Apparatus for synchronized playback of audio-video signals
AssigneeNEC Corporation
InventorsMasaru Terashima, Takashi Samejima, Mitsumasa Tanaka, Hideki Sawada
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Abstract
An apparatus for producing synchronized playback of compressed digital data of audio-video signals from a desired portion of the digital data. The apparatus can be used in a system having comparatively low data processing ability, and work independent of the resolution of a software timer of the system. The apparatus comprises a frame counter for obtaining a reference time indicating reproduction time passage of the audio signal component from a reproduced data amount of the audio signal component. A delay detector detects progress of the video signal component in reference to the reference time.
Claims16
An apparatus for synchronized playback of system signals having an audio signal component and a video signal component, said apparatus comprising:
- a clock generator which calculates a reference time indicating reproduction time passage of said audio signal component from an amount of reproduced data of said audio signal component added with a compensation amount, and by referring to a sampling rate of the audio signal component and a frame rate of the video signal component;
- a delay detector coupled to said clock generator, said delay detector detects a progress of said video signal component by comparing a real frame number added with a compensation number of said video signal component to an ideal frame number, said real frame number indicating a number of processed picture frames of said video frame component, said ideal frame number being the product of said reference time and said frame rate of said video signal component;
- an audio data counter compensator coupled to said clock generator, said audio data counter compensator calculates said compensation amount from a playback point of said system signal where synchronized playback is requested;
- and
- a video frame counter compensator coupled to said delay detector, said video frame counter compensator calculates said compensation number from said playback point of said system signal where synchronized playback is requested.
A method for synchronizing playback of system signals having an audio signal component and a video signal component, said method comprising:
- calculating a reference time indicating reproduction time passage of said audio signal component from an amount of reproduced data of said audio signal component added with a compensation amount, and by referring to a sampling rate of the audio signal component and a frame rate of the video signal component;
- detecting a progress of said video signal component by comparing a real frame number added with a compensation number of said video signal component to an ideal frame number, said real frame number indicating a number of processed picture frames of said video frame component, said ideal frame number being the product of said reference time and said frame rate of said video signal component;
- calculating said compensation amount from a playback point of said system signal where synchronized playback is requested;
- and
- calculating said compensation number from a playback point of said system signal where synchronized playback is requested.
Dependencies are inferred from the claim text.