Add -aa and -aai options to record audio only from selected applications

Use the --list-application-audio option to list available applications
to record from.

3 files changed, 128 insertions, 3 deletions

diff --git a/include/pipewire_audio.h b/include/pipewire_audio.h
index ae14cb3..8cfb2d2 100644
--- a/include/pipewire_audio.h
+++ b/include/pipewire_audio.h
@@ -1,4 +1,112 @@
 #ifndef GSR_PIPEWIRE_AUDIO_H
 #define GSR_PIPEWIRE_AUDIO_H
 
+#include <pipewire/thread-loop.h>
+#include <pipewire/context.h>
+#include <pipewire/core.h>
+#include <spa/utils/hook.h>
+
+#include <stdbool.h>
+
+#define GSR_PIPEWIRE_AUDIO_MAX_STREAM_NODES 64
+#define GSR_PIPEWIRE_AUDIO_MAX_PORTS 64
+#define GSR_PIPEWIRE_AUDIO_MAX_REQUESTED_LINKS 32
+
+typedef enum {
+    GSR_PIPEWIRE_AUDIO_NODE_TYPE_STREAM_OUTPUT, /* Application audio */
+    GSR_PIPEWIRE_AUDIO_NODE_TYPE_STREAM_INPUT,  /* Audio recording input */
+    GSR_PIPEWIRE_AUDIO_NODE_TYPE_SINK
+} gsr_pipewire_audio_node_type;
+
+typedef struct {
+    uint32_t id;
+    char *name;
+    gsr_pipewire_audio_node_type type;
+} gsr_pipewire_audio_node;
+
+typedef enum {
+    GSR_PIPEWIRE_AUDIO_PORT_DIRECTION_INPUT,
+    GSR_PIPEWIRE_AUDIO_PORT_DIRECTION_OUTPUT
+} gsr_pipewire_audio_port_direction;
+
+typedef struct {
+    uint32_t id;
+    uint32_t node_id;
+    gsr_pipewire_audio_port_direction direction;
+    char *name;
+} gsr_pipewire_audio_port;
+
+typedef enum {
+    GSR_PIPEWIRE_AUDIO_LINK_OUTPUT_TYPE_STREAM,
+    GSR_PIPEWIRE_AUDIO_LINK_OUTPUT_TYPE_SINK
+} gsr_pipewire_audio_link_output_type;
+
+typedef struct {
+    char **app_names;
+    int num_app_names;
+    char *output_name;
+    bool inverted;
+    gsr_pipewire_audio_link_output_type output_type;
+} gsr_pipewire_audio_requested_link;
+
+typedef struct {
+    struct pw_thread_loop *thread_loop;
+    struct pw_context *context;
+    struct pw_core *core;
+    struct spa_hook core_listener;
+    struct pw_registry *registry;
+    struct spa_hook registry_listener;
+    int server_version_sync;
+
+    gsr_pipewire_audio_node stream_nodes[GSR_PIPEWIRE_AUDIO_MAX_STREAM_NODES];
+    int num_stream_nodes;
+
+    gsr_pipewire_audio_port ports[GSR_PIPEWIRE_AUDIO_MAX_PORTS];
+    int num_ports;
+
+    gsr_pipewire_audio_requested_link requested_links[GSR_PIPEWIRE_AUDIO_MAX_REQUESTED_LINKS];
+    int num_requested_links;
+} gsr_pipewire_audio;
+
+bool gsr_pipewire_audio_init(gsr_pipewire_audio *self);
+void gsr_pipewire_audio_deinit(gsr_pipewire_audio *self);
+
+/*
+    This function links audio source outputs from applications that match the name |app_names_output| to the input
+    that matches the name |stream_name_input|.
+    If an application or a new application starts outputting audio after this function is called and the app name matches
+    then it will automatically link the audio sources.
+    |app_names_output| and |stream_name_input| are case-insensitive matches.
+*/
+bool gsr_pipewire_audio_add_link_from_apps_to_stream(gsr_pipewire_audio *self, const char **app_names_output, int num_app_names_output, const char *stream_name_input);
+/*
+    This function links audio source outputs from all applications except the ones that match the name |app_names_output| to the input
+    that matches the name |stream_name_input|.
+    If an application or a new application starts outputting audio after this function is called and the app name doesn't matche
+    then it will automatically link the audio sources.
+    |app_names_output| and |stream_name_input| are case-insensitive matches.
+*/
+bool gsr_pipewire_audio_add_link_from_apps_to_stream_inverted(gsr_pipewire_audio *self, const char **app_names_output, int num_app_names_output, const char *stream_name_input);
+
+/*
+    This function links audio source outputs from applications that match the name |app_names_output| to the input
+    that matches the name |sink_name_input|.
+    If an application or a new application starts outputting audio after this function is called and the app name matches
+    then it will automatically link the audio sources.
+    |app_names_output| and |sink_name_input| are case-insensitive matches.
+*/
+bool gsr_pipewire_audio_add_link_from_apps_to_sink(gsr_pipewire_audio *self, const char **app_names_output, int num_app_names_output, const char *sink_name_input);
+/*
+    This function links audio source outputs from all applications except the ones that match the name |app_names_output| to the input
+    that matches the name |sink_name_input|.
+    If an application or a new application starts outputting audio after this function is called and the app name doesn't matche
+    then it will automatically link the audio sources.
+    |app_names_output| and |sink_name_input| are case-insensitive matches.
+*/
+bool gsr_pipewire_audio_add_link_from_apps_to_sink_inverted(gsr_pipewire_audio *self, const char **app_names_output, int num_app_names_output, const char *sink_name_input);
+
+/* Return true to continue */
+typedef bool (*gsr_pipewire_audio_app_query_callback)(const char *app_name, void *userdata);
+void gsr_pipewire_audio_for_each_app(gsr_pipewire_audio *self, gsr_pipewire_audio_app_query_callback callback, void *userdata);
+
 #endif /* GSR_PIPEWIRE_AUDIO_H */
diff --git a/include/sound.hpp b/include/sound.hpp
index 7bcc120..018ff4a 100644
--- a/include/sound.hpp
+++ b/include/sound.hpp
@@ -26,6 +26,11 @@ typedef struct {
     unsigned int frames;
 } SoundDevice;
 
+enum class AudioInputType {
+    DEVICE,
+    APPLICATION
+};
+
 struct AudioInput {
     std::string name;
     std::string description;
@@ -37,8 +42,14 @@ struct AudioDevices {
     std::vector<AudioInput> audio_inputs;
 };
 
+struct ApplicationAudio {
+    std::string name;
+};
+
 struct MergedAudioInputs {
     std::vector<AudioInput> audio_inputs;
+    AudioInputType type = AudioInputType::DEVICE;
+    bool inverted = false;
 };
 
 typedef enum {
@@ -48,12 +59,15 @@ typedef enum {
 } AudioFormat;
 
 /*
-    Get a sound device by name, returning the device into the @device parameter.
-    The device should be closed with @sound_device_close after it has been used
-    to clean up internal resources.
+    Get a sound device by name, returning the device into the |device| parameter.
     Returns 0 on success, or a negative value on failure.
 */
 int sound_device_get_by_name(SoundDevice *device, const char *device_name, const char *description, unsigned int num_channels, unsigned int period_frame_size, AudioFormat audio_format);
+/*
+    Creates a module-combine-sink and connects to it for recording, returning the device into the |device| parameter.
+    Returns 0 on success, or a negative value on failure.
+*/
+int sound_device_create_combined_sink_connect(SoundDevice *device, const char *combined_sink_name, unsigned int num_channels, unsigned int period_frame_size, AudioFormat audio_format);
 
 void sound_device_close(SoundDevice *device);
 
@@ -64,5 +78,6 @@ void sound_device_close(SoundDevice *device);
 int sound_device_read_next_chunk(SoundDevice *device, void **buffer, double timeout_sec, double *latency_seconds);
 
 AudioDevices get_pulseaudio_inputs();
+std::vector<ApplicationAudio> get_pulseaudio_applications();
 
 #endif /* GPU_SCREEN_RECORDER_H */
diff --git a/include/utils.h b/include/utils.h
index 9ccd26e..984b963 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -28,6 +28,8 @@ typedef struct {
 } get_monitor_by_name_userdata;
 
 double clock_get_monotonic_seconds(void);
+bool generate_random_characters(char *buffer, int buffer_size, const char *alphabet, size_t alphabet_size);
+bool generate_random_characters_standard_alphabet(char *buffer, int buffer_size);
 
 typedef void (*active_monitor_callback)(const gsr_monitor *monitor, void *userdata);
 void for_each_active_monitor_output_x11_not_cached(Display *display, active_monitor_callback callback, void *userdata);