Interlaced question

[kyviquel]

Hi,

I implemented an h264 compression solution using Intel Media SDK.

In case of interlaced video: I interlace the 2 uncompressed fields to have a frame at the Input of the encoder and set PicStruc = MFX_PICTRUCT_FIELD_TFF to generate interlaced h264 bitstream. This solution works pretty well but I want to remove the interlace process.

Can I call EncodeFrameAsync() twice (one for each field) and have only one mfxSyncPt for the output to signal that the frame interlaced is encoded ?

Is there any way to do this ? 

Thanks

Karine

[Anthony_P_Intel]

Hi Karine, If I understand your desire to "remove the interlace process" correctly, you'd like to generate a progressive bitstream from the 2 uncompressed fields. I'd recommend using our VPP component to convert the fields to progressive frames for input to the encode. See the Intel_Media_Developers_Guide.pdf section 4.9.2. If this is not what you are looking to do, can you explain a bit more what you mean? THANKS -Tony

[kyviquel]

Hi Tony,

What I meant by "remove the interlace process" is that I want to give the encoder two fields and receive a compressed bitstream with field macroblocks.

For example in NTSC: I tried to send 2 fields 720x243 with the option PicStruc = MFX_PICTRUCT_FIELD_TFF and I received an compressed bitstream with field macroblok but the compressed size is 720x243 instead of 720x486.

I want to know if it is possible to do that with your encoder?

Am I right to think that we lose some processing power by interleaving the input since the encoder will deinterlace to compress in fields macroblocks?

Thanks

Karine

[kyviquel]

Hi,

Is it true that in field your encoder does "MBAFF:Macroblock Adaptative Field Frame" and not "PAFF:Picture Adaptative Field Frame"?

I found this link that explains what is MBAFF and PAFF: http://forum.doom9.org/archive/index.php/t-120317.html

It could explain why in input you accept only the whole frame.

Thanks

Karine

[kyviquel]

Hi,

I would like to know what you expect me to do when I have 2 NV12 field surfaces at the input of your encoder and I would like a compressed bitstream field composed of those 2 fields.

Thanks.

[Anthony_P_Intel]

Hi Karine,

Sorry for the slow response. 

You are correct, the encoder does not support PAFF, but we are looking at this "feature request".

I'm still not exactly sure I understand the desire of "compressed bitstream field composed of those 2 fields", but I believe you may be looking of the field encoding mode that is available if you use the FieldOutput flag of the "mfxExtCodingOption" structure when encoding.