Frame rate

[Vassili_Yakovlev]

Is there any reason why Video encoder won't initialize with framerate parameter higher than172 fps?
I have live video streams from GigE camera's with frame rate for example 300 fps which I encode with Intel Media SDK, but I have to initialize encoder with frame rate just 172 fps and let encode stream as is - 300 fps as I receive from camera, which actually works.

[Anthony_P_Intel]

Hi,

I can look into the limits. What standard Profile & Level are you targeting? (resolution, bitrate, etc.)

-Tony

[Vassili_Yakovlev]

Hi,

I've tested with all three profiles: baseline, main and high, also different levels, mainly 4.1 (btw. when I choose 5.0/5.1 encoder cannot be initialized with hardware acceleration),with resolution 640x480 and using CQP (MFX_RATECONTROL_CQP), target usage is set to MFX_TARGETUSAGE_BEST_SPEED for this frame rate, and chosen AVC codec.

[Anthony_P_Intel · Accepted solution]

Hi,

The Media SDK uses an HRD-compliant process to calculate all the encode parameters it needs, and I believe any fps value greater than 172 causes some variables to be larger than the some internal variables were originally designed to handle (16-bit 'short' variables vs. 'long' variables). The Media SDK checks the values of parameters for validity, and returns the 'unsupported' error message to avoid overflow issues.

I will ask developers to look into this apparent limitation on fps, and either update documentation or provide information on updated Media SDK.

THANKS for the question.

-Tony