aes67-ESP32-P4/main/player.c

#include "player.h"

#include <math.h>
#include <string.h>

#include "aes67_cfg.h"
#include "aes67_ota.h"
#include "aes67_tx.h"
#include "aes67_web.h"
#include "audio_out.h"
#include "audio_ring.h"
#include "decoder.h"
#include "hls.h"
#include "spotify.h"
#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define RATE            48000
#define CHANNELS        2
#define RING_FRAMES     (4 * RATE)      // 4 s in PSRAM
#define PREFILL_FRAMES  (RATE)          // 1 s before (re)starting output

static const char *TAG = "player";

static const char *const SRC_NAME[] = { "tone", "off", "hls", "spotify" };

static volatile player_src_t s_src = PLAYER_SRC_OFF;
static volatile bool s_playing;         // ring output running (after prefill)
static volatile bool s_flush;           // consumer drops buffered audio on the next read
static volatile bool s_paused;          // Spotify paused: silence, buffer kept, no underrun
static audio_conv_t *s_spotify_conv;
// Player volume, applied after the ring so a change is heard at once (not a ring length later).
static volatile float s_target_gain = 1.0f;
static float s_gain = 1.0f;             // TX task only; ramps to s_target_gain
static volatile int s_volume_pct = 100;

// 0..100 % -> amplitude: cubic curve (about -18 dB at 50 %, 0 % = mute).
static void set_volume(int pct)
{
    pct = pct < 0 ? 0 : pct > 100 ? 100 : pct;
    float r = pct / 100.0f;
    s_volume_pct = pct;
    s_target_gain = r * r * r;
}

// Apply the volume, ramping linearly from the previous gain over this buffer (no zipper noise).
static void apply_gain(int32_t *buf, size_t frames)
{
    float target = s_target_gain;
    if (s_gain == target && target == 1.0f) {
        return;
    }
    float step = (target - s_gain) / frames;
    for (size_t i = 0; i < frames; i++) {
        s_gain += step;
        buf[i * 2] = (int32_t)(buf[i * 2] * s_gain);
        buf[i * 2 + 1] = (int32_t)(buf[i * 2 + 1] * s_gain);
    }
    s_gain = target;
}

static player_src_t mode_of(const char *m)
{
    return !strcmp(m, "tone") ? PLAYER_SRC_TONE : !strcmp(m, "hls") ? PLAYER_SRC_HLS :
           !strcmp(m, "spotify") ? PLAYER_SRC_SPOTIFY : !strcmp(m, "auto") ? PLAYER_SRC_HLS /* failover: step 7 */ : PLAYER_SRC_OFF;
}

// AES67 TX pull callback (TX task, must not block). Silence while buffering or off: not an underrun.
static size_t player_read(int32_t *buf, size_t frames)
{
    if (s_flush) {
        audio_ring_flush();
        s_flush = false;
        s_playing = false;
    }
    if (s_src == PLAYER_SRC_OFF || (s_src == PLAYER_SRC_SPOTIFY && s_paused)) {
        memset(buf, 0, frames * CHANNELS * sizeof(int32_t));
        return frames;
    }
    if (!s_playing) {
        if (audio_ring_level() < PREFILL_FRAMES) {
            memset(buf, 0, frames * CHANNELS * sizeof(int32_t));
            return frames;
        }
        s_playing = true;
    }
    size_t got = audio_ring_read(buf, frames);
    apply_gain(buf, got);
    if (got < frames) {
        s_playing = false;          // ran dry: underrun (counted by TX), prefill again
    }
    return got;
}

void player_apply(const cJSON *source)
{
    if (s_spotify_conv) {       // after player_init: Spotify follows mode / name / credentials live
        spotify_apply();
    }
    player_src_t src = mode_of(cJSON_GetObjectItemCaseSensitive(source, "mode")->valuestring);
    if (src == s_src) {
        return;
    }
    s_src = src;
    s_flush = true;
    // The test tone is TX's own (phase-locked to PTP); everything else goes through player_read.
    aes67_tx_set_source(src == PLAYER_SRC_TONE ? NULL : player_read);
    ESP_LOGI(TAG, "source: %s", SRC_NAME[src]);
}

// Source side: write converted 48 kHz frames, waiting for space at playback speed.
// Frames of a source that is not active are dropped.
size_t player_write(player_src_t src, const int32_t *frames, size_t n)
{
    size_t done = 0;
    while (done < n) {
        if (s_src != src) {
            return n;               // not the active source: drop
        }
        size_t w = audio_ring_write(frames + done * CHANNELS, n - done);
        if (!w) {
            vTaskDelay(pdMS_TO_TICKS(20));
        }
        done += w;
    }
    return done;
}

/* ----- Spotify ----- */

static size_t spotify_pcm(const int16_t *pcm, size_t frames)
{
    audio_conv_write(s_spotify_conv, pcm, frames, 2, 44100);   // blocks while the ring is full
    return frames;
}

static void spotify_event(spotify_event_t ev, int value)
{
    switch (ev) {
    case SPOTIFY_EV_PLAY:
        s_paused = false;
        break;
    case SPOTIFY_EV_PAUSE:
        s_paused = true;
        break;
    case SPOTIFY_EV_FLUSH:
        if (s_src == PLAYER_SRC_SPOTIFY) {
            s_flush = true;         // skip/seek: don't play out the old buffer
        }
        break;
    case SPOTIFY_EV_VOLUME: {
        // Spotify sends 0..65535; the app's slider stays the master of the player volume.
        int pct = (value * 100 + 32767) / 65535;
        set_volume(pct);
        float g = s_target_gain;
        ESP_LOGI(TAG, "volume %d%% (%.1f dB)", pct, g > 0 ? 20.0f * log10f(g) : -INFINITY);
        break;
    }
    }
}

// Firmware upload: flash writes stall tasks for > 20 ms at a time; with a Spotify session running,
// uploads crawled and sometimes ended in a reset (pausing was not enough). End the session (its
// tasks and connections are gone before the first write) and stop HLS fetching meanwhile. The
// device reboots after a good upload anyway; after a failed one the sources come back (Spotify
// waits for the app to reconnect).
static void on_ota(bool starting)
{
    if (starting) {
        spotify_suspend(true);
        hls_suspend(true);
        ESP_LOGI(TAG, "firmware update: Spotify session ended, HLS suspended");
    } else {
        hls_suspend(false);
        spotify_suspend(false);
        ESP_LOGI(TAG, "firmware update failed: sources resumed");
    }
}

static void player_status(cJSON *st)
{
    const char *state = s_src == PLAYER_SRC_TONE ? "playing" : s_src == PLAYER_SRC_OFF ? "idle" :
                        s_src == PLAYER_SRC_SPOTIFY && s_paused ? "paused" : s_playing ? "playing" : "buffering";
    cJSON_AddStringToObject(st, "active_source", SRC_NAME[s_src]);
    cJSON_AddStringToObject(st, "source_state", state);
    cJSON_AddStringToObject(st, "spotify_state", spotify_state());
    cJSON_AddNumberToObject(st, "buffer_ms", (double)(audio_ring_level() * 1000 / RATE));
}

esp_err_t player_init(void)
{
    esp_err_t err = audio_ring_init(RING_FRAMES, CHANNELS);
    if (err != ESP_OK) {
        ESP_LOGE(TAG, "ring buffer: %s", esp_err_to_name(err));
        return err;
    }
    cJSON *src = cfg_get("source");
    s_src = (player_src_t)-1;
    player_apply(src);
    cJSON_Delete(src);
    err = decoder_init();
    if (err != ESP_OK) {
        return err;
    }
    s_spotify_conv = audio_conv_create(PLAYER_SRC_SPOTIFY, "spotify");
    if (!s_spotify_conv) {
        return ESP_ERR_NO_MEM;
    }
    spotify_init(spotify_pcm, spotify_event, audio_ring_written, audio_ring_read_pos);
    aes67_ota_on_update(on_ota);
        err = hls_start(decoder_feed);
    if (err != ESP_OK) {
        return err;
    }
    return status_register(player_status);
}