Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
|
14th August 2009, 12:32 | #1 | Link |
Registered User
Join Date: May 2008
Posts: 9
|
motion estimation in x264
Hi people,
Is there any document that explains how motion estimation in is done in x264? I would assume that it uses some kind of fast motion estimation (i.e. not full search), but I would appreciate if someone could point me to a document that describes this process, if such a document exists. Thanks |
14th August 2009, 12:39 | #2 | Link |
x264 developer
Join Date: Sep 2005
Posts: 8,666
|
This overview has some information, but it's outdated.
x264 has 5 fullpel motion estimation modes: radius-1 diamond, radius-2 hex (default), UMH (somewhat similar to JM), exhaustive (implemented fast via sequential elimination), and Hadamard exhaustive (implemented approximately via thresholded sequential elimination). This mostly overlooks the main power behind x264's motion search (11 predictors including single-level hierarchical search, qpel-RD). If you want more specific details, ask on #x264dev on Freenode IRC.
__________________
Follow x264 development progress | akupenguin quotes | x264 git status ffmpeg and x264-related consulting/coding contracts | Doom10 Last edited by Dark Shikari; 14th August 2009 at 12:45. |
14th August 2009, 15:53 | #3 | Link |
Registered User
Join Date: May 2008
Posts: 9
|
Thanks for your answer. If I will have more detailed questions about the implementations I will ask at your proposed place. Generally I am just interested if any kind of performance/complexity measurement between Hexagon search and UMH exist? According to my understanding the Hexagon search suffers from the problem that it will more likely stuck in the local minimum, while the UMH is more robust in that sense, but also more complex. Is my understanding correct?
Thanks |
14th August 2009, 16:00 | #4 | Link | |
x264 developer
Join Date: Sep 2005
Posts: 8,666
|
Quote:
|
|
22nd August 2011, 00:01 | #6 | Link |
Registered User
Join Date: Aug 2011
Posts: 1
|
Hi
I have been reading about block motion estimation algorithms such as the three step search, four step search, diamond search, new three step search, adaptive rood pattern search etc How comes these are not an option with x264. Do the hexagon and multi-hex have different names they are known by? |
Thread Tools | Search this Thread |
Display Modes | |
|
|