# US 7,609,947 B2 · Method and apparatus for coordinating playback from multiple video sources > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,609,947 B2 - Document ID: US7609947B2 - Status: Granted - Kind: B2 - Application number: 11/216,409 - Filed: 2005-08-31 - Published: 2008-02-07 - Granted: 2009-10-27 - Earliest claimed: 2004-09-10 - Assignees: Panasonic Corporation - Inventors: Wataru Ikeda; Tomoyuki Okada; Keiichi Tanaka; Masahiro Oashi - Web page: https://patentgrep.com/patent/US7609947B2 ## CPC - H04N 9/8205: {involving the multiplexing of an additional signal and the colour video signal} - G11B 27/10: Indexing; Addressing; Timing or synchronising; Measuring tape travel - G11B 27/329: {on a disc [VTOC]} - G11B 20/0021: {involving encryption or decryption of contents recorded on or reproduced from a record carrier} - G11B 2020/1288: {Formatting by padding empty spaces with dummy data, e.g. writing zeroes or random data when de-icing optical discs} - G11B 2220/213: Read-only discs - G11B 2220/2541: Blu-ray discs; Blue laser DVR discs - H04N 5/765: Interface circuits between an apparatus for recording and another apparatus - H04N 5/775: between a recording apparatus and a television receiver - H04N 5/85: on discs or drums - H04N 9/8042: {involving data reduction} - H04N 9/8063: {using time division multiplex of the PCM audio and PCM video signals} - H04N 9/8227: {the additional signal being at least another television signal} - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) ## Abstract A playback apparatus performs multiangle playback by selectively playing back a plurality of video streams stored on a BD-ROM and a hard disk. In response to a user operation requesting an angle change, the playback apparatus reads a video stream corresponding to the requested angle either from the BD-ROM or the hard disk. During playback of a video stream stored on the hard disk, a drive device of the optical disc is controlled so that the optical pickup always points to an area of the BD-ROM where a video stream is stored. ## Claims ### Claim 1 A playback apparatus for selectively playing back a plurality of video streams stored on a plurality of recording media, comprising: a plurality of drive devices, each operable to access a different one of the recording media; a selecting unit operable to select one of the video streams in accordance with a user operation or a state of the playback apparatus; a control unit operable to control the drive devices, so that the selected video stream is read from one of the recording media; and a playback unit operable to play the read video stream, wherein one of the recording media is an optical disc, and another of the recording media is a secondary medium used as an additional medium to the optical disc, and when the video stream to be read is switched from the video stream stored on the optional disc to the video stream stored on the secondary medium, the control unit causes an optical pickup of an optical disc drive device to point to an area on the optical disc where the video stream is stored, despite that the video stream stored on the optical disc is not played, wherein the optical pickup is caused to point at a position in the area on the optical disc where the video stream is stored, the position corresponding to a current read position in the digital stream stored on the secondary medium. ### Claim 2 (depends on 1) The playback apparatus according to claim 1, wherein the control unit causes the optical pickup to track a position on the optical disc corresponding to the current read position in the video stream stored on the secondary medium. ### Claim 3 (depends on 2) The playback apparatus according to claim 2, wherein read positions on the secondary storage medium are indicated by time information, and the tracking control by the control unit is carried out by converting the time information indicating the current read position to an address on the optical disc and causing the optical pickup to access the address. ### Claim 4 (depends on 2) The playback apparatus according to claim 2, wherein read positions on the secondary storage medium are indicated by addresses, and the tracking control by the control unit is carried out by causing the optical pickup to access a position on the optical disc having a same address as an address of the current read position on the secondary medium. ### Claim 5 (depends on 1) The playback apparatus according to claim 1, wherein the plurality of video streams stored on the plurality of recording media is a plurality of video streams composing multiangle video images, and the selective playback of the plurality of video streams provides an angle change presentation. ### Claim 6 A method for use by a playback apparatus to selectively play back a plurality of video streams stored on a plurality of recording media, said method comprising: a selecting step of selecting one of the video streams in accordance with a user operation or a state of the playback apparatus; a control step of controlling a plurality of drive devices each operable to access a different one of the recording media, so that the selected video stream is read from one of the recording media; and a playback step of playing the read digital stream, wherein one of the recording media is an optical disc, and another of the recording media is a secondary medium used as an additional medium to the optical disc, and in the control step, when the video stream to be read is switched from the video stream stored on the optical disc to the video stream stored on the secondary medium, an optical pickup of an optical disc drive device is caused to point to an area on the optical disc where the video stream is stored, despite that the video stream stored on the optical disc is not played, wherein the optical pickup is caused to point at a position in the area on the optical disc where the video stream is stored, the position corresponding to a current read position in the video stream stored on the secondary medium.