Digital video playback apparatus and method

[0002] 1. Field of the Invention

[0003] The present invention relates to a digital video playback apparatus in a digital video device and method therefor, and more particularly, to a digital video playback apparatus for playing-back the video and audio signals that have been recorded by a plurality of cameras at different angles and method therefor.

[0004] 2. Description of the Related Art

[0005] As illustrated in FIG. 1, in the case of taking a motion picture or a music video, a camera is set in front of an object and four microphones SL (Surround Left), SR (Surround Right), FL (Front Left), and FR (Front Right) are set surrounding the object to secure the presence of the sounds. The audio and video signals from the camera and the microphones are recorded, on a recording medium such as a disc, by a known video recorder illustrated in FIG. 2.

[0006] Referring to FIG. 2, a multiplexer (MUX) 14 receives system information which includes the number of video blocks, the number of audio blocks, a start address for each video block, and a start address for each audio block. A video encoder 10 converts an analog video signal input into digital video data, and formats the digital video data in a predetermined manner. The video data output from the video encoder 10 are applied to the multiplexer 14. An audio encoder 12 converts the 4-channel analog audio signals FL, FR, SL and SR from the microphones into digital audio data, and formats the digital audio data in a predetermined manner. The audio data output from the audio encoder 12 are transferred to the multiplexer 14. As illustrated in FIG. 3, the multiplexer 14 generates by turn the system information, the video data, and the audio data. A digital recorder 16 records, by turn, the system information, the video data, and the audio data on the recording medium.

[0007] FIG. 4 illustrates a conventional video playback apparatus for playing-back the audio and video data recorded as shown in FIG. 3. As illustrated, a digital playback apparatus 20 reads out video and audio data which are compressed and recorded on the recording medium such as a disc. The read video and audio data undergo an error correction and deinterleaving process. A demultiplexer (DMUX) 22 separates a signal output of the digital playback apparatus 20 into the system information, the video data, and the audio data. A video decoder 24 decodes compressed video stream data output from the demultiplexer 22, to expand the compressed video stream data into the original video signal. The video decoder 24 may be realized by a chip CL480 or CL9100 manufactured by C-Cube Co. An NTSC (National Television System Committee) encoder 26 encodes a video signal output from the video decoder 24 into an NTSC video signal. The NTSC encoder 26 may be realized by a chip CXA1145P manufactured by Sony Co., or a chip KA2194D manufactured by Samsung Electronics Co. An audio decoder 28 decodes the compressed audio stream data output from the demultiplexer 22, to expand the compressed audio stream data into the 4-channel audio data. A digital-to-analog converter and amplifier 29 converts the expanded 4-channel audio data from the audio decoder 28 into the original 4-channel analog audio signals RL, FR, SL and SR, and amplifies the converted 4-channel analog audio signals. However, since such a video playback apparatus reproduces the video signal from only one camera, it is not possible to reproduce a video signal from another camera at a different angle.

[0008] It is therefore an object of the present invention to provide a digital video playback apparatus capable of selectively reproducing video signals which are recorded by using a plurality of cameras each at different angles.

[0009] Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

[0010] The above and other objects of the present invention are achieved by providing a digital video playback apparatus which includes a digital playback apparatus to read out first and second video stream data and first and second audio stream data, which are compressed and recorded on a recording medium, the first and second video and audio stream data undergoing an error correction and deinterleaving process; a demultiplexer to separate a signal output of the digital playback apparatus into system information, the first and second video stream data, and the first and second audio stream data; first and second video decoders to expand the first and second compressed video stream data outputs from the demultiplexer, respectively; first and second audio decoders to respectively decode the first and second audio stream data outputs from the demultiplexer and to expand the first and second audio stream data decoded into original 4-channel audio signals, respectively; a key input section to generate first and second angle selection signals; a controller to analyze the system information from the demultiplexer and the angle selection signals from the key input section, to generate a switching control signal; and first and second switches to select the first and second video stream data from the first and second video decoders and the first and second audio stream data from the first and second audio decoders according to the switching control signal.

[0011] The above and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of an exemplary embodiment thereof taken with the attached drawings in which:

[0012] FIG. 1 is a schematic diagram for showing an arrangement of a camera and microphones in a conventional telerecording (video and audio data) recording system;

[0013] FIG. 2 is a block diagram of a conventional video recording apparatus to record video and audio data in accordance with the system shown in FIG. 1;

[0014] FIG. 3 is a diagram for showing a data stream recorded on a recording medium according to the conventional video recording apparatus shown in FIG. 2;

[0015] FIG. 4 is a block diagram of a conventional video playback apparatus in accordance with the system shown in FIG. 1;

[0016] FIG. 5 is a schematic diagram for showing an arrangement of cameras and microphones in a telerecording system according to an embodiment of the present invention;

[0017] FIG. 6 is a block diagram of a video recording apparatus according to the embodiment of the present invention;

[0018] FIG. 7 is a block diagram of a video playback apparatus according to the embodiment of the present invention;

[0019] FIG. 8 is a diagram for showing a data stream recorded on a recording medium according to the embodiment of the present invention; and

[0020] FIG. 9 is a flow chart for selectively reproducing video signals from a plurality of cameras at different angles according to the embodiment of the present invention.

[0021] A preferred embodiment of the present invention will be described in detail hereinbelow with reference to the attached drawings.

[0022] Referring to FIG. 5, a telerecording system according to an embodiment of the present invention includes at least two cameras CA1 and CA2 at different angles. The first camera CA1 includes four microphones M1-M4, and the second camera CA2 includes four microphones M5-M8. It should be understood that the number of cameras may be freely varied at the user's discretion.

[0023] Referring to FIG. 6, a video recording apparatus according to the embodiment of the present invention includes first and second video encoders 30 and 32, first and second audio encoders 34 and 36, a multiplexer 38, and a digital recorder 40.

[0024] Referring to FIG. 7, a video playback apparatus according to the embodiment of the present invention includes a digital playback apparatus 42 for reading out first and second video stream data, and first and second audio stream data, which are compressed and recorded on a recording medium. The read video and audio stream data undergo an error correction and deinterleaving process. A demultiplexer 44 separates a signal output of the digital playback apparatus 42 into the system information, the first and second video stream data, and the first and second audio stream data. First and second video decoders 46 and 48 expand the first and second compressed video stream data from the demultiplexer 44, respectively. First and second audio decoders 50 and 52 decode the first and second compressed audio stream data from the demultiplexer 44 respectively, to expand the audio stream data into the 4-channel audio data. A key input section 64 includes first and second angle selection keys to generate first and second angle selection signals. A controller 62 analyzes the system information generated from the demultiplexer 44. Further, the controller 62 generates a switching control signal according to the first and second angle selection signals generated from the key input section 64. A first switch 54 selects one of the first and second video data from the first and second video decoders 46 and 48 according to the switching control signal. Similarly, a second switch 56 selects one of the first and second audio data from the first and second audio decoders 50 and 52 according to the switching control signal. An NTSC encoder 58 encodes the video data selected by the first switch 54 into an NTSC video signal. The NTSC encoder 58 may be realized by a chip CXA1145P manufactured by Sony Co., or a chip KA2194D manufactured by Samsung Electronics Co. A digital-to-analog converter and amplifier 60 converts the audio stream data selected by the second switch 56 into the original 4-channel analog audio signals, and amplifies the 4-channel analog audio signals.

[0025] FIG. 8 illustrates the data stream recorded on a recording medium according to an embodiment of the present invention, in which the system information, the first and second video data, and the first and second audio data are arranged in order. The system information according to the present invention includes synchronization data, the number of angles, the number of video blocks, the number of audio blocks, a start address for each video block, and a start address for each audio block.

[0026] Now, referring to FIGS. 5 through 9, a detailed description will be made of the operation of the preferred embodiment of the invention. The multiplexer 38 receives the system information shown in FIG. 8. The first video encoder 30 converts an analog video signal output from the first camera CA1 into digital video data, and formats the digital video data in a predetermined manner. The second video encoder 32 converts an analog video signal output from the second camera CA2 into digital video data, and formats the digital video data in a predetermined manner. The first audio encoder 34 converts 4-channel audio signals FL1, FR1, SL1, and SR1 from the microphones M1-M4 into digital audio data, and formats the digital audio data in a predetermined manner. The second audio encoder 36 converts 4-channel audio signals FL2, FR2, SL2, and SR2 from the microphones M5-M8 into digital audio data, and formats the digital audio data in a predetermined manner. The multiplexer 38 sequentially generates the system information, the first and second video data, and the first and second audio data, as shown in FIG. 8. The digital recorder 40 sequentially records the system information, the first and second video data, and the first and second audio data, from the multiplexer 38.

[0027] Referring to FIG. 7, the digital playback apparatus 42 reads out the first and second video data and the first and second audio data, which are compressed and recorded on the recording medium such as a disc. The read video and audio data undergo an error correction and deinterleaving process. The demultiplexer 44 separates a signal output of the digital playback apparatus 42 into the system information, the first and second video data, and the first and second audio data. The first video decoder 46 expands the first compressed video data output from the demultiplexer 44. The second video decoder 48 expands the second compressed video data output from the demultiplexer 44. The first and second video decoders 46 and 48 may be realized by a chip CL480 or a chip CL9100 manufactured by C-Cube Co. The first audio decoder 50 decodes the compressed first audio stream data output from the demultiplexer 44, to expand the compressed first audio stream data into the first 4-channel audio data. Similarly, the second audio decoder 52 decodes the compressed second audio stream data output from the demultiplexer 44, to expand the compressed second audio stream data into the second 4-channel audio data.

[0028] At the moment, if a user depresses the first or second angle selection key prepared on the key input section 64 to generate the first or second angle selection signal, the controller 62 generates the switching control signal to control the first and second switches 54 and 56. With reference to FIG. 9, the controller 62 analyzes, at a step 101, the system information and checks whether the number of angles is one or not. If the number of the angles is one, the controller 62 generates the switching control signal of a first logic state to switch respective common terminals of the first and second switches 54 and 56 to respective terminals “A” thereof, at a step 102. Then, the first video stream data output from the first video decoder 46 is transferred to the NTSC encoder 58. The NTSC encoder 58 encodes a video signal output from the first video decoder 46 into an NTSC video signal. Further, the first audio stream data output from the first audio decoder 50 is transferred to the digital-to-analog converter and amplifier 60. The digital-to-analog converter and amplifier 60 converts the audio-stream data generated from the first audio decoder 50 into the 4-channel analog audio signals, and amplifies the converted 4-channel analog audio signals. However, if the number of the angles is not one at the step 101, the controller 62 will check at a step 103 whether or not the user has depressed the second angle selection key of the key input section 64. If the first angle selection key is depressed, the process proceeds to step 102 and this step is performed as set forth above. If the second angle selection key is depressed, the controller 62 generates the switching control signal of a second logic state to switch the common terminals of the first and second switches 54 and 56 to terminals “B” thereof, at a step 104. Then, the second video stream data output from the second video decoder 48 is transferred to the NTSC encoder 58. Further, the second audio stream data output from the second audio decoder 52 is transferred to the digital-to-analog converter and amplifier 60. Therefore, the video playback apparatus reproduces the second video stream data and second audio stream data from the second video decoder 48 and the second audio decoder 52, respectively.

[0029] As can be appreciated from the foregoing descriptions, the video playback apparatus of the present invention can selectively reproduce video signals which are recorded on a recording medium by using a plurality of cameras each at different angles. Thus, the user may selectively watch the videos at different angles, together with the associated real sounds.

[0030] Although a preferred embodiment of the present invention has been described in detail hereinabove, it should be clearly understood that many variations and/or modifications of the basic inventive concepts herein taught which may appear to those skilled in the art will still fall within the spirit and scope of the present invention as defined in the appended claims.