Motion Vector and SAD for MPEG4 and H.264 of DM365

Seog-Hong Park

Dear All,

I'm not expert in Video compression technology, so, i have several questions about motion vector and SAD for MPEG4 and H.264 of DM365.

(1) Motion Vector of MPEG4

In MPEG4 Encoder DM365 datasheet,

"One motion vector encoding for motion estimation (1MV/MB) with (-32,+31) half pel search range supported"

but, I can get motion vector with (-15, 15). I want to know whether the motion vector obtained is correct?

(2) Motion Vector Range of H.264 High Profile

With H.264 High Profile Encoder of DM365, I can get motion vector MVx with (-115, 115) and motion vector MVy with (-303, 296 ).

Is it right? If so, what's the range of motion vector?

Also, as i know, normally, motion vector range for horizontal is greater than motion vector range for vertical.

Also, as i know, H.264 standard say that 8 frames are referenced, I want to know how many frames are referenced in H.264 High Profile Encoder of DM365?

(3) SAD or SATD?

Last one question is the value which can get with MV is SAD or SATD?

over 15 years ago

0 Mahant S over 15 years ago

TI__Prodigy 635 points

Hi Park,

1. The motion vector got is correct.

2. MVx looks fine. But MVy is correct, if you have set meAlgo = 0.

Range of motion vectors is not fixed. It depends on Level set for encoding.

In DM365 encoder we refer to only one frame.

3. ME module always returns SAD.

rgds, mahant

0 Seog-Hong Park over 15 years ago in reply to Mahant S

Prodigy 70 points

Thanks a lot.

By the way, motion vector values which i have got is very fast camera P/T movement.

Regarding your answer, I'm still somewhat questionable.

1. Your answer for 1. means the max/min value of motion vector MVx, MVy is (15,-15) or

due to the fact that (15, -15) is inside (-32, 31), you said "the motion vector got is correct".

Which is the correct?

2. Does Level set for encoding mean levelIdc set for encoding?

When I changed Level set for encoding from 31 to 22, only MVx is changed, and motion vector MVy is unchanged.

Is it correct? Could you provide the range of motion vector for Level or resolution in H.264 of DM365?

Regards

0 Yashwant Dutt over 15 years ago in reply to Seog-Hong Park

TI__Genius 17215 points

Hi,

Please check the wiki post http://tiexpressdsp.com/index.php/Using_MV_SAD_Info_of_DM365_encoder_in_Application

It has a document which details MV SAD information and usage.

Also, there was a known issue with H.264 encoder which is fixed in latest codec release. Please check the post: http://e2e.ti.com/support/dsp/davinci_digital_media_processors/dm3x/f/100/t/33256.aspx

Let us know if you have any further query.

regards

Yashwant

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Motion Vector and SAD for MPEG4 and H.264 of DM365