Add PUT /api/stream/phone: raw PCM audio push from a phone app

New endpoint accepts chunked, header-less, 16-bit LE stereo PCM @ 48 kHz in the request body and writes it straight to the shared I2S sink for as long as the connection stays open. Chosen deliberately unencoded (no MP3/AAC/Opus decode) to keep this path as simple and low-risk as possible — the companion app controls the encoding on its side. Extracted the I2S TX channel that used to be owned outright by web_radio_stream.cpp into main/esp32_i2s_sink.cpp, shared by both producers with a simple tryAcquire()/release() exclusivity guard — web radio streaming and a phone PCM stream would otherwise fight over the same physical wire. web_radio_stream.cpp now acquires/releases around each streamWhileEnabled() cycle instead of owning the channel itself. net::PhoneStreamSink is a plain function-pointer struct (not a class hierarchy) threaded through NetBootstrap::start() -> SetupWebServer::start() -> HttpRouteContext, so components/net stays free of I2S driver headers; main/phone_stream.cpp supplies the concrete functions (bound to esp32_i2s_sink) and does the int16->ADAU 32-bit-slot conversion, batched per chunk rather than per sample for the same reason as the web radio stutter fix (6974095/7e65394 lineage). Verified by build only — not confirmed live yet (board disconnected this session); the actual phone app that will exercise this endpoint doesn't exist yet either. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_0178rASQ6ZETPMUamvpoR2KR
2026-08-18 08:03:39 +02:00
parent 39984a97d1
commit e8f79c4b79
11 changed files with 394 additions and 70 deletions
@@ -0,0 +1,109 @@
+/**
+ * @file    esp32_i2s_sink.cpp
+ * @brief   Shared ESP32 -> ADAU1701 I2S TX channel (web radio / phone stream).
+ *
+ * DigiRadio firmware — https://github.com/manvalan/DigiRadio
+ *
+ * Copyright 2026 Michele Bigi
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "esp32_i2s_sink.hpp"
+
+#include "board_pins.hpp"
+
+#include "driver/i2s_std.h"
+#include "esp_log.h"
+#include "freertos/FreeRTOS.h"
+
+#include <atomic>
+
+namespace esp32_i2s_sink {
+
+namespace {
+
+constexpr char kTag[] = "i2s_sink";
+constexpr int kSampleRateHz = 48000;
+
+i2s_chan_handle_t gTxHandle = nullptr;
+std::atomic<bool> gInUse{false};
+
+} // namespace
+
+bool open()
+{
+    if (gTxHandle != nullptr) {
+        return true;
+    }
+
+    i2s_chan_config_t chanCfg =
+        I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_SLAVE);
+    // See main/web_radio_stream.cpp history: default (6 x 240 frames =
+    // ~30 ms) leaves almost no headroom against producer jitter (network
+    // stalls, HTTP scheduling); widen it for both producers that share
+    // this channel.
+    chanCfg.dma_desc_num = 12;
+    chanCfg.dma_frame_num = 480;
+
+    if (i2s_new_channel(&chanCfg, &gTxHandle, nullptr) != ESP_OK) {
+        ESP_LOGE(kTag, "i2s_new_channel failed");
+        gTxHandle = nullptr;
+        return false;
+    }
+
+    i2s_std_config_t stdCfg = {
+        .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(kSampleRateHz),
+        // 32-bit slots match ADAU1701 SerialOutRegister1 (64 BCLKs/frame).
+        .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(
+            I2S_DATA_BIT_WIDTH_32BIT, I2S_SLOT_MODE_STEREO),
+        .gpio_cfg = {
+            .mclk = I2S_GPIO_UNUSED,
+            .bclk = static_cast<gpio_num_t>(board::pins::I2sBclk),
+            .ws = static_cast<gpio_num_t>(board::pins::I2sLrclk),
+            .dout = static_cast<gpio_num_t>(board::pins::I2sDataOut),
+            .din = I2S_GPIO_UNUSED,
+            .invert_flags = {
+                .mclk_inv = false,
+                .bclk_inv = false,
+                .ws_inv = false,
+            },
+        },
+    };
+
+    if (i2s_channel_init_std_mode(gTxHandle, &stdCfg) != ESP_OK
+        || i2s_channel_enable(gTxHandle) != ESP_OK) {
+        ESP_LOGE(kTag, "I2S TX channel init/enable failed");
+        i2s_del_channel(gTxHandle);
+        gTxHandle = nullptr;
+        return false;
+    }
+    ESP_LOGI(kTag, "I2S slave TX started (BCLK=%d WS=%d DOUT=%d)",
+             board::pins::I2sBclk, board::pins::I2sLrclk,
+             board::pins::I2sDataOut);
+    return true;
+}
+
+bool tryAcquire()
+{
+    bool expected = false;
+    return gInUse.compare_exchange_strong(expected, true);
+}
+
+void release()
+{
+    gInUse.store(false);
+}
+
+bool writeSamples(const std::int32_t* samples, std::size_t sampleCount)
+{
+    if (gTxHandle == nullptr) {
+        return false;
+    }
+    std::size_t written = 0U;
+    const esp_err_t err =
+        i2s_channel_write(gTxHandle, samples, sampleCount * sizeof(std::int32_t),
+                          &written, portMAX_DELAY);
+    return err == ESP_OK;
+}
+
+} // namespace esp32_i2s_sink