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#1 2016-07-04 08:13:46

olive
Member
From: Belgium
Registered: 2008-06-22
Posts: 1,490

Video not very smooth

I have an AMD HD6570 video card and I use the ati video driver.

Each time I play a video (whatever the software vlc, chromium HTML5, etc.), the motion is not very smooth (especially when played full screen). The difference is obvious with a standalone TV. The standalone TV can play mp4 file directly (via a usb key) and when it does the video are super smooth while it is somewhat jerkily when played with the computer (not that much, it remains acceptable, but it is definitively less good). This is not a performance problem (I usually use not more than 10% CPU time) less with vlc that can use vdpau. The difference is flagrant if I actually connect the computer to the TV so that the monitor is exactly the same in both case. I know that the TV has "technology" related to that that we can set in the preference (this usually involves vague and pretensions words like virtual 100Hz motion, etc (the TV is not 100Hz). It seems that the TV has nevertheless powerful post processing algorithm for that. Do you know if there are anything like this in Linux.

Note that the problem is not typical to Archlinux (or Linux in general), the video are less smooth played from Windows that directly in the TV (although the proprietary catalyst driver for Windows do somewhat better that the the driver I use in Archlinux).

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#2 2016-07-04 10:39:35

Morn
Member
Registered: 2012-09-02
Posts: 886

Re: Video not very smooth

I would give mpv or totem a try, they seem to have the smoothest playback in my experience. Or you could install Catalyst, although the latest Catalystc version will not work with your video card I think. Catalyst-test and mpv (in KDE Plasma) is my preferred video playback solution at the moment.

Last edited by Morn (2016-07-04 10:39:56)

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#3 2016-07-04 20:13:12

olive
Member
From: Belgium
Registered: 2008-06-22
Posts: 1,490

Re: Video not very smooth

I wil try mpv, but don't they use all the same libraries. I usually use vlc. As for the catalyst driver, my card is supported by the driver but I had problems in the past. While 3D acceleration was marginally better, 2D acceleration like moving windows on the screen was terrible. Moreover it is a pain to maintain having to downgrade Xorg and the like.

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#4 2016-07-04 20:41:29

V1del
Forum Moderator
Registered: 2012-10-16
Posts: 21,410

Re: Video not very smooth

VLC's VDPAU implementation doesn't really seem to be up to snuff yet, chances that mpv will provide better performance aren't unrealistic.

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#5 2016-07-05 00:05:50

Morn
Member
Registered: 2012-09-02
Posts: 886

Re: Video not very smooth

And VLC's stream-based architecture apparently means all data has to be sent to the video card twice, which is not very helpful for smooth playback.

I mainly use VLC when I need its playlist or other GUI features such as subtitle selection, otherwise I'm quite happy with mpv. (Totem does not work with Catalyst sadly.)

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#6 2016-07-06 21:17:22

olive
Member
From: Belgium
Registered: 2008-06-22
Posts: 1,490

Re: Video not very smooth

mpv seems indeed better than vlc. One of the reason I use vlc is that it is easier to configure. It supports DVD with all their features (menu, etc.) out of the box. It supports my TV tuner card (that I have been unable to use with mplayer, so I suppose mpv will be a problem too).

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#7 2016-07-06 23:52:45

Morn
Member
Registered: 2012-09-02
Posts: 886

Re: Video not very smooth

kaffeine also works reasonably well for TV tuner cards. I haven't tried vlc for that yet. Doing the initial frequency scan is always the most annoying part.

But I have to say all DVB-C apps I've tried so far have been either hard to use or a bit crash-prone, so in the end I just got myself a TV and put it next to the computer. Compared to the old analog TV capture cards, digital TV has been too unreliable and finicky for me. Which seems strange, you would think that digital would work much better on a computer than analog, but not in my experience.

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#8 2016-07-07 06:40:56

olive
Member
From: Belgium
Registered: 2008-06-22
Posts: 1,490

Re: Video not very smooth

@Morn. We divert but your comment about TV tuner card is interesting. Ivy TV broke, but maybe I will replace it indeed..

The point you say about unreliability of TV tuner card is interesting because I have somewhat the same feeling. After an investigation (and comparison with the Windows driver and software), I have been able to see two main reasons.

1) Clearly the tuner of TVs are of better quality. Maybe some tuner cards works better, but they could come rather expensive (not much less than the price of a cheap TV).
2) vlc does not have a good algorithm to deal with transmission errors. It get confused because it lost audio/image sync signal for a few seconds only (as seen in the terminal from which it was launched). Do the following experiment: disconnect the antenna and reconnect it a minute later, it will need a lot of time to recover. Clearly the TV deals much better with an occasional transmission error.  It seems that vlc read TV streams as it would read a file. I don't know for other players.

Last edited by olive (2016-07-07 06:49:15)

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#9 2016-07-07 09:50:52

Morn
Member
Registered: 2012-09-02
Posts: 886

Re: Video not very smooth

The Windows software for my PCTV QuatroStick is not particularly impressive either, so it's not just a Linux problem. Switching channels takes forever and the overall UI experience is not that great.

But on Linux I also experienced USB issues, i.e. the PC would not go to suspend anymore after the stick had been plugged in, even if you removed the stick before going to suspend! The screen would go dark, but the fans kept spinning. I think that issue is now fixed in the latest kernels, but it was extremely annoying at the time. Especially if you forgot you had plugged in the stick a few hours ago, then went to suspend in the evening, and boom, the PC was stalled, with your only option being to hit the power off button.

And as you say, lack of error recovery during playback is a major problem. I have a quadruple-shielded antenna cable now, so this should be less of an issue now I hope.

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#10 2016-09-14 20:14:39

osalas
Member
From: Kaiserslautern, Germany
Registered: 2015-08-05
Posts: 25

Re: Video not very smooth

I'm late to this party but I just wanted to say that the TV probably has a motion interpolation or a smoothmotion option.

For that you have 3 options:

1. You can add to the mpv conf file the following lines:

vo=opengl-hq:interpolation
display-fps=60
video-sync=display-resample

This will add some extra frames so the playback looks smooth but is not real motion interpolation, you can read more about that in the mpv Wiki.

2. Install mpv with vapoursynth support and the vapoursynth-plugin-mvtools package from AUR, now you can make a script that will make real motion interpolation.

You can find examples here and here.
Note: this is very hard on the CPU, you may need to tweak some parameters to get better results.

3. The last method is the most obvious one. You need to install SVP4 and mpv with vapoursynth support from AUR and you need to add to the mpv conf file the line:

input-ipc-server=/tmp/mpvsocket

All versions bring better quality to the playback but they are all different. In my opinion the second method brings better results but the third method is friendlier and may support your GPU.

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