TSU (video scaler) quality degradation at scaling

Dongfeng.Judah

Hi Hongmei / Paula / Vivek / All,

we are seeing a significant video quality drop when we try scaling 720x1280 to 400x736 on TSU test application provided by you at link. Please see the tsu-le.zip

Is there any limitation at this particular resolution? We tried scaling down 720p to much lower resolutions and it is working well but not at the specified resolution of 400x736.

Can you please look into this?

Our setup.

Little Endian Application on c6678 EVM

mcsdk_video_2_2_0_33 / bios_6_33_06_50 / framework_components_3_24_02_15 / xdais_7_24_00_04 / edma3_lld_02_11_07_04

Regards, Judah

over 10 years ago

0 Raja over 10 years ago

TI__Guru* 81335 points

Hi Judah,

Working with our experts to answer this. We will get back to you shortly. Thank you for the post and patience.

0 Dongfeng.Judah over 10 years ago in reply to Raja

Intellectual 415 points

Hi Rajasekaran,
Thank you. Any update on this?
Regards, Judah

0 Paula Carrillo over 10 years ago in reply to Dongfeng.Judah

TI__Mastermind 40580 points

Hi Judah, could you give us an example of Video Quality drop at 400x736? which algorithm are you using bicubic or polyphase?
thank you,Paula

0 Dongfeng.Judah over 10 years ago in reply to Paula Carrillo

Intellectual 415 points

Hi Paula,

We are using polyPhase. I have attached the input/output/config file in my previous communication (by the name tsu-le.zip).

Let me if you can access it .

Regards, Judah

0 Dongfeng.Judah over 10 years ago in reply to Dongfeng.Judah

Intellectual 415 points

Hi Paula, did you get a chance to reproduce this issue at your end?
Best Regards, Judah.

0 Paula Carrillo over 10 years ago in reply to Dongfeng.Judah

TI__Mastermind 40580 points

Hi Judah, apologize, currently I don't have bandwidth for reproduce it.. but I was wondering, what is the closest vertical resolution that looks OK?.. It seems to me horizontal scaling is OK, so maybe just please play a little bit with Vertical resolution.
Also, from the code I see it is possible to change number of filter taps. Currently it is set to l_hh=4. Could we tried 8 or 16?
Thank you,Paula

0 Dongfeng.Judah over 10 years ago in reply to Paula Carrillo

Intellectual 415 points

Hi Paula,
Did you get a chance to reproduce this at your end?

We tried other scaling resolutions and the results suggests that there is a problem with this particular width of 736.
Scaled outputs from 720Hx1280W to 400Hx720W / 400Hx752W / 200Hx368 all looked well. But
Scaled outputs from 720Hx1280W to 400Hx736W / 384Hx736W has the quality degration.

Can you please look into this?

Regards, Judah

0 Paula Carrillo over 10 years ago in reply to Dongfeng.Judah

TI__Mastermind 40580 points

Hi Judah, I was able to reproduce the issue with Polyphase algorithm. On the other, just FYI, "TSU_BICUBIC" algorithm generates correct output. We think it is related to some assumptions on the alignment for input/output buffers, but still it is not clear.

thank you,

Paula

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TSU (video scaler) quality degradation at scaling