docs: update (#4995)

Author: aler9

docs/1-kickoff/2-installation.md

@@ -16,7 +16,7 @@ There are several installation methods available: standalone binary, Docker imag
 
 Download and launch the image:
 
-```
+```sh
 docker run --rm -it --network=host bluenviron/mediamtx:latest
 ```
 
@@ -33,7 +33,7 @@ The `--network=host` flag is mandatory for RTSP to work, since Docker can change
 
 If the `--network=host` cannot be used (for instance, it is not compatible with Windows or Kubernetes), you can disable the RTSP UDP transport protocol, add the server IP to `MTX_WEBRTCADDITIONALHOSTS` and expose ports manually:
 
-```
+```sh
 docker run --rm -it \
 -e MTX_RTSPTRANSPORTS=tcp \
 -e MTX_WEBRTCADDITIONALHOSTS=192.168.x.x \
@@ -60,7 +60,7 @@ makepkg -si
 
 Available via ports tree or using packages (2025Q2 and later) as listed below:
 
-```
+```sh
 cd /usr/ports/multimedia/mediamtx && make install clean
 pkg install mediamtx
 ```

docs/2-usage/2-publish.md

@@ -524,7 +524,7 @@ audiotestsrc ! audioconvert ! avenc_aac ! mux.
 
 Make sure that GStreamer version is at least 1.22, and that if the codec is H264, the profile is baseline. Use the `whipclientsink` element:
 
-```
+```sh
 gst-launch-1.0 videotestsrc \
 ! video/x-raw,width=1920,height=1080,format=I420 \
 ! x264enc speed-preset=ultrafast bitrate=2000 \

docs/2-usage/23-rtsp-specific-features.md

@@ -75,6 +75,24 @@ gst-launch-1.0 filesrc location=file.mp4 ! qtdemux name=d \
 d.video_0 ! rtspclientsink location=rtsp://localhost:8554/mystream tls-validation-flags=0 profiles=GST_RTSP_PROFILE_SAVP
 ```
 
+## Tunneling
+
+In environments where HTTP is the only protocol available for exposing services (for instance, when there are mandatory API gateways or strict firewalls), the RTSP protocol can be tunneled inside HTTP. There are two standardized HTTP tunneling variants:
+
+- RTSP over WebSocket: more efficient, requires WebSocket support from the gateway / firewall
+- RTSP over HTTP: older variant, should work even in extreme cases
+
+_MediaMTX_ is automatically able to handle incoming HTTP tunneled connections, without any configuration required.
+
+In order to read a RTSP from an external server using HTTP tunneling, you can use the `rtsp+http` scheme:
+
+```yml
+paths:
+  source: rtsp+http://standard-rtsp-url
+```
+
+There are also the `rtsp+https`, `rtsp+ws`, `rtsp+wss` schemes to handle any variant.
+
 ## Decreasing corrupted frames
 
 In some scenarios, when publishing or reading from the server with RTSP, frames can get corrupted. This can be caused by several reasons:

docs/2-usage/3-read.md

@@ -246,7 +246,7 @@ vlc --network-caching=50 rtsp://localhost:8554/mystream
 
 The VLC shipped with Ubuntu 21.10 doesn't support playing RTSP due to a license issue (see [here](https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=982299) and [here](https://stackoverflow.com/questions/69766748/cvlc-cannot-play-rtsp-omxplayer-instead-can)). To fix the issue, remove the default VLC instance and install the snap version:
 
-```
+```sh
 sudo apt purge -y vlc
 snap install vlc
 ```

docs/2-usage/4-configuration.md

@@ -8,7 +8,7 @@ There are several ways to change the configuration:
    - included into the release bundle
    - available in the root folder of the Docker image (`/mediamtx.yml`); it can be overridden in this way:
 
-     ```
+     ```sh
      docker run --rm -it --network=host -v "$PWD/mediamtx.yml:/mediamtx.yml:ro" bluenviron/mediamtx
      ```