US6078725A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for a synchronized playback of audio-video signals
Assignee: NEC Personal Computers Ltd
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Filing: 1998-01-07
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Granted: 2000-06-20
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Expires: 2018-01-07
Abstract
Abstract To provide an apparatus for a synchronized playback of com- pressed digital data of audio-video signals adequately even when there are data errors with a simple configuration to be applied to a system having comparatively low data processing ability, independent of resolution of a software timer of the system, the apparatus obtains a reference time indicating production time passage of the audio signal component from reproduced data amount added with rejected error data amount of the audio signal component, and detects progress of the video signal component in reference to the reference time considering rejected error video data amount.
Inventors
- 👤 Mitsumasa Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:26
CPC Classifications
H; H04; H04N; H04N21/00; H04N21/40; H04N21/43; H04N21/4302; H04N21/4307; H04N21/43072
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
156 words
An apparatus for synchronized playback of audio-video signals representing an audio signal component and a video signal component in synchronization with each other by decompressing compressed digital data of the audio signal component and the video signal component, said apparatus comprising: means for obtaining a reference time indicating a reproduction time passage of the audio signal component from a sum of a reproduced data amount of the audio signal component and an error data amount of said audio signal component rejected because of a data error, based upon header information of the compressed digital data, which includes a sampling rate of the audio signal component and a frame rate of the video signal component; and means for detecting a progress of the video signal component by comparing said reference time to a real frame number of the video signal component, said real frame number indicating a number of processed picture frames and rejected error picture frames.
Claim 2
Independent Claim
156 words
An apparatus for synchronized playback of audio-video signals representing an audio signal component and a video signal component in synchronization with each other by decompressing compressed digital data of the audio signal component and the video signal component, said apparatus comprising: means for obtaining a reference time indicating a reproduction time passage of the audio signal component from a sum of a reproduced data amount of the audio signal component and an error data amount of said audio signal component rejected because of a data error, based upon header information of the compressed digital data, which includes a sampling rate of the audio signal component and a frame rate of the video signal component; and means for detecting a progress of the video signal component by comparing said reference time to a real frame number of the video signal component, said real frame number indicating a number of processed picture frames and rejected error picture frames.
Claim 3
Dependent Claim
138 words
The apparatus for synchronized playback of audio-video signals recited in claim 1, said means for detecting the progress of the video signal component having: a video frame counter for counting and maintaining said real frame number by accumulating a number of picture frames actually decompressed and a number of picture frames omitted from being decompressed; a video error detector for adding an error frame number of the video signal component, which corresponds to a number of picture frames rejected without reproduction because of a data error, to said real frame number; and a delay detector for calculating an ideal frame number of the video signal component to be displayed according to said reference time and said frame rate, and detecting said progress of the video signal component by comparing said real frame number to said ideal frame number.
Claim 4
Dependent Claim
52 words
The apparatus for synchronized playback of audio-video signals recited in claim 1, further comprising means for restoring a difference in display timing between the video signal component and said reference time by performing frame omission and delaying decompression of the video signal component according to said progress of the video signal component.
Claim 5
Dependent Claim
47 words
The apparatus for synchronized playback of audio-video signals recited in claim 3; wherein said frame omission is performed according to an order of priority attributed to frames of the video signal component subject to said frame omission in connection with kinds of compressed data of said frames.
Claim 6
Dependent Claim
52 words
The apparatus for synchronized playback of audio-video signals recited in claim 3; wherein said decompression delay is performed by controlling decompression of compressed data of a frame of the video signal component be delayed until said difference of display timing of said frame from said reference time becomes within a threshold value.
Claim 7
Independent Claim
150 words
A method for synchronizing playback of audio-video signals representing an audio signal component and a video signal component in synchronization with each other by decompressing compressed digital data of the audio signal component and the video signal component, comprising: obtaining a reference time indicating a reproduction time passage of the audio signal component from a sum of a reproduced data amount of the audio signal component and an error data amount of said audio signal component rejected because of a data error, based upon header information of the compressed digital data, which includes a sampling rate of the audio signal component and a frame rate of the video signal component; and detecting a progress of the video signal component by comparing said reference time to a real frame number of the video signal component, said real frame number indicating a number of processed picture frames and rejected error picture frames.
Claim 8
Independent Claim
150 words
A method for synchronizing playback of audio-video signals representing an audio signal component and a video signal component in synchronization with each other by decompressing compressed digital data of the audio signal component and the video signal component, comprising: obtaining a reference time indicating a reproduction time passage of the audio signal component from a sum of a reproduced data amount of the audio signal component and an error data amount of said audio signal component rejected because of a data error, based upon header information of the compressed digital data, which includes a sampling rate of the audio signal component and a frame rate of the video signal component; and detecting a progress of the video signal component by comparing said reference time to a real frame number of the video signal component, said real frame number indicating a number of processed picture frames and rejected error picture frames.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-06-20 | 2003-12-20 | 2004-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-20 | 2007-12-20 | 2008-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-20 | 2011-12-20 | 2012-06-20 | $7700.00 | Window Closed / Lapsed |