This is my setting. I take a scheme that has only one I-frame (GopPicSize = 0), so I think I will get a bit-streaming has low bit-rate in idle scene.
But I find I get too many "P_L0_16x16 mode" MBs, not p-Skip MBs in idle scene. The judgement of MB mode is strange.
I still get the bit-streaming with 1Mbps in idle scene.
Do you give me some suggestion? Thanks.

******************************************************************************************************
m_mfxEncParams.mfx.CodecId = MFX_CODEC_AVC; // H.264
m_mfxEncParams.mfx.TargetUsage = MFX_TARGETUSAGE_BEST_SPEED
m_mfxEncParams.mfx.TargetKbps = 5000;
m_mfxEncParams.mfx.RateControlMethod = MFX_RATECONTROL_VBR;
ConvertFrameRate(pInParams->dFrameRate, &m_mfxEncParams.mfx.FrameInfo.FrameRateExtN, &m_mfxEncParams.mfx.FrameInfo.FrameRateExtD);
m_mfxEncParams.mfx.NumThread = 0; // if 0 then encoder decides
m_mfxEncParams.mfx.EncodedOrder = 0; // binary flag, 0 signals encoder to take frames in display order

m_mfxEncParams.mfx.CodecProfile = MFX_PROFILE_AVC_BASELINE;
m_mfxEncParams.mfx.CodecLevel = MFX_LEVEL_AVC_4;
m_mfxEncParams.mfx.GopPicSize = 0;
m_mfxEncParams.mfx.GopRefDist = 1; // only i-frame, p-frame
m_mfxEncParams.mfx.GopOptFlag = 0;//MFX_GOP_CLOSED | MFX_GOP_STRICT;
m_mfxEncParams.mfx.NumRefFrame = 1;
m_mfxEncParams.mfx.NumSlice = 1;

My application is about remote desktop.When I encode the idle scene of my desktop, I see the bitrate is about 1.2Mbps and too high.
I put my analyzed result in the attached file "idlescene.jpg". A idle frame need 40 kbit. (40K*30 frames= 1.2Mbps)
There are 20% MBs of P_L0_16x16 in a frame, but this is a idle frame.
I think there are something wrong.

Another problem. I set GopPicSize to Zero. But I still get I frame every 257 frame.
Please see the attached file "Strange_Iframe.jpg".

Hi Tony,

I use the hardware Encoder(MFX_IMPL_HARDWARE), the driver of graphics driver is 8.15.10.2761. the Intel media SDK is v.3.5.915.45249.

Thanks.
Rouyun

Hi Tony:

I test this Intel QSV encoder with two idle scene.
The bitrate of the idle scene 1 is ok (avg. 260 Kbps), but the bitrate of the idle scene 2 is too high (2710 Kbps).
I think there is something wrong.
The attached figure is the bitrate information which I get from our client.

Thanks.
RouYun

Hi Tony:

I see the intel media sdk 2013. any update for this issue in this sdk?

- Rouyun

Hi Tony:

I update the new driver 15.31.3.64.3071 with intel HD 2500. The bitrate is too high(about 2Mbps) in idle scence.

B.R.

Peter

Hi Tony:

I already removed old driver, and install the new driver.  I didn't get any error, and still got the same encoding results.

I can use the sample code of Intel media SDK to reproduce the same status.

There are my modifyed pipeline_encode.cpp and you can rebuilded sample_encode.exe in the attached file.

I modifyed some configurations of encoder like "m_mfxEncParams.mfx.RateControlMethod = MFX_RATECONTROL_VBR; " in pipeline_encode.cpp.

my test arguments is 

sample_encode.exe h264 -i ..\content\input.yuv -o ..\content\output.264 -w 1024 -h 768 -f 30 -b 5000 -nv12 -hw -u speed

After I run the sample_encode.exe,  I get a the bistream "Output.264".

You can see the size is 6,281,247 bytes(6281247*8 =50249976 bits ), and you can see the input file has 272 frames with 1024x768 and NV12 format.

the average bitrate is 5.540 Mbps (272/30 = 9.07 Secs, 50249976/9.07=5540240 bps)

My input .yuv file is always idle scene. I think the bitrate is too high with VBR.

Please help me check these issue. Thanks.

P.S. the input .yuv file is too big, I put it in Dropbox. https://www.dropbox.com/s/jlz9durq2390fyj/input.yuv

B.R.

Hi Tony:

Do you have any update dor this issue?

B.R.

RouYun