Mplayer runs TOO FAST!

obsidian_fox · n00b Joined: 17 Dec 2002 Posts: 15

I was running an AVI in Mplayer after setting up my laptop machine. It sounded like Alvin and the Chipmunks because people were talking too fast, and everybody was walking around really fast, as though the system was running in fast forward.

A quick check showed that Mplayer had failed to detect /dev/rtc and was using usleep() instead to control speed. (Obviously it wasn't working). It ran at ~38 fps despite the detected speed of 29.97 fps.

What I've tried:
I tried to compile rtc into the kernel, but no matter how I tried the compilation failed at some point (a conflict, I think, although I'm not sure where it lies). Use of character device /dev/rtc was reccomended against in the Gentoo docs anyway, and I don't have this problem OR /dev/rtc on my desktop machine.

Stats:
Mobile Intel Pentium IV, 1.7 GHz, Geforce 4 420 Go, integrated AC97 sound. I installed the Nvidia kernel and GLX, then turned on XV, and ran my sound in ALSA.

The AVI file was not broken; I've used it many times on other machines.

I'm using the most recent Gentoo Kernel (as of two weeks ago; 2.4.19, I think).

Does anyone have any idea why this might occur?

BonezTheGoon · Posted: Tue Dec 17, 2002 11:24 pm Post subject:

The only mention I know of about the RTC in the install guide is for the PPC architecture. There shouldn't be any issues with the RTC default settings for a p4 (that I know of.) I have not messed with my RTC settings in the kernel at all.

The speedy mplayer might have something to do with the jiffies, like back when people's system clocks were drifting and such (other such strange problems too.) The Jiffy setting in the kernel should be set to 100 (not 1000) for the ix86 architecture in the 2.4.x series of Linux Kernels (from what I was told.) Thats my only "off-the-wall" idea.

Regards,
BonezTheGoon

obsidian_fox · n00b Joined: 17 Dec 2002 Posts: 15

Thanks for the idea. I'll check it out when I have the opportunity. I have not observed it long enough to see if my system clock is drifting.

zez · Posted: Thu Dec 19, 2002 2:04 am Post subject:

Maybe your mobile chip is scaling down under load, but mplayer/linux doesn't know that? I think somebody had a similar issue where playing Half-Life under Wine would cause the game to run faster then everybody else, and it was brought up in the thread that many mobile processors scale back in speed when they get hot. This is all I can think of. Maybe try running a video when the notebook is cold?

If the timer isn't adjusted for a new clock frequency, I would think the speed would start to get wacky. In a way, this is similar to bonez' comment.