} mp4ff_t;
int32_t mp4ff_total_tracks(const mp4ff_t *f);
-int32_t mp4ff_get_decoder_config(const mp4ff_t *f, const int track,
+void mp4ff_get_decoder_config(const mp4ff_t *f, const int track,
unsigned char** ppBuf, unsigned int* pBufSize);
mp4ff_t *mp4ff_open_read(mp4ff_callback_t *f);
void mp4ff_close(mp4ff_t *f);