bool mp4_is_audio_track(const struct mp4 *f, int32_t track);
struct mp4 *mp4_open_read(const struct mp4_callback *cb);
void mp4_close(struct mp4 *f);
bool mp4_is_audio_track(const struct mp4 *f, int32_t track);
struct mp4 *mp4_open_read(const struct mp4_callback *cb);
void mp4_close(struct mp4 *f);