AVC vs. VC1 vs. h264 vs. My Computer

[CelticWhisper]

It's late so I'll keep this brief for now.

I downloaded a movie trailer ("Juno") that's in 1080p HD, and it stutters like nobody's business. I'm on a G5 quad 2.5GHz, so there's no good reason it should be this jittery when it plays back.

VLC shows the video codec as "avc1." However, researching it turns up only "avc1decoder" which is a QuickTime component that doesn't help much if at all, and a plethora of specs and comparisons between h.264 (which is called "AVC") and VC-1.

But what in the hell is AVC1? Some combination of the two? Something completely different? And why can a G5 quad, 2.5GHz, with a GeForce 6600/256MB and six and a half gigs of memory not play it back smoothly?

I had a similar file before, a music video, that I was able to play back just fine by re-encoding to XviD with FFMpeg, resulting in a 600MB file. Worked, but that's not exactly optimal for anything I might want to keep around for a while.

Sorry if I'm coming across harsh here, it's just late and I'm tired (and tired of fighting with a thousand different video codecs). I really, really, truly appreciate the help.

[kjordan2001]

It's late so I'll keep this brief for now.

I downloaded a movie trailer ("Juno") that's in 1080p HD, and it stutters like nobody's business. I'm on a G5 quad 2.5GHz, so there's no good reason it should be this jittery when it plays back.

VLC shows the video codec as "avc1." However, researching it turns up only "avc1decoder" which is a QuickTime component that doesn't help much if at all, and a plethora of specs and comparisons between h.264 (which is called "AVC") and VC-1.

But what in the hell is AVC1? Some combination of the two? Something completely different? And why can a G5 quad, 2.5GHz, with a GeForce 6600/256MB and six and a half gigs of memory not play it back smoothly?

I had a similar file before, a music video, that I was able to play back just fine by re-encoding to XviD with FFMpeg, resulting in a 600MB file. Worked, but that's not exactly optimal for anything I might want to keep around for a while.

Sorry if I'm coming across harsh here, it's just late and I'm tired (and tired of fighting with a thousand different video codecs). I really, really, truly appreciate the help.

AVC1 is just H.264/MPEG-4 AVC, it has nothing to do with VC-1. No clue why your system wouldn't be able to handle it. My E6600 with 2GB of RAM and GeForce 7950GT on XP using Quicktime to play it off of Apple's site works just fine. You might check just to see how much of your resources are being taken and if you have a lot open or any intensive apps open, that might be the problem.

[SnowRanger13]

Do you have the latest version of VLC? 0.8.6d is the latest. Maybe try playing it with quicktime? If you need the codec for it it's probably included in Perian, install Perian and try it in quicktime.

[CelticWhisper]

Unfortunately I tried that. It fared better than VLC, but not by much. Lots of dropped frames, audio and video out of sync, jittery motion, etc...

I can check for updates to Perian but the avc1decoder.component that I downloaded and plopped into /Library/QuickTime didn't do much to help.

I read on the VLC forums that the FFmpeg team is working on an AVC1 decoder and that the current incarnation of it is not multithreaded, resulting in some processors being unable to play it back. I can't imagine that the PPC970 would be too slow, but at the same time I can see how there would be a disadvantage in not having my 4 cores available to share the load.

KJordan - E6600 is a C2D chip, right? Is that in an Apple system running OS X or are you talking Windows/Linux? I know there's a decoder called CoreAVC for Windows that supposedly does a very good job of playing back AVC, but of course that's not an available option to me.

Okay, anyway, I'll check for updates to Perian and see what that can do for me. Otherwise I'll try to whip up a script to convert videos to another codec via FFMpeg and just deal with the time cost. Yarg.

[CelticWhisper]

Small update:

Perian has no currently available updates - I'm on the latest version.

I did whip up that FFmpeg script I was talking about in case anybody needs it. Purely command-line so the FFmpeg core binary is all you need, no GUI tools or anything.

ffmpeg -i (your input file here) -vcodec mpeg4 -vtag xvid -sameq -acodec libmp3lame -ab 320k output_file.avi

A few notes:

-Output_file can be whatever you want, obviously.

-I'm using libmp3lame for audio because try as I might, I can't seem to get any other codecs to work properly with an AVI container. Vorbis and m4a don't work, and I can't seem to get ffmpeg to encode to PCM (don't know which codec is the right one, those I try just bomb out with errors).

The resulting file will be...big. That's all I can say, not really HOW big, but usually 2x the original filesize at least. However, it'll play back on VLC just fine.