MKV multiple video tracks plays simultaneously

[giaur]

Hello,

I've added 2 video tracks to mkv file using mkvmerge. First video track - anaglyph 3d, second video track - normal video (both the same video resolution). And when I open this mkv file in vlc, all video tracks are played simultaneously in their own windows. It's impossible to select only one video track.

Is this normal?

[TypX]

Did you set both tracks as default?

[giaur]

It does not matter if any of these tracks is marked as default or not. Always the same - first track is played in embedded display and second video track playing in standalone window (for example, called Direct3D output).

The same issue if I set first track as default and second track as not default. And menu option to select video track does nothing. SMplayer plays the same file correctly - I can select video track to play.

This bug exist in vlc since I remember. So, I think 2.0 release is good time to fix it. This was not reported probably because not many people really need multiple video tracks and no one tested this.

[Jean-Baptiste Kempf]

No, VLC plays all Enabled video tracks, which is what the spec says.

[giaur]

Sorry. Vlc always play simultaneously all video track present in mkv file. First track: default flag=yes, second track default flag=no. And 2 track are played simultaneously. So, how should I set track flags in mkvmerge to make it play single in vlc?

I don't know very much about specs, but playing multiple track simultaneously in this case has no sense and this is only vlc issue. If you want to check it out, tell me where can I upload sample.

Am I right? What is video track select option for, if all track always plays simultaneously?

[TypX]

There is a flag "enabled" in the tracks too.

[giaur]

Where can I find it in mkvmerge gui window? I can only mark track as default/forced and remove it from mkv by uncheck checkbox next to track name. The same as audio tracks, but audio tracks don't play simultaneously.

I'm confused - what's the problem exactly? I still don't understand what do you mean and how to prepare mkv with 2 video tracks to play it correctly in vlc. How to mux mkv with mkvmerge to make vlc able to select only one of multiple video tracks?

[yggdrasil343]

Where can I find it in mkvmerge gui window? I can only mark track as default/forced and remove it from mkv by uncheck checkbox next to track name. The same as audio tracks, but audio tracks don't play simultaneously.

I'm confused - what's the problem exactly? I still don't understand what do you mean and how to prepare mkv with 2 video tracks to play it correctly in vlc. How to mux mkv with mkvmerge to make vlc able to select only one of multiple video tracks?

It's in File->Header Editor. Just drag and drop your MKV on to that to see all variables available. But I still have this problem, even after disabling the second video track. It's only when I disable all tracks in VLC, then reenable the one I want to use do I get only 1 video stream.

Update: Upgraded to 2.0.1 and now at least it only starts with 1 video output. Enabling the other track without first disabling all tracks in VLC will cause another output window to pop up now. I assume that this is actually the intended behaviour.

[Jean-Baptiste Kempf]

Update: Upgraded to 2.0.1 and now at least it only starts with 1 video output. Enabling the other track without first disabling all tracks in VLC will cause another output window to pop up now. I assume that this is actually the intended behaviour.

Yep. the MKV spec was made clearer, so it is fixed in 2.0.1

[Gregoire]

Hi, Jean-Baptise et al,

I am afraid this issue does not appear to be resolved in 2.1.5 Ricewind, at least in .wmv files.

Clarification: If the video contains multiple tracks, a separate window from the main "Qt?" interface is spawned, and they all play simultaneously, which, for most is both a cumbersome annoyance but also resource intensive - which for some is a significant performance problem. I can't see an option to disable this "Spawn each video track in a separate window".

It is also worth pointing out that a successive .wmv file with only one video track listed, also spawned that window in a separate "Direct3D" window.

While arguably this could be desired behavior under some conditions -- for example security video footage from multiple cameras, for most situations it isn't. The solution should be fairly simple - by default render just the first track (or default track for containers that allow this) unless a user specifies otherwise, or render them sequentially. Optionally, though far less desirable, render all tracks (current behavior) simultaneously, but allow users the ability to disable this.

Two other suggestions, unrelated, I'll post elsewhere, but briefly, just for cross reference, they are:
1) Need a function to play video as-is and suppress the prompt for the user to either index then play, play as is, or do not play. A window which pops up in the middle of a playlist forcing user interaction.
2) Have the ability to either a) suppress error reporting (never pop the message box in the first place) or, less desirable, pop the message minimized to the task bar such that it does not require user interaction.

Generally, requiring user interaction necessary is a Bad Thing. Alerting users to problems is not, but better off to just pop an alert graphic and make a log entry. VLC has evolved from being a workstation utlity to play video files to where it can serve on a dedicated multimedia machine for users (such as someone's children viewing random cartoons dad set up, or music videos for a club scene) that have no idea how to deal with a popup window that steals focus and hides the video.

Kind regards,
Gregoire

[Rémi Denis-Courmont]

This thread is about MKV. WMV has different rules for video track selection. Please don't hijack threads.

[Gregoire]

Didn't know that... can someone on the team please just add the issue to your bug tracker, wherever it belongs? It's been present for several years.

[Akida]

So I had the multiple stream issue playing .m4a files using version 2.2.6 and this is the first thread that I came across. I found a work around that I didn't see mentioned anywhere else and I hope this helps others.

I went into prefs>video then under video where is says output, I set it to disable.

This only disabled one of the tracks, why? /shrug

Of course if you play a video with a single video track you have to set it back to automatic or you'll get nothing.

[Like2Watch]

Is there any update to this thread?
I actually WANT to watch both / all tracks inside an MKV simultaneously in seperate windows. This is the old behaviour but no matter what flags i set when creating the mkv, it ALWAYS only plays a single video stream and only lets me "switch" between video streams instead of watching BOTH Simultaneoulsy.

[Tobit]

Is there any update to this thread?
I actually WANT to watch both / all tracks inside an MKV simultaneously in seperate windows. This is the old behaviour but no matter what flags i set when creating the mkv, it ALWAYS only plays a single video stream and only lets me "switch" between video streams instead of watching BOTH Simultaneoulsy.

Old thread, I know. But in case it's useful in the future for anyone who stumbles upon this, you can have VLC open all tracks (including all audio and subtitles) by starting VLC with the following options:

Code: Select all

vlc --sout-all --sout #display

e.g. I put a shortcut on my desktop with the following Target:

Code: Select all

"C:\Program Files\VideoLAN\VLC\vlc.exe" --sout-all --sout #display

The Video tracks will each open in a separate window. After opening the file, if you Disable the audio and subtitles (using the Audio and Subtitle menu items), then you can select the track you want. Selecting tracks basically becomes additive (e.g. if you select audio track 1 then audio track 2, both will be playing).