The VideoLAN Forums

Posted: **16 Jan 2016 18:25**

Hi,

I am using MobileVLCKit for tvOS. So far mostly fine.
After a rebuild a few days ago, I found this one.

Looking at the trackinfo of the video track of 720p stream (ARD HD streamed from my Settopbox) the result is:

Code: Select all

 2016-01-16 18:09:47.613 vuplusTV[6374:3637017] track info {
    bitrate = 0;
    codec = 875967080;
    "frame_rate_den" = 1;
    "frame_rate_num" = 100;
    height = 720;
    id = 0;
    level = "-1";
    profile = "-1";
    "sar_den" = 1;
    "sar_num" = 1;
    type = video;
    width = 1280;
}

A PAL-stream (576i] looks like this:

Code: Select all

2016-01-16 18:10:22.024 vuplusTV[6374:3637017] track info {
    bitrate = 0;
    codec = 1986490477;
    "frame_rate_den" = 1;
    "frame_rate_num" = 25;
    height = 576;
    id = 0;
    level = "-1";
    profile = "-1";
    "sar_den" = 45;
    "sar_num" = 64;
    type = video;
    width = 720;
}

Basically almost fine.
The values for "frame_rate_num" are fine, but for a progressive stream "frame_rate_den" should be 2. This will then result in 50 fps (what is actually used at playback).

Before my local rebuild, the values were correctly.

Posted: **21 Feb 2016 10:23**

I added a ticket but no progress on it

But I got a more urgent one... see new thread.

Posted: **22 Feb 2016 16:13**

May I ask why you need that feature besides for statistical purposes? (it should be fixed still, but that's another topic).

Posted: **19 Sep 2016 15:05**

Popping this up again.
Still VLCKit is reporting incorrect track info for 720p streams like ARTE HD from a tv receiver.
It is still reported as 100 / 1 fps, but I assume it should be 100 / 2 = 50 fps.

I could live with the fact, that this info is displayed incorrectly, but it looks like libVLC internally is also fooled by the info.
Usually libVLC is disabling deinterlacers, when a progressive stream is played (depends on the auto-enable option).
So my assumption would be, that for a 720p stream no deinterlacing is used, regardless what I pass to [self.mediaplayer setDeinterlaceFilter:<NSString or nil>].

But the deinterlacer is always enabled, maybe because libVLC doen't know, it is progressive but it thinks it is a interlaced streams with 100 frames per second.

As result the performance penalty is higher, playback may drop and the quality is poorer.
I also can only "guess", if it is a progressive stream and then disable deinterlaceing by code.

SSB

Posted: **03 Oct 2016 14:54**

Popping it up again once more.
I verified the issue with VLC 3.0 for Mac, and same behavior there. Progressive Streams (PAL 720p) are shown with 100 FPS as well, compared to VLC 2.2.x
I post on the appropriate Section as well. Just to bring this one to your attention as well.

See update and screenshot in https://trac.videolan.org/vlc/ticket/16422

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trackinfo incorrect for 720p stream

trackinfo incorrect for 720p stream

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