问题
I have corrupted video stream with this header / parameters in the beginning.
00 00 00 01 67 64 00 1E AC D9 40 B0 33 FB C0 44
00 00 03 00 04 00 00 03 00 C8 3C 58 B6 58 00 00
00 01 68 EB EC B2 2C
I’m trying to figure out the actual values, but all I have guessed is that
67 – AVC / H264
64 00 - High Profile
1E – Level 30 (in decimal)
Does anybody know what other bytes stand for?
At least, how to calculate video dimensions (Width x Height). I thought it should be decimal numbers but apparently it’s not. Or am I all wrong and it doesn’t work this way?
回答1:
You will find answers here:
- How to decode sprop-parameter-sets in a H264 SDP?
- Parsing Rtsp response parameter that is sprop-parameter-sets
- Fetching the dimensions of a H264Video stream
Your data decodes like this:
Sequence Parameter Set
profile_idc 100
constraint_set0_flag 0
constraint_set1_flag 0
constraint_set2_flag 0
constraint_set3_flag 0
level_idc 30
seq_parameter_set_id 0
chroma_format_idc 1
// ...
num_ref_frames 4
gaps_in_frame_num_value_allowed_flag 0
pic_width_in_mbs_minus1 43
pic_height_in_map_units_minus1 24
frame_mbs_only_flag 1
direct_8x8_inference_flag 1
frame_cropping_flag 1
frame_crop_left_offset 0
frame_crop_right_offset 0
frame_crop_top_offset 0
frame_crop_bottom_offset 2
vui_parameters_present_flag 1
// ...
Picture Parameter Set
pic_parameter_set_id 0
seq_parameter_set_id 0
entropy_coding_mode_flag 1
num_slice_groups_minus1 0
// ...
回答2:
If frame_cropping_flag is 1, to get the dimensions you do:
width = ((pic_width_in_mbs_minus1 +1)*16) - frame_crop_left_offset*2 - frame_crop_right_offset*2;
height= ((2 - frame_mbs_only_flag)* (pic_height_in_map_units_minus1 +1) * 16) - (frame_crop_top_offset * 2) - (frame_crop_bottom_offset * 2)
来源：https://stackoverflow.com/questions/7923752/h-264-stream-header