On Thu, Dec 25, 2008 at 10:49 PM, Peter Stuge <pe...@stuge.se> wrote: > Markus Rechberger wrote: >> > If I connect the device to the root hub, the artefact disappears. >> >> Then it seems to be a problem with the USB Hub. Those analog TV >> devices require 170 mbit (more than 20 mbyte per second). Most USB >> gadgets only use a very low bitrate. The transfer also uses the >> isochronous transfer method so the host won't ask again if it >> receives a damaged packet. > > Yeah, high speed hubs aren't trivial, I've been through a bunch of > them. This one has been working pretty well so far though. > > >> > What physical issue do you think causes this? Could it be a power >> > problem? >> >> Yes, it could also be a power problem, but you already isolated the >> issue to your hub if it works without it. >> >> > Whatever the cause it's strange that I only see the artefact when >> > muting, and only when muting one particular channel. > > Can you say something about what happens when muting? >
Muting might shut down the audio transfer, it's separated from the video transfer. Back then with Kernel 2.6.16 there was a packet synchronization problem when both transfers were enabled at the same time, though this is solved now actually. When looking at your screenshots some isochronous packets are damaged (some bytes only actually). Did you try to start the video without audio by using mplayer? mplayer tv:// -tv driver=v4l2:width=720:height=576 > Sorry to be a little persistent, but I am curious about why it only > happens when I mute the audio. > no problem :) Markus > >> best regards & Merry Christmas, > > Thanks! Happy Holidays! > > > //Peter > > _______________________________________________ > Em28xx mailing list > Em28xx@mcentral.de > http://mcentral.de/mailman/listinfo/em28xx > _______________________________________________ Em28xx mailing list Em28xx@mcentral.de http://mcentral.de/mailman/listinfo/em28xx
