Data processing: speech signal processing – linguistics – language – Audio signal bandwidth compression or expansion
Reexamination Certificate
2000-02-18
2003-01-14
McFadden, Susan (Department: 2654)
Data processing: speech signal processing, linguistics, language
Audio signal bandwidth compression or expansion
C704S501000, C704S502000, C704S503000, C704S504000
Reexamination Certificate
active
06507819
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a video and voice signal processing apparatus that outputs an intelligible voice signal even if frame decimation is applied to a video signal when processing digital video and digital audio signals.
The invention also relates to a sound signal processing apparatus that reduces the amount of information in a digital sound signal.
BACKGROUND ART
Nowadays, encoding is often performed when transmitting or storing video signals and voice signals. Especially, in the case of video signals which carry enormous amounts of data, high-efficiency encoding (hereinafter called compression) is performed to reduce the amount of data, thereby reducing transmission or storage costs.
Encoded signals are subjected to decoding for reproduction; when the signals are in compressed form, expansion must also be performed. Generally, expansion often requires complex calculations, and in the case of moving images and the like which are to be processed in real time, high processing speed is needed.
There are, however, not a few cases where sufficient processing speeds cannot be obtained, for example, when performing processing by computer software. In such cases, appropriate decimation is applied to the input moving image signal to reduce the amount of data and to permit realtime processing.
One decimation technique frequently used is frame decimation. This technique decimates an input signal on a frame by frame basis when it is input.
A description will be given below of one example of a prior art video and voice signal processing apparatus in which an input moving image signal is first subjected to frame decimation and then to expansion and decoding, thus outputting a video signal and a voice signal.
FIG. 7
is a block diagram showing the configuration of the prior art video and voice signal processing apparatus. In
FIG. 7
,
701
is a signal receiving circuit,
702
is a signal extraction circuit,
703
is a video signal processing circuit,
704
is a voice signal processing circuit,
705
is an input signal,
706
is an encoded video signal,
707
is an encoded voice signal,
708
is a video signal, and
709
is a voice signal.
FIG. 8
is an explanatory diagram showing individual frames of the input signal
705
arranged along the time axis. In
FIG. 8
,
801
a
and
802
d
are frames to be decoded, and
802
b,
802
c,
802
e,
and
802
f
are frames to be discarded by frame decimation.
The operation of the thus configured video and voice signal processing apparatus will be described. As an example, it is assumed here that two frames out of every three frames are discarded by frame decimation. In
FIG. 7
, the signal receiving circuit
701
receives the input signal
705
, and supplies it to the signal extraction circuit
702
. The signal extraction circuit
702
extracts signals corresponding to the frames
801
a and
801
d from the thus supplied input signal
705
, separates the encoded video signal
706
and the encoded voice signal
707
from the extracted signals, and supplies them to the video signal processing circuit
703
and the voice signal processing circuit
704
, respectively. At this time, signals corresponding to the frames
802
b,
802
c,
802
e,
and
802
f
of the input signal
705
are discarded. The video signal processing circuit
703
decodes the encoded video signal
706
thus supplied, and outputs the decoded signal as the video signal
708
. Likewise, the voice signal processing circuit
704
decodes the encoded voice signal
707
thus supplied, and outputs the decoded signal as the voice signal
709
.
However, in the above-described prior art configuration, not only the video signal but the voice signal is also decimated as a result of the frame decimation. Generally, when frame decimation is applied to a video signal, the video can still be recognized as a moving image though the motion becomes jerky; on the other hand, when frame decimation is applied to a voice signal, there occurs the problem that the voice can no longer be recognized as voice since signal continuity is lost.
The present invention has been devised in view of the frame decimation problem of the prior art, and an object of the invention is to provide a video and voice signal processing apparatus capable of outputting a voice signal recognizable as voice even when frame decimation is applied.
On the other hand, with the advance of digital signal technologies, sound is increasingly being recorded and reproduced using digital signals.
Nowadays, compact discs and minidiscs on which sound is recorded using digital sound signals are predominant as sound recording media for recording sound. In television broadcasting also, systems for transmitting both video and sound using digital signals are beginning to be employed, as seen in digital satellite broadcasting. Further, personal computers are increasingly used for sound processing such as recording or reproduction using digital sound signals; nowadays, with improvements in the performance of personal computers, it is not uncommon for personal computers to reproduce video and sound simultaneously by using digital signals.
As shown in
FIG. 9
, a prior art sound signal processing apparatus
1
is an apparatus that accepts at its input a reproduced sound signal A of a digital sound signal transmitted from a sound signal transmitting apparatus
2
, and that converts it into an analog sound signal and outputs the analog sound signal as an output sound signal B.
In recent years, advances have been made in sound quality and sound multiplexing in stereo broadcasting or the like, and the reproduced sound signal A from the sound signal transmitting apparatus
2
may contain a large amount of information.
However, since the above prior art sound signal processing apparatus
1
converts the reproduced sound signal A into an analog sound signal in the order in which it is input, if the reproduced sound signal A is a signal containing a large amount of information, problems will occur, such as interruptions in the sound corresponding to the reproduced sound signal A, unless the speed with which the sound signal processing apparatus
1
converts the reproduced sound signal A into the analog output sound signal B is fast enough.
DISCLOSURE OF THE INVENTION
A first aspect of the present invention concerns a video and voice signal processing apparatus which comprises: signal receiving means for receiving an input signal containing an encoded video signal and an encoded voice signal, and for recovering from the input signal the encoded video signal and encoded voice signal for output; video signal extracting means for extracting a designated frame from the encoded video signal, and for outputting the extracted frame as a representative video signal; video signal processing means for applying prescribed processing to the representative video signal, and for outputting the thus processed signal as a video signal; and voice signal processing means for applying prescribed processing to the encoded voice signal, and for outputting the thus processed signal as a voice signal.
In this configuration, frame decimation is applied to the encoded video signal, but is not applied to the encoded voice signal; therefore, all voice signals can be output unchanged.
This invention also provides a video and voice signal processing apparatus which comprises: signal receiving means for receiving an input signal containing an encoded video signal and an encoded voice signal, and for recovering from the input signal the encoded video signal and encoded voice signal for output; video signal extracting means for extracting a designated frame from the encoded video signal, and for outputting the extracted frame as a representative video signal; video signal processing means for applying prescribed processing to the representative video signal, and for outputting the thus processed signal as a video signal; voice signal extracting means for extracting designated information frame by frame from the encoded voice signal, and for outputting the extracted info
Iketani Akira
Juri Tatsuro
Matsumi Chiyoko
Yoshida Junji
Matsushita Electric - Industrial Co., Ltd.
McFadden Susan
RatnerPrestia
LandOfFree
Sound signal processor for extracting sound signals from a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sound signal processor for extracting sound signals from a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sound signal processor for extracting sound signals from a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3030443