H264/H265 Codec Specs in Jetson

Hi all,

We are developing a product based on Jetson Xavier AGX and have some specific questions on the codecs (not the API to access them). The questions apply for H264 and H265:

  1. Does the H264/H265 codec perform tone mapping in the input frame before encoding?

  2. In case of bitrate, does the codec support CRF and not just CBR and VBR?

  3. When using VBR, do you know if the codec does two-pass-encoding?

Thanks,
-David

Hi,

No, it is not supported in encoding. You would need to apply it to the frames before feeding to encoder.

Not sure what CRF is. Per the webpage:
https://slhck.info/video/2017/03/01/rate-control.html
It looks close to qp-range.

  qp-range            : Qunatization range for P, I and B frame,
                         Use string with values of Qunatization Range
                         in MinQpP-MaxQpP:MinQpI-MaxQpI:MinQpB-MaxQpB order, to set the property.
                        flags: readable, writable
                        String. Default: null

Please set the property and see if it gives the same function as CRF.

The function is supported in CBR mode. Not supported in VBR mode.

Hi DaneLLL,

  1. Understood
  2. Yes, CRF is pretty similar to Variable Bitrate when you set a target quality or the same level of control that you achieve using the qp-range. Let me chat with the customer to see if these two modes are enough. In any case I believe are the only modes supported by Jetson at this point.
  3. Understood.

Thank you,
-David