feat: Add audio support for videos with a sound track

src/audio.h

@@ -0,0 +1,33 @@
+#ifndef AUDIO_H
+#define AUDIO_H
+
+#include <SDL2/SDL.h>
+#include <libavcodec/avcodec.h>
+#include <libavformat/avformat.h>
+#include <libavutil/channel_layout.h>
+#include <libswresample/swresample.h>
+#include <stdbool.h>
+
+typedef struct AudioPlayer {
+  AVFormatContext* format_ctx;
+  AVCodecContext* codec_ctx;
+  SwrContext* swr_ctx;
+  AVFrame* frame;
+  int stream_index;
+  int sample_rate;
+  int channels;
+  SDL_AudioDeviceID audio_device;
+  SDL_AudioSpec desired_spec;
+  SDL_AudioSpec obtained_spec;
+  uint8_t* audio_buffer;
+  int audio_buffer_size;
+  int audio_buffer_pos;
+  int audio_buffer_filled;
+} AudioPlayer;
+
+bool init_audio_player(AudioPlayer* player, const char* path);
+void cleanup_audio_player(AudioPlayer* player);
+int decode_audio_frame(AudioPlayer* player, uint8_t* out_buffer, int out_size);
+void audio_callback(void* userdata, uint8_t* stream, int len);
+
+#endif  // AUDIO_H