[GEM-dev] Playing HDV video with frame accurate seeking on Linux

[Roman Haefeli]

hi b.

if playing it in Gem is too slow (i guess, not only decoding, but
especially in Gem also the transport to the gpu takes quite some
processing power), it should be possible to use mplayer to display the
movie, while using pd to control mplayer. if it's about displaying
movies with 'big' (depends on the computer, of course) dimensions
without any further processing, i found this setup to be more performant
than playing the movie with [pix_film] directly. 

just a few hints:

$ mknod mplayer.control p
$ DISPLAY=:0.1 mplayer -slave -input file=mplayer.control -fs
yourfile.m2t

DISPLAY=:0.1 assumes, that you have an xserver running on two monitors,
so that still can edit the patch, while mplayer is playing in fullscreen
mode. you can omitt it, of course.

and now you can write mplayer commands to 'mplayer.pipe' from pd using
[textfile].


[commands(  <- e.g. 'seek -10', 'seek 300' (relative values in seconds)
|
[t b a]
|     |
|     [list prepend add        
|     |
|     [list trim]
|     /
[write mplayer.pipe cr, clear(
| /
[textfile]

!! important!!
mplayer HAS to be listening on the pipe 'mplayer.pipe', otherwise pd
will hang until 'mplayer.pipe' is flushed (either by mplayer or by 'cat
mplayer.pipe').


if you find a way, that is less likely to block pd (by not using pipes),
let us/me know.

roman


On Mon, 2009-08-24 at 17:06 -0700, B. Bogart wrote:
> Hey all,
> 
> I'm doing a new version of "Step and Repeat" and want to do the video in HD.
> 
> I'm already shot HDV footage, which plays very well in mplayer, but not
> so well in Gem.
> 
> I need to do frame seeking, so I've taken my original HDV (m2t) video
> and converted into a large mpeg2 with 1 frame GOPs and loading the TOC.
> 
> Everything plays fine, but the playback is extremely slow.
> 
> What are the best options for HDV playback on linux?
> 
> I could lower the resolution, and load all frames into a pix_buffer.
> 
> I could lower the resolution and just play the file.
> 
> Looks like there is no "RAM" message to load the whole file into RAM and
> playing from RAM on linux?
> 
> The target machine is a AMD dualcore 4500+ (or something close).
> 
> Any advice appreciated.
> 
> Anyone know if you can do frame-accurate mpg seeking in mplayer?
> 
> Thanks,
> B.
> 
> _______________________________________________
> GEM-dev mailing list
> GEM-dev at iem.at
> http://lists.puredata.info/listinfo/gem-dev


		
___________________________________________________________ 
Telefonate ohne weitere Kosten vom PC zum PC: http://messenger.yahoo.de