Expose MallocFrameAllocator.

[bmusb] / bmusb.h

diff --git a/bmusb.h b/bmusb.h
index 5b7c0f9c8e35a501c91bf40bdc81fb8d79f3770f..17b5bc082d7a4dc266d25d80d93dcf1e3123b242 100644 (file)
--- a/bmusb.h
+++ b/bmusb.h
@@ -7,6 +7,7 @@
 #include <deque>
 #include <functional>
 #include <mutex>
+#include <stack>
 #include <string>
 #include <thread>
 #include <vector>
@@ -57,6 +58,26 @@ 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>.
+};
+
 struct VideoFormat {
        uint16_t id = 0;  // For debugging/logging only.
        unsigned width = 0, height = 0, second_field_start = 0;