case 18:
      printf("ER AAC SSR\n");
      break;
    case 19:
      printf("ER AAC LTP\n");
      break;
    case 20:
      printf("ER AAC scaleable\n");
      break;
    case 21:
      printf("ER TwinVQ\n");
      break;
    case 22:
      printf("ER Fine Granule Audio\n");
      break;
    case 23:
      printf("ER AAC LD\n");
      break;
    case 24:
      printf("ER CELP\n");
      break;
    case 25:
      printf("ER HVXC\n");
      break;
    case 26:
      printf("ER HILN\n");
      break;
    case 27:
      printf("ER Parametric\n");
      break;
    case 28:
      printf("reserved\n");
      break;
    case 29:
      printf("reserved\n");
      break;
    case 30:
      printf("reserved\n");
      break;
    case 31:
      printf("reserved\n");
      break;
    default:
      printf("unknown\n");
  }

  // Sample Frequency Index
  temp = bs->GetBits(4);
  printf("Sampling frequency Index (4 bit) - 0x%x\n", temp);
  if(temp == 0xf) {
    temp = bs->GetBits(24);
    printf("Sampling frequency (24 bit) - 0x%x\n", temp);
  }

  // Channel configuration
  channelConfiguration = bs->GetBits(4);
  printf("Channel configuration (4 bit) - 0x%x\n", channelConfiguration);

  if ( audioObjectType == 1 || audioObjectType == 2 ||
       audioObjectType == 3 || audioObjectType == 4 ||
       audioObjectType == 6 || audioObjectType == 7 ||
      /* the following Objects are Amendment 1 Objects */
       audioObjectType == 17 || audioObjectType == 19 ||
       audioObjectType == 20 || audioObjectType == 21 ||
       audioObjectType == 22 || audioObjectType == 23 ) {
    // GASpecificConfig
    printf("GASpecificConfig\n");
    temp = bs->GetBits(1);
    printf("  FrameLength (1 bit) - 0x%x\n", temp);
    temp = bs->GetBits(1);
    printf("  DependsOnCoreCoder (1 bit) - 0x%x\n", temp);
    if(temp) {
      temp = bs->GetBits(14);
      printf("    CoreCoderDelay (14 bit) - 0x%x\n", temp);
    }
    extensionFlag = bs->GetBits(1);
    printf("  ExtensionFlag (1 bit) - 0x%x\n", extensionFlag);

    if ( !channelConfiguration ) {
      //program_config_element();
      CheckProgramConfigElement(bs);
    }
    if ( extensionFlag ) {
      if ( audioObjectType == 22 ) {
        temp = bs->GetBits(5);
        printf("  NumOfSubFrame (5 bit) - 0x%x\n", temp);
        temp = bs->GetBits(11);
        printf("  Layer_length (11 bit) - 0x%x\n", temp);
      }
      if( audioObjectType==17 || audioObjectType == 18 ||
          audioObjectType == 19 || audioObjectType == 20 ||
          audioObjectType == 21 || audioObjectType == 23) {
        temp = bs->GetBits(1);
        printf("  AacSectionDataResilienceFlag (1 bit) - 0x%x\n", temp);
        temp = bs->GetBits(1);
        printf("  AacScalefactorDataResilienceFlag (1 bit) - 0x%x\n", temp);
        temp = bs->GetBits(1);
        printf("  AacSpectralDataResilienceFlag (1 bit) - 0x%x\n", temp);
      }
      temp = bs->GetBits(1);
      printf("  ExtensionFlag3 (1 bit) - 0x%x\n", temp);
      if ( temp ) {
        /* tbd in version 3 */
      }
    }
    printf("End of GASpecificConfig\n");
  }