feat(*): rewritten the project with C/C++ (#1172)

include/filter.h

@@ -0,0 +1,20 @@
+#ifndef FILTER_H
+#define FILTER_H
+
+#include <vector>
+
+extern "C" {
+#include <libavcodec/avcodec.h>
+#include <libavfilter/avfilter.h>
+}
+
+// Abstract base class for filters
+class Filter {
+   public:
+    virtual ~Filter() {}
+    virtual int init(AVCodecContext *dec_ctx, AVCodecContext *enc_ctx) = 0;
+    virtual AVFrame *process_frame(AVFrame *input_frame) = 0;
+    virtual int flush(std::vector<AVFrame *> &processed_frames) = 0;
+};
+
+#endif  // FILTER_H