[edge.it]

Hello. I am having some playback issues on my Mac Pro running high def 1080p files that I RIPPED into .mkv format when playing through my Sony Bravia KDL-40S4100. (while playing any other move that is @ 720p/576p there is no chopyness)

This issue has been apparent through my upgrade from 10.5.9/10/11 -> 10.6.1

I am playing files through VLC 1.0.2

I connect my Mac Pro (2.66 Xeon x2 / 5.5TB / 4GB / NVIDIA GFORCE 7300 GT 256MB) via my second video port (I unplug my 24 inch dell LCD) and run it to my SONY TV via DVI -> HDMI -> extension adapter -> 50ft HDMI cable -> HDMI port on TV. (this problem occurred prior to my new media center set up when the cable was a 12ft DVI -> HDMI, so I know length is not the culprit.

When I watch the video locally on my Dell monitor the video playback glitches arent apparent. But when I play through the Sony the video get choppy and unwatchable, after a while.

After the monthes of troubleshooting I have decided the bitrate of file size / quality of the 1080 rips are to much for my (in my eyes) very powerful mac pro. The only peice I can upgrade to specs that are enough is the video card? Are my assumptions wrong, Is there something else im missing?

[Spheric Harlot]

I don't know whether it's just the mac implementation, but .mkv is a really crap format and the only one that's been consistently unplayable here.

Oh, and I don't think 10.5 has gone beyond 10.5.9 yet.

[reader50]

1080p playback is rough for a single CPU core. It's not the MKV container, which is quite modern. It's the high bitrate h264 video. The higher refresh rate on the computer monitor is probably concealing some of the frame drops.

What you need is a multithreaded video decoder. Download MPlayer OSX Extended. Within it, go into Preferences -> Video tab -> Checkbox "Use multithreaded ffmpeg build".

It's listed as an experimental feature, but works well. And this is the only multithread video player on OSX so far.

[mduell]

I've noticed the same thing, appears to be an implementation, API, or system issue.

Single core (Pentium M) Windows box can play MKV/264 files that a dual core (Core Duo) Mac can't (same clockrate).

[edge.it]

"Oh, and I don't think 10.5 has gone beyond 10.5.9 yet. "\
Thanks. Yeah that is what I meant.

" 1080p playback is rough for a single CPU core"I thought my mac pro Xeons were dual core? No?

[reader50]

Your MacPro is a multicore, but normal video players use a single thread for video decode. ie - even an 8-core MacPro will show only a single core maxed out, with the rest of the cores mostly idle. Hence my suggestion of a player that can multithread the video decode.

[angelmb]

You could try the DivX Player 7, which with my Mac Pro (2.0 GHz CPUs) goes over 180% of CPU usage, BUT I guess that says next to nothing cause it only takes a random clic over the movie timeline to get the audio out of sync. So far, that doesn't happen with MPlayer OS X Extended.