Amplifier, correcting method of correcting difference in processing time between video signal and audio signal, and correcting system

• US 8,004,609 B2
• Filed: 05/26/2005
• Issued: 08/23/2011
• Est. Priority Date: 05/27/2004
• Status: Active Grant

• Current Assignee: Yamaha Corporation
• Original Assignee: Yamaha Corporation
• Inventors: Maegaki, Hirochika
• Primary Examiner(s): Tran; Trang U
• Application Number:
  US11/597,283
• Publication Number:
  US 20080044160A1
• Time in Patent Office: 2,280 Days
• Field of Search: 348515-518, 348/512, 348/180, 348/192, 348/194, 348/423.1
• US Class Current: 348/515
• CPC Class Codes: H04N 17/04 for receivers
• CPC Class Codes: H04N 21/43072 of multiple content streams on the same device
• CPC Class Codes: H04N 5/04 Synchronising for television systems using pulse code modulation H04N7/56

Abstract

There is provided an amplifier that measures a display delay time caused until a video is displayed actually after a video signal is generated, and sets automatically a delay time of an audio signal such that an audio synchronizes with this display. Test video data is stored in a memory 11. This test video data is video data that generates a clear change in luminance in such a manner that a screen is changed suddenly from deep black to pure white. This test video is output to a video display device 2 such as PDP, for example, and a delay time generated until the test video is displayed actually after this test video is output is measured. Since the luminance of the screen is changed suddenly when the test video is displayed actually, this change can be sensed by an optical sensor 20. The audio signal is delayed by setting this delay time in an audio signal processing portion 13, so that the video can synchronize with the audio.

Claims

1. An amplifier to which at least an audio signal associated with a video signal is input and which reproduces the inputted audio signal, comprising:

an audio processing portion that executes a reproducing process of the inputted audio signal;

a test video generating portion that generates a test video signal and transmits the test video signal to a video display device;

a sensing portion that senses a change in test video, which is generated based on the test video signal and displayed on the video display device; and

a controlling portion that senses a time required from when the test video generating portion generates the test video signal until the sensing portion senses a change in a video being displayed on the video display device as a delay time of the video, and delays a reproduction of the audio signal based on the sensed delay time of the video, wherein

the controlling portion calculates an audio delay time, which is a time to delay the reproduction of the audio signal, based on the delay time of the video, and sets the audio delay time in the audio processing portion;

the audio processing portion senses a type of the audio signal;

the controlling portion has a memory portion which stores the audio delay time for every type of the audio signal; and

the controlling portion reads a corresponding audio delay time stored in the memory portion based on the type of the audio signal, and sets the audio delay time in the audio processing portion.

2. The amplifier according to claim 1, wherein the audio processing portion has a buffer memory to store the audio signal, and the controlling portion controls the audio delay time by controlling a buffered amount of the audio signal to be stored in the buffer.

3. The amplifier according to claim 1, wherein the controlling portion has a memory portion which stores a decode processing time that is a time necessary for a decoding process of the audio signal;

and

wherein the controlling portion calculates the audio delay time based on the delay time of the video and the decode processing time.

4. An amplifier to which at least an audio signal associated with a video signal is input and which reproduces the inputted audio signal, comprising:

an audio processing portion that executes a reproducing process of the inputted audio signal;

a test audio signal generating portion that generates a test audio signal;

a test video signal generating portion that generates a test video signal in synchronism with generation of the test audio signal, and transmits the test video signal to a video display device;

a video sensing portion that senses a change in video, which is generated based on the test video signal and displayed on the video display device;

a content sensing portion that senses a change in type or content of the test audio signal; and

a controlling portion that senses a time required from when the content sensing portion senses the change in type or content of the test audio signal until the video sensing portion senses a change in the video being displayed on the video display device as a delay time of the video, calculates an audio delay time, which is a time to delay the reproduction of the audio signal, based on the sensed delay time of the video, and sets the audio delay time in the audio processing portion, wherein

the audio processing portion senses a type of the audio signal;

the controlling portion has a memory portion which stores the audio delay time for every type of the audio signal; and

the controlling portion reads a corresponding audio delay time stored in the memory portion based on the type of the audio signal, and sets the audio delay time in the audio processing portion.

5. The amplifier according to claim 4, wherein the audio processing portion has a buffer memory to store the audio signal;

and

wherein the controlling portion controls the audio delay time by controlling a buffered amount of the audio signal to be stored in the buffer.

6. The amplifier according to claim 4, wherein the controlling portion has a memory portion which stores a decode processing time that is a time necessary for a decoding process of the audio signal;

and

wherein the controlling portion calculates the audio delay time based on the delay time of the video and the decode processing time.

7. A correcting method of correcting a difference between a processing time of a video signal and a processing time of an audio signal, comprising the steps of:

generating a test video signal;

displaying the test video signal on a video display device;

sensing a change in video, which is generated based on the test video signal and displayed on the video display device;

sensing a time required from when the test video signal is generated until a change in a video being displayed on the video display device is sensed as a delay time of the video;

sensing a type of the audio signal; and

reading a corresponding audio delay time stored in a memory portion based on the type of the audio signal, and delaying the reproduction of the audio signal based on the delay time of the video.

8. The correcting method according to claim 7, wherein an amount of delay to delay the reproduction of the audio signal is controlled by controlling a buffered amount of the audio signal stored in a buffer.

9. The correcting method according to claim 7, further comprising a step of calculating an audio delay time that is a time to delay the reproduction of the audio signal, based on the delay time of the video and a decode processing time required for a decoding process of the audio signal.

10. A correcting method of correcting a difference between a processing time of a video signal and a processing time of an audio signal, comprising the steps of:

generating a test audio signal;

generating a test video signal in synchronism with a generation of the test audio signal;

displaying the test video signal on a video display device;

sensing a change in video, which is generated based on the test video signal and displayed on the video display device;

sensing a time required from when a change in type or content of the audio signal is sensed until a change in the video being displayed on the video display device is sensed as a delay time of the video;

calculating an audio delay time that is a time to delay a reproduction of the audio signal, based on the delay time of the video;

writing the audio delay to a memory portion;

sensing a type of the audio signal;

reading a corresponding audio delay time stored in the memory portion based on the type of the audio signal; and

executing a reproducing process of the inputted audio signal based on the read audio delay time.

11. The correcting method according to claim 10, wherein an amount of delay to delay the reproduction of the audio signal is controlled by controlling a buffered amount of the audio signal stored in a buffer.

12. The correcting method according to claim 10, further comprising a step of calculating the audio delay time based on the delay time of the video and a decode processing time required for a decoding process of the audio signal.

13. A correcting system for correcting a difference between a processing time of a video signal and a processing time of an audio signal, comprising:

an audio processing portion that executes a reproducing process of the audio signal;

a test video signal generating portion that generating a test video signal;

a video displaying portion that displays the test video signal;

a video sensing portion that senses a change in video, which is generated based on the test video signal and displayed on the video display device; and

a controlling portion that senses a time required from when the test video generating portion generates the test video signal until the video sensing portion senses a change in the video being displayed on the video display device as a delay time of the video, and delays a reproduction of the audio signal based on the delay time of the video, wherein

the audio processing portion senses a type of the audio signal;

the controlling portion has a memory portion which stores an audio delay time for every type of the audio signal; and

the controlling portion reads a corresponding audio delay time stored in the memory portion based on the type of the audio signal and provides the read audio delay time to the audio processing portion.

14. The correcting system according to claim 13, wherein the controlling portion calculates the audio delay time that is a time to delay the audio signal based on the sensed delay time of the video and a decode processing time required for a decoding process of the audio signal, and sets the audio delay time in the audio processing portion.

15. A correcting system for correcting a difference between a processing time of a video signal and a processing time of an audio signal, comprising:

an audio processing portion that executes a reproducing process of the inputted audio signal;

a test audio signal generating portion that generates a test audio signal;

a test video signal generating portion that generates a test video signal in synchronism with a generation of the test audio signal;

a video displaying portion that displays the test video signal;

a video sensing portion that senses a change in video, which is generated based on the test video signal and displayed on the video display device;

a content sensing portion that senses a change in type or content of the test audio signal;

a sensing portion that senses a time required from when the content sensing portion senses the change in type or content of the test audio signal until the video sensing portion senses a change in the video as a delay time of the video;

a calculating portion that calculates an audio delay time that is a time to delay the reproduction of the audio signal, based on the sensed delay time of the video; and

a setting portion that sets the audio delay time in the audio processing portion, wherein

the audio processing portion senses a type of the audio signal;

the setting portion has a memory portion which stores the audio delay time for every type of the audio signal; and

the setting portion reads a corresponding audio delay time stored in the memory portion based on the type of the audio signal and sets the read audio delay time in the audio processing portion.

16. The correcting system according to claim 15, wherein the calculating portion calculates the audio delay time based on the delay time of the video and a decode processing time required for a decoding process of the audio signal.