audio_play_case

# audio_play_test

This example validates the unified `audio_play_*` API together with:

- `AUDIO_PLAY_TYPE_PLAYBACK`
- `AUDIO_PLAY_TYPE_PROMPT`
- `audio_feeder_*`
- `audio_processor_mixer_open()`
- `audio_processor_ramp_control()`

After boot, the example:

- opens one playback handle and one prompt handle
- opens a PCM feeder and continuously feeds raw PCM data from SD card
- enables the mixer in balanced mode
- starts a console REPL for manual testing

Console commands:

- `play <url>`
- `prompt <url>`
- `pause`
- `resume`
- `stop`
- `focus <playback|feeder|balanced>`
- `feeder <on|off|status>`
- `feeder_path <path>`
- `status`

Notes:

- `play <url>` uses the playback handle and is intended for normal playback.
- `prompt <url>` uses the prompt-type handle and plays with `block_until_done = true`.
- The feeder reads the current PCM path in a loop. The default path is `/sdcard/feeder.pcm`.
- You can switch the feeder source at runtime with `feeder_path <path>`.
- Expected feeder PCM format: 16 kHz, 16-bit, mono, raw PCM.