snapshot of https://github.com/pion/webrtc.git (main, 2026-09-15; blobs > 131072B omitted)

examples/play-from-disk-playlist-control/README.md

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+# ogg-playlist-sctp
+Streams Opus pages from multi or single track Ogg containers, exposes the playlist over an SCTP DataChannel, and lets the browser hop between tracks while showing artist/title metadata parsed from OpusTags.
+
+## What this showcases
+- Reads multi-stream Ogg containers with `oggreader` and keeps per-serial playback state.
+- Publishes playlist + now-playing metadata (artist/title/vendor/comments) over a DataChannel.
+- Browser can send `next`, `prev`, or a 1-based track number to jump around.
+- Audio is sent as an Opus `TrackLocalStaticSample` over RTP, metadata/control ride over SCTP.
+
+## Prepare a demo playlist
+The example looks for `playlist.ogg` in the working directory.
+You can provide your own `playlist.ogg` or generate it by running one of the following ffmpeg commands:
+
+**Fake two-track Ogg with metadata (artist/title per stream)**
+```sh
+ffmpeg \
+  -f lavfi -t 8 -i "sine=frequency=330" \
+  -f lavfi -t 8 -i "sine=frequency=660" \
+  -map 0:a -map 1:a \
+  -c:a libopus -page_duration 20000 \
+  -metadata:s:a:0 artist="Pion Artist" -metadata:s:a:0 title="Fake Intro" \
+  -metadata:s:a:1 artist="Open-Source Friend" -metadata:s:a:1 title="Fake Outro" \
+  playlist.ogg
+```
+
+**Single-track fallback with tags**
+```sh
+ffmpeg -f lavfi -t 10 -i "sine=frequency=480" \
+  -c:a libopus -page_duration 20000 \
+  -metadata artist="Solo Bot" -metadata title="One Track Demo" \
+  playlist.ogg
+```
+
+## Run it
+1. Build the binary:
+   ```sh
+   go install github.com/pion/webrtc/v4/examples/play-from-disk-playlist-control@latest
+   ```
+2. Run it from the directory containing `playlist.ogg` (override port with `-addr` if you like):
+   ```sh
+   play-from-disk-playlist-control
+   # or
+   play-from-disk-playlist-control -addr :8080
+   ```
+3. Open the hosted UI in your browser and press **Start Session**:
+   ```
+   http://localhost:8080
+   ```
+   Signaling is WHEP-style: the browser POSTs plain SDP to `/whep` and the server responds with the answer SDP. Use the buttons or type `next` / `prev` / a track number to switch tracks. Playlist metadata and now-playing updates arrive over the DataChannel; Opus audio flows on the media track.