{"action":"opened","issue":{"url":"https://api.github.com/repos/cisco/openh264/issues/2201","labels_url":"https://api.github.com/repos/cisco/openh264/issues/2201/labels{/name}","comments_url":"https://api.github.com/repos/cisco/openh264/issues/2201/comments","events_url":"https://api.github.com/repos/cisco/openh264/issues/2201/events","html_url":"https://github.com/cisco/openh264/issues/2201","id":113965781,"number":2201,"title":"About encoder parameter","user":{"login":"octalflow","id":6919518,"avatar_url":"https://avatars.githubusercontent.com/u/6919518?v=3","gravatar_id":"","url":"https://api.github.com/users/octalflow","html_url":"https://github.com/octalflow","followers_url":"https://api.github.com/users/octalflow/followers","following_url":"https://api.github.com/users/octalflow/following{/other_user}","gists_url":"https://api.github.com/users/octalflow/gists{/gist_id}","starred_url":"https://api.github.com/users/octalflow/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/octalflow/subscriptions","organizations_url":"https://api.github.com/users/octalflow/orgs","repos_url":"https://api.github.com/users/octalflow/repos","events_url":"https://api.github.com/users/octalflow/events{/privacy}","received_events_url":"https://api.github.com/users/octalflow/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-10-29T02:31:41Z","updated_at":"2015-10-29T02:31:41Z","closed_at":null,"body":"Hello.\r\nI have a question about decoder's frame buffering.(NOT OPENH264 decoder BUT OMX)\r\n\r\nWhen I feed encoded data to OMX, OMX decoder always buffer 2 to 4 frames.\r\nSo there are big latency problem.\r\n\r\nIf encder is INTEL Mfx(quickSync), OMX buffer 2 frames.\r\nIf encoder is OPENH264, OMX buffer 3 frames.\r\nIf encoder is Apple VideoToolbox, OMX buffer 4 frames.\r\n\r\nwhat is the difference between two ?\r\n\r\nThis is openh264 encoder parameter.\r\n\r\nNal length 20 start code 4 bytes\r\n ref 3 type 7 Sequence parameter set\r\n   profile: 66\r\n   constaint_set0_flag: 1\r\n   constaint_set1_flag: 1\r\n   constaint_set2_flag: 0\r\n   constaint_set3_flag: 0\r\n   level_idc: 40\r\n   seq parameter set id: 0\r\n   log2_max_frame_num_minus4: 11\r\n   pic_order_cnt_type: 0\r\n    log2_max_pic_order_cnt_lsb_minus4: 12\r\n   num_ref_frames: 1\r\n   gaps_in_frame_num_value_allowed_flag: 0\r\n   pic_width_in_mbs_minus1: 119 (1920)\r\n   pic_height_in_map_minus1: 67\r\n   frame_mbs_only_flag: 1\r\n     derived height: 1088\r\n   direct_8x8_inference_flag: 0\r\n   frame_cropping_flag: 1\r\n     frame_crop_left_offset: 0\r\n     frame_crop_right_offset: 0\r\n     frame_crop_top_offset: 0\r\n     frame_crop_bottom_offset: 4\r\n   vui_parameters_present_flag: 1\r\n    aspect_ratio_info_present_flag: 0\r\n    overscan_info_present_flag: 0\r\n    video_signal_info_present_flag: 0\r\n    chroma_loc_info_present_flag: 0\r\n    timing_info_present_flag: 0\r\n    nal_hrd_parameters_present_flag: 0\r\n    vcl_hrd_parameters_present_flag: 0\r\n    pic_struct_present_flag: 0\r\n    motion_vectors_over_pic_boundaries_flag: 1\r\n    max_bytes_per_pic_denom: 0\r\n    max_bits_per_mb_denom: 0\r\n    log2_max_mv_length_horizontal: 16\r\n    log2_max_mv_length_vertical: 16\r\n    num_reorder_frames: 0\r\n     max_dec_frame_buffering: 1\r\nNal length 8 start code 4 bytes\r\n ref 3 type 8 Picture parameter set\r\n   pic_parameter_set_id: 0\r\n   seq_parameter_set_id: 0\r\n   entropy_coding_mode_flag: 0\r\n   pic_order_present_flag: 0\r\n   num_slice_groups_minus1: 0\r\n   num_ref_idx_l0_active_minus1: 0\r\n   num_ref_idx_l1_active_minus1: 0\r\n   weighted_pred_flag: 0\r\n   weighted_bipred_idc: 0\r\n   pic_init_qp_minus26: 0\r\n   pic_init_qs_minus26: 0\r\n   chroma_qp_index_offset: 0\r\n   deblocking_filter_control_present_flag: 1\r\n   constrained_intra_pred_flag: 0\r\n   redundant_pic_cnt_present_flag: 0\r\n   \r\n\r\nAND\r\nthis is INTEL MFX h/w encoder parameter\r\n\r\nNal length 28 start code 4 bytes\r\n ref 1 type 7 Sequence parameter set\r\n   profile: 66\r\n   constaint_set0_flag: 0\r\n   constaint_set1_flag: 0\r\n   constaint_set2_flag: 0\r\n   constaint_set3_flag: 0\r\n   level_idc: 40\r\n   seq parameter set id: 0\r\n   log2_max_frame_num_minus4: 4\r\n   pic_order_cnt_type: 2\r\n   num_ref_frames: 1\r\n   gaps_in_frame_num_value_allowed_flag: 0\r\n   pic_width_in_mbs_minus1: 119 (1920)\r\n   pic_height_in_map_minus1: 67\r\n   frame_mbs_only_flag: 1\r\n     derived height: 1088\r\n   direct_8x8_inference_flag: 1\r\n   frame_cropping_flag: 1\r\n     frame_crop_left_offset: 0\r\n     frame_crop_right_offset: 0\r\n     frame_crop_top_offset: 0\r\n     frame_crop_bottom_offset: 4\r\n   vui_parameters_present_flag: 1\r\n    aspect_ratio_info_present_flag: 1\r\n     aspect_ratio_idc:1\r\n    overscan_info_present_flag: 0\r\n    video_signal_info_present_flag: 0\r\n    chroma_loc_info_present_flag: 0\r\n    timing_info_present_flag: 1\r\n     num_units_in_tick: 1\r\n     time_scale: 2\r\n     fixed_frame_scale: 1\r\n    nal_hrd_parameters_present_flag: 0\r\n    vcl_hrd_parameters_present_flag: 0\r\n    pic_struct_present_flag: 0\r\n    motion_vectors_over_pic_boundaries_flag: 1\r\n    max_bytes_per_pic_denom: 2\r\n    max_bits_per_mb_denom: 1\r\n    log2_max_mv_length_horizontal: 13\r\n    log2_max_mv_length_vertical: 11\r\n    num_reorder_frames: 0\r\n     max_dec_frame_buffering: 1\r\nNal length 8 start code 4 bytes\r\n ref 1 type 8 Picture parameter set\r\n   pic_parameter_set_id: 0\r\n   seq_parameter_set_id: 0\r\n   entropy_coding_mode_flag: 0\r\n   pic_order_present_flag: 0\r\n   num_slice_groups_minus1: 0\r\n   num_ref_idx_l0_active_minus1: 0\r\n   num_ref_idx_l1_active_minus1: 0\r\n   weighted_pred_flag: 0\r\n   weighted_bipred_idc: 0\r\n   pic_init_qp_minus26: 0\r\n   pic_init_qs_minus26: 0\r\n   chroma_qp_index_offset: 0\r\n   deblocking_filter_control_present_flag: 1\r\n   constrained_intra_pred_flag: 0\r\n   redundant_pic_cnt_present_flag: 0\r\n\r\nthank you.\r\n"}}