Question about the intraFrameQP and interPFrameQP Parameter

Kowin Hsieh

Dear sir

According to the Spec, the intraFrameQP and interPFrameQP are useful only when

rateControlPreset of IVIDENC1_Params is equal IVIDEO_NONE.
rcAlgo = 2 (Fixed QP) and targetBitRate = 0

but in the notes the rcAlgo values are used only when IVIDENC1_Params ->RateControlPreset = IVIDEO_USER_DEFINED.

Is this a conflict?? If I want to use the Fixed QP and intraFrameQP and interPFrameQP , what should I set for the rateControlPreset???

0 Girish Srinivasa over 14 years ago

Can you let us know which is the platform and the codec version used?

0 Kowin Hsieh over 14 years ago in reply to Girish Srinivasa

Hi Girish

I use the DM368 and the codec is the H.264 version.02.00.00.10.

The Codec is platform-independent, isn't it??

0 Yashwant Dutt over 14 years ago in reply to Kowin Hsieh

Hi,

You can either set

rateControlPreset = IVIDEO_NONE + targetBitRate = 0

RateControlPreset = IVIDEO_USER_DEFINED + rcAlgo = 2 + targetBitRate = 0

Both the above will allow you to set Fixed QP for encoding.

Setting targetBitRate = 0 is optional.

regards
Yashwant

0 Kowin Hsieh over 14 years ago in reply to Yashwant Dutt

Hi Yashwant

Thanks for your reply. One more question. How can I verify if the Fixed QP is work??

What will be observed in the stream??

best regard

0 Yashwant Dutt over 14 years ago in reply to Kowin Hsieh

You may have to see the stream in some bitstream analyzer. All the MBs will be coded with the QP as provided through teh interface.

regards

Yashwant

0 Kowin Hsieh over 14 years ago in reply to Yashwant Dutt

Oh I see. Thanks. Yashwant.

best regards

Processors forum