Regarding DM8168 MPEG-2 Decoder

Yongying Gao

I have a question regarding the DM8168 MPEG_2 Decoder:

I am currently working on decoding the MPEG-2 bitstream using the OMX-based MPEG-2 decoder while I found the interlaced video was not correctly decoded. I use the provided tool to cut the bitstream into frame unit. However, according to the source code, the segment is PICTURE but NOT FRAME in case of interlaced video. So what I am concerned is: does the current SDK cannot handle the interlace video(the MPEG-2 decoder shall do it in terms of the spec) or it can but I need to modifiy the bitstream-cutting tool to feed the decoder a whole frame?

Thanks in advance for your nice help!

Regards,

-Yongying

over 13 years ago

0 Yashwant Dutt over 13 years ago

TI__Genius 17215 points

Sorry for the delay, looks like this post got missed, are you still chasing this issue ?

regards

Yashwant

0 llano4 over 13 years ago in reply to Yashwant Dutt

Prodigy 230 points

Hi,

I also encountered interlaced issue of MPEG2.

All Mpeg2 bitstream I am using is interlaced ones. I write a tool to cut the bitstream in frame basis.

It can correctly feed the decoder a whole frame and decoder does correctly output the frame.

However the output YUV of decoder is field separate which the top and bottom field are the same.

I thought it is not a big deal as I will encode this YUV by h262 encoder and h264 encode should handle this field separate YUV buffer.

But, I tried so many h264 parameter settings and still can not get it.

I am using EZSDK504, can you help me out of here? what parameters should I use in 264 encoder or mpeg2 decoder?

0 Yongying Gao over 13 years ago in reply to Yashwant Dutt

Prodigy 80 points

Dear Yashwant,

Yeah...We are still struggling against this interlace issue....Do you have any ideas about it?

Thanks.....

Yongying

0 Yashwant Dutt over 13 years ago in reply to Yongying Gao

TI__Genius 17215 points

I have fwded this to EZSDK experts, they will reply back soon.

regards

Yashwant

0 Vimal Jain over 13 years ago in reply to Yashwant Dutt

TI__Expert 6535 points

Hi,

which cutting tool are you using for giving frames to MPEG2 decoder. Parser available in EZSDK is for example purpose and can not parse all the streams. Also decoder gives both fields in same buffer ( top and bottom field which can look same), It needs to be de-interlaced for display.

Regards

Vimal

0 llano4 over 13 years ago in reply to Vimal Jain

Prodigy 230 points

Hi Vimal,

The parser is written by us and can make sure it feeds one frame per time correctly.

The decoder's ouptut, just as you said, is field separate. We don't display it but need re-encode it into h264 stream.

The question is h264 can encoder encode this buffer just as normal NV12 picture format, so encoded h264 stream will show two same fields when decoded.

So, how can we feed this field separate buffer to h264 encoder?

Thanks,

Llano

0 Vimal Jain over 13 years ago in reply to llano4

TI__Expert 6535 points

Hi,

You would need to set inputContentType in static parameters. For details on static parameter refer to codec user guide.

Also Have a look at following link for setting up static parameters in OMX.

http://processors.wiki.ti.com/index.php/OMX_VENC --

" How to modify static parameters of codec ? "

Regards

Vimal

0 llano4 over 13 years ago in reply to Vimal Jain

Prodigy 230 points

Hi Vimal,

We tried inputContentType, but didn't work.

We will try again.

Thanks,

Llano

0 llano4 over 13 years ago in reply to Vimal Jain

Prodigy 230 points

Hi Jain，

It works now, thanks a lot.

Regards,

Llano

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Regarding DM8168 MPEG-2 Decoder