Coding method conversion apparatus

A coding method conversion method of converting first coded data into second coded data, the first coded data being coded according to a first coding method, said method comprising:

• decoding, using a processor, the first coded data;
• determining a deblocking filtering position, on which deblocking filtering is to be performed, as one of (a) a first boundary of blocks, each of the blocks of the first boundary of blocks having an orthogonal transform size used in coding the first coded data, and (b) a second boundary of blocks, each of the blocks of the second boundary of blocks having an orthogonal transform size to be used in re-coding the first coded data decoded by said decoding as the second coded data ;
• and
• performing the deblocking filtering on the deblocking filtering position, and re-coding the first coded data decoded in said decoding,
• wherein, when the second coded data is to be less compressed than the first coded data, (i) the first boundary of blocks is determined as the deblocking filtering position when the orthogonal transform size of the blocks of the first boundary of blocks is smaller than the orthogonal transform size of the blocks of the second boundary of blocks, and (ii) the second boundary of blocks is determined as the deblocking filtering position when the orthogonal transform size of the blocks of the second boundary of blocks is smaller than the orthogonal transform size of the blocks of the first boundary of blocks.

A non-transitory computer readable recording medium having stored thereon, a program used in a coding method conversion apparatus which converts first coded data into second coded data, the first coded data being coded according to a first coding method, wherein, when executed, said program causes the coding method conversion apparatus to perform a method comprising:

• decoding the first coded data;
• determining a deblocking filtering position, on which deblocking filtering is to be performed, as one of (a) a first boundary of blocks, each of the blocks of the first boundary of blocks having an orthogonal transform size used in coding the first coded data, and (b) a second boundary of blocks, each of the blocks of the second boundary of blocks having an orthogonal transform size to be used in re-coding the first coded data decoded by said decoding as the second coded data and
• performing the deblocking filtering on the deblocking filtering position, and re-coding the first coded data decoded in said decoding,
• wherein, when the second coded data is to be less compressed than the first coded data, (i) the first boundary of blocks is determined as the deblocking filtering position when the orthogonal transform size of the blocks of the first boundary of blocks is smaller than the orthogonal transform size of the blocks of the second boundary of blocks, and (ii) the second boundary of blocks is determined as the deblocking filtering position when the orthogonal transform size of the blocks of the second boundary of blocks is smaller than the orthogonal transform size of the blocks of the first boundary of blocks.