Take out video length from IDR or non-IDR (H.264/AVC – Bitstream Organization)

Question

I have a stream for a flash player that comes from H.264 Chunks - SPS, PPS, IDR and non-IDR. So far the FLV stucture is generated from the bytearray. The only problem left for me is to understand how I can get those Timestamp UI24 that FLVTag need.

Answer 1

To get the time for each FLVTag you do:

1. First get the frame rate from SPS file, you need to check for timing_info_present_flag to be 1;

timing_info_present_flag : 1

num_units_in_tick : 1000

time_scale :120000

fixed_frame_rate_flag : 1

So you count it like:

time_scale / (2 * num_units_in_tick) = frame_rate fps;
120000 /

2 * 1000 = 60 fps

After that you get the miliseconds per frame -> 1 / 60 = 0.01666(6) So you count the frames (IDR and NDR) and you increase the timestamp accordingly. For SPS and PPS frame I drop the current timestamp to where we are currently.