questions about EDMA

The following app note may help: http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=spraak3b .  It uses resizer to do the conversion to 4:2:0; it is written for DM644x, but DM6437 has the same hardware resizer...

Hi Juan,

Can i have the link for example program(code) for the same?(unable to find sprc 374.gz )

Thank you,

Thupakula.

you should be able to donwload this from the same link I sent in the previous post: http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=spraak3b; I just tried this and it seems to work for me.

FYI, this is likely a Linux sample application which exercises the Linux-based resizer driver on DM644x; the software (ARM/Linux based) will likely not be applicable to DM6437.  The primary reason I referred you to this is to make you aware that it can be done via resizer hardware (dm6437 has same resizer hw) and the app note hopefully does a decent job of explaining the overall process.  With regards to SW though, you will likely have to write sw specific to DM6437 resizer driver (DPS/BIOS based)

Hi Juan,

In this document ,they used the RESIZE to just for de interlacing

// ask resizer to do de-interlacing
ioctl( resizerFd, RSZ_RESIZE, &resize );

but In DM6437 , I am using this IOCTL to resize the image..

On what basis this can be used for deinterlacing.. ( Is it based on filter coefficients ?)

If so how to define them ?

Thank u,

Thupakula.

If you need to resize as well, then you simply will need one pass thru resizer to convert 4:2:2 to 4:2:0 (yes two passes take additional time, but considering the alternatives which can also take time and other resources...); that said, there are a few (most can be set to zero) coefficients that need to be set for deinterlacing to 4:2:0; these are detailed in the App Note I referred you to.  http://focus.ti.com/lit/an/spraak3b/spraak3b.pdf.  Again, I am not familiar with DM6437 software, but just trying to point out an alternative (resizer ) to doing 4:2:0 conversion rather than using DMA.

Hi Juan,

I tried to resize the frame from 720*576 to 352 *288 by using the filter coefficients  which are given in the demo application. They are

#define gRDRV_reszFilter4TapHighQuality  0, 256, 0, 0, -6, 246, 16, 0, -7, \
    219, 44, 0, -5, 179, 83, -1, -3, 130, 132, -3, -1, 83, 179, -5, 0, \
44, 219, -7, 0, 16, 246, -6

and my output frame  looks like asbelow

 And Iam not sure how to calculate these coefficients such that i will get proper frame.

  According to spraai7b , Do i need to use MATLAB to calculate the filter coeffiecients? and what is S10Q8 format ? and how to convert the coffeients in to this format?

Is there any predefined tool (like A Linux utility called calccoeff ) in windows xp that can be used to calculate these coefficients? Can you please provide me the appropriate coeffecients for this resolution.

Thanks,

thupakula.

The following App Note includes that calccoeff utility you can use to compute these coefficients: http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=spraai7b (see sprc238.gz file).  I have ran this utility for you and am attaching the file generated; please read over the App Note to determine how to interpret and use these coefficients.

Hi Juan,

Thank you very much for the help.

Now I am using EDMA 3 for YUV422 to YUV420 conversion. I am just checking the demo application edma3test. I used the same function conversion_YUV422 toYUV420 in my application with the different resolution(iam using for 720 * 576) as below.

 
   if (test_422to420_conversion(hEdma,(signed char *)frameBuffPtr->frame.frameBufferPtr, bufExt1 ) != EDMA3_DRV_SOK )
   {
    printf("test_422to420_conversion() failed!\n");
    exit(1);
   }
   else
   {
   
    out = fopen("..\\input.yuv","wb");
      if ( out == NULL)
      {
      printf("unable to create output file");
      }
  
    fwrite(bufExt1,(720*864),1,out);
    printf("test_422to420_conversion() passed!\n");

    }

fclose(out);

I am getting below output frame which is weird.

If I recall correctly, you are using DM6437; I am not very familiar with the software stack on this platform so maybe someone else can chime in and offer some advice. 

Yes, I am using DM6437.

Can some one suggest me what would e the cause for this?

Thanks,

Thupakula.

Hallo  Juan n Bernie,

Finally i finished my application to get CIF YUV420 frame on DM6437 Platform.

Thank you very much for all ur support.

Thupakula.

Thupakula,

This is great news; we are happy to help.