1080p plays slowly in smplayer when I'm downloading.

[mothqueen]

Hello. Using linuxmint with mate version 17 'Quiana'.

When I play 1080p videos when I'm downloading files to either my HDD or external HDD, they play slowly (like slow speed motion). I don't get this problem when playing 720p. Also, when I'm NOT downloading, 1080p plays just fine.

Any reason for this? And is there a fix? I'm on a laptop, btw.

[Hoser Rob]

What's your hardware spec? Smplayer is pretty fast but on old/slow/hardware ...

The first thing I'd do is go to preferences -> performance -> cache. Set the local file cache buffer to 8192.

Also, go to mplayer arguments in preferences -> advanced and enter:

-cache-min 50

which will make the cache always fill halfway before playing. It makes videos start playing slower, but once it's going it'll work faster.

Also try decreasing swappiness. This doesn't always work like many seem to think but it often does.

[BigEasy]

mothqueen, it is because your system (CPU, GPU, HDD, e.t.c) is unable to process all frames of that video in required time and to do something else at the same time.

There is option named something like "frame drop" in many video players. In smplayer that option exists.
When enabled, player dropping frame of video if player decide that specific frame is impossible to process in time. So, when enabled, whole playback come in designed speed, but video looks more or less jerky.

When disabled, player process all frames ignoring fact that frame processing is late. So, when disabled whole playback looks slower then designed, but smooth. If video longer than designed, so audio often lagging behind.

All story was about perfomance of system. Radical solution is transcode specific video to less bitrate. For example from 10 Mbit/sec to 5Mbit/sec and look.

[Hoser Rob]

Yes, frame drop can help. But it affects the quality too. It's something to try if the tweaks I mentioned don't work.