Add standalone NVENC encoder

src/nvenc/nvenc_base.h

@@ -0,0 +1,79 @@
+#pragma once
+
+#include "nvenc_colorspace.h"
+#include "nvenc_config.h"
+#include "nvenc_encoded_frame.h"
+
+#include "src/stat_trackers.h"
+#include "src/video.h"
+
+#include <ffnvcodec/nvEncodeAPI.h>
+
+namespace nvenc {
+
+  class nvenc_base {
+  public:
+    nvenc_base(NV_ENC_DEVICE_TYPE device_type, void *device);
+    virtual ~nvenc_base();
+
+    nvenc_base(const nvenc_base &) = delete;
+    nvenc_base &
+    operator=(const nvenc_base &) = delete;
+
+    bool
+    create_encoder(const nvenc_config &config, const video::config_t &client_config, const nvenc_colorspace_t &colorspace, NV_ENC_BUFFER_FORMAT buffer_format);
+
+    void
+    destroy_encoder();
+
+    nvenc_encoded_frame
+    encode_frame(uint64_t frame_index, bool force_idr);
+
+    bool
+    invalidate_ref_frames(uint64_t first_frame, uint64_t last_frame);
+
+  protected:
+    virtual bool
+    init_library() = 0;
+
+    virtual bool
+    create_and_register_input_buffer() = 0;
+
+    virtual bool
+    wait_for_async_event(uint32_t timeout_ms) { return false; }
+
+    bool
+    nvenc_failed(NVENCSTATUS status);
+
+    const NV_ENC_DEVICE_TYPE device_type;
+    void *const device;
+
+    std::unique_ptr<NV_ENCODE_API_FUNCTION_LIST> nvenc;
+
+    void *encoder = nullptr;
+
+    struct {
+      uint32_t width = 0;
+      uint32_t height = 0;
+      NV_ENC_BUFFER_FORMAT buffer_format = NV_ENC_BUFFER_FORMAT_UNDEFINED;
+      bool rfi = false;
+    } encoder_params;
+
+    // Derived classes set these variables
+    NV_ENC_REGISTERED_PTR registered_input_buffer = nullptr;
+    void *async_event_handle = nullptr;
+
+    std::string last_error_string;
+
+  private:
+    NV_ENC_OUTPUT_PTR output_bitstream = nullptr;
+
+    struct {
+      uint64_t last_encoded_frame_index = 0;
+      bool rfi_needs_confirmation = false;
+      std::pair<uint64_t, uint64_t> last_rfi_range;
+      stat_trackers::min_max_avg_tracker<float> frame_size_tracker;
+    } encoder_state;
+  };
+
+}  // namespace nvenc