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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?

Sathyajith Bhat
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Amy Joyce
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2 Answers2

6

You will find answers here:

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 
// ...
Community
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Roman R.
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  • Thank you very very much. I didn’t even imagine how complicated H.264 could be. I have to re-re-read all your answers on the subject to get closer to fully understand it. (so I got my dimensions 704x396) Thanks again, you seem to be an expert. – Amy Joyce Nov 02 '11 at 11:14
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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)
malhal
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