Slow playback of 720p

[uralop]

Hi,
I encoded a video of Jay leno I recorded in TS format.
Here is the setting I used:
bframes=3:subq=6:me=umh:mixed-refs=1:ref=3:merange=24:analyse=all:8x8dct=1:weightb=1:brdo=1:bime=1:direct=auto:level=41:trellis=1
Using Quicktime (Mac), the playback slows down when there is some motion (15 fps).
The bitrate is ~6.5mbps.

What is the parameter who can slow down that much my encode?

Thanks. :)

[Dust Signs]

Hi,

maybe your hardware is not powerful enough? 720p without acceleration by the graphics card is still a challenging task (considering your settings) for a middle class CPU. Which CPU do you currently have?

Dust Signs

[foxyshadis]

CABAC is the biggest decoding speed killer, use :nocabac=1 to disable that. However, you may prefer to retain cabac and find the maximum peak bitrate your system can decode (which is well above the average bitrate), and then use x264's VBV settings to keep it from rising above that.

[uralop]

Thanks for your answers.

My CPU is a Core 2 Duo, 2.2Ghz.

What is strange is that I played some 720p before without any problems. But yes, I don't know what was the settings used.

I will try to disable CABAC to see.

[Inventive Software]

Try VLC or MPlayer and see if that helps. Quicktime isn't renowned as being a particularly speedy player, even on Macs. :)

[Trahald]

What is strange is that I played some 720p before without any problems. But yes, I don't know what was the settings used.Yes but you can have an easy to decode 720p and a hard to decode 720p depending on the settings used. resolution is only part of the equation. When you playback the file, check your cpu usage.

[uralop]

CPU usage is 100% :p
Are there players which use both cores of a cpu?

[uralop]

Moreover, I used CAVLC to see, and yes, playback was normal.

[nm]

CPU usage is 100% :p
Are there players which use both cores of a cpu?
Did you already try VLC and MPlayer? They might be fast enough even though their H.264 decoder (libavcodec/ffh264) is not multithreaded on all streams. There is a patch (http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-September/035877.html) for libavcodec that splits CABAC decoding to another thread, but I'm not sure if it can be applied without modifications anymore, and you would need to compile the player yourself.

[Irakli]

Did you already try VLC and MPlayer? They might be fast enough even though their H.264 decoder (libavcodec/ffh264) is not multithreaded on all streams. There is a patch (http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-September/035877.html) for libavcodec that splits CABAC decoding to another thread, but I'm not sure if it can be applied without modifications anymore, and you would need to compile the player yourself.

It is indeed a good idea to try Mplayer or VLC. I run WinXP and use Mplayer which can easily decode 720p video (encoded with all advanced settings turned on) on my 2Ghz Pentium M notebook.

[Blue_MiSfit]

Bitrate matters too :)

Since you have an intel mac - watch HD under Boot Camp in XP or Vista ;)

I bet you never thought Windows would do video better, since everyone seems to have this mass delusion that Mac is the only way to go for audio / video work... Rofl...

~MiSfit