PROBLEM:
When streaming Radio Paradise blocks via HTTP using FFPlay, the buffer
would cycle between 0KB and ~130KB approximately once per second, causing
audio dropouts and interruptions. VLC worked fine, but FFPlay was sensitive
to the burst transmission pattern.
ROOT CAUSE:
In StreamingFlacSink::broadcast_flac_stream(), the broadcaster was reading
8KB (8192 bytes) at a time from the FLAC encoder and sending the entire
chunk at once to all HTTP clients. This created a "burst" pattern:
- Read 8KB from encoder
- Send entire 8KB chunk to all clients
- Sleep if ahead of real-time pacing
- Repeat
FFPlay's buffer would fill rapidly with each 8KB burst, then drain completely
before the next burst arrived, causing the observed cycling behavior.
SOLUTION:
Reduced the HTTP broadcast buffer size from 8KB to 512 bytes in
StreamingFlacSink::broadcast_flac_stream(). This creates a much smoother,
more continuous data flow that FFPlay can handle without buffer cycling.
The 512-byte buffer size is:
- Small enough to prevent burst transmission
- Large enough to avoid excessive overhead
- Sufficient for smooth streaming with real-time pacing
CHANGES:
- Restore stream_block.rs example from git history
- Restore StreamingFlacSink and StreamingOggFlacSink from git history
- Add "streaming" feature to pmoaudio-ext
- Reduce broadcast buffer from 8192 to 512 bytes
- Update pmoparadise to use pmoaudio-ext streaming feature
TESTING:
Test with FFPlay to verify smooth buffering:
```bash
cargo run --example stream_block --features full -- 0
# In another terminal:
ffplay http://localhost:8080/test/stream
```
Watch the "aq=" value in FFPlay output. It should now remain stable
instead of cycling between 0KB and 130KB.
The old streaming API has been completely replaced by RadioParadiseStreamSource
which integrates directly with the pmoaudio pipeline.
Removed:
- src/stream.rs (179 lines) - BlockStream, stream_block(), download_block()
- src/track.rs - Per-track extraction functionality
- examples/stream_block.rs - Obsolete streaming example
- examples/extract_track.rs - Per-track extraction example
- Feature "per-track" and dependencies (hound, tempfile)
Updated:
- Cargo.toml: Removed per-track feature and obsolete examples
- lib.rs: Removed module declarations and re-exports
The new RadioParadiseStreamSource provides:
- Direct integration with pmoaudio pipeline
- FLAC decoding via pmoflac
- Automatic TrackBoundary insertion
- Better performance and lower latency
