Information processing device for relaying streaming data

According to one embodiment, a method is described for relaying streaming data from a first external device and to transmit streaming data to a second external device. The method comprises (i) receiving a first delay time to be needed by the second external device from the second external device, (ii) calculating a third delay time by adding the first delay time to a second delay time to be needed in the information processing device, and (iii) transmitting the third delay time to the first external device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2004-376453, filed Dec. 27, 2004, the entire contents of which are incorporated herein by reference.

BACKGROUND

Embodiments of the present invention relate to an information processing device for receiving and processing streaming data, such as video data and/or audio data for an externally connected device and an information relaying method in the information processing device.

2. Description of the Related Art

As is well known, digital visual interface (also referred as “DVI”) standard have widely been provided for transmission of digital video data. Recently, high definition multimedia interface (also referred as “HDMI”) standards have been used as digital data transmission standards, an improvement of the DVI standard.

This HDMI standard involves multiplexing digital audio data during a blanking period of a digital video data for transmission of audio data, transmitting the digital video data in RGB signal format as well as in YCbCr signal format or in higher-quality YPbPr signal format, connecting with the use of small sized HDMI connectors similar to universal serial bus (also referred as “USB”) connectors, and featuring other functions which are not available in the common DVI standard.

In the HDMI standard, when streaming data such as video and/or audio data is transmitted from a transmitting device to a receiving device, the transmitting device acquires extended display identification (also referred as “EDID”) data fro the receiving device. This enables the output of the data in a format corresponding to the display specification of a display accompanied with the receiving device.

In the HDMI standard, it is also possible to transmit streaming data such as video and/or audio data from a transmitting device to a receiving device through one or more repeaters or relays. In this case, the transmitting device acquires the EDID data from the receiving device through the repeater.

The streaming data output form the transmitting device, namely the video and audio mutually in synchronization with each other, passes through the repeater, and the receiving device performs the data processing for displaying the video and playback of the audio. Thereby, a different time lag may be generated, and a synchronization deviation may occur between the video and audio.

The Japanese Patent Application Publication (Kokai) No. 2002-6817 discloses a system for converting the format of video signals outputted from an image supplying device by a signal format converter and displaying the signals on a display device. Each of the signal format converter and the display in the system has a storage medium, which stores its own characteristic information therein, and the image supplying device acquires the characteristic information stored in the storage mediums so as to adjust the image quality to be output. However, the above reference does not disclose anything about a synchronization deviation.

DETAILED DESCRIPTION

Various embodiments according to the present invention will be described hereinafter with reference to the accompanying drawings. In general, according to one embodiment of the invention, an information processing device coupled between a first external device and a second external device comprises a first receiver to receive streaming data from the first external device, a processor to perform a data processing on the streaming data received by the receiver, a memory to store first data indicating a first delay time in which the processor takes for the data processing, a first transmitter to transmit the streaming data to the second external device after the data processing by the processor, a second receiver to receive second data indicating a second delay time to be needed in the second external device before display of the streaming data; an adder to calculate a third delay time by adding the first delay time and the second delay time, and a second transmitter to transmit third data indicating the third delay time to the first external device.

FIG. 1shows an exemplary streaming data transmission system according to a first embodiment of the present invention. The streaming data transmission system transmits streaming data, such as video data and/or audio data for example, which is a digital signal. The streaming data transmission system includes a transmitter11, a repeater15, and a receiver23. According to this embodiment of the invention, the transmitter11is an electronic device operating as a source such as an optical disk player, which reproduces streaming data stored in an optical disk such as a digital versatile disk (also referred as “DVD”). The repeater15relays streaming data from the transmitter11to the receiver23, and is also referred to as a “relay”.

More specifically, according to one embodiment of the invention, the transmitter11comprises a signal reproducing unit12, an HDMI transmitter13coupled to the signal reproducing unit12, a delay unit16coupled to the signal reproducing unit12and externally coupled to a speaker17, a controller C1coupled to the delay unit16, and a memory18coupled to the controller C1.

The signal reproducing unit12reproduces video signals (also referred as “video data”) and audio signals (also referred as “audio data”) from, for example, the DVD and the like. The video signal reproduced by the signal reproducing unit12is supplied to the HDMI transmitter13. The HDMI transmitter13converts the video signal into the form conforming to the HDMI standard, the HDMI streaming data. Then, the HDMI transmitter13transmits the HDMI streaming data to the repeater15which is an electronic device through a transmission channel14. The repeater15is, for example, an optical disk player such as a DVD player.

The audio signal reproduced by the signal reproducing unit12is supplied to the delay unit16. The delay unit16delays output of the audio signal for a predetermined time, and then, supplies the audio signal to the speaker17for playback of the sound.

The delay unit16controls a delay time for the audio signal on the basis of data indicating delay time or delay amount stored in the memory18provided in the transmitter11.

The repeater15comprises an HDMI receiver19coupled to the transmission channel14, a video processing unit15coupled to the HDMI receiver19, and an HDMI transmitter21coupled to the video processing unit15. In addition, the repeater15includes a memory24, a controller C2coupled to the memory24and having a function as an adder, and a memory26coupled to the controller C2.

The HDMI receiver19in the repeater15receives the HDMI streaming data including the video signal supplied from the transmitter11through the transmission channel14. The HDMI receiver19converts the inputted HDMI streaming data in the form conforming to the HDMI standard into the original video signal, and supplies the video signal to the video processing unit20.

The video processing unit20performs the video signal processing such as restoring the deterioration occurring in the transmission on the inputted video signal and like. The video signal processing in the video processing unit20includes any processing to be needed as the repeater15.

The video signal outputted from the video processing unit20is supplied to the HDMI transmitter21. The HDMI transmitter21converts the video signal into the form conforming to the HDMI standard again, the HDMI streaming data, and transmits the HDMI streaming data to a receiver23through a transmission channel22. The receiver23is, for example, a TV receiver or the like.

The memory24in the repeater15stores data indicating a video delay time or amount D1(hereinafter collectively referred as “video delay amount D1”) required for the signal processing by the video processing unit20.

The controller C2in the repeater15acquires a video delay time or amount D2(hereinafter collectively referred as “video delay amount D2”) from the receiver23, and adds the video delay amount D1stored in the memory24to the video delay amount D2. The controller C2stores the added video delay time or amount D3(hereinafter collectively referred as “video delay amount D3”) into the memory26as an Extended Display Identification (also referred as “EDID”) data.

The receiver23comprises an HDMI receiver27coupled to the transmission channel22, a video processing unit28coupled to the HDMI receiver27and externally coupled to a display29, and a memory30.

The HDMI receiver27in the receiver23receives the HDMI streaming data including video signal supplied from the repeater15through the transmission channel22. The HDMI receiver27converts the inputted video signal in the form conforming to the HDMI standard into the original video signal, and supplies the video signal to the video processing unit28. The video processing unit28performs on the inputted video signal, the signal processing in accordance with a display specification corresponding to the display29, so as to show the video on the display29.

The memory30in the receiver23stores the video delay amount D2required for the signal processing by the video processing unit28as the EDID data.

FIG. 2shows an exemplary processing operation of the controller C2in the repeater15ofFIG. 1. Upon starting the processing (block S2a), the controller C2in the repeater15ofFIG. 1detects whether or not the receiver23is connected (block S2b). If a cable complying with the HDMI standard connects between the repeater15and the receiver23, the controller C2, which complies with the HDMI standard, detects the connection. The cable configures the transmission channel22, and transmits the data stored in the memory30.

When the controller C2detects that the receiver23is connected, the controller C2requests the receiver23to transmit the video delay amount D2as shown in block S2c.

The controller C2receives the video delay amount D2, and calculates a video delay amount D3by adding the video delay amount D2from the receiver23to the video delay amount D1stored into the memory24(block S2d). Then, the controller C2stores the video delay amount D3into the memory26as the EDID data (block S2e), and the controller C2in the repeater15finishes the processing (block S2f).

FIG. 3shows an exemplary processing operation of the transmitter11, mainly a processing operation of the controller C1ofFIG. 1. Upon staring the processing (block S3a), the controller C1detects whether or not the repeater15is connected (block S3b). If a cable complying with the HDMI standard connects between the transmitter11and the repeater15, the controller C1, which complies with the HDMI standard, detects the connection. The cable configures the transmission channel14, and transmits the data stored in the memory26to the transmitter11.

When the controller C1detects that the repeater15connected thereto exists, the controller C1in the transmitter11requests the repeater15to transmit the video delay amount D3(block S3c).

Thereafter, the controller C1in the transmitter11stores the video delay amount D3acquired from the repeater15into the memory18ofFIG. 1(block S3d), whereby setting the delay amount D3in the delay unit16. The transmitter11outputs the video and audio signals from the signal reproducing unit12(block S3e), and the transmitter11finishes the processing (block S3f).

According to the first embodiment, as described above, when the receiver23is connected, the controller C2in the repeater15obtains the video delay amount D2, adds it to the video delay amount D1, and stores the video delay amount D3as the EDID data.

Therefore, when the repeater15is connected, the controller C1in the transmitter11may obtain the video delay amount D3obtained from the repeater15, and sets the video delay amount into the delay unit16.

Accordingly, the transmitter11may delay the audio signal on the basis of the video delay amount D3, and the video outputted from the transmitter11and showed on the display of the receiver23through the repeater15may be synchronized with the audio outputted from the transmitter11and then the speaker17for playback.

FIG. 4shows an exemplary streaming data transmission system according to a second embodiment of the present invention. InFIG. 4, the same reference numerals are attached to the same components as inFIG. 1. In the second embodiment, the repeater15includes an audio processing unit31coupled to the HDMI receiver19, a delay unit32coupled to the audio processing unit31and externally coupled to a speaker33, a controller C3, and a memory35. The controller C3has a function as a subtracter in addition to as an adder.

The signal reproducing unit12in the transmitter11reproduces the video signals and the audio signals, and the HDMI transmitter13converts the video signals and the audio signals into the form conforming to the HDMI standard, the HDMI streaming data. The HDMI transmitter13transmits the HDMI streaming data to the repeater15through the transmission channel14.

In the repeater15, the HDMI receiver19receives the HDMI streaming data including the video and the audio signals, and converts it into the original video and audio signals. The video signals are supplied to the video processing unit20, and the audio signals are supplied to the audio processing unit31. The audio processing unit31performs, on the inputted audio signal, an audio signal processing such as restoring the deterioration caused during the transmission.

After the audio signal processing performed by the audio processing unit31, the audio signals are supplied to the delay unit32and delayed for a predetermined time, and then supplied to the speaker33for the audio playback. The delay unit32is to control the delay time or amount as for the audio signal on the basis of a delay time or amount outputted from the controller C3in the repeater15.

As described above, the repeater15includes the memory35having stored therein the audio delay time or amount D4(hereinafter “audio delay amount D4”) required for the audio signal processing by the audio processing unit31. The controller C3calculates a delay time or amount D5(hereinafter “delay amount D5”) by subtracting the audio delay amount D4stored in the memory35from the video delay amount D3stored in the memory26. The delay amount D5calculated by the controller C3is given to the delay unit32.

FIG. 5shows an exemplary processing operation of the controller C3in the repeater15shown inFIG. 4. Upon starting the processing (block S5a), the controller C3detects whether or not the receiver23is connected (block S5b). Similar to the first embodiment, if a cable complying with the HDMI standard connects between the repeater15and the receiver23, the controller C3, which complies with the HDMI standard, detects the connection. The cable configures the transmission channel22, and transmits the data stored in the memory30.

When the controller C3detects that the receiver23is connected, the controller C3requests the receiver23as shown in block S5cto transmit the video delay amount D2.

The controller C3receives the video delay amount D2from the receiver23, and calculates its video delay amount D3by adding the video delay amount D2to the video delay amount D1stored into the memory24(block S5d). Then, the controller C3stores the video delay amount D3into the memory26as the EDID data as shown in block S5e.

Next, as shown in block s5f, the controller C3as a subtracter calculates the delay amount D5by subtracting the audio delay amount D4stored in the memory35from the video delay amount D3stored in the memory26, and sets the delay amount in the delay unit32as the delay amount D5of the subtraction result (block S5g). Thereafter, the controller C3of the repeater15finishes the processing (block S5h).

According to the second embodiment shown inFIG. 4, the controller C3subtracts the audio delay amount D4in the repeater15from the video delay amount D3which is obtained by adding the video delay amount D2of the receiver23and the own video delay amount D1, and sets the delay amount into the delay unit32so as to delay the audio signal according to the subtracted delay amount D5.

Accordingly, the video outputted from the transmitter11and shown on the display29of the receiver23through the repeater15may be synchronized with the audio outputted from the transmitter11and output by the speaker33through the repeater15.

Here, in the first and second embodiments, the description has been made in the case where the video signal outputted from the transmitter11is shown on the display29of the receiver23, and the audio signal outputted from the transmitter11is output to the speaker17coupled to the transmitter11or the speaker33coupled to the repeater15, respectively.

However, the invention is not restricted to this, but the video may be synchronized with the audio similarly in the case where the audio signal output from the transmitter11is output to the speaker provided in the receiver23for playback and the video signal output from the transmitter11is shown on the display provided on the transmitter11or the repeater15. In such the case, the total of the audio delay amounts is calculated and the video output is delayed accordingly.

The invention is also not restricted to the above-mentioned embodiments themselves, but various modifications of the components may be embodied within departing from the scope. By properly combining a plurality of components disclosed in the above embodiments, various inventions may be formed. For example, some of the whole components shown in the embodiments may be deleted. Further, the components according to the different embodiments may be properly combined together.