feat(*): switched to spdlog for logging and organized headers (#1183)

* feat: updated PKGBUILD description
* feat: updated workflow syntax and dependencies
* feat: switched logging to spdlog
* chore: adjusted library defaults
* ci: fixed spdlog format string issues
* docs: fixed docs for libvideo2x functions
* feat: organized header files
* fix: fixed header installation directory
* feat: link spdlog statically if compiled from source
* feat: adjusted libvideo2x log level enum names
* feat: added version.h header

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

include/libvideo2x/libvideo2x.h

@@ -0,0 +1,104 @@
+#ifndef LIBVIDEO2X_H
+#define LIBVIDEO2X_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <time.h>
+
+#ifdef _WIN32
+#ifdef LIBVIDEO2X_EXPORTS
+#define LIBVIDEO2X_API __declspec(dllexport)
+#else
+#define LIBVIDEO2X_API __declspec(dllimport)
+#endif
+#else
+#define LIBVIDEO2X_API
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+
+// Enum to specify filter type
+enum FilterType {
+    FILTER_LIBPLACEBO,
+    FILTER_REALESRGAN
+};
+
+// Enum to specify log level
+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
+};
+
+// Configuration for Libplacebo filter
+struct LibplaceboConfig {
+    int output_width;
+    int output_height;
+    const char *shader_path;
+};
+
+// Configuration for RealESRGAN filter
+struct RealESRGANConfig {
+    int gpuid;
+    bool tta_mode;
+    int scaling_factor;
+    const char *model;
+};
+
+// Unified filter configuration
+struct FilterConfig {
+    enum FilterType filter_type;
+    union {
+        struct LibplaceboConfig libplacebo;
+        struct RealESRGANConfig realesrgan;
+    } config;
+};
+
+// Encoder configuration
+struct EncoderConfig {
+    int output_width;
+    int output_height;
+    bool copy_streams;
+    enum AVCodecID codec;
+    enum AVPixelFormat pix_fmt;
+    const char *preset;
+    int64_t bit_rate;
+    float crf;
+};
+
+// Video processing context
+struct VideoProcessingContext {
+    int64_t processed_frames;
+    int64_t total_frames;
+    time_t start_time;
+    bool pause;
+    bool abort;
+    bool completed;
+};
+
+// C-compatible process_video function
+LIBVIDEO2X_API int process_video(
+    const char *input_filename,
+    const char *output_filename,
+    enum Libvideo2xLogLevel log_level,
+    bool benchmark,
+    enum AVHWDeviceType hw_device_type,
+    const struct FilterConfig *filter_config,
+    struct EncoderConfig *encoder_config,
+    struct VideoProcessingContext *proc_ctx
+);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // LIBVIDEO2X_H