Commit Graph

4 Commits

Author SHA1 Message Date
Glenn Thompson 2649a8169a AAC encoding fixes, crossfade, buffer tuning, README rewrite
- Fix FDK-AAC C shim: use proper OUT_BITSTREAM_DATA=3 constant and INT types
- Add frame-aligned PCM accumulation buffer to AAC encoder for clean output
- Add fdkaac_encode and fdkaac_close to C shim (all FDK-AAC calls in C)
- Implement crossfade between tracks (3s overlap, 2s fade-in/out)
- Tune buffer: 90% drain sleep for encoding headroom, 64KB burst-on-connect
- Add FFI bindings for new shim functions
- Rewrite README.org with full architecture docs and integration plan
2026-03-03 20:20:43 +03:00
Glenn Thompson fcda723577 feat: Broadcast buffer, sequential playlist, ICY metadata
- Broadcast buffer: single-producer multi-consumer ring buffer with
  per-client read cursors. 32KB burst-on-connect for fast playback.
  Never blocks producer (overwrites old data for slow clients).
- Sequential playlist: play-list runs tracks one at a time using
  Harmony's on-end callback + condition variable for completion.
- ICY metadata: set-now-playing called on each track change.
- Fixed string vs pathname bug in harmony:play (etypecase mismatch).
- Debug logging for client disconnect diagnosis.

Verified: browser plays shuffled FLAC playlist via 128kbps MP3 stream.
2026-03-03 18:15:31 +03:00
Glenn Thompson a9e8276e9a feat: End-to-end streaming working! Custom streaming-drain + fixes
Major changes:
- streaming-drain: Custom drain that captures PCM from Harmony's pack
  buffer (raw IEEE 754 floats in unsigned-byte-8 array), converts to
  signed-16 PCM via CFFI, encodes to MP3 via LAME, and writes to
  stream server's ring buffer
- Fixed ring buffer deadlock: buffer-read/buffer-write held lock then
  called buffer-available which tried to acquire same lock. Created
  internal %buffer-available/%buffer-free-space without locking.
- Fixed ring buffer zero-length guard for unbound variable in finally
- Fixed sleep duration in drain: was dividing raw byte count by
  samplerate, now correctly converts to frames first
- Added flexi-streams wrapper for bivalent HTTP socket I/O
- Exported all public API symbols from cl-streamer package
- Added test-stream.lisp end-to-end test script

Verified: Amon Tobin FLAC -> 128kbps MP3 stream at localhost:8000
  file reports: MPEG ADTS, layer III, v1, 128kbps, 44.1kHz, JntStereo
2026-03-03 17:46:55 +03:00
Glenn Thompson 9d5166c562 feat: Add Harmony backend with dummy drain for streaming pipeline
- harmony-backend.lisp: Audio pipeline connecting Harmony to encoders
- Uses :dummy drain to capture PCM without audio output
- Reads from packer bip-buffer via request-read/finish-read API
- Encodes PCM to MP3 via LAME and feeds to stream server

All three systems compile cleanly:
  cl-streamer, cl-streamer/encoder, cl-streamer/harmony
2026-03-03 16:56:24 +03:00