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.

 

Go Back   Doom9's Forum > Video Encoding > MPEG-4 AVC / H.264

Reply
 
Thread Tools Search this Thread Display Modes
Old 26th February 2007, 21:27   #1  |  Link
agilpwc
Registered User
 
Join Date: Jun 2005
Location: Los Angeles
Posts: 28
x264 parameters / decode speed

Which of the x264 parameters or options make a video harder to decode?

What I'm looking for is the best parameters for a video that will be played back on a older computer. For example I have some 1280x720 videos that I'm trying to encode and even my dual core laptop has trouble playing it back, using the inefficient QT. Of course with VLC no problem, but I want to distrubute the video.

currently I've come up with
--bitrate 2500 --direct temporal --subme 6 --analyse p8x8,b8x8,i4x4,p4x4 --no-cabac --me dia --threads auto --thread-input --progress --no-psnr --no-ssim

For example, I know subme 6 slows encode time, but does it slow decode time?
agilpwc is offline   Reply With Quote
Old 26th February 2007, 21:40   #2  |  Link
shon3i
BluRay Maniac
 
shon3i's Avatar
 
Join Date: Dec 2005
Posts: 2,426
cabac slow down decoding process
shon3i is offline   Reply With Quote
Old 26th February 2007, 22:15   #3  |  Link
Manao
Registered User
 
Join Date: Jan 2002
Location: France
Posts: 2,855
Major speed factors ( from the most important to the least )
- cabac
- deblocking
- resolution
- bitrate
- bframes
- p4x4
- i4x4
- i8x8
- 8x8

No effect at all ( quality settings )
- subme
- me
- threads
- trellis
- ...
__________________
Manao is offline   Reply With Quote
Old 27th February 2007, 10:29   #4  |  Link
Dethis
Registered User
 
Join Date: Jan 2006
Posts: 57
Just add to the above that cabac's influence in decoding speed is not steady but almost totally proportional to the bitrate.
So the conclusion is that when we encode with cabac on, the bitrate is the major factor in decoding speed.
Dethis is offline   Reply With Quote
Old 28th February 2007, 03:40   #5  |  Link
DeathTheSheep
<The VFW Sheep of Death>
 
DeathTheSheep's Avatar
 
Join Date: Dec 2004
Location: Deathly pasture of VFW
Posts: 1,149
I've also found (at least with CoreAVC plugin for Win32 TCPMP 0.72rc1) that a stream with 16 references decoded almost 10% more slowly than a stream with similar encoding settings but with 1 reference (mixed).
__________________
Recommended all-in-one stop for x264/GCC needs on Windows: Komisar x264 builds!
DeathTheSheep is offline   Reply With Quote
Old 2nd March 2007, 18:59   #6  |  Link
bond
Registered User
 
Join Date: Nov 2001
Posts: 9,779
Quote:
Originally Posted by agilpwc View Post
Which of the x264 parameters or options make a video harder to decode?

What I'm looking for is the best parameters for a video that will be played back on a older computer. For example I have some 1280x720 videos that I'm trying to encode and even my dual core laptop has trouble playing it back, using the inefficient QT. Of course with VLC no problem, but I want to distrubute the video.

currently I've come up with
--bitrate 2500 --direct temporal --subme 6 --analyse p8x8,b8x8,i4x4,p4x4 --no-cabac --me dia --threads auto --thread-input --progress --no-psnr --no-ssim

For example, I know subme 6 slows encode time, but does it slow decode time?
check the decoder comparison sticky for getting an idea on how things influence decoding
__________________
Between the weak and the strong one it is the freedom which oppresses and the law that liberates (Jean Jacques Rousseau)
I know, that I know nothing (Socrates)

MPEG-4 ASP FAQ | AVC/H.264 FAQ | AAC FAQ | MP4 FAQ | MP4Menu stores DVD Menus in MP4 (guide)
Ogg Theora | Ogg Vorbis
use WM9 today and get Micro$oft controlling the A/V market tomorrow for free
bond is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 20:15.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.