Issue about decoding interlaced video

do van quyen

Dear Experts,

I am working on RDK Version 3.5

My decoder can decode H264 progressive video very well but when it decodes H264-interlaced, I saw the screen displayed duplicate frame. I feel my decoder didn't care data input is interlaced video, it only understand interlaced video as data input because whenever i got a NALbuffer(one slice) i will put it to decode buffer. I don't know why and how to resolve this problem. Please approach or give me some information to resolve this issue

Interlaced-video like below picture

thanks!

over 12 years ago

0 Badri Narayanan over 12 years ago

TI__Guru 59700 points

Pls migrate to DVRRDK 4.01 where interlaced decoding is supported. You have to set

decPrm.chCreateParams[i].processCallLevel = VDEC_FIELDLEVELPROCESSCALL.

0 do van quyen over 12 years ago in reply to Badri Narayanan

Intellectual 365 points

Hi Nara,

As i know for this case I have two slices which have same number are bottom field and top filed data respectively, So for this case I should combine 2 NAL-buffer(2 slices) which have same number(example: two H264 P slice #1) into one buffer, after that I must put it to decoder buffer. Is my think correct?

0 Badri Narayanan over 12 years ago in reply to do van quyen

TI__Guru 59700 points

No you should not combine NAL units. You should feed top field and bottom field AUs separately.

There also changes required in swms to deinterlace and display interlaced fields which are also present only in DVRRDK 4.01

0 do van quyen over 12 years ago in reply to Badri Narayanan

Intellectual 365 points

Could you share information how to changes required in swms to deinterlace and display interlaced fields

0 Badri Narayanan over 12 years ago in reply to do van quyen

TI__Guru 59700 points

The changes in both swms and decLink are too many to be listed. Only option is to migrate to DVRRDK 4.01.

0 do van quyen over 12 years ago in reply to Badri Narayanan

Intellectual 365 points

Hi Nara,

Now, decode can work with intelaced video but it seems the picture to show in wrong order on the screen. As I understand the intelaced video contains B-frame but i didn't set timestamp or displayDelay for decoder hence frames will be out of order. Is it correct? .

0 Badri Narayanan over 12 years ago in reply to do van quyen

TI__Guru 59700 points

Yes you should set displayDelay correctly .For sequence above it should be atleast 4 .You should also increase numBufPerCh to say 10. Disable avsync if you are not setting correct timestamp.multich_vdec_vdis.c set avsyncEnable to FALSE

0 do van quyen over 12 years ago in reply to Badri Narayanan

Intellectual 365 points

Thanks Nara,

How to know(calculate) exactly the value of numBufPerCh and displayDelay. Maybe that value only correct for my case but not sure correctness for an other case.

Now my decoder can work but sometime got error :Assertion @ Line: 665 in links_m3video/iva_dec/decLink_common.c: (freeFrameInfo->pVdecOrgFrame == NULL) && (freeFrameInfo->vdecRefCount > 0) : failed !!!

0 Badri Narayanan over 12 years ago in reply to do van quyen

TI__Guru 59700 points

You should set displayDelay to -1 and numBufPerCh to 16 in which case it will work for any h264 stream. Since this is too much memory app usually determine the stream characteristics like num_ref_frames and set displayDelay based on whether B_frame is present .Attach the H264 bitstream so that it can be checked on TI development setup.

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Issue about decoding interlaced video