Add a way to get the current video mode.

[bmusb] / bmusb.h

diff --git a/bmusb.h b/bmusb.h
index 5b7c0f9c8e35a501c91bf40bdc81fb8d79f3770f..9ba27bcc111234040d807bbcd0fafbb3f3cd9275 100644 (file)
--- a/bmusb.h
+++ b/bmusb.h
@@ -6,7 +6,9 @@
 #include <condition_variable>
 #include <deque>
 #include <functional>
+#include <map>
 #include <mutex>
+#include <stack>
 #include <string>
 #include <thread>
 #include <vector>
@@ -57,6 +59,36 @@ class 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 {
+       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;
@@ -81,6 +113,10 @@ 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;
+
        // Does not take ownership.
        virtual void set_video_frame_allocator(FrameAllocator *allocator) = 0;
 
@@ -116,6 +152,10 @@ class BMUSBCapture : public CaptureInterface {
 
        ~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;
+
        // Does not take ownership.
        void set_video_frame_allocator(FrameAllocator *allocator) override
        {