High minimum bitrates of DM8148 Encoder

Vaibhav Dhingani

Hello,

We are working on TIDM8148EVM board.

We tested the encode application that's come with EzSDK on our EVM.
Regarding to rate control we get very limited results. For 720p input the minimum bitrate we are able to produce is ~0.8Mbps and for 480p it's ~1Mbps.
This means we are unable to set bit rate lower then this, it remains constant after the limit mentioned above.
For us these are very high minimum bitrates.

Can we configure bitrates lower then this? Is there any hardcoding inside encoder?

over 12 years ago

0 Margarita Gashova over 12 years ago

TI__Guru* 80190 points

Hello,

You could check here:

http://e2e.ti.com/support/embedded/multimedia_software_codecs/f/356/t/235532.aspx

Best Regards,

Margarita

0 Vaibhav Dhingani over 12 years ago in reply to Margarita Gashova

Expert 1540 points

Hello,

Can you provide me a link of user guide you suggested in above thread.

0 Margarita Gashova over 12 years ago in reply to Vaibhav Dhingani

TI__Guru* 80190 points

Hello,

Vaibhav Dhingani said:
Can you provide me a link of user guide you suggested in above thread.

ti-ezsdk_dm814x-evm_5_05_02_00/component-sources/omx_05_02_00_48/src/ti/omx/docs

H264_Encoder_HDVICP2_UserGuide.pdf

Best Regards,

Margarita

0 Yashwant Dutt over 12 years ago in reply to Margarita Gashova

TI__Genius 17215 points

You can set rateControlPreset to IVIDEO_STORAGE and specify targetBitrate of choice to achieve the desired bitrate. The bitrate for 480p and 720p can go well below 1mbps.

regards

Yashwant

0 Hitesh Viradiya over 12 years ago in reply to Yashwant Dutt

Expert 1505 points

Hi Yashwant,

Thanks for your reply. Actually we are using rateControlPreset as IVIDEO_STORAGE and encoding profile as OMX_VIDEO_AVCProfileHigh. These are two major changes that we did in the default encoding demo and we are getting results as Vaibhav mentioned.

Do you have any idea on this ?

Regards,

HiteshV

0 Yashwant Dutt over 12 years ago in reply to Hitesh Viradiya

TI__Genius 17215 points

What is the targetBitrate which you are setting ? Ideally, with this setting, you should get the o/p bitrate as the value you set for targetBitrate unless the traget bitrate is absurd for the content resolution and framerate.

regards

Yashwant

0 Hitesh Viradiya over 12 years ago in reply to Yashwant Dutt

Expert 1505 points

Hi,

I am setting bit rate with various range from 60 Mbps to 1Mbps (We do have requirement of min. bit rate of ~100 to ~300 kbps) by keeping the same frame rate of 60 fps. I tested this with two different resolution of 480p and 720p.

And the resultant min. bit rate which i can set is ~800 kbps to ~1 Mbps. Let me know if you need more input.

Regards,

Hitesh

0 Hitesh Viradiya over 12 years ago in reply to Hitesh Viradiya

Expert 1505 points

Hello TI,

I achieved min. bit-rate by adjusting QP settings. You can close this thread.

Many thanks,

Hitesh

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High minimum bitrates of DM8148 Encoder