Support audio-only FFmpeg inputs. Somewhat wonky, though.

[nageru] / alsa_input.h

diff --git a/alsa_input.h b/alsa_input.h
index 84e46b0887707dd6b273419d29cf2fada00c43d7..060b9212690fce317f9dfac701af37d597af908a 100644 (file)
--- a/alsa_input.h
+++ b/alsa_input.h
@@ -10,23 +10,32 @@
 // as a whole, since that's what AudioMixer::add_audio() wants.
 
 #include <alsa/asoundlib.h>
-
+#include <stdint.h>
+#include <sys/types.h>
 #include <atomic>
+#include <chrono>
 #include <functional>
+#include <memory>
 #include <string>
 #include <thread>
-#include <vector>
 
 #include "bmusb/bmusb.h"
-#include "timebase.h"
+#include "quittable_sleeper.h"
+
+class ALSAPool;
 
 class ALSAInput {
 public:
-       typedef std::function<bool(const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length)> audio_callback_t;
+       typedef std::function<bool(const uint8_t *data, unsigned num_samples, bmusb::AudioFormat audio_format, int64_t frame_length, std::chrono::steady_clock::time_point ts)> audio_callback_t;
 
-       ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback);
+       ALSAInput(const char *device, unsigned sample_rate, unsigned num_channels, audio_callback_t audio_callback, ALSAPool *parent_pool, unsigned internal_dev_index);
        ~ALSAInput();
 
+       // If not called before start_capture_thread(), the capture thread
+       // will call it until it succeeds.
+       bool open_device();
+
+       // Not valid before the device has been successfully opened.
        // NOTE: Might very well be different from the sample rate given to the
        // constructor, since the card might not support the one you wanted.
        unsigned get_sample_rate() const { return sample_rate; }
@@ -34,19 +43,22 @@ public:
        void start_capture_thread();
        void stop_capture_thread();
 
-       // TODO: Worry about hotplug.
-       struct Device {
-               std::string address;  // E.g. “hw:0,0”.
-               std::string name, info;
-               unsigned num_channels;
-       };
-       static std::vector<Device> enumerate_devices();
+       // Set access, sample rate and format parameters on the given ALSA PCM handle.
+       // Returns the computed parameter set and the chosen sample rate. Note that
+       // sample_rate is an in/out parameter; you send in the desired rate,
+       // and ALSA picks one as close to that as possible.
+       static bool set_base_params(const char *device_name, snd_pcm_t *pcm_handle, snd_pcm_hw_params_t *hw_params, unsigned *sample_rate);
 
 private:
        void capture_thread_func();
        int64_t frames_to_pts(uint64_t n) const;
-       void die_on_error(const char *func_name, int err);
-       static bool set_base_params(const char *device, snd_pcm_t *pcm_handle, snd_pcm_hw_params_t *hw_params, unsigned *sample_rate);
+
+       enum class CaptureEndReason {
+               REQUESTED_QUIT,
+               DEVICE_GONE,
+               OTHER_ERROR
+       };
+       CaptureEndReason do_capture();
 
        std::string device;
        unsigned sample_rate, num_channels, num_periods;
@@ -55,10 +67,12 @@ private:
        bmusb::AudioFormat audio_format;
        audio_callback_t audio_callback;
 
-       snd_pcm_t *pcm_handle;
+       snd_pcm_t *pcm_handle = nullptr;
        std::thread capture_thread;
-       std::atomic<bool> should_quit{false};
+       QuittableSleeper should_quit;
        std::unique_ptr<uint8_t[]> buffer;
+       ALSAPool *parent_pool;
+       unsigned internal_dev_index;
 };
 
 #endif  // !defined(_ALSA_INPUT_H)