Downloaded videos on Computer Don't Play Steadily. They start and stop but the sound is fine. What is causing this?

July 2, 2011 11:44 PM

Whenever I download videos onto my hard drive, they play at a halting pace. The sound will work well, continuing uninterrupted, but the video images start and stop catching up with the words of the characters in the shows.

I have increased my Virtual Memory thinking that it might be due to a paucity of it but that hasn't had any real impact. I have also experimented by watching the videos in VLC and in Windows Media Explorer. None of that has made any difference. I am thinking that perhaps I should buy more RAM but that might not have any impact if increasing Virtual RAM didn't have any positive impact. Can anyone offer me some advice on what to do?

Note that this does not happen to streaming videos as much. The problem I am speaking of happens to videos that have been downloaded to my hard drive.

Below are my computer specifications:
Toshiba Computer Satellite L645D
Processor: AMD Phenom II P820 Triple Core Processor 1.80 Ghz
Installed RAM: 4.00 GB (3.74 Usable)
Windows 7 64-bit operating system
Display Device: ATI Mobility Radeon HD 4200 Series
ATI Technologies Inc.
ATI Display Adaptor
Internal DAC (400 Mhz)
Approx Total Memory: 1913 MB

posted by lackadaisical to Computers & Internet (11 answers total)

is this a laptop? can you test its performance when connected to a different network provider?
posted by thelonius at 12:03 AM on July 3, 2011 [1 favorite]

You have plenty of RAM to play videos. The symptom of video not keeping up with sound is typical of a processing bottleneck.
This is much more likely to be a problem with something else (other software) running at the same time and hogging the CPU or RAM. My guess is that you have real-time antivirus software interrupting the video playback. Try disabling your antivirus software (disable your internet connection first), then try playing your videos.
You can also look in task manager, to see which processes are using most processor (CPU) or memory, then Google what these are. I'll bet you have something installed that is running in the background and interrupting your video processing. Then you can stop whichever program is hogging resources before you play videos. Just remember to start these processes back up again - you do not want to disable things such as security software for long ... :-)
posted by Susurration at 12:23 AM on July 3, 2011 [1 favorite]

Response by poster: I have tried it on several networks but the problem persists. Also I dont think the network provider is at fault since the videos are already on my hard drive.
posted by lackadaisical at 12:24 AM on July 3, 2011

Seconding that there is plenty of RAM for just about any purpose here - you certainly shouldn't have issues playing back video. As well as possibly being a background load issue as Susurration suggests, it could be a graphics driver issue. Have you recently updated your graphics driver (or made any other change for that matter), or is this something that has always happened?
posted by Dysk at 1:32 AM on July 3, 2011

Try a different media player.

This one is much better at using your graphics card to decode video:

http://mpc-hc.sourceforge.net/
posted by Alan2000 at 1:34 AM on July 3, 2011 [1 favorite]

Forget RAM. I'm typing this on a Mac with 4gb that won't play 720p content that's x264 encoded, whereas my WDTV Live player has 512mb of RAM and happily plays 1080p content.

What format are these videos in? Are they 1080p, 720p, 480p, standard def? AVI or MKV containers? XviD or x264 encoding? What sound format - DTS, AAC, MP3...? Your media player should have an information window that will tell you this (Ctrl-I in VLC or Quicktime).
posted by obiwanwasabi at 2:29 AM on July 3, 2011

(Something else to check - is the laptop on mains power? Is your power saving profile set to desktop / always on mode? My laptop starts to spit with fairly simple content if I've got it set on max battery.)
posted by obiwanwasabi at 2:39 AM on July 3, 2011

I always blame anti-virus first. Are you running one?
posted by benito.strauss at 6:59 AM on July 3, 2011

This may be a totally stupid suggestion, but how is your hard drive with respect to defragging? Is it possible that the video is stored in such little pieces all over the drive that it's hard to get it back together during playback?
posted by CathyG at 7:47 AM on July 3, 2011

To be clear, all these people who are telling you you have enough RAM are not making explicit an important point: you never want your videos to play from virtual memory. Virtual memory takes data that belongs in RAM and writes it to your hard drive instead, then reads it off your hard drive again, which is way slower than read/write to RAM. This would lead to exactly the sort of skipping/starting/stopping you describe. The best thing you could hope for, in increasing virtual memory, would be that other processes might write their stuff to VM and save RAM for your VLC. But as they all say, you have plenty of RAM. You might try turning off VM altogether to be absolutely sure no memory pages are getting written to disk.
posted by xueexueg at 10:34 AM on July 3, 2011

Might want to check and see if your video drivers are correct and up to date. Does the video card use shared ram? Can you "up" the percentage of shared ram?

Another thought is that if something is overheating (processor or video card), it will often throttle down and make the experience very slow. This is hard to diagnose, but one way is to watch the CPU percentage and see what it is doing. If it is maxxing out and performance is low, this could be the issue.
posted by gjc at 11:45 AM on July 3, 2011