Hello, It would be probably a good idea to discuss different possibilities for improving multimedia support on 770/N800.
Now we have a fast JIT scaler that runs on ARM core, it solves all the video resolution related performance problems. I'm going to work on improving quality, performance and its inclusion into upstream ffmpeg library, this task is in my nearest plans: http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/2007-January/051209.html As for the ways of improving multimedia support on Nokia 770, it may be done in the following ways (in no particular order): 1. Continue ffmpeg optimizations (motion compensation functions, finetune idct, have a look at the possibilities to optimize codecs other than mpeg4 and its variants) 2. Implement Xvideo extension support for Nokia 770 (using scaling done on ARM core) 3. Implement XvMC in some way (using C55x DSP for it as it is supposedly good for IDCT and motion compensation stuff) 4. Improve GStreamer plugins (replacements for dspfbsink and dspmpeg4sink running on ARM core, it could probably improve mpeg4 playback performance a lot and allow using higher video bitrates and resolutions that are currently available in MPlayer) 5. Try to relay color format conversion and scaling to DSP. If it works as expected, video scaling can be done with almost zero overhead for ARM core. Theoretically the same trick could probably also work for GStreamer if video output sink can provide its own buffer (::buffer_alloc). The first step would be to try just doing nonscaled color format conversion. If it is successful, some more advanced stuff can be tried such as JIT dynamic code generation on C55x. 6. Try porting vorbis decoder (tremor) to DSP 7. Try porting libmpeg2 to DSP. With audio decoding and scaling done on ARM core, it might improve overall mpeg2 playback performance, I wonder if nonconverted DVD video playback is even theoretically possible on Nokia 770. That's quite a big list and it contains some things that might be generally nice to have, but have relatively low practical value and are actually not worth efforts implementing :) There are two issues that need to be solved for this all to become reality: 1. We need some way of applying community developed upgrades for core system components such as xserver and xlib (if we go after Xvideo support on Nokia 770). They must be easy to install by end users, otherwise this all development does not make much sense. It would be also nice to integrate these improvements into official firmware later, but I wonder if Nokia has spare resources for doing this integration and its quality assurance. 2. Reliable information that is detailed enough for performing graphics and audio output from DSP, see http://maemo.org/pipermail/maemo-developers/2007-February/007949.html _______________________________________________ maemo-developers mailing list maemo-developers@maemo.org https://maemo.org/mailman/listinfo/maemo-developers
