Transcoder, method of transcoding, and digital recorder

A method of transcoding for converting a first coded stream to at least part of which intra prediction is applied, into a second coded stream to which intra prediction and inter prediction are applied, said method comprising:

• decoding the first coded stream on a per predetermined unit basis to generate decoded image data;
• obtaining a prediction mode of intra prediction applied when decoding the first coded stream in said decoding;
• and
• coding the decoded image data by applying intra prediction or inter prediction on the per predetermined unit basis to generate the second coded stream,
• wherein in said coding, the prediction mode obtained in said obtaining is used when intra prediction is applied.

A digital recorder which converts a first coded stream to at least part of which intra prediction is applied, into a second coded stream to which intra prediction and inter prediction are applied, said digital recorder comprising:

• a decoding unit configured to decode the first coded stream on a per predetermined unit basis to generate decoded image data;
• a prediction mode obtaining unit configured to obtain a prediction mode of intra prediction applied when said decoding unit decodes the first coded stream;
• a coding unit configured to code the decoded image data by applying intra prediction or inter prediction on the per predetermined unit basis to generate the second coded stream;
• and
• a control unit configured to control said coding unit so that said coding unit uses the prediction mode obtained by said prediction mode obtaining unit, when said coding unit applies intra prediction.

A program for causing a computer to execute a method of transcoding for converting a first coded stream to at least part of which intra prediction is applied, into a second coded stream to which intra prediction and inter prediction are applied,

• wherein the method of transcoding includes:
• decoding the first coded stream on a per predetermined unit basis to generate decoded image data;
• obtaining a prediction mode of intra prediction applied when decoding the first coded stream in the decoding;
• and
• coding the decoded image data by applying intra prediction or inter prediction on the per predetermined unit basis to generate the second coded stream,
• wherein in the coding, the prediction mode obtained in the obtaining is used when intra prediction is applied.