Forums

DM642:::video encoder

Started by suren porwar December 18, 2004

  Hi All,

I just wanted to know whether the video encoder(latest or older version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have to resample it to YUV 4:2:0 from YUV 4:2:2.
I referred few documents in TI site  all the examples, using evm dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
I wanted to know whether Directly YUV4:2:0 could be accepted???
If yes how???

Thanks,
Regards
Suren.



hi there

i use dsp/bios APIs to write a real time program with  PIP and SWI modules i define two pipe objects (rxPIPE and txPIPE and a SWI object (audioSWI) and manage when occuring a receive interrupt from MCBSP0 (which is connected to codec) a predefined subroutine copes a full word from DRR register to one of rxPIPE farame words.as well a world from txPipe is copied tp DXR register when a rxPipe is full and a txPipe get empty SWI(audioSWI) must be triggered to call a subroutine named audio thes function copies a full frame from rxPipe to an empty frame of txPipe .but there is a problem here.

software interrupt is not enabled even posting software interrupt in the main routine (by SWI_post or SWI_dec and etc) audio function will not be called.

how i can enable and trigger a predefined DSP/BIOS software interrupt object

please help me

thanks

regards

yasser  



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Dear Suren,
The output from the Video port will be a YUV 422 frame. You need to perform a color conversion which I think is supported in CSL or can be written independently.
Hope this Helps.
Cheers,
Ganesh
----- Original Message -----
From: suren porwar
To: c...@yahoogroups.com
Sent: Saturday, December 18, 2004 9:12 PM
Subject: [c6x] DM642:::video encoder

  Hi All,

I just wanted to know whether the video encoder(latest or older version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have to resample it to YUV 4:2:0 from YUV 4:2:2.
I referred few documents in TI site  all the examples, using evm dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
I wanted to know whether Directly YUV4:2:0 could be accepted???
If yes how???

Thanks,
Regards
Suren.



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Actually, there is a "chrominance-resampling" feature that can be
used to capture 420 frames from the video ports.

Refer document: SPRU629C.pdf
"TMS320C64x DSP Video Port/VCXO Interpolated Control (VIC) Port
Reference Guide"

Check out Section 3.5 on "Video Input Filtering"

~ka

--- In , "Ganesh Vijayan" <ganesh@e...> wrote:
> Dear Suren,
> The output from the Video port will be a YUV 422 frame. You need to
perform a color conversion which I think is supported in CSL or can
be written independently.
> Hope this Helps.
> Cheers,
> Ganesh
> ----- Original Message -----
> From: suren porwar
> To:
> Sent: Saturday, December 18, 2004 9:12 PM
> Subject: [c6x] DM642:::video encoder > Hi All,
>
> I just wanted to know whether the video encoder(latest or older
version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have to
resample it to YUV 4:2:0 from YUV 4:2:2.
> I referred few documents in TI site all the examples, using evm
dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
> I wanted to know whether Directly YUV4:2:0 could be accepted???
> If yes how???
>
> Thanks,
> Regards
> Suren.




Dear Anand,
I guess you are speaking about Sec 3.5.2 of the document. My initial statement that we can't get YUV420 conversion is wrong to some extent. As you have rightly pointed out that we can use the Chrominance Resampling operation. But in the section, it is mentioned that sub-sampling happens only in horizontal direction. To quote the text, "The vertical portion of the conversion must be performed in the software". Hence, we can get only the horizontally sub-sampled version and we need to handle in vertical direction i.e. skipping chroma samples for alternate lines. So I was partially wrong and partially correct :O) .. Please correct me if my understanding is wrong.
Cheers,
Ganesh
----- Original Message -----
From: Anand K
To: c...@yahoogroups.com
Sent: Monday, December 20, 2004 8:53 PM
Subject: [c6x] Re: DM642:::video encoder

Actually, there is a "chrominance-resampling" feature that can be
used to capture 420 frames from the video ports.

Refer document: SPRU629C.pdf
"TMS320C64x DSP Video Port/VCXO Interpolated Control (VIC) Port
Reference Guide"

Check out Section 3.5 on "Video Input Filtering"

~ka

--- In c...@yahoogroups.com, "Ganesh Vijayan" <ganesh@e...> wrote:
> Dear Suren,
> The output from the Video port will be a YUV 422 frame. You need to
perform a color conversion which I think is supported in CSL or can
be written independently.
> Hope this Helps.
> Cheers,
> Ganesh
>   ----- Original Message -----
>   From: suren porwar
>   To: c...@yahoogroups.com
>   Sent: Saturday, December 18, 2004 9:12 PM
>   Subject: [c6x] DM642:::video encoder>     Hi All,
>
>   I just wanted to know whether the video encoder(latest or older
version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have to
resample it to YUV 4:2:0 from YUV 4:2:2.
>   I referred few documents in TI site  all the examples, using evm
dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
>   I wanted to know whether Directly YUV4:2:0 could be accepted???
>   If yes how???
>
>   Thanks,
>   Regards
>   Suren.>
>   

 




You are right Ganesh, but usually for the vertical direction, a
subsampling (without filtering) is good enough for most practical
uses. In which case, simply discard the color info from alternate
fields. The data will still be Edma-ed by the port into the buffers,
but discarded by the user. (very easy to do with the Y/C capture
mode, where Y and C are NOT interleaved)

The chrominance-resampling feature, along with the 1/2-scaling
feature, helps us do the above even with CIF-resolution. (4-CIF is
straighforward: where you discard color info for every alternate
field).

Of course this is not the perfect approach, but a practical one, in
applications with high frame rates where very high color-fidelity
between frames isnt needed.

~ka

--- In , "Ganesh Vijayan" <ganesh@e...> wrote:
> Dear Anand,
> I guess you are speaking about Sec 3.5.2 of the document. My
initial statement that we can't get YUV420 conversion is wrong to
some extent. As you have rightly pointed out that we can use the
Chrominance Resampling operation. But in the section, it is mentioned
that sub-sampling happens only in horizontal direction. To quote the
text, "The vertical portion of the conversion must be performed in
the software". Hence, we can get only the horizontally sub-sampled
version and we need to handle in vertical direction i.e. skipping
chroma samples for alternate lines. So I was partially wrong and
partially correct :O) .. Please correct me if my understanding is
wrong.
> Cheers,
> Ganesh
> ----- Original Message -----
> From: Anand K
> To:
> Sent: Monday, December 20, 2004 8:53 PM
> Subject: [c6x] Re: DM642:::video encoder > Actually, there is a "chrominance-resampling" feature that can be
> used to capture 420 frames from the video ports.
>
> Refer document: SPRU629C.pdf
> "TMS320C64x DSP Video Port/VCXO Interpolated Control (VIC) Port
> Reference Guide"
>
> Check out Section 3.5 on "Video Input Filtering"
>
> ~ka
>
> --- In , "Ganesh Vijayan" <ganesh@e...> wrote:
> > Dear Suren,
> > The output from the Video port will be a YUV 422 frame. You
need to
> perform a color conversion which I think is supported in CSL or
can
> be written independently.
> > Hope this Helps.
> > Cheers,
> > Ganesh
> > ----- Original Message -----
> > From: suren porwar
> > To:
> > Sent: Saturday, December 18, 2004 9:12 PM
> > Subject: [c6x] DM642:::video encoder
> >
> >
> > Hi All,
> >
> > I just wanted to know whether the video encoder(latest or
older
> version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have
to
> resample it to YUV 4:2:0 from YUV 4:2:2.
> > I referred few documents in TI site all the examples, using
evm
> dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
> > I wanted to know whether Directly YUV4:2:0 could be
accepted???
> > If yes how???
> >
> > Thanks,
> > Regards
> > Suren.
> >
> >
> >
> >
> >
>



Dear Anand,
Discarding the chroma samples becomes an application feature i.e. depends on the application builder how he wishes to perform the same, which will depend on the computational complexity and memory requirements to perform the same. If we are capturing YUV422 Interleaved data, then it becomes a bit of a tedious task and hence I felt that conversion to YUV420 Planar is better. However, if we capture in Y/C capture mode without interleave, then your suggestion works fine.
Cheers,
Ganesh
----- Original Message -----
From: Anand K
To: c...@yahoogroups.com
Sent: Thursday, December 23, 2004 12:24 AM
Subject: [c6x] Re: DM642:::video encoder

You are right Ganesh, but usually for the vertical direction, a
subsampling (without filtering) is good enough for most practical
uses. In which case, simply discard the color info from alternate
fields. The data will still be Edma-ed by the port into the buffers,
but discarded by the user. (very easy to do with the Y/C capture
mode, where Y and C are NOT interleaved)

The chrominance-resampling feature, along with the 1/2-scaling
feature, helps us do the above even with CIF-resolution. (4-CIF is
straighforward: where you discard color info for every alternate
field).

Of course this is not the perfect approach, but a practical one, in
applications with high frame rates where very high color-fidelity
between frames isnt needed.

~ka

--- In c...@yahoogroups.com, "Ganesh Vijayan" <ganesh@e...> wrote:
> Dear Anand,
> I guess you are speaking about Sec 3.5.2 of the document. My
initial statement that we can't get YUV420 conversion is wrong to
some extent. As you have rightly pointed out that we can use the
Chrominance Resampling operation. But in the section, it is mentioned
that sub-sampling happens only in horizontal direction. To quote the
text, "The vertical portion of the conversion must be performed in
the software". Hence, we can get only the horizontally sub-sampled
version and we need to handle in vertical direction i.e. skipping
chroma samples for alternate lines. So I was partially wrong and
partially correct :O) .. Please correct me if my understanding is
wrong.
> Cheers,
> Ganesh
>   ----- Original Message -----
>   From: Anand K
>   To: c...@yahoogroups.com
>   Sent: Monday, December 20, 2004 8:53 PM
>   Subject: [c6x] Re: DM642:::video encoder>   Actually, there is a "chrominance-resampling" feature that can be
>   used to capture 420 frames from the video ports.
>
>   Refer document: SPRU629C.pdf
>   "TMS320C64x DSP Video Port/VCXO Interpolated Control (VIC) Port
>   Reference Guide"
>
>   Check out Section 3.5 on "Video Input Filtering"
>
>   ~ka
>
>   --- In c...@yahoogroups.com, "Ganesh Vijayan" <ganesh@e...> wrote:
>   > Dear Suren,
>   > The output from the Video port will be a YUV 422 frame. You
need to
>   perform a color conversion which I think is supported in CSL or
can
>   be written independently.
>   > Hope this Helps.
>   > Cheers,
>   > Ganesh
>   >   ----- Original Message -----
>   >   From: suren porwar
>   >   To: c...@yahoogroups.com
>   >   Sent: Saturday, December 18, 2004 9:12 PM
>   >   Subject: [c6x] DM642:::video encoder
>   >
>   >
>   >     Hi All,
>   >
>   >   I just wanted to know whether the video encoder(latest or
older
>   version) on EVM DM642 accepts frames in YUV 4:2:0 or do we have
to
>   resample it to YUV 4:2:0 from YUV 4:2:2.
>   >   I referred few documents in TI site  all the examples, using
evm
>   dm642 accept YUV4:2:2 and then convert it into YUV4:2:0.
>   >   I wanted to know whether Directly YUV4:2:0 could be
accepted???
>   >   If yes how???
>   >
>   >   Thanks,
>   >   Regards
>   >   Suren.
>   >
>   >
>   >
>   >   
>   >
>