Bump avm dependency to tag research-v13.0.0

[y-guyon]

No description provided.

[wantehchang]

Yannis: Thank you for writing this pull request. I will try to review it today.

[wantehchang]

Yannis: I only did a partial review today. Sorry1 I will try to do a complete review tomorrow.

[wantehchang]

We should try to track down why this is necessary.

@jzern James: Do you have any speculations?

[wantehchang]

@jzern @vrabaud

I wonder if there is a way to import another project into a namespace in CMake. Otherwise we will need to audit all the add_custom_target() calls in the libaom and AVM CMake build systems and make sure the custom target names have the "aom_" or "avm_" prefix.

[wantehchang]

Unless we are sure that the code in common/av2_config.c is correct, it is better to follow the read_sequence_header_obu() function in av2/decoder/obu.c as an example.

[wantehchang]

This if statement (lines 515-520) corresponds to the following code in read_sequence_header_obu():

  av2_read_conformance_window(rb, seq_params);
  av2_validate_seq_conformance_window(seq_params, &cm->error);

Afterwards, read_sequence_header_obu() does the following:

#if CONFIG_CWG_F270_CI_OBU
  av2_read_chroma_format_bitdepth(rb, seq_params, &cm->error);
#else
  av2_read_color_config(rb, seq_params, &cm->error);
#endif  // CONFIG_CWG_F270_CI_OBU

So we should have similar code here. If CONFIG_CWG_F270_CI_OBU is equal to 1, we should only parse the chroma format and the bit depth. We can use a structure similar to the following code in av2/decoder/decodeframe.c:

void av2_read_chroma_format_bitdepth(
    struct avm_read_bit_buffer *rb,
#else
void av2_read_color_config(
    struct avm_read_bit_buffer *rb,
#endif  // CONFIG_CWG_F270_CI_OBU
    SequenceHeader *seq_params, struct avm_internal_error_info *error_info) {
  const uint32_t seq_chroma_format_idc = avm_rb_read_uvlc(rb);
  set_seq_chroma_format(seq_chroma_format_idc, seq_params, error_info);

  read_bitdepth(rb, seq_params, error_info);

  const int is_monochrome = (seq_chroma_format_idc == CHROMA_FORMAT_400);
  seq_params->monochrome = is_monochrome;
#if !CONFIG_CWG_F270_CI_OBU
  int color_description_present_flag = avm_rb_read_bit(rb);
  if (color_description_present_flag) {
    seq_params->color_primaries = avm_rb_read_literal(rb, 8);
    seq_params->transfer_characteristics = avm_rb_read_literal(rb, 8);
    seq_params->matrix_coefficients = avm_rb_read_literal(rb, 8);
  } else {
    seq_params->color_primaries = AVM_CICP_CP_UNSPECIFIED;
    seq_params->transfer_characteristics = AVM_CICP_TC_UNSPECIFIED;
    seq_params->matrix_coefficients = AVM_CICP_MC_UNSPECIFIED;
  }
  if (is_monochrome) {
    // [16,235] (including xvycc) vs [0,255] range
    seq_params->color_range = avm_rb_read_bit(rb);
    seq_params->subsampling_y = seq_params->subsampling_x = 1;
    seq_params->chroma_sample_position = AVM_CSP_UNSPECIFIED;
  } else {
    if (seq_params->color_primaries == AVM_CICP_CP_BT_709 &&
        seq_params->transfer_characteristics == AVM_CICP_TC_SRGB &&
        seq_params->matrix_coefficients == AVM_CICP_MC_IDENTITY) {
      seq_params->subsampling_y = seq_params->subsampling_x = 0;
      seq_params->color_range = 1;  // assume full color-range
      if (!(seq_params->profile == PROFILE_1 ||
            (seq_params->profile == PROFILE_2 &&
             seq_params->bit_depth == AVM_BITS_12))) {
        avm_internal_error(
            error_info, AVM_CODEC_UNSUP_BITSTREAM,
            "sRGB colorspace not compatible with specified profile");
      }
    } else {
      // [16,235] (including xvycc) vs [0,255] range
      seq_params->color_range = avm_rb_read_bit(rb);
      if (seq_params->matrix_coefficients == AVM_CICP_MC_IDENTITY &&
          (seq_params->subsampling_x || seq_params->subsampling_y)) {
        avm_internal_error(
            error_info, AVM_CODEC_UNSUP_BITSTREAM,
            "Identity CICP Matrix incompatible with non 4:4:4 color sampling");
      }
      if (seq_params->subsampling_x && !seq_params->subsampling_y) {
        // YUV 4:2:2
        seq_params->chroma_sample_position = AVM_CSP_UNSPECIFIED;
        const int csp_present_flag = avm_rb_read_bit(rb);
        if (csp_present_flag) {
          seq_params->chroma_sample_position = avm_rb_read_bit(rb);
        }
      } else if (seq_params->subsampling_x && seq_params->subsampling_y) {
        // YUV 4:2:0
        seq_params->chroma_sample_position = AVM_CSP_UNSPECIFIED;
        const int csp_present_flag = avm_rb_read_bit(rb);
        if (csp_present_flag) {
          const int chroma_sample_position = avm_rb_read_literal(rb, 3);
          if (chroma_sample_position > AVM_CSP_BOTTOM) {
            avm_internal_error(error_info, AVM_CODEC_UNSUP_BITSTREAM,
                               "Invalid chroma_sample_position");
          }
          seq_params->chroma_sample_position = chroma_sample_position;
        }
      }
    }
  }
#endif  // !CONFIG_CWG_F270_CI_OBU
}

[wantehchang]

Yannis: I only did a partial review today. Sorry1 I will try to do a complete review tomorrow.