chore(libvideo2x)!: replace the C API with C++ API (#1245)

* chore(libvideo2x)!: replace the C API with C++ API
* fix: convert wide string to u8 for av_opt_set
* style: removed unnecessary enum and struct specifiers

Signed-off-by: k4yt3x <i@k4yt3x.com>

include/libvideo2x/libvideo2x.h

@@ -1,20 +1,17 @@
 #ifndef LIBVIDEO2X_H
 #define LIBVIDEO2X_H
 
-#include <stdbool.h>
-#include <stdint.h>
-#include <time.h>
+#include <filesystem>
+#include <variant>
+#include <vector>
 
-#ifdef __cplusplus
 extern "C" {
-#endif
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
-#ifdef __cplusplus
 }
-#endif
 
-#include "char_defs.h"
+#include "fsutils.h"
+#include "logging.h"
 
 #ifdef _WIN32
 #ifdef LIBVIDEO2X_EXPORTS
@@ -26,38 +23,24 @@ extern "C" {
 #define LIBVIDEO2X_API
 #endif
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-enum ProcessingMode {
-    PROCESSING_MODE_FILTER,
-    PROCESSING_MODE_INTERPOLATE,
+enum class ProcessingMode {
+    Filter,
+    Interpolate,
 };
 
-enum ProcessorType {
-    PROCESSOR_LIBPLACEBO,
-    PROCESSOR_REALESRGAN,
-    PROCESSOR_RIFE,
-};
-
-enum Libvideo2xLogLevel {
-    LIBVIDEO2X_LOG_LEVEL_TRACE,
-    LIBVIDEO2X_LOG_LEVEL_DEBUG,
-    LIBVIDEO2X_LOG_LEVEL_INFO,
-    LIBVIDEO2X_LOG_LEVEL_WARNING,
-    LIBVIDEO2X_LOG_LEVEL_ERROR,
-    LIBVIDEO2X_LOG_LEVEL_CRITICAL,
-    LIBVIDEO2X_LOG_LEVEL_OFF
+enum class ProcessorType {
+    Libplacebo,
+    RealESRGAN,
+    RIFE,
 };
 
 struct LibplaceboConfig {
-    const CharType *shader_path;
+    StringType shader_path;
 };
 
 struct RealESRGANConfig {
     bool tta_mode;
-    const CharType *model_name;
+    StringType model_name;
 };
 
 struct RIFEConfig {
@@ -65,34 +48,30 @@ struct RIFEConfig {
     bool tta_temporal_mode;
     bool uhd_mode;
     int num_threads;
-    const CharType *model_name;
+    StringType model_name;
 };
 
 // Unified filter configuration
 struct ProcessorConfig {
-    enum ProcessorType processor_type;
+    ProcessorType processor_type;
     int width;
     int height;
     int scaling_factor;
     int frm_rate_mul;
     float scn_det_thresh;
-    union {
-        struct LibplaceboConfig libplacebo;
-        struct RealESRGANConfig realesrgan;
-        struct RIFEConfig rife;
-    } config;
+    std::variant<LibplaceboConfig, RealESRGANConfig, RIFEConfig> config;
 };
 
 // Encoder configurations
 struct EncoderConfig {
     // Non-AVCodecContext options
-    enum AVCodecID codec;
+    AVCodecID codec;
     bool copy_streams;
 
     // Basic video options
     int width;
     int height;
-    enum AVPixelFormat pix_fmt;
+    AVPixelFormat pix_fmt;
 
     // Rate control and compression
     int64_t bit_rate;
@@ -115,51 +94,34 @@ struct EncoderConfig {
     int delay;
 
     // Extra AVOptions
-    struct {
-        const char *key;
-        const char *value;
-    } *extra_options;
-    size_t nb_extra_options;
+    std::vector<std::pair<StringType, StringType>> extra_opts;
+};
+
+struct HardwareConfig {
+    uint32_t vk_device_index;
+    AVHWDeviceType hw_device_type;
 };
 
 // Video processing context
 struct VideoProcessingContext {
     int64_t processed_frames;
     int64_t total_frames;
-    time_t start_time;
+    std::time_t start_time;
     bool pause;
     bool abort;
     bool completed;
 };
 
-/**
- * @brief Process a video file using the selected filter and encoder settings.
- *
- * @param[in] in_fname Path to the input video file
- * @param[in] out_fname Path to the output video file
- * @param[in] log_level Log level
- * @param[in] benchmark Flag to enable benchmarking mode
- * @param[in] vk_device_index Vulkan device index
- * @param[in] hw_device_type Hardware device type
- * @param[in] filter_config Filter configurations
- * @param[in] encoder_config Encoder configurations
- * @param[in,out] proc_ctx Video processing context
- * @return int 0 on success, non-zero value on error
- */
-LIBVIDEO2X_API int process_video(
-    const CharType *in_fname,
-    const CharType *out_fname,
-    enum Libvideo2xLogLevel log_level,
-    bool benchmark,
-    uint32_t vk_device_index,
-    enum AVHWDeviceType hw_device_type,
-    const struct ProcessorConfig *filter_config,
-    struct EncoderConfig *encoder_config,
-    struct VideoProcessingContext *proc_ctx
+// Process a video file using the specified configurations
+[[nodiscard]] LIBVIDEO2X_API int process_video(
+    const std::filesystem::path in_fname,
+    const std::filesystem::path out_fname,
+    const HardwareConfig hw_cfg,
+    const ProcessorConfig proc_cfg,
+    EncoderConfig enc_cfg,
+    VideoProcessingContext *proc_ctx,
+    Libvideo2xLogLevel log_level,
+    bool benchmark
 );
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif  // LIBVIDEO2X_H