H264 SPS, How to change the gaps_in_frame_num_value_allowed_flag value?

Autonomous Machines Jetson & Embedded Systems Jetson TX2
1

Hi,When I parser the sprop-parameter-sets=Z00MH5WgKA9oQAAAAwBAAAAPIQ==,aO48gA==, I got results as follows:

Start dumping SPS:
  profile_idc = 77
  constrained_set0_flag = 0
  constrained_set1_flag = 0
  constrained_set2_flag = 0
  constrained_set3_flag = 0
  level_idc = 31
  seq_parameter_set_id = 0
  chroma_format_idc = 1
  bit_depth_luma_minus8 = 0
  bit_depth_chroma_minus8 = 0
  seq_scaling_matrix_present_flag = 0
  log2_max_frame_num_minus4 = 4
  pic_order_cnt_type = 2
  log2_max_pic_order_cnt_lsb_minus4 = 0
  delta_pic_order_always_zero_flag = 0
  offset_for_non_ref_pic = 0
  offset_for_top_to_bottom_field = 0
  num_ref_frames_in_pic_order_cnt_cycle = 0
  num_ref_frames = 1
  gaps_in_frame_num_value_allowed_flag = 0
  pic_width_in_mbs_minus1 = 39
  pic_height_in_mbs_minus1 = 29
  frame_mbs_only_flag = 1
  mb_adaptive_frame_field_flag = 0
  direct_8x8_interence_flag = 1
  frame_cropping_flag = 0
  frame_cropping_rect_left_offset = 0
  frame_cropping_rect_right_offset = 0
  frame_cropping_rect_top_offset = 0
  frame_cropping_rect_bottom_offset = 0
  vui_parameters_present_flag = 1

Start dumping PPS:
  pic_parameter_set_id = 0
  seq_parameter_set_id = 0
  entropy_coding_mode_flag = 1
  pic_order_present_flag = 0
  num_slice_groups_minus1 = 0
  slice_group_map_type = 0
  num_ref_idx_l0_active_minus1 = 0
  num_ref_idx_l1_active_minus1 = 0
  weighted_pref_flag = 0
  weighted_bipred_idc = 0
  pic_init_qp_minus26 = 0
  pic_init_qs_minus26 = 0
  chroma_qp_index_offset = 0
  deblocking_filter_control_present_flag = 1
  constrained_intra_pred_flag = 0
  redundant_pic_cnt_present_flag = 0
  transform_8x8_mode_flag = 0
  pic_scaling_matrix_present_flag = 0
  second_chroma_qp_index_offset = 0

As we can see, gaps_in_frame_num_value_allowed_flag = 0. But I want to get gaps_in_frame_num_value_allowed_flag = 1.
So I want to ask, how to change it? should we set the omxh264 parameter or the caps(‘video/x-h264, stream-format=(string)byte-stream’)?

2

Hi,
Please share more information about gaps_in_frame_num_value_allowed_flag. The parameters are filled in according to encoded h264 stream. What is the difference in the encoded streams between gaps_in_frame_num_value_allowed_flag = 0 and 1?

Please also share your release version(r28.3 or r32.2).

3

Hi,Thank you for you answer.
Our platform is TX2, jetpack4.2.1, deepstream4.0, the release version is r32.2.

Because we have the special decoder should gaps_in_frame_num_value_allowed_flag=1
Our current decoding behavior returns a failure when sps:gaps_in_frame_num_value_allowed_flag is set 0.

4

Hi,
Please share why the decoder throws error out when
gaps_in_frame_num_value_allowed_flag=0.
It seems not right because 3rdparty decoders like JM decoder or ffmpeg do not complain about it.