subWindow offset support with MPEG4 codec on DM365?

Tracy lee

Hi all:

As we know, We can encode a subwindow with MPEG4 codec, but i don't know how to adjust the subwindows position, cause the parameter "subWindowHozOfst" and "subWindowVerOfst" don't support on DM365 platform, is there any other way that can adjust the subwindow position, for example, encode the subwindow as:

over 15 years ago

0 Yashwant Dutt over 15 years ago

TI__Genius 17215 points

Hi,

The codec assumes the subwindow to start at [0,0] location, i.e. top left corner of image. But this is not a limitation. You can still adjust the subwindow at any postion in the frame. You just need to give the top left of the subwindow as the start location with subWindowWidth and Height populated as before. This is an extra computation(book keeping) which you need to take care in your application.

regards

Yashwant

0 Tracy lee over 15 years ago in reply to Yashwant Dutt

Expert 1505 points

Hi Yashwant:

Appreciate for you help!

It's worked after adjust some parameters.

Thanks very much!

0 Tracy lee over 15 years ago in reply to Yashwant Dutt

Expert 1505 points

Hi all:

Does MPEG4 codec subwindow solution support crop 160x120 from a 256x144 image? I have found two issue under this case:

1). The color is not correct.

2). The QQVGA image is not correct.

Any comments would be appreciated!

0 Tej Pandey over 15 years ago in reply to Tracy lee

Intellectual 340 points

Hi Tracy,

What input format are you using?

If it is 420SP, then it is a known issue that there are Chroma Artifacts for widths below 240 (documented in Release Notes).

If it is 422ILE, then further investigation is needed - perhaps you can share the parameters here.

Regards,

0 Tracy lee over 15 years ago in reply to Tej Pandey

Expert 1505 points

Hi Tej Pandey:

Appreciate for you response.

The RAW data input is YUV420SP, so we can't encode the correct MPEG4 image if the widths below 240.

Does TI has any schedule for fixed this issue in next release?

BTW, I fount that VIVOTEC IP8161 use DM365 solution, and it can encode QCIF(176x144) MPEG4 stream, is there any way that can fixed this bugs?

Here is the VIVOTEC IP8161 camera link for you reference:

http://www.vivotek.com/products/model.php?network_camera=ip8161&tab=over

Thanks.

0 Tej Pandey over 15 years ago in reply to Tracy lee

Intellectual 340 points

No, as of now there is no plan to fix this limitation.

For 422ILE input data, the minimum supported width is 160. If possible, please use 422ILE input format for lower resolution (<=240).

Regards,

Tej

0 Tracy lee over 15 years ago in reply to Tej Pandey

Expert 1505 points

Hi Tej:

Yes, 422ILE support encode width is 160 for MPEG4 encode, but H.264 only support 420SP as input, what should i do if i want to encode MPEG4 QQVGA and H264 QQVGA stream at the same time?

I had checked the latest DM365 codec here:

http://software-dl.ti.com/dsps/dsps_public_sw/codecs/DM365/index_FDS.html

I can't find the limitation on version MPEG4 Encoder, Version 2.00.00.05 releasenotes, is that means this version has fixed this issue?

Could you help confirm this?

Thanks.

0 Jing Lee79304 over 14 years ago in reply to Tracy lee

Prodigy 180 points

In which H264Enc release the sub-window feature is supported?

I found a statement about sub-window here. http://processors.wiki.ti.com/index.php/DM365_Codecs_FAQ#What_are_the_main_features_of_H.264_encoder.3F

What are the main features of H.264 encoder?

Supports sub-window encoding, frame width >= encoded image width, no support for offset

0 Yashwant Dutt over 14 years ago in reply to Jing Lee79304

TI__Genius 17215 points

Hi,

Subwindow encoding is supported in all versions of encoder. This feature is supported using captureWidth and InputWidth.

1. You should give the input buffer pointer as the address of first valid pixel.

2. The inputWidth and inputHeight should be the actual heignt and wodth which you wish to encode

3. The caotureWidth should be the stride length to jump from one pixel to the corresponding(same column) pixel in next row,

regards

Yashwant

0 Jing Lee79304 over 14 years ago in reply to Yashwant Dutt

Prodigy 180 points

Thank you, Yashwant.

CaptureWidth was the trick and it's set to 0 by default.

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subWindow offset support with MPEG4 codec on DM365?