How Do I do X?
This document contains a bunch of Q&A from users that asked how to do a specific operation with LibVLC or LibVLCSharp.
As a general rule, it's a good idea to check how to perform a given operation on official VLC app (iOS, Android, Windows, etc.). From there, logs can give you information, and looking at the code as well.
How do I play a DVD?
Create your media with dvd:/// as per the documentation.
How do I cast my media to my Chromecast?
Check out our Chromecast sample
How do I browse and play media on my local network (NAS/UPnP)?
Check out our LocalNetwork sample
How do I record a media to the file system?
Check out our RecordHLS sample
How do I create a mosaic of views for videos?
Check out our VideoMosaic sample
How do I navigate a 360 video and change viewpoint?
Check out our Gestures sample
How do I get codec information about a media?
Inspect the Video and Audio tracks objects with Media.Tracks.
How do I get libvlc logs?
Subscribe to the LibVLC.Log event.
How do I play media with RTSP or HLS protocols?
Like any other media. Here is a non exhaustive list of protocols we support.
How do I get individual frames out of a video?
We have a sample using ImageSharp and one using SkiaSharp doing exactly this.
From a libvlc standpoint, that means using libvlc_video_set_callbacks and libvlc_video_set_format_callbacks.
How do I do transcoding?
Pretty similarly to how you would do it from the CLI. Read https://wiki.videolan.org/Transcode/ and try media options with Media.AddOption.
How do I enable/disable hardware decoding?
MediaPlayer.EnableHardwareDecoding = true
How do I play a YouTube video?
Like this, for example:
using(var libVLC = new LibVLC())
{
var media = new Media(libVLC, "https://www.youtube.com/watch?v=dQw4w9WgXcQ", FromType.FromLocation);
await media.Parse(MediaParseOptions.ParseNetwork);
using (var mp = new MediaPlayer(media.SubItems.First()))
{
var r = mp.Play();
Console.ReadKey();
}
}
Try the sample here https://code.videolan.org/mfkl/libvlcsharp-samples/-/blob/master/YoutubePlayback
Subtitles
Full list commands and arguments https://wiki.videolan.org/VLC_command-line_help/
How do I set subtitles?
using(var libVLC = new LibVLC())
{
var media = new Media(_libVLC, "http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/BigBuckBunny.mp4", FromType.FromLocation);
using (var mp = new MediaPlayer(media))
{
mp.AddSlave(MediaSlaveType.Subtitle, "file:///C:\\Users\\Me\\Desktop\\subs.srt", true);
var r = mp.Play();
Console.ReadKey();
}
}
How do I change the subtitle font size?
media.AddOption(":freetype-rel-fontsize=10"); // Usually 10, 13, 16 or 19
How do I change the subtitle color?
media.AddOption(":freetype-color=16711680"); // Red
How do I change the subtitle encoding?
media.AddOption(":subsdec-encoding=Windows-1252");
How do I change aspect ratio?
If you are using the MediaPlayerElement, then it is built-in in the UI.
If not, you should play with the Scale and AspectRatio MediaPlayer properties.
How do I change the movie play rate?
MediaPlayer.SetRate(float rate)
How do I change deblocking filter settings?
new LibVLC("--avcodec-skiploopfilter=2")
--avcodec-skiploopfilter={0 (None), 1 (Non-ref), 2 (Bidir), 3 (Non-key), 4 (All)}
Skip the loop filter for H.264 decoding
Skipping the loop filter (aka deblocking) usually has a detrimental
effect on quality. However it provides a big speedup for high
definition streams.
How do I take a snapshot of the video?
MediaPlayer.TakeSnapshot(uint num, string? filePath, uint width, uint height)
How do I enable loopback playback?
new LibVLC("--input-repeat=2")
https://stackoverflow.com/questions/56487740/how-to-achieve-looping-playback-with-libvlcsharp
How do I retrieve Video/Audio/Subtitle track information?
using var libVLC = new LibVLC();
using var media = new Media(libVLC, new Uri("http://commondatastorage.googleapis.com/gtv-videos-bucket/sample/ElephantsDream.mp4"));
await media.Parse(MediaParseOptions.ParseNetwork);
foreach(var track in media.Tracks)
{
switch(track.TrackType)
{
case TrackType.Audio:
Debug.WriteLine("Audio track");
Debug.WriteLine($"{nameof(track.Data.Audio.Channels)}: {track.Data.Audio.Channels}");
Debug.WriteLine($"{nameof(track.Data.Audio.Rate)}: {track.Data.Audio.Rate}");
break;
case TrackType.Video:
Debug.WriteLine("Video track");
Debug.WriteLine($"{nameof(track.Data.Video.FrameRateNum)}: {track.Data.Video.FrameRateNum}");
Debug.WriteLine($"{nameof(track.Data.Video.FrameRateDen)}: {track.Data.Video.FrameRateDen}");
Debug.WriteLine($"{nameof(track.Data.Video.Height)}: {track.Data.Video.Height}");
Debug.WriteLine($"{nameof(track.Data.Video.Width)}: {track.Data.Video.Width}");
break;
}
}
How do I use marquee ?
Enable
1 to enable marquee displaying. Marquee can be seen.
0 to disable marquee displaying. Marquee will not be visible.
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Enable, 1);
Size
Font size in pixels. The default value is 0.
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Size, 32);
Position
Marquee position: 0=center, 1=left, 2=right, 4=top, 8=bottom
You can also use combinations of these values, like 6 = top-right. The default value is 0.
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Position, 8);
Y and X axis
^
| Y axis
|
|50x
|--------*
| |
| | 90y
| |
| |
<----------|------------------>
| X axis
|
The symbol "*" shows your text position, it will be appear like in diagram above if you set axis like below:
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.X, 50); //X offset, from the left screen edge. default_value=0
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Y, 90); //Y offset, down from the top. default_value=0
Opacity
Value should be within this range [0-255].
0 = transparent, 255 = totally opaque.
default value: 255
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Opacity, 100);
Text
Text to be displayed as marquee text
MediaPlayer.SetMarqueeString(VideoMarqueeOption.Text, "my text"); //Text to display
Color
Set color in decimal (hex will not work).
Use Hex2Dec to convert hex to decimal.
The default value is 16777215 (white).
Example usage for red.
MediaPlayer.SetMarqueeInt(VideoMarqueeOption.Color, 16711680); // red
More Advance options here wiki.videolan.org
How do I use LibVLC's advanced options?
LibVLC has many advanced options to customize playback and streaming features.
Multiple kinds of syntax are accepted to set these options:
- Using the LibVLC constructor, like this:
using var libvlc = new LibVLC("--verbose=2");
or like this
using var libvlc = new LibVLC("--verbose", "2");
- Using the
Media.AddOptionmethod, like this:
media.AddOption(":no-audio");
Several points to note:
- Some options may not be available on some platforms.
- Some options may be incompatible when used together.
- Some options name may change or get removed from one version of libvlc to another.
- Some options only work with LibVLC constructor, or only with
media.AddOption.
How do I get the size of a video?
Once the video has started playing, you can do this
uint videoHeight = 0;
uint videoWidth = 0;
mediaPlayer.Size(0, ref videoWidth, ref videoHeight);
Do pay attention to the orientation of the video. You can check it analyzing the video track of the media. If the orientation turns out to be "Bottom right", you might want to switch width/height values.
How do I put UI controls and buttons over my video view?
You might be encountering the airspace issue, which is the result of a tradeoff between performance and ease of use, and the way GUI frameworks such as WPF are implemented. See this for more info.