v0.1.0

Changed

• Audio sample rate raised from 16 kHz to 32 kHz. The mic source, RTP
  payload (L16/32000/1), filter coefficients, and high-cut bounds
  (now capped at the new 16 kHz Nyquist) all move together. Bit depth
  stays at 16-bit mono. The MEMS capsules this targets (e.g. INMP441)
  can't faithfully capture much above 16 kHz, so 32 kHz is the balance
  point — voice plus the ambient detail (footsteps, doors, bird calls)
  in the 8–16 kHz octave, without spending CPU and Wi-Fi bandwidth on
  content the mic can't reproduce. On an ESP32-S3 the audio path still
  sits well under the comfort budget reported by cpu_use_pct. RTP
  packets roughly double in size (~1.3 KB at 20 ms), still well under
  MTU. See the README's "Audio format" section.
• Ring buffer reduced from 2 s to 1 s of jitter slack so the
  component fits on bare ESP32 boards without PSRAM. At 32 kHz the
  2 s buffer was 128 KB, which routinely fails to allocate as a
  contiguous chunk on WROOM / RISC-V parts that only have ~320 KB
  internal SRAM total. 1 s (~64 KB) keeps the same byte budget as the
  previous 16 kHz / 2 s buffer; the RTSP client's own jitter buffer
  brings end-to-end resilience back to ~1.5–2 s. See the README's
  "Sized to fit ESP32 internal SRAM" section for the rationale and a
  note on possible PSRAM-aware sizing in future.

Added

• High-cut filter, tunable from Home Assistant. Opt-in number: on
  platform: rtsp_audio exposing a high-cut frequency slider
  (high_cut_frequency_hz, default 20000 Hz / off, 1000–20000 Hz
  range) that rolls off energy above the cutoff — useful for taming
  mic hiss, wind noise, and out-of-band content downstream consumers
  don't need (narrow-band voice models, NVR storage). At the maximum
  the stage is skipped and the audio path is bit-identical to a build
  without it. See
  docs/configuration.md.
• Low-cut filter, tunable from Home Assistant. Opt-in number: on
  platform: rtsp_audio exposing a low-cut frequency slider
  (low_cut_frequency_hz, default 100 Hz, 20–500 Hz range) that
  strips MEMS-mic DC bias and sub-100 Hz rumble (HVAC, handling, wind)
  before the audio leaves the device, so downstream consumers get a
  cleaner signal with more usable dynamic range. See
  docs/configuration.md.
• RTSP session inactivity timeout to better handle silent client disconnects.
  A client that disappears without sending TEARDOWN (ue to crash,
  sleep, Wi-Fi drop) is now reaped after 60 s instead of blocking the
  single client slot for minutes until the OS-level TCP timeout fires.
• Peak-level diagnostic sensor (peak_level_dbfs). Opt-in sensor:
  on platform: rtsp_audio reporting peak audio level in dBFS
  (0 dBFS = clipping) over the last 5 s window. Designed as the
  missing feedback channel for the gain_db slider — previously the
  user had to guess the right gain by listening to the receiving
  client. See
  docs/configuration.md.
• CPU-use diagnostic sensor (cpu_use_pct). Opt-in sensor: on
  platform: rtsp_audio reporting what fraction of wall-clock the
  RTSP audio path consumes, so you can tell whether the chip has
  headroom for the current sample rate, DSP settings, and enabled
  features — and decide whether to upgrade or back off. See
  docs/configuration.md.
• Audio gain in dB, tunable from Home Assistant. Opt-in number:
  on platform: rtsp_audio exposing a software audio gain slider
  (gain_db, -20 to +40 dB, 1 dB step, default 0 dB, persisted) so a
  quiet mic can be lifted without re-flashing. 0 dB is bit-identical
  to a no-gain build; overflow is saturating-clamped, never wrapped.
  See docs/configuration.md.
• Diagnostic sensors for Home Assistant. Opt-in client_connected
  (binary_sensor), client_ip (text_sensor), and bytes_sent (sensor)
  so an HA dashboard can see in real time whether a client is pulling
  audio, who it is, and at what bitrate without watching serial logs.
  See
  docs/configuration.md.

Fixed

• Use-after-free on session teardown
  (#5).
  deallocate_stream_buffers_() could free the ring buffer while a
  trailing I²S DMA callback on the mic's own FreeRTOS task was still
  writing into it, occasionally crashing the node on TEARDOWN /
  Wi-Fi drop / peer close. Deallocation is now deferred until
  mic_source_->is_stopped() confirms the mic task has actually
  exited, so the writer is guaranteed gone before the buffer goes
  away.