Matteo Sisti Sette wrote:
tep wrote:
> I'm using a few computers to play some synced videos, but i can't get
> satisfying results using pix_movie.
What is that is unsatisfying?
Is the playback on each computer unsatisfying by itself (in which case I
cannot be of help, whatever unsatisfying means),
or is the syncronization between computers that is not perfect?
In this second case, "how much" do you lose syncronization, i.e., how
many frames of difference between any two computers do you accumulate
per minute?
If you just send a "start" signal to all computer and have them play the
videos, and expect them to keep synchronized just by the exactness of
their clock, I think it is impossible (with whatever software or codec)
to maintain an acceptable synchro (meaning no much more than a couple of
frames of difference) for more than a few minutes.
I once had to do a synced playback of 3 videos and, if left to drift,
they could stay apparently synchronized for as long as about 5 minutes.
Indeed I was surprised by GEM's "clock" stability, I didn't expect so
much (well actually i did, but I had been surprised a few months earlier
with a similar application).
To guarantee synchro within a given tolerance "forever", I did a patch
with one "master" and several (in my case 3) "slaves" where the master
broadcast (via udp) its current time every N seconds (e.g. N=5) and each
slave compared the received time with its own, and if the difference was
greater than a threshold (e.g. 2 frames), it forced itself to skip or
pause the needed amount of frames.
It worked quite well. With a slightly more sofisticated patch you could
correct the drift in a more gentle way than abruptly pausing or skipping
a few frames.
I used Windows (not sure whether xp or vista, I think xp) and DV-PAL codec.
By the way, I never used pix_movie's "auto" mode: I turned it off and
fed the right inlet with a counter incremented by bangs taken from the
[gemhead]. But i dubt this makes any difference.
I have synced several computers on a LAN successfully using a master,
with a counter run by a [metro], sending frame numbers to the slaves via
[netsend] and [netreceive], sending the frame number to each [pix_film]
object.
This way the master can also play audio which remains in sync, and
pausing, scrubbing etc are all possible.
Simon
_______________________________________________
Pd-list@iem.at mailing list
UNSUBSCRIBE and account-management ->
http://lists.puredata.info/listinfo/pd-list
