--- /dev/null
+#ifndef _BMUSB_H
+#define _BMUSB_H
+
+#include <libusb.h>
+#include <stdint.h>
+#include <atomic>
+#include <condition_variable>
+#include <deque>
+#include <functional>
+#include <map>
+#include <mutex>
+#include <stack>
+#include <string>
+#include <thread>
+#include <vector>
+
+namespace bmusb {
+
+class BMUSBCapture;
+
+// An interface for frame allocators; if you do not specify one
+// (using set_video_frame_allocator), a default one that pre-allocates
+// a freelist of eight frames using new[] will be used. Specifying
+// your own can be useful if you have special demands for where you want the
+// frame to end up and don't want to spend the extra copy to get it there, for
+// instance GPU memory.
+class FrameAllocator {
+ 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();
+
+ // Request a video frame. Note that this is called from the
+ // USB thread, which runs with realtime priority and is
+ // very sensitive to delays. Thus, you should not do anything
+ // here that might sleep, including calling malloc().
+ // (Taking a mutex is borderline.)
+ //
+ // The Frame object will be given to the frame callback,
+ // which is responsible for releasing the video frame back
+ // once it is usable for new frames (ie., it will no longer
+ // be read from). You can use the "userdata" pointer for
+ // whatever you want to identify this frame if you need to.
+ //
+ // Returning a Frame with data==nullptr is allowed;
+ // if so, the frame in progress will be dropped.
+ virtual Frame alloc_frame() = 0;
+
+ 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.
+// 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).
+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;
+ bool is_connected = true; // If false, then has_signal makes no sense.
+};
+
+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, AudioFormat audio_format)>
+ frame_callback_t;
+
+typedef std::function<void(libusb_device *dev)> card_connected_callback_t;
+typedef std::function<void()> card_disconnected_callback_t;
+
+class CaptureInterface {
+ public:
+ virtual ~CaptureInterface() {}
+
+ virtual std::map<uint32_t, VideoMode> get_available_video_modes() const = 0;
+ virtual uint32_t get_current_video_mode() const = 0;
+ virtual void set_video_mode(uint32_t video_mode_id) = 0;
+
+ virtual std::map<uint32_t, std::string> get_available_video_inputs() const = 0;
+ virtual void set_video_input(uint32_t video_input_id) = 0;
+ virtual uint32_t get_current_video_input() const = 0;
+
+ virtual std::map<uint32_t, std::string> get_available_audio_inputs() const = 0;
+ virtual void set_audio_input(uint32_t audio_input_id) = 0;
+ virtual uint32_t get_current_audio_input() const = 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;
+
+ // If a card is disconnected, it cannot come back; you should call stop_dequeue_thread()
+ // and delete it.
+ virtual bool get_disconnected() const = 0;
+};
+
+// The actual capturing class, representing capture from a single card.
+class BMUSBCapture : public CaptureInterface {
+ public:
+ BMUSBCapture(int card_index, libusb_device *dev = nullptr)
+ : card_index(card_index), dev(dev)
+ {
+ }
+
+ ~BMUSBCapture() {}
+
+ std::map<uint32_t, VideoMode> get_available_video_modes() const override;
+ uint32_t get_current_video_mode() const override;
+ void set_video_mode(uint32_t video_mode_id) override;
+
+ virtual std::map<uint32_t, std::string> get_available_video_inputs() const override;
+ virtual void set_video_input(uint32_t video_input_id) override;
+ virtual uint32_t get_current_video_input() const override { return current_video_input; }
+
+ virtual std::map<uint32_t, std::string> get_available_audio_inputs() const override;
+ virtual void set_audio_input(uint32_t audio_input_id) override;
+ virtual uint32_t get_current_audio_input() const override { return current_audio_input; }
+
+ // Does not take ownership.
+ void set_video_frame_allocator(FrameAllocator *allocator) override
+ {
+ video_frame_allocator = allocator;
+ if (owned_video_frame_allocator.get() != allocator) {
+ owned_video_frame_allocator.reset();
+ }
+ }
+
+ 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;
+ if (owned_audio_frame_allocator.get() != allocator) {
+ owned_audio_frame_allocator.reset();
+ }
+ }
+
+ 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;
+ bool get_disconnected() const override { return disconnected; }
+
+ // TODO: It's rather messy to have these outside the interface.
+ static void start_bm_thread();
+ static void stop_bm_thread();
+
+ // Hotplug event (for devices being inserted between start_bm_thread()
+ // and stop_bm_thread()); entirely optional, but must be set before
+ // start_bm_capture(). Note that your callback should do as little work
+ // as possible, since the callback comes from the main USB handling
+ // thread, which is very time-sensitive.
+ //
+ // The callback function transfers ownership. If you don't want to hold
+ // on to the device given to you in the callback, you need to call
+ // libusb_unref_device().
+ static void set_card_connected_callback(card_connected_callback_t callback)
+ {
+ card_connected_callback = callback;
+ }
+
+ // Similar to set_card_connected_callback(), with the same caveats.
+ // (Note that this is set per-card and not global, as it is logically
+ // connected to an existing BMUSBCapture object.)
+ void set_card_disconnected_callback(card_disconnected_callback_t callback)
+ {
+ card_disconnected_callback = callback;
+ }
+
+ 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);
+ static int cb_hotplug(libusb_context *ctx, libusb_device *dev, libusb_hotplug_event event, void *user_data);
+
+ void update_capture_mode();
+
+ 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;
+ std::unique_ptr<FrameAllocator> owned_video_frame_allocator;
+ std::unique_ptr<FrameAllocator> owned_audio_frame_allocator;
+ frame_callback_t frame_callback = nullptr;
+ static card_connected_callback_t card_connected_callback;
+ card_disconnected_callback_t card_disconnected_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];
+
+ // If <dev> is nullptr, will choose device number <card_index> from the list
+ // of available devices on the system. <dev> is not used after configure_card()
+ // (it will be unref-ed).
+ int card_index = -1;
+ libusb_device *dev = nullptr;
+
+ std::vector<libusb_transfer *> iso_xfrs;
+ int assumed_frame_width = 1280;
+
+ libusb_device_handle *devh = nullptr;
+ uint32_t current_video_input = 0x00000000; // HDMI/SDI.
+ uint32_t current_audio_input = 0x00000000; // Embedded.
+
+ bool disconnected = false;
+};
+
+} // namespace bmusb
+
+#endif
--- /dev/null
+#ifndef _FAKE_CAPTURE_H
+#define _FAKE_CAPTURE_H 1
+
+#include <stdint.h>
+#include <functional>
+#include <string>
+
+#include "bmusb/bmusb.h"
+
+namespace bmusb {
+
+class FakeCapture : public CaptureInterface
+{
+public:
+ FakeCapture(unsigned width, unsigned height, unsigned fps, unsigned audio_frequency, int card_index);
+ ~FakeCapture();
+
+ // CaptureInterface.
+ void set_video_frame_allocator(FrameAllocator *allocator) override
+ {
+ video_frame_allocator = allocator;
+ if (owned_video_frame_allocator.get() != allocator) {
+ owned_video_frame_allocator.reset();
+ }
+ }
+
+ 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;
+ if (owned_audio_frame_allocator.get() != allocator) {
+ owned_audio_frame_allocator.reset();
+ }
+ }
+
+ FrameAllocator *get_audio_frame_allocator() override
+ {
+ return audio_frame_allocator;
+ }
+
+ void set_frame_callback(frame_callback_t callback) override
+ {
+ frame_callback = callback;
+ }
+
+ 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;
+ }
+
+ std::string get_description() const override
+ {
+ return description;
+ }
+
+ void configure_card() override;
+ void start_bm_capture() override;
+ void stop_dequeue_thread() override;
+ bool get_disconnected() const override { return false; }
+
+ std::map<uint32_t, VideoMode> get_available_video_modes() const override;
+ void set_video_mode(uint32_t video_mode_id) override;
+ uint32_t get_current_video_mode() const override { return 0; }
+
+ std::map<uint32_t, std::string> get_available_video_inputs() const override;
+ void set_video_input(uint32_t video_input_id) override;
+ uint32_t get_current_video_input() const override { return 0; }
+
+ std::map<uint32_t, std::string> get_available_audio_inputs() const override;
+ void set_audio_input(uint32_t audio_input_id) override;
+ uint32_t get_current_audio_input() const override { return 0; }
+
+private:
+ void producer_thread_func();
+
+ unsigned width, height, fps, audio_frequency;
+ uint8_t y, cb, cr;
+
+ bool has_dequeue_callbacks = false;
+ std::function<void()> dequeue_init_callback = nullptr;
+ std::function<void()> dequeue_cleanup_callback = nullptr;
+
+ FrameAllocator *video_frame_allocator = nullptr;
+ FrameAllocator *audio_frame_allocator = nullptr;
+ std::unique_ptr<FrameAllocator> owned_video_frame_allocator;
+ std::unique_ptr<FrameAllocator> owned_audio_frame_allocator;
+ frame_callback_t frame_callback = nullptr;
+
+ std::string description;
+
+ std::atomic<bool> producer_thread_should_quit{false};
+ std::thread producer_thread;
+};
+
+} // namespace bmusb
+
+#endif // !defined(_FAKE_CAPTURE_H)
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