Return in 'buf' the path with '%d' replaced by a number.
Also handles the '%0nd' format where 'n' is the total number of digits and '%%'.
@param buf destination buffer @param buf_size destination buffer size @param path numbered sequence string @param number frame number @param flags AV_FRAME_FILENAME_FLAGS_* @return 0 if OK, -1 on format error
See Implementation
Return in 'buf' the path with '%d' replaced by a number.
Also handles the '%0nd' format where 'n' is the total number of digits and '%%'.
@param buf destination buffer @param buf_size destination buffer size @param path numbered sequence string @param number frame number @param flags AV_FRAME_FILENAME_FLAGS_* @return 0 if OK, -1 on format error