[ppolitop]

Maybe I am beating a dead horse, but I really need to ask.

I have done some research and it seems that mac mini, or a powerbook/mac of the latest generation are capable of reproducing at least 720p of .264 content and that includes all of the popular profiles. What we really lack is a capable player that takes advantage of altivec and maybe some of the GPU acceleration features (even the simpler ones present on old ATI cards these machines use).

I have been experimenting with mplayer altivec build, the highly experimental and now abandoned project accelent. Even though accelent is good only for inverse discrete cosine transform calculations and motion compensation copies of mpeg2, I believe these procedures take place even during the playback of mpeg4 content.

Newer builds of VLC and mplayer get slower for PowerPC macs over time and that saddens me.

Would it be a good idea to start a project for a PPC optimized player, with faster/cleaner code and use of the mentioned acceleration techniques? Given that my time is really restricted at the moment is any member interested and capable of joining this cause?

Peter

[Dorian Gray]

I am nowhere near knowledgeable enough to help you, but I've wondered whether it would be possible to tap into the power of this cheap hardware dongle to decode H.264. The Elgato Turbo.264 only encodes H.264 in its commercial form, but surely decoding would be a simple matter of pushing the bits in the other side?

Edit: Incidentally, I would guess that QuickTime uses AltiVec quite heavily to decode H.264 on a G4. I base this on the fact that G4s were far closer than they had any right to be to Intel speeds at playing H.264 back when the first Intel Mac came out. With time QuickTime's Intel performance got much better.

[ppolitop]

Even though it wouldn't really be that simple as pushing the bits the other side maybe it could help. The device you mention has a Mobilygen MG1264 codec chip inside. So you are right it *can* also decode with the correct modification on its driver. But still, I think it is limited to low resolutions, specific framerates, AAC sound (2 channels) and I am not sure that 100 bucks for a g4 upgrade is cheap. I mean our software, if it could be done, would be cheaper
If the turbo.264 project is easier (sounds so at least) I wonder, would it be feasible to utilize it for higher resolutions than 800x600 (or higher bitrates) by splitting the job between the device and the CPU?

Peter

[ppolitop]

Originally Posted by Dorian Gray Edit: Incidentally, I would guess that QuickTime uses AltiVec quite heavily to decode H.264 on a G4. I base this on the fact that G4s were far closer than they had any right to be to Intel speeds at playing H.264 back when the first Intel Mac came out. With time QuickTime's Intel performance got much better.

That makes sense, but why a specific mplayer build with altivec support (ask me if you want me to send it to you) can play apple's HD gallery 720p video files on my G4 quite faster than qt? Bare in mind that quicktime has access to several optimization of core video etc that the simple fb of mplyer does not.

Peter