KR20020062752A - Video playback device for variable speed play back of pre-recorded video without pitch distortion of audio - Google Patents

Abstract

A device for reproducing audio associated with a video program during a fast forward mode and a slow operation mode is disclosed for use in a video playback device for playing a video program in a fast forward mode and a slow mode on a television set connected with the video playback device. have. The apparatus comprises: 1) a video playback controller capable of receiving a user input command indicative of the amount of relative acceleration of the video program during a fast forward mode; 2) an audio processor capable of receiving an audio track and compressing the duration of the audio track with minimal pitch distortion, wherein the compression is proportional to the amount of relative acceleration of the video program; And a video processor coupled to an audio processor capable of receiving a compressed audio track, the video processor capable of receiving an accelerated video signal associated with the video program during a fast forward mode. The video signal is synchronously transmitted to the television set.

Description

Video playback device for variable speed play back of pre-recorded video without pitch distortion of audio}

A variety of video playback devices are available on the market. Most people own or are familiar with video cassette recorders (VCRs), also called video tape recorders (VTRs). More recently, video recorders have appeared on the market that use computer magnetic hard disks instead of magnetic cassette tapes to store video programs. For example, the replay TV recorder and TiVO digitally record television programs on a hard disk drive, for example using MPEG-2 compression. In addition, some video playback devices record on readable / writable digital versatile disks (DVDs) instead of magnetic disks.

In fact, all systems capable of playing video programs have fast forward and reverse features, and some systems have variable forward and rewind speeds. During the fast forward execution of a video program, the audio portion of the video program is typically muted. As is known in the art, increasing or decreasing the speed of a video program causes audio distortion, regardless of rewind or forward execution. This is due to the fact that audio cannot be easily subsampled. There are ways to boost voice playback by 50% with minimal impact on quality. However, this is insufficient for high speed modes of operation and non-speech segments of the audio track.

Accordingly, there is a need in the art for an apparatus for playing an audio track with minimal pitch distortion in association with a video program during the fast forward mode and the slow mode.

The present invention relates generally to video playback apparatus, and more particularly to a system for playing video in fast forward mode and slow mode without pitch distortion of an audio track.

1 illustrates an exemplary video playback device and television set in accordance with one embodiment of the present invention.

FIG. 2 illustrates in more detail an exemplary video playback device in accordance with an embodiment of the present invention. FIG.

3 is a flow diagram illustrating operation of an exemplary video playback device in accordance with one embodiment of the present invention.

To overcome the above-mentioned deficiencies of the prior art, for use in a video playback apparatus capable of playing back video programs in a fast forward mode and a slow mode on a television set connected to the video playback apparatus, It is a primary object of the present invention to provide an apparatus for playing associated audio. According to one advantageous embodiment of the invention, the apparatus comprises: 1) a video playback controller capable of receiving a user input command indicative of the amount of relative acceleration of the video program during a fast forward mode; 2) an audio processor capable of receiving the audio track and compressing the duration of the audio track with minimal pitch distortion, wherein the compression is proportional to the amount of relative acceleration of the video program; And 3) a video processor coupled to an audio processor capable of receiving a compressed audio track and capable of receiving an accelerated video signal associated with the video program during a fast forward mode, wherein the video processor is capable of receiving the compressed audio track and acceleration. And a video processor for synchronizing the transmitted video signal to a television set.

According to one embodiment of the invention, the video playback controller can receive a user input command indicating the amount of relative deceleration of the video program during the slow mode, and the audio processor can extend the duration of the audio track with minimal pitch distortion. And the expansion is proportional to the amount of the relative deceleration of the video program.

According to another embodiment of the present invention, a video processor may receive a slowed down video signal associated with an extended audio track and a video program during a slow mode, wherein the video processor is configured to synchronize the extended audio track and the slowed down video signal. Transmits to a television set.

According to another embodiment of the invention, the apparatus further comprises a memory coupled to the audio processor capable of storing executable instructions associated with at least one compression algorithm.

According to yet another embodiment of the present invention, the memory may store executable instructions associated with at least one extension algorithm.

The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that those skilled in the art may better understand the following detailed description of the invention. In the following, additional features and advantages of the invention will be described which form the subject of the claims of the invention. Those skilled in the art will readily appreciate the concept and specific embodiments disclosed as a basis for designing modifications or other structures for achieving the same purpose as the present invention. Those skilled in the art will also appreciate that such equivalent structures do not depart from the spirit and scope of the present invention in its broad form.

Before making a detailed description, it may be advantageous to clarify the specific words and phrases used throughout this patent document; The terms "include" and "comprise" and their derivatives mean unlimited inclusion; The term “or” includes imitate and / or; The terms “associated with” and “associated therewith” and derivatives thereof include, are included within, interconnected with, accepts, received within, connects to or connects to, and To, communicate with, cooperate with, interleave (insert), parallel to, adjacent to, or bound to, have, have the nature of, etc .; The term “controller” means any device, system or portion thereof that controls at least one operation, and such device means hardware, firmware or software, or at least some combination of the two. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote. In particular, the controller may include one or more data processors and associated input / output devices and memories that execute one or more application programs and / or operating system programs. Definitions of specific words and phrases may be found herein. Provided in the patent document, those of ordinary skill in the art should, in many but not most cases, understand that such definitions apply to the conventional and future use of words and phrases so defined.

BRIEF DESCRIPTION OF DRAWINGS In order that the present invention and its advantages may be more fully understood, reference is made to the following description in conjunction with the accompanying drawings, wherein like numerals represent like objects.

The various embodiments used to describe the principles of the invention in FIGS. 1 to 3 and the present patent document discussed below are illustrative only and should not be construed to limit the invention. Those skilled in the art will appreciate that the principles of the present invention may be implemented in any suitably arranged video playback device.

1 shows a video reproducing apparatus 150 and a television set 105 according to an embodiment of the present invention. The video playback device 150 receives incoming television signals from a cable television provider or telephone company's set-top box, a local antenna, the Internet, or an external source such as an attached DVD or VHS tape player. The select channel is sent to the television set 105. In the recording mode, the video reproducing apparatus 150 demodulates the incoming radio frequency (RF) television signal to generate a baseband video signal recorded or stored in a storage medium connected to or connected to the video reproducing apparatus 150. In the play mode, the video reproducing apparatus 150 reads the stored baseband video signal (ie, a program) selected by the user from the storage medium and transmits it to the television set 105.

For example, if the video reproducing apparatus 150 is a video cassette recorder (VCR) also referred to as a video tape recorder (VTR), the video reproducing apparatus 150 stores the incoming television signal in a magnetic cassette tape and retrieves it from the tape. If the video playback device 150 is a disk drive-based device such as a replay TV recorder or a TiVO recorder, the video playback device 150 stores in a computer magnetic hard disk instead of a magnetic cassette tape and retrieves from that disk. In still other embodiments, video playback device 150 will store and retrieve from local read / write (R / W) digital versatile disc (DVD) or R / W CD-ROM. As such, the local storage medium may be fixed (i.e., hard disk drive) or removable (i.e., DVD, CD-ROM, VCR tape).

The video playback device 150 is infrared (IR) for receiving commands (channel up, channel down, volume up, volume down, record, playback, fast forward execution (FF), retrograde, etc.) from a remote control device operated by the viewer. ) Sensor 160 is included. Television set 105 is a conventional television that includes a screen 110, an infrared (IR) sensor 115, and one or more passive controls 120 (indicated by dashed lines). The IR sensor 115 also receives commands (volume up, volume down, power on / off) from the remote control operated by the viewer.

It should be noted that video playback device 150 is not limited to receiving a particular type of incoming television signal from a particular type of source. As above, the external source may be a cable service provider, a conventional RF broadcast antenna, a satellite dish antenna, an Internet connection, or other local storage such as a DVD player or a VHS tape player. In some embodiments, video playback device 150 may not be able to record, but will be limited to playing television signals retrieved from a removable DVD or CD-ROM. Thus, the incoming signal may be a digital signal, an analog signal or Internet Protocol (IP) packets of any other communication protocol. However, to simplify and clarify the principles of the present invention, the following will generally relate to an embodiment in which the video playback device 150 receives television signals (analog and / or digital) from a cable service provider. . However, those skilled in the art will understand that the principles of the present invention can be readily adapted for use with wireless broadcast television signals, local storage systems, incoming streams of IP packets containing MPEG data, and the like.

2 illustrates in more detail an exemplary video playback device 150 according to one embodiment of the invention. Video playback device 150 includes IR sensor 160, video processor 210, MPEG2 encoder 220, hard disk drive 230, MPEG2 decoder / NTSC encoder 240, and video recorder (VR) controller 250. ) Is included. Video playback device 150 is thereon, as a sequence of program instructions executed by video buffer 260, audio compression / expansion processor 270, and audio compression / expansion processor 270. It includes a compression / expansion algorithm 280 that can be implemented with a memory that stores one or more of a number of known audio compression and audio expansion algorithms.

Audio compression and techniques can be used to play back audio signals with low pitch distortion or minimum pitch distortion. An apparatus and method for compressing or expanding an audio signal during faster or slower playback is referred to as "Apparatus and Method for Playing Back Audio at Faster or Slower Rates Without Pitch Distortion". And US Patent No. 5,386,493 to Degan et al., Entitled "Method and Apparatus for Manipulating Pitch and / or Duration of a Signal," a method and apparatus for adjusting the pitch and / or duration of a signal. US Patent No. 5,479,564 to Vogten et al. And US Patent No. 5,694,521 to Sholmot et al., Entitled " Variable Speed Playback System ". U.S. Patent Nos. 5,386,493, 5,479,564 and 5,694,521 are incorporated herein by reference as if fully set forth herein. In an advantageous embodiment of the invention, one or more of the compression / extension algorithms disclosed in US Pat. Nos. 5,386,493, 5,479,564 and 5,694,521 are stored in compression / extension algorithm 280 and stored in compression / extension processor 270. Could be executed by

The VR controller 250 directs the overall operation of the video playback device 150, particularly including the viewing mode, the recording mode, the playback mode, the fast forward execution (FF), the retrograde mode. In the viewing mode, the VR controller 250 causes the incoming television signal from the cable service provider to be demodulated and processed by the video processor 270, without being stored or retrieved by the hard disk drive 230. Video processor 210, which may be, for example, a TriMedia (TM) 1100 media processor, receives television signals from a cable service provider, tunes them to a consumer selected channel, and displays the selected RF signals on television set 105. Radio frequency (RF) potential circuitry for converting into suitable baseband television signals (e.g., super video signals). Video processor 210 may also receive conventional NTSC, PAL or SECAM signals from MPEG2 decoder / NTSC encoder 240 and transmit baseband television signals (eg, super video signals) to television set 105 during playback mode. .

In the recording mode, the VR controller 250 causes the incoming television signal to be stored in the hard disk drive 230. Under the control of the VR controller 250, the MPEG2 encoder 220 receives a television signal from a cable service provider and converts the received RF signal into MPEG format for storage on the hard disk drive 230. In the playback mode, the VR controller 250 instructs the hard disk drive 230 to send a stored television signal (i.e., program) to the MPEG2 decoder / NTSC encoder 240, which is a hard disk drive ( MPEG2 data from 230 is converted, for example, to Super Video (S-Video) buffered in video buffer 260 before being transmitted to television set 105 by video processor 210.

It should be noted that the selection of MPEG2 criteria for MPEG2 decoder / NTSC encoder 240 is for illustrative purposes only. In alternative embodiments of the present invention, the MPEG encoder and decoder may conform to one or more of the MPEG-1, MPEG-2, MPEG-4 and MPEG-7 standards.

For purposes of this application and the following claims, hard disk drive 230 is a conventional magnetic disk drive, magnetic tape for video cassette recorder (VCR) or video tape recorder (VTR), and R / W digital versatile disk. (DVD-RW), an optical disc drive for rewritable CD-ROM, etc., is defined as including any readable and recordable mass storage device. Otherwise, hard disk drive 230 includes any mass storage device provided to a video playback device for storing recorded video and audio programs. Thus, such a hard disk drive 230 may be a peripheral or removable disk drive (inserted or attached), such as a juke box device that holds a read / write DVD or a rewritable CD-ROM. Will contain). Further, in an advantageous embodiment of the invention, hard disk drive 230 includes, for example, a disk drive in a user's home personal computer (PC) or a disk drive in a server of the user's Internet service provider (ISP), Video playback device 150 includes an external mass storage device that can be accessed and controlled via a network connection (eg, an Internet Protocol (IP) connection).

During the playback mode, the VR controller 250 will receive a fast forward run (FF) command from the user via the IR sensor 160. In the FF mode, the video playback device 150 may play the selected portion of the audio signal with minimum pitch distortion using the video buffer 260, the audio compression / expansion processor 270, and the compression expansion algorithm 280. When an FF command is received, the VR controller 250 causes the hard disk drive 230 and the MPEG2 decoder / NTSC encoder 240 to play the video at a faster forward speed. However, the VR controller 250 also executes the video processor 210 to stop receiving the audio output of the MPEG2 decoder / NTSC encoder 240 as a source of the audio signal. Instead, video processor 210 is switched to receive the audio signal from the output of audio compression / expansion processor 270 as a source of audio signal.

3 shows a flowchart illustrating the operation of an example video playback device 150 in accordance with an embodiment of the present invention. A fast forward or slow mode input command is received by the VR controller 250 during the playback mode. The VR controller 250 determines the speed of acceleration or deceleration from the user input (processing step 305). Because the playback speed is faster or slower, the duration of the audio track is compressed with minimal pitch distortion. The corresponding video is buffered in video buffer 260. Compression is directly proportional to the speed of relative acceleration or deceleration of the video program (processing 310).

The process continues and audio tracks from the reproduced video are received by the audio compression / expansion processor 270. Audio is expanded for slow playback and compressed for fast forward mode. Expansion or compression is proportional to the speed of deceleration or acceleration selected by the user (processing step 315). The compressed or expanded audio is sent to the television set in synchronization with the corresponding portion of the fast forward video or slow playback video from the video buffer 260 (processing step 320).

Audio compression / expansion algorithms are used to adjust the audio signal according to the playback speed. As the playback speed increases, audio compression increases. As the playback speed decreases, the algorithm causes the compression speed to decrease. As the playback speed slows below normal, the audio expansion speed increases. The audio compression and expansion speed is directly proportional to the playback speed.

While the invention has been described in detail, it should be understood that those skilled in the art can make various changes, substitutions and alterations without departing from the spirit and scope of the invention.

Claims (23)

The video program during the fast forward mode and the slow mode, for use in a video playback device 150 capable of playing video programs in a fast forward mode and a slow mode on a television set 105 connected to the video playback device 150. An apparatus for playing an audio track associated with A video playback controller (250) capable of receiving a user input command indicative of the amount of relative acceleration of said video program during said fast forward mode; An audio processor 270 capable of receiving the audio track and compressing the duration of the audio track with minimal pitch distortion, wherein the compression is proportional to the amount of the relative acceleration of the video program. ); And A video processor 210 coupled to an audio processor 270 capable of receiving the compressed audio track and receiving an accelerated video signal associated with the video program during the fast forward mode, wherein the compressed audio track And the video processor (210) for synchronizing and transmitting the accelerated video signal to the television set (105). The method of claim 1, The video playback controller 250 may receive a user input command indicating the amount of relative deceleration of the video program during the slow mode, and the audio processor 270 extends the duration of the audio track with minimal pitch distortion. And the extension is proportional to the amount of the relative deceleration of the video program. The method of claim 2, The video processor 210 may receive a reduced video signal associated with the extended audio track and the video program during the slow mode, and the video processor 210 may receive the extended audio track and the reduced video signal. To the television set (105) in synchronization with each other. The method of claim 3, wherein And the apparatus further comprises a memory coupled to the audio processor (270) capable of storing executable instructions associated with at least one compression algorithm. The method of claim 4, wherein And the memory is capable of storing executable instructions associated with at least one extension algorithm. In a video playback device 150 capable of playing back video programs in a fast forward mode and a slow mode on a television set 105 connected to the video playback device 150, A magnetic disk drive 230 capable of storing a plurality of video programs; A video playback controller 250 capable of receiving a user input command indicative of the relative amount of acceleration of the first selected video program to be played during the fast forward mode; An audio processor 270 capable of receiving an audio track associated with the first selected video program and compressing the duration of the audio track with a minimum pitch distortion, wherein the compression is equal to the relative acceleration of the first selected video program. The audio processor 270 proportional to an amount; And A video processor (210) coupled to an audio processor (270) capable of receiving the compressed audio track and receiving an accelerated video signal associated with the first selected video program during the fast forward mode; And a video processor (210) for synchronizing the transmitted audio track and the accelerated video signal to the television set (105). The method of claim 6, The video playback controller 250 may receive a user input command indicating the amount of relative deceleration of the video program during the slow mode, and the audio processor 270 extends the duration of the audio track with minimal pitch distortion. And the expansion is proportional to the amount of the relative deceleration of the video program. The method of claim 7, wherein The video processor 210 may receive a reduced video signal associated with the extended audio track and the video program during the slow mode, and the video processor 210 may receive the extended audio track and the reduced video signal. To the television set (105) in synchronization with each other. The method of claim 8, The apparatus further comprises a memory coupled to the audio processor 270 capable of storing executable instructions associated with at least one compression algorithm. The method of claim 9, And the memory is capable of storing executable instructions associated with at least one expansion algorithm. In a video playback device 150 capable of playing video programs in a fast forward mode and a slow mode on a television set 105 connected to the video playback device 150, A video cassette drive capable of receiving a video cassette tape and retrieving a first selected video program stored on said video cassette tape; A video playback controller 250 capable of receiving a user input command indicative of the relative amount of acceleration of the first selected video program to be played during the fast forward mode; An audio processor 270 capable of receiving an audio track associated with the first selected video program and compressing the duration of the audio track with a minimum pitch distortion, wherein the compression is equal to the relative acceleration of the first selected video program. The audio processor 270 proportional to an amount; And A video processor (210) coupled to an audio processor (270) capable of receiving the compressed audio track and receiving an accelerated video signal associated with the first selected video program during the fast forward mode; And a video processor (210) for synchronizing the audio track and the accelerated video signal to the television set (105). The method of claim 11, The video playback controller 250 may receive a user input command indicating the amount of relative deceleration of the video program during the slow mode, and the audio processor 270 extends the duration of the audio track with minimal pitch distortion. And the expansion is proportional to the amount of the relative deceleration of the video program. The method of claim 12, The video processor 210 may receive a reduced video signal associated with the extended audio track and the video program during the slow mode, and the video processor 210 may receive the extended audio track and the reduced video signal. To the television set (105) in synchronization with each other. The method of claim 13, The apparatus further comprises a memory coupled to the audio processor 270 capable of storing executable instructions associated with at least one compression algorithm. The method of claim 14, And the memory is capable of storing executable instructions associated with at least one expansion algorithm. In a video playback device 150 capable of playing video programs in a fast forward mode and a slow mode on a television set 105 connected to the video playback device 150, A digital multipurpose disc (DVD) drive capable of receiving a digital multipurpose disc and retrieving a first selected video program stored on said digital multipurpose disc; A video playback controller 250 capable of receiving a user input command indicative of the relative amount of acceleration of the first selected video program to be played during the fast forward mode; An audio processor 270 capable of receiving an audio track associated with the first selected video program and compressing the duration of the audio track with a minimum pitch distortion, wherein the compression is equal to the relative acceleration of the first selected video program. The audio processor 270, proportional to the amount; A video processor 210 coupled to the audio processor 270 capable of receiving the compressed audio track and receiving an accelerated video signal associated with the first selected video program during the fast forward mode, wherein And a video processor (210) for synchronizing the compressed audio track and the accelerated video signal to the television set (105). The method of claim 16, The video playback controller 250 may receive a user input command indicating the amount of relative deceleration of the video program during the slow mode, and the audio processor 270 extends the duration of the audio track with minimal pitch distortion. And the expansion is proportional to the amount of the relative deceleration of the video program. The method of claim 17, The video processor 210 may receive a reduced video signal associated with the extended audio track and the video program during the slow mode, and the video processor 210 may receive the extended audio track and the reduced video signal. To the television set (105) in synchronization with each other. The method of claim 18, The apparatus further comprises a memory coupled to the audio processor 270 capable of storing executable instructions associated with at least one compression algorithm. The method of claim 19, And the memory is capable of storing executable instructions associated with at least one expansion algorithm. Audio associated with the video program during the fast forward mode and the slow mode for use in the video playback device 150 capable of playing the video program in the fast forward mode and the slow mode on the television set 105 connected to the video playback device 150. In the method for playing a track, Receiving a user input command indicative of the amount of relative acceleration of the video program during a fast forward mode; Receiving the audio track and compressing the duration of the audio track with minimal pitch distortion, wherein the compression is proportional to the amount of relative acceleration of the video program; And Synchronizing the compressed audio track and the accelerated video signal to a television set (105). The method of claim 21, Receiving a user input command indicative of the amount of relative deceleration of the video program during a low speed mode; And Extending the duration of the audio track with a minimum pitch distortion, wherein the expansion further comprises an expansion step proportional to the amount of relative deceleration of the video program. The method of claim 22, Synchronizing the extended audio track and the reduced video signal to a television set (105).