#include <condition_variable>
#include <deque>
#include <functional>
+#include <map>
#include <mutex>
+#include <stack>
#include <string>
#include <thread>
#include <vector>
virtual void release_frame(Frame frame) = 0;
};
+// Audio is more important than video, and also much cheaper.
+// By having many more audio frames available, hopefully if something
+// starts to drop, we'll have CPU load go down (from not having to
+// process as much video) before we have to drop audio.
+#define NUM_QUEUED_VIDEO_FRAMES 16
+#define NUM_QUEUED_AUDIO_FRAMES 64
+
+class MallocFrameAllocator : public FrameAllocator {
+public:
+ MallocFrameAllocator(size_t frame_size, size_t num_queued_frames);
+ Frame alloc_frame() override;
+ void release_frame(Frame frame) override;
+
+private:
+ size_t frame_size;
+
+ std::mutex freelist_mutex;
+ std::stack<std::unique_ptr<uint8_t[]>> freelist; // All of size <frame_size>.
+};
+
+// Represents an input mode you can tune a card to.
+struct VideoMode {
+ std::string name;
+ bool autodetect = false; // If true, all the remaining fields are irrelevant.
+ unsigned width = 0, height = 0;
+ unsigned frame_rate_num = 0, frame_rate_den = 0;
+ bool interlaced = false;
+};
+
+// Represents the format of an actual frame coming in.
struct VideoFormat {
uint16_t id = 0; // For debugging/logging only.
unsigned width = 0, height = 0, second_field_start = 0;
unsigned extra_lines_top = 0, extra_lines_bottom = 0;
unsigned frame_rate_nom = 0, frame_rate_den = 0;
bool interlaced = false;
+ bool has_signal = false;
+};
+
+struct AudioFormat {
+ uint16_t id = 0; // For debugging/logging only.
+ unsigned bits_per_sample = 0;
+ unsigned num_channels = 0;
};
typedef std::function<void(uint16_t timecode,
FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
- FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)>
+ FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)>
frame_callback_t;
+class CaptureInterface {
+ public:
+ virtual ~CaptureInterface() {}
+
+ virtual std::map<uint32_t, VideoMode> get_available_video_modes() const = 0;
+
+ virtual void set_video_mode(uint32_t video_mode_id) = 0;
+
+ // Does not take ownership.
+ virtual void set_video_frame_allocator(FrameAllocator *allocator) = 0;
+
+ virtual FrameAllocator *get_video_frame_allocator() = 0;
+
+ // Does not take ownership.
+ virtual void set_audio_frame_allocator(FrameAllocator *allocator) = 0;
+
+ virtual FrameAllocator *get_audio_frame_allocator() = 0;
+
+ virtual void set_frame_callback(frame_callback_t callback) = 0;
+
+ // Needs to be run before configure_card().
+ virtual void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) = 0;
+
+ // Only valid after configure_card().
+ virtual std::string get_description() const = 0;
+
+ virtual void configure_card() = 0;
+
+ virtual void start_bm_capture() = 0;
+
+ virtual void stop_dequeue_thread() = 0;
+};
+
// The actual capturing class, representing capture from a single card.
-class BMUSBCapture {
+class BMUSBCapture : public CaptureInterface {
public:
BMUSBCapture(int card_index)
: card_index(card_index)
{
}
+ ~BMUSBCapture() {}
+
+ std::map<uint32_t, VideoMode> get_available_video_modes() const override;
+
+ void set_video_mode(uint32_t video_mode_id) override;
+
// Does not take ownership.
- void set_video_frame_allocator(FrameAllocator *allocator)
+ void set_video_frame_allocator(FrameAllocator *allocator) override
{
video_frame_allocator = allocator;
}
- FrameAllocator *get_video_frame_allocator()
+ FrameAllocator *get_video_frame_allocator() override
{
return video_frame_allocator;
}
// Does not take ownership.
- void set_audio_frame_allocator(FrameAllocator *allocator)
+ void set_audio_frame_allocator(FrameAllocator *allocator) override
{
audio_frame_allocator = allocator;
}
- FrameAllocator *get_audio_frame_allocator()
+ FrameAllocator *get_audio_frame_allocator() override
{
return audio_frame_allocator;
}
- void set_frame_callback(frame_callback_t callback)
+ void set_frame_callback(frame_callback_t callback) override
{
frame_callback = callback;
}
// Needs to be run before configure_card().
- void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup)
+ void set_dequeue_thread_callbacks(std::function<void()> init, std::function<void()> cleanup) override
{
dequeue_init_callback = init;
dequeue_cleanup_callback = cleanup;
}
// Only valid after configure_card().
- std::string get_description() const {
+ std::string get_description() const override {
return description;
}
- void configure_card();
- void start_bm_capture();
- void stop_dequeue_thread();
+ void configure_card() override;
+ void start_bm_capture() override;
+ void stop_dequeue_thread() override;
+ // TODO: It's rather messy to have these outside the interface.
static void start_bm_thread();
static void stop_bm_thread();