Line data    Source code

       1             : /*
       2             :  *  Copyright (C) 2004-2026 Savoir-faire Linux Inc.
       3             :  *
       4             :  *  This program is free software: you can redistribute it and/or modify
       5             :  *  it under the terms of the GNU General Public License as published by
       6             :  *  the Free Software Foundation, either version 3 of the License, or
       7             :  *  (at your option) any later version.
       8             :  *
       9             :  *  This program is distributed in the hope that it will be useful,
      10             :  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
      11             :  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
      12             :  *  GNU General Public License for more details.
      13             :  *
      14             :  *  You should have received a copy of the GNU General Public License
      15             :  *  along with this program. If not, see <https://www.gnu.org/licenses/>.
      16             :  */
      17             : 
      18             : #pragma once
      19             : 
      20             : #include <pulse/pulseaudio.h>
      21             : #include <pulse/thread-mainloop.h>
      22             : #include <pulse/error.h>
      23             : #include <string>
      24             : #include <functional>
      25             : #include <vector>
      26             : #include <iostream>
      27             : #include <thread>
      28             : #include <mutex>
      29             : #include <atomic>
      30             : #include <cstring>
      31             : #include <unistd.h>
      32             : 
      33             : class PulseLoopbackCapture
      34             : {
      35             : public:
      36             :     using AudioFrameCallback = std::function<void(const void* data, size_t length)>;
      37             : 
      38             :     PulseLoopbackCapture();
      39             :     ~PulseLoopbackCapture();
      40             : 
      41             :     bool startCaptureAsync(AudioFrameCallback callback);
      42             :     void stopCapture();
      43             : 
      44           0 :     bool isRunning() const { return running_.load(); }
      45           0 :     uint32_t sampleRate() const { return SAMPLE_SPEC.rate; }
      46           0 :     uint8_t channels() const { return SAMPLE_SPEC.channels; }
      47             : 
      48             : private:
      49             :     // PulseAudio callbacks
      50             :     static void contextStateCallback(pa_context* c, void* userdata);
      51             :     static void serverInfoCallback(pa_context* c, const pa_server_info* i, void* userdata);
      52             :     static void moduleLoadedCallback(pa_context* c, uint32_t idx, void* userdata);
      53             :     static void subscribeCallback(pa_context* c, pa_subscription_event_type_t t, uint32_t idx, void* userdata);
      54             :     static void sinkInputInfoCallback(pa_context* c, const pa_sink_input_info* i, int eol, void* userdata);
      55             :     static void streamReadCallback(pa_stream* s, size_t length, void* userdata);
      56             : 
      57             :     // Internal logic
      58             :     void runMainLoop();
      59             :     void moveStreamIfNeeded(uint32_t streamIdx, pid_t streamPid, uint32_t ownerModuleIdx, const char* streamName);
      60             :     void setupModules(const std::string& default_sink);
      61             :     void startRecordingStream();
      62             :     void unloadModulesAndQuit();
      63             : 
      64             :     // Configuration
      65             :     std::string uniqueSinkName_;
      66             :     const pa_sample_spec SAMPLE_SPEC = {PA_SAMPLE_S16LE, 48000, 2};
      67             : 
      68             :     // State
      69             :     pa_threaded_mainloop* mainloop_ = nullptr;
      70             :     pa_mainloop_api* mainloopApi_ = nullptr;
      71             :     pa_context* context_ = nullptr;
      72             :     pa_stream* recordStream_ = nullptr;
      73             : 
      74             :     std::atomic<bool> running_ {false};
      75             : 
      76             :     AudioFrameCallback dataCallback_;
      77             : 
      78             :     pid_t myPid_;
      79             :     std::string defaultSinkName_;
      80             :     uint32_t nullSinkModuleIdx_ = PA_INVALID_INDEX;
      81             :     uint32_t loopbackModuleIdx_ = PA_INVALID_INDEX;
      82             : };