Disclosed are a transcoding apparatus and method between two codecs each including a deblocking filter. The transcoding method between first and second codecs each including a deblocking filter, may include decoding input data encoded according to the first codec, according to the first codec so as to generate decoded data; and encoding the decoded data according to the second codec. The decoded data may include data on which deblocking filtering is not performed by the first codec, or data on which deblocking filtering is adaptively performed by the first codec. The decoded data may further include data on which deblocking filtering is performed by the first codec. The decoded data may be used as input data when the second codec performs encoding and/or when the second codec performs motion estimation.