Le mardi 04 novembre 2014, 15:42:37 Rémi Denis-Courmont a écrit : > Le 2014-11-04 14:58, Sakari Ailus a écrit : > >> > Have you tried with a different application to see if the problem > >> > >> persists? > >> > >> Tried mplayer and cheese now, and it seems they are not affected, so > >> it's an issue with vlc. I wonder why it doesn't like newer flags.. > >> > >> Ohwell, sorry for the noise. > > > > I guess the newer VLC could indeed pay attention to the monotonic > > timestamp > > flag. Remi, any idea? > > VLC takes the kernel timestamp, if monotonic, since version 2.1. > Otherwise, it generates its own inaccurate timestamp. So either that > code is wrong, or the kernel timestamps are. >From a quick check with C920, the timestamps from the kernel are quite jittery, and but seem to follow a pattern. When requesting a 10 Hz frame rate, I actually get a frame interval of about 8/9 (i.e. 89ms) jumping to 1/3 every approximately 2 seconds. >From my user-space point of view, this is a kernel issue. The problem probably just manifests when both VLC and Linux versions support monotonic timestamps. Whether the root cause is in the kernel, the device driver or the firmware, I can´t say. -- Rémi Denis-Courmont http://www.remlab.net/ -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
