#define _BMUSB_H
#include <stdint.h>
+#include <atomic>
+#include <condition_variable>
+#include <deque>
#include <functional>
+#include <mutex>
+#include <stack>
+#include <string>
+#include <thread>
+#include <vector>
+
+struct libusb_transfer;
// An interface for frame allocators; if you do not specify one
// (using set_video_frame_allocator), a default one that pre-allocates
public:
struct Frame {
uint8_t *data = nullptr;
+ uint8_t *data2 = nullptr; // Only if interleaved == true.
size_t len = 0; // Number of bytes we actually have.
size_t size = 0; // Number of bytes we have room for.
+ size_t overflow = 0;
void *userdata = nullptr;
FrameAllocator *owner = nullptr;
+
+ // If set to true, every other byte will go to data and to data2.
+ // If so, <len> and <size> are still about the number of total bytes
+ // so if size == 1024, there's 512 bytes in data and 512 in data2.
+ bool interleaved = false;
};
virtual ~FrameAllocator();
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 {
+ uint32_t id = 0;
+ 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, uint16_t video_format,
- FrameAllocator::Frame audio_frame, size_t audio_offset, uint16_t audio_format)>
+ FrameAllocator::Frame video_frame, size_t video_offset, VideoFormat video_format,
+ FrameAllocator::Frame audio_frame, size_t audio_offset, AudioFormat audio_format)>
frame_callback_t;
-void set_video_frame_allocator(FrameAllocator *allocator); // Does not take ownership.
-FrameAllocator *get_video_frame_allocator();
+class CaptureInterface {
+ public:
+ virtual ~CaptureInterface() {}
+
+ virtual std::vector<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 : public CaptureInterface {
+ public:
+ BMUSBCapture(int card_index)
+ : card_index(card_index)
+ {
+ }
+
+ ~BMUSBCapture() {}
+
+ std::vector<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) override
+ {
+ video_frame_allocator = allocator;
+ }
+
+ FrameAllocator *get_video_frame_allocator() override
+ {
+ return video_frame_allocator;
+ }
+
+ // Does not take ownership.
+ void set_audio_frame_allocator(FrameAllocator *allocator) override
+ {
+ audio_frame_allocator = allocator;
+ }
+
+ FrameAllocator *get_audio_frame_allocator() override
+ {
+ return audio_frame_allocator;
+ }
+
+ 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) override
+ {
+ dequeue_init_callback = init;
+ dequeue_cleanup_callback = cleanup;
+ has_dequeue_callbacks = true;
+ }
+
+ // Only valid after configure_card().
+ std::string get_description() const override {
+ return description;
+ }
+
+ 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();
-void set_audio_frame_allocator(FrameAllocator *allocator); // Does not take ownership.
-FrameAllocator *get_audio_frame_allocator();
+ private:
+ struct QueuedFrame {
+ uint16_t timecode;
+ uint16_t format;
+ FrameAllocator::Frame frame;
+ };
+
+ void start_new_audio_block(const uint8_t *start);
+ void start_new_frame(const uint8_t *start);
+
+ void queue_frame(uint16_t format, uint16_t timecode, FrameAllocator::Frame frame, std::deque<QueuedFrame> *q);
+ void dequeue_thread_func();
+
+ static void usb_thread_func();
+ static void cb_xfr(struct libusb_transfer *xfr);
+
+ std::string description;
+
+ FrameAllocator::Frame current_video_frame;
+ FrameAllocator::Frame current_audio_frame;
+
+ std::mutex queue_lock;
+ std::condition_variable queues_not_empty;
+ std::deque<QueuedFrame> pending_video_frames;
+ std::deque<QueuedFrame> pending_audio_frames;
+
+ FrameAllocator *video_frame_allocator = nullptr;
+ FrameAllocator *audio_frame_allocator = nullptr;
+ frame_callback_t frame_callback = nullptr;
+
+ std::thread dequeue_thread;
+ std::atomic<bool> dequeue_thread_should_quit;
+ bool has_dequeue_callbacks = false;
+ std::function<void()> dequeue_init_callback = nullptr;
+ std::function<void()> dequeue_cleanup_callback = nullptr;
+
+ int current_register = 0;
+
+ static constexpr int NUM_BMUSB_REGISTERS = 60;
+ uint8_t register_file[NUM_BMUSB_REGISTERS];
+
+ int card_index;
+ std::vector<libusb_transfer *> iso_xfrs;
+ int assumed_frame_width = 1280;
+};
-void set_frame_callback(frame_callback_t callback);
-void start_bm_capture();
-void stop_bm_capture();
+// Get details for the given video format; returns false if detection was incomplete.
+// Note: Frame rate is _frame_ rate, not field rate. So 1080i60 gets 30/1, _not_ 60/1.
+// "second_field_start" is only valid for interlaced modes; it signifies
+// how many lines from the very top of the frame there are before the second field
+// starts (so it will always be >= height/2 + extra_lines_top).
+bool decode_video_format(uint16_t video_format, VideoFormat *decoded_video_format);
#endif