Determining Frame rate in H.264 elementary stream

[divs]

Hello,

Is there a way to determine the frame rate in a H.264 elementary stream? I googled for it, and found that using VUI_parameters, the frame rate can be determined. But the stream I have has the vui_parameters_present_flag set to 0.

Any info related to this would be helpful.


Regards,
Divya

[Shevach]

If timing_info_present_flag=0 in VUI parameters then it is impossible to derive the actual frame rate. Unfortunately the default frame rate (i.e. the frame rate when timing_info_present_flag=0) is not specified in the standard (as far as I know).

According to my experience in H.264 encoders if VUI parameters are not present then the frame rate usually is 30fps.

[Dust Signs]

If timing_info_present_flag=0 in VUI parameters then it is impossible to derive the actual frame rate. Unfortunately the default frame rate (i.e. the frame rate when timing_info_present_flag=0) is not specified in the standard (as far as I know).
Agree.

According to my experience in H.264 encoders if VUI parameters are not present then the frame rate usually is 30fps.
Disagree. This also strongly depends on the country the file was created for and the different frame rates in the TV and broadcasting systems. In most of Central Europe for example one would assume 25fps due to PAL.
Just wanted to mention this so that it is taken into consideration. Normally, the container the H.264 stream is embedded in should contain additional information like the frame rate.

Dust Signs

[Shevach]

Normally, the container the H.264 stream is embedded in should contain additional information like the frame rate.

Dust Signs

For example if H.264 elementary stream is embedded into Transport stream or Program stream then frame rate can be derived from PTS values of successive (in presentation order) frames.