Smtube on Mint13

[josip1]

Since I'm not satisfied with non smooth viewing of youtube with Firefox I tried to install SMtube.
PC is an old one: x86, 1200 Mhz, RAM 512 MB, Asus, S3 Graphics ProSavage 8A26, linux mint 13 xfce
After the fresh installation of Mint13 on this PC I've installed a SMtube with the commands in a terminal:
sudo add-apt-repository ppa:rvm/smplayer
sudo apt-get update
sudo apt-get install smtube

Smtube starts ok, I see youtube videos, double click on any-one, but video doesn't start. Can Record video, but cannot Play video.
A month ago I had a fresh installation of Mint13 on the same PC and Smtube was runnig without problems. After then I was reinstalling PC and now cannot run Smtube.
What to do?

[rvm]

Did you install smplayer (or at least mplayer) as well?

[josip1]

I see now: Media player included in installation pack of Mint13 is not Mplayer.
I've installed now Mplayer:
sudo apt-get install mplayer
Tried to run Smtube - video didn't start.
Installed Smplayer:
sudo add-apt-repository ppa:rvm/smplayer
sudo apt-get update
sudo apt-get install smplayer smtube smplayer-themes
When I run Smtube, I see Smplayer starting with black screen with: Mplayer has crashed.

May be my installation of Mplayer was not correct.

[josip1]

I removed Mplayer and installed it again (all done now in Software Manager).
Then changed Smtube settings:
- Player: Mplayer
- Reading Quality: 360p (MP4)
- Playback Quality: 360p (MP4)
Now I can view youtube video clips running smoothly / normaly!

I could close this post as solved at this point but I have still 2 problems:

1. if I set in Smtube Smplayer as Player, I can see video but audio is anticipating (rush, in front of) the video (3-4 seconds non sync).
2. if I play the mp4 video from my desktop with Smplayer or Mplayer, video is running smoothly but audio is anticipating (rush, in front of, non sync) the video.

How to correct this synchronizing (sync) audio/video error?
Where could I find the settings for Smplayer to run smoothly on an old PC?

[rvm]

Maybe you need to enable frame drop (preferences -> performance).

[josip1]

After many attempts I've got it:
- Smplayer - Options (>>) - Help - Open config folder - (close Smplayer!) - delete Smplayer.ini
- removed SMplayer and installed it again (all done now in Software Manager)
- Menu - Settings - Display - Resolution: 800x600 or 1024x768 (for mp4 running smoothly)
- changed SMplayer settings in Preferences:
--- Performance - Allow frame drop (enable), - Youtube quality 360p
--- General - Audio - A-V sync correction (enable), Max.correction 1.00
Point 1 from previous reply is solved: Smtube can have now Mplayer or Smplayer in Settings.
Point 2: playing mp4 video from my desktop with Smplayer is ok, with Mplayer still not (A-V sync not good).
I don't know how to set/enable A-V sync in Mplayer.