DM8168 Breathing artifects

Abdul Rahman Rasool

Intellectual 740 points

Hi all,

we have developed our own DM8168 based H264 encoder and we are using the EZSDK version 5.05.02.00

In this We made the following modification on the code on both static and dynamic setup

tDynParams.videoDynamicParams.h264EncDynamicParams.rateControlParams.HRDBufferSize = (EncoderConfig.Bitrate*1000)

tDynParams.videoDynamicParams.h264EncDynamicParams.rateControlParams.initialBufferLevel = (EncoderConfig.Bitrate*1000)

tDynParams.videoDynamicParams.h264EncDynamicParams.rateControlParams.minPicSizeRatioI = 0; /*3*/

tDynParams.videoDynamicParams.h264EncDynamicParams.rateControlParams.maxPicSizeRatioI = 960; /*960*/

for framerate of 30fps we can decrease the “breathing artifacts” for the lower bitrate by setting the quality of the “I” frame closer to the “P” frame so the artifacts are not noticeable as before. However, when the frame rate changed to 15fps or lower down to 5fps then the “breathing artifacts” appears again. Why the artifacts appear again when frame rate lower then 30fps? Since the settings setting the “I” and “P” frame quality closer why it become further apart again when running in 15fps or lower? Is there other settings that I could control when running in lower frame rate to improve the breathing artifacts?

Thanks a lot

Regards

R.Abdul Rahman

over 9 years ago

0 Abdul Rahman Rasool over 9 years ago

Intellectual 740 points

Hi Margarita,

Could you please answer my question

Regards
R.Abdul Rahman

0 Margarita Gashova over 9 years ago in reply to Abdul Rahman Rasool

TI__Guru* 80190 points

Hello,

Let us check.

BR
Margarita

0 Margarita Gashova over 9 years ago in reply to Margarita Gashova

TI__Guru* 80190 points

Hello,

What is the intraframeinteval?

BR
Margarita

0 Joe Lam over 9 years ago in reply to Margarita Gashova

Prodigy 40 points

Hi Margarita,

The Intraframeinterval is 30

Regards
Joe Lam

0 Margarita Gashova over 9 years ago in reply to Joe Lam

TI__Guru* 80190 points

Hello,

Could you reduce the maxPicSizeRatioI range from 960 to 33 for intraframeinterval = 30?

Let us know the result.

BR
Margarita

0 Joe Lam over 9 years ago in reply to Margarita Gashova

Prodigy 40 points

Hi Margarita,

After the maxPicSizeRatioI range changed from 960 to 33 for intraframeinterval of 30 the video looks worst and have more breathing artifacts with I frame loss more detail compare to P frames. Following I attached the current testing parameters

Resolution: 1280 x 720 p
Frame rate: 15fps
Encode Bitrate: 750kbps
Constant bitrate mode
I to P ratio = 30

I can attached the streams with maxPicSizeRatioI of 960 or maxPicSizeRatioI of 33 with the same above settings to you if you want to see the differences

Regards
Joe Lam

0 Gajanan Maske over 9 years ago in reply to Joe Lam

Expert 2325 points

Hi Joe,

Ideally I think the quality should be fine with maxPicSizeRatioI 480. With multiple experiments , try to reduce the maxPicSizeRatioI from 960 to 33. Please note this is Gradually maxPicsizeRatioI. So best way is to reduce the MaxpicsizeRatioI around X for each experiment. Observe the quality & based on this take a decision.

Experiment 1 - MaxpicsizeratioI = 960

Experiment 2 - MaxpicsizeratioI = 900

Experiment 3 - MaxpicsizeratioI = 720

.....

Experiment X - MaxpicsizeratioI = 480

Experiment X+1 - MaxpicsizeratioI = 420

Experiment X - MaxpicsizeratioI = 360

......

Experiment Final - MaxpicsizeratioI = 33

The decision of reduction of maxpicsizeratioI can be taken based on better quality .

Regards

Gajanan

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DM8168 Breathing artifects