View source for VLC HowTo/Make a mosaic

==VLC mosaic howto==

This is a small example about how to use VLC to create a mosaic. What we basically want is a video mosaic mixing 3 video channels (channels 1, 2 and 3) on a background image (background.png) and streaming the resulting video on the network. Note that we will also be streaming the 3 sound tracks from channels 1, 2 and 3 in the same mpeg-ts stream.

Starting with VLC 0.8.5-test2, the http interface features a "Mosaic wizard". You might want to use it if you have no knowledge of VLC command line usage.

http://people.via.ecp.fr/~dionoea/videolan/mosaic1.png

Other neat examples :

[http://people.via.ecp.fr/~dionoea/videolan/mosaic2.jpg 12 video mosaic]

[http://people.via.ecp.fr/~dionoea/videolan/mos1.png 20 video mosaic]

[http://people.via.ecp.fr/~dionoea/videolan/mos2.png 20 video mosaic]

===Step 0===

Read the VLC streaming howto (chapters 3 and 5 concerning command line and vlm usage in VLC) : http://videolan.org/doc/

===Step 1===

Get [[VLC]] 0.8.4-test1 or newer and install it on your computer.

===Step 2===

You now have to get a background image. Many image formats are supported (JPEG, PNG ...).

You can also test it with VLC to see if it displays locally :
<pre>
./vlc --fake-file background.png --fake-aspect-ratio "4:3" fake:
</pre>

===Step 3===

You now need to configure VLC to get the 3 source streams and blend them on the background image.

The vlm configuration file looks like :

<pre>
new channel1 broadcast enabled                                                       
setup channel1 input udp://@239.255.2.60:1234                                        
setup channel1 output #duplicate{dst=mosaic-bridge{id=1,height=144,width=180},select=video,dst=bridge-out{id=1},select=audio}                                                         
                                                                                
new channel2 broadcast enabled
setup channel2 input udp://@239.255.10.200:1234
setup channel2 output #duplicate{dst=mosaic-bridge{id=2,height=144,width=180},select=video,dst=bridge-out{id=2},select=audio}                                                         

new channel3 broadcast enabled
setup channel3 input udp://@239.255.6.9:1234
setup channel3 output #duplicate{dst=mosaic-bridge{id=3,height=144,width=180},select=video,dst=bridge-out{id=3},select=audio}                                                         

new background broadcast enabled
setup background input fake:
setup background output #transcode{sfilter=mosaic,vcodec=mp2v,vb=10000,scale=1}:bridge-in{delay=400,id-offset=100}:standard{access=udp,mux=ts,url=239.255.12.42,sap,name="mosaic"}

control background play
control channel1 play
control channel2 play
control channel3 play
</pre>

Note that the source streams are network streams, which is likely to be the case if you're considering doing a mosaic.

===Step 4===

And now, the right command to launch vlc :

<pre>
./vlc --color -I telnet --vlm-conf ../mosaic.vlm.conf --ttl 12 \
 --fake-file background.png --fake-aspect-ratio "4:3" \
 --mosaic-width 360 --mosaic-height 288 --udp-caching 800 \
 --mosaic-keep-picture --mosaic-rows 2 --mosaic-cols 2 \
 --mosaic-position 1 --mosaic-order 1,2,3
</pre>

===Small Diagram That Might Help===
[http://people.via.ecp.fr/~dionoea/videolan/mosaic-diagram.png Small Diagram That Might Help]

==Appendix==

===Mosaic video sub filter===
The full set of mosaic commands is :

<pre>
 Mosaic video sub filter
      --mosaic-alpha <integer>   Alpha blending
          Alpha blending (0 -> 255). Default is 255
      --mosaic-height <integer>  Height in pixels
          Height in pixels
      --mosaic-width <integer>   Width in pixels
          Width in pixels
      --mosaic-align {0 (Center), 1 (Left), 2 (Right), 4 (Top), 8 (Bottom), 5 (Top-Left), 6 (Top-Right), 9 (Bottom-Left), 10 (Bottom-Right)}
                                 Mosaic alignment
          Mosaic alignment
      --mosaic-xoffset <integer> Top left corner x coordinate
          Top left corner x coordinate
      --mosaic-yoffset <integer> Top left corner y coordinate
          Top left corner y coordinate
      --mosaic-vborder <integer> Vertical border width in pixels
          Vertical border width in pixels
      --mosaic-hborder <integer> Horizontal border width in pixels
          Horizontal border width in pixels
      --mosaic-position {0 (auto), 1 (fixed)}
                                 Positioning method
          Positioning method. auto : automatically
          choose the best number of rows and columns.
          fixed : use the user-defined number of rows
          and columns.
      --mosaic-rows <integer>    Number of rows
          Number of rows
      --mosaic-cols <integer>    Number of columns
          Number of columns
      --mosaic-keep-aspect-ratio, --no-mosaic-keep-aspect-ratio
                                 Keep aspect ratio when resizing (default
                                 disabled)
          Keep aspect ratio when resizing (default
          disabled)
      --mosaic-keep-picture, --no-mosaic-keep-picture
                                 Keep original size (default disabled)
          Keep original size (default disabled)
      --mosaic-order <string>    Order as a comma separated list of
                                 picture-id(s)
          Order as a comma separated list of
          picture-id(s)
      --mosaic-delay <integer>   Delay
          Pictures coming from the picture video
          outputs will be delayed accordingly (in
          milliseconds). For high values you will need
          to raise file-caching and others.
</pre>

===Mosaic bridge stream output===
The full set of mosaic bridge stream output commands is :

<pre>
 Mosaic bridge stream output
      --sout-mosaic-bridge-id <string>
                                 ID
          Specify an identifier string for this
          subpicture
      --sout-mosaic-bridge-width <integer>
                                 Video width
          Allows you to specify the output video width.
      --sout-mosaic-bridge-height <integer>
                                 Video height
          Allows you to specify the output video height.
</pre>

===Bridge stream output===
The full set of bridge stream output commands is :

<pre>
 Bridge stream output
      --sout-bridge-out-id <integer>
                                 ID
          Specify an identifier integer for this
          elementary stream
      --sout-bridge-in-delay <integer>
                                 Delay
          Pictures coming from the picture video
          outputs will be delayed accordingly (in
          milliseconds, >= 100 ms). For high values you
          will need to raise file-caching and others.
      --sout-bridge-in-id-offset <integer>
                                 ID Offset
          Offset to add to the stream IDs specified in
          bridge_out to obtain the stream IDs bridge_in
          will register.
</pre>

===Fake input module===
The full set of the fake input options is :
<pre>
 Fake video decoder
      --fake-file <string>       Image file
          Path of the image file when using the fake
          input.
      --fake-width <integer>     Video width
          Allows you to specify the output video width.
      --fake-height <integer>    Video height
          Allows you to specify the output video height.
      --fake-keep-ar, --no-fake-keep-ar
                                 Keep aspect ratio (default disabled)
          If selected, width and height will be
          considered as maximum values. (default
          disabled)
      --fake-aspect-ratio <string>
                                 Background aspect ratio
          Aspect ratio of the image file (4:3, 16:9).
          Default is square pixels.
      --fake-deinterlace, --no-fake-deinterlace
                                 Deinterlace video (default disabled)
          Allows you to deinterlace the image after
          loading. (default disabled)
      --fake-deinterlace-module {deinterlace,ffmpeg-deinterlace}
                                 Deinterlace module
          Specifies the deinterlace module to use.
</pre>