void mp4_close(struct mp4 *f);
int32_t mp4_get_sample_size(const struct mp4 *f, int track, int sample);
uint32_t mp4_get_sample_rate(const struct mp4 *f, int32_t track);
uint32_t mp4_get_channel_count(const struct mp4 * f, int32_t track);
int32_t mp4_num_samples(const struct mp4 *f, int track);
uint64_t mp4_get_duration(const struct mp4 *f, int32_t track);
void mp4_close(struct mp4 *f);
int32_t mp4_get_sample_size(const struct mp4 *f, int track, int sample);
uint32_t mp4_get_sample_rate(const struct mp4 *f, int32_t track);
uint32_t mp4_get_channel_count(const struct mp4 * f, int32_t track);
int32_t mp4_num_samples(const struct mp4 *f, int track);
uint64_t mp4_get_duration(const struct mp4 *f, int32_t track);