[video] RE: [Mp4-tech] Effect of sub-pel motion estimation on bit rate

[i.g.richardson rgu.ac.uk]

Dear all
I sent the following reply to Simon with a graph attachment - rather than send it to the entire list, if you would like to see the graph please email me and I'll send it to you-
------
Attached is an example of rate-distortion results for H.264 encoding of the "foreman" test sequence, a reasonably high-activity video clip. I encoded the clip at a range of quantization parameters. There are two curves on the graph: encoding parameters for both are identical except that quarter-pel motion compensation is enabled for the red curve (the default for H.264) and only half-pel compensation is enabled for the blue curve. You will see that quarter-pel gives a significant benefit at all bitrates.
It is worth mentioning that good half- and quarter-pel performance depends on the choice of filter to carry out sub-pel interpolation. In H.264/AVC, a 6-tap filter is used in each direction for half-pel interpolation; quarter-pel samples are produced by a further linear interpolation step.
-------
Iain Richardson
The Robert Gordon University
UK
-----Original Message-----
From: mp4-tech-bounces lists.mpegif.org [mailto:mp4-tech-bounces lists.mpegif.org] On Behalf Of Simon Denman
Sent: 06 May 2024 15:02
To: mp4-tech lists.mpegif.org
Subject: [Mp4-tech] Effect of sub-pel motion estimation on bit rate
Can anyone point me at any resources documenting the effect of varying motion resolution (integer-pel, half-pel and quarter-pel) on bit rate?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Simon Denman
Elixent Ltd, Castlemead, Lower Castle Street, Bristol, BS1 3AG
Tel: 0117 917 5756
Email: simon.denman elixent.com
---
Incoming mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.676 / Virus Database: 438 - Release Date: 03/05/2024
---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.676 / Virus Database: 438 - Release Date: 03/05/2024
-------------- next part --------------
An HTML attachment was scrubbed...
URL: /pipermail/mp4-tech/attachments/20040507/45dea08a/attachment.html