Video data playback system using effective scheme for producing coded video data for fast playback mode

An apparatus for producing fast playback coded video data for N times faster playback than a normal playback, where N is a natural number, for use in a video data playback system operable in a normal playback mode and a fast playback mode, the apparatus comprising:

• a first encoder for encoding each video frame of original video data by a first video coding scheme using both intra-frame coding and inter-frame coding, to obtain normal playback coded video data;
• a decoder for decoding only each coded frame data in every N frames of the normal playback coded video data obtained by the first encoder;
• and
• a second encoder for encoding every video frame decoded at the decoder by a second video coding scheme using only intra-frame coding, to obtain the fast playback coded video data satisfying a prescribed fast playback bit rate.

A method for producing fast playback coded video data for N times faster playback than a normal playback, where N is a natural number, for use in a video data playback system operable in a normal playback mode and a fast playback mode, the method comprising the steps of:

• (a) encoding each video frame of original video data by a first video coding scheme using both intra-frame coding and inter-frame coding, to obtain normal playback coded video data satisfying a prescribed normal playback bit rate;
• (b) selectively encoding each video frame in every N frames of the original video data by a second video coding scheme using only intra-frame coding, to obtain the fast playback coded video data satisfying a prescribed fast playback bit rate;
• and
• (c) synchronizing start and end of encoding at the step (a) and the step (b) so as to obtain the normal playback coded video data and the fast playback coded video data simultaneously.

An apparatus for producing fast playback coded video data for N times faster playback than a normal playback, where N is a natural number, for use in a video data playback system operable in a normal playback mode and a fast playback mode, the apparatus comprising:

• a first encoder for encoding each video frame of original video data by a first video coding scheme using both intra-frame coding and inter-frame coding, to obtain normal playback coded video data satisfying a prescribed normal playback bit rate;
• a second encoder for selectively encoding each video frame in every N frames of the original video data by a second video coding scheme using only intra-frame coding, to obtain the fast playback coded video data satisfying a prescribed fast playback bit rate;
• and
• a control unit for synchronizing start and end of encoding by the first encoder and the second encoder so as to obtain the normal playback coded video data and the fast playback coded video data simultaneously.

A method of video data playback in a video data playback system operable in a normal playback mode and a fast playback mode, the method comprising the steps of:

• (1) producing and storing normal playback coded video data encoded by a first video coding scheme using both intra-frame coding and inter-frame coding;
• (2) producing and separately storing fast playback coded video data for N times faster playback than a normal playback, where N is a natural number, which are encoded by a second video coding scheme using only intra-frame coding and having a playback bit rate and a frame rate identical to those of the normal playback coded video data produced and stored at the step (1);
• and
• (3) reproducing requested video data by switching coded video data to be reproduced between the normal playback coded video data produced and stored at the step (1) and the fast playback coded video data produced and stored at the step (2) according to a requested playback mode.

A video data playback system operable in a normal playback mode and a fast playback mode, comprising:

• first means for producing and storing normal playback coded video data encoded by a first video coding scheme using both intra-frame coding and inter-frame coding;
• second means for producing and separately storing fast playback coded video data for N times faster playback than a normal playback, where N is a natural number, which are encoded by a second video coding scheme using only intra-frame coding and having a playback bit rate and a frame rate identical to those of the normal playback coded video data produced and stored by the first means;
• and
• third means for reproducing requested video data by switching coded video data to be reproduced between the normal playback coded video data produced and stored by the first means and the fast playback coded video data produced and stored by the second means according to a requested playback mode.