Encrypted video data is decrypted as first image data. If a first image processing module includes an output processing to an outside of a first secure memory which an access from an outside of an apparatus is restricted, the first image processing module is converted to a second image processing module including the output processing invalidated. The first image data is processed using the second image processing module, by accessing the first secure memory, and second image data is generated. If a first rendering module includes an output processing to an outside of a second secure memory which an access from the outside of the apparatus is restricted, the first rendering module is converted to a second rendering module including the output processing invalidated. The second image data is rendered using the second rendering module, by accessing the second secure memory.