COMMUNICATION DEVICE AND COMMUNICATION METHOD
One embodiment provides a communication device for transmitting a video to an external device through first to third transmission lines, the communication device including: a transmission module configured to transmit first color difference information and second color difference information concerned with adjacent two pixels through the first transmission line, to transmit first luminance information concerned with one of the two pixels through the second transmission line, and to transmit second luminance information concerned with the other of the two pixels through the third transmission line.
This application claims priority/priorities from Japanese Patent Application No. 2011-231186 filed on Oct. 20, 2011; and Japanese Patent Application No. 2012-111976 filed on May 15, 2012; the entire contents of which are incorporated herein by reference.
FIELDEmbodiments described herein relate generally to a communication device and a communication method.
BACKGROUNDThere is known HDMI (High Definition Multimedia Interface) Specification, as a multimedia interface between a video transmitter such as a DVD player or a set-top box and a video receiver such as a TV set or a monitor. A device having an HDMI output terminal is called source device, whereas a device having an HDMI input terminal is called sink device. For example, the video transmitter is a source device, whereas the video receiver is a sink device. And, a device having both an HDMI input terminal and an HDMI output terminal to function as both of a source device and a sink device is called repeater device.
An HDMI communication device for performing communication according to the HDMI Specification has: a TMDS (Transition Minimized Differential Signaling) transmission module which transmits video, audio and auxiliary information; a +5V power supply signal transmission module for informing a sink device or a repeater device of connection in the form of a source ready signal when a source device is connected to the sink device or the repeater device; an HPD (Hot Plug Detect) signal transmission module which transmits an HPD signal as a sink ready signal indicating that the sink device or the repeater device is ready for receiving video information; an EDID (Extended Display Identification Data) transmission module which transmits EDID which are data such as product information of the connected sink device and an adequate video format; an HDCP (High-bandwidth Digital Content Protection) authentication module which authenticates the sink device; and a CEC (Consumer Electronics Control) transmission module which transmits CEC including a device control signal and a control protocol.
There is a recently increasing demand for high-definition video of 3840×2160 called 4K2K. However, in transmission of such high quality video, the load imposed on a communication interface will increase.
A general architecture that implements the various features of the present invention will now be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments and not to limit the scope of the present invention.
In general, one embodiment provides a communication device for transmitting a video to an external device through first to third transmission lines, the communication device including: a transmission module configured to transmit first color difference information and second color difference information concerned with adjacent two pixels through the first transmission line, to transmit first luminance information concerned with one of the two pixels through the second transmission line, and to transmit second luminance information concerned with the other of the two pixels through the third transmission line.
An embodiment will be described blow with reference to the drawings.
In this data transmission system, a playback device 100 serving as a source device and a display device 200 serving as a sink device in this embodiment are connected to each other by an HDMI cable 300.
The playback device 100 has a reading module 101 and a storage module 102 (not shown in
The playback device 100 has the reading module 101, the storage module 102, a decoding module 103, an HDMI transmission module 104, etc. The reading module 101 reads coded video data stored in an optical disk and outputs the coded video data to the decoding module 103. For example, the storage module 102 stores coded video data which has been recorded, and outputs the stored coded video data to the decoding module 103. The decoding module 103 decodes the input coded video data, for example, into video data of 8 bits in each of RGB, (YCrCb) 4:2:0 format, (YCrCb) 4:2:2 format or (YCrCb) 4:4:4 format. The HDMI transmission module 104 converts the decoded video data into a video signal of a specific transmission format, and outputs the video signal to the display device 200 through the HDMI cable 300.
The display device 200 has an HDMI reception module 201, a display processor 202, the display module 203, a tuner 204, a signal processor 205, etc. The HDMI reception module 201 receives a video signal and converts the received video signal into video data of a format (e.g. baseband data of 8 bits in each of RGB) compatible with the display processor 202. The display processor 202 converts the video data inputted from the HDMI reception module 201 and the signal processor 205 into a video signal of a format compatible with the display module 203, and outputs the video signal to the display module 203. The display module 203 displays video based on the input video signal.
The tuner 204 receives a television broadcasting signal. The signal processor 205 converts the received broadcasting signal into video data, and outputs the video data to the display processor 202.
The HDMI transmission module 104 has a TMDS encoder 151, a micro-computer 152, a communication module 153, etc. The HDMI reception module 201 has a TMDS decoder 251, a micro-computer 252, an EDID 253, etc.
Decoded video data from the decoding module 103 are, inputted to the TMDS encoder 151. The TMDS encoder 151 converts the input video data into video data of a format which will be described later with reference to
The differential amplifiers (not shown) corresponding to CH0-CH2 respectively are provided in the HDMI reception module 201. Upon reception of the differential signals from CH0-CH2, the differential amplifiers convert the differential signals into data, and output the data to the TMDS decoder 251. The TMDS decoder 251 decodes these data into video data of 8 bits in each of RGB, and outputs the video data to the display processor 202.
The micro-computer 152 of the source device is connected to the micro-computer 252 of the sink device by a CEC line and an HPD line. The micro-computer 152 and the micro-computer 252 transmit information for mutual control of the devices through the CEC line. And, the micro-computer 152 informs the source device of signal transmission ready completion corresponding to power-on completion of the sink device through the HPD line.
The communication module 153 of the micro-computer 152 is connected to the EDID 253 of the sink device through a DDC line. The communication module 153 reads EDID data from the EDID 253.
(YCrCb) 4:2:0 format will be described below with reference to
For example, when the source video decoded in the playback device 100 is RGB 4:4:4, a large amount of data is required to transmit the video. Therefore, (YCrCb) 4:2:0 sampling is considered so that the amount of data is halved.
Similarly, luminance information Y02 shows luminance of pixel P3. First color difference information Cb02 shows color differences Cb concerned with four pixels, that is, pixel P3, pixel P4 adjacent to the pixel P3, and pixels P7 and P8 downward adjacent to the pixels P3 and P4. The first color difference information Cb02 may show the color difference Cb only for the pixel P3. Second color difference information Cr12 shows color differences Cr concerned with four pixels, that is, pixel P7, pixel P8 adjacent to the pixel P7, and pixels P3 and P4 upward adjacent to the pixels P7 and P8. The second color difference information Cr12 may show the color difference Cr only for the pixel P7. Luminance information Y03 shows luminance of pixel P4. Luminance information Y12 shows luminance of pixel P7. Luminance information Y13 shows luminance of pixel P8.
On this occasion, for example, as shown in
Therefore, as shown in
In
That is, in the formats of
The timing formats of
For example, in the case of
An example of a video transmission processing in the playback device 100 will be described below with reference to
Although transmission of 4K2K video is exemplified in the embodiment, video of general HD image quality (1920×1080) may be transmitted by means of YCrCb 4:2:0 sampling like this embodiment.
Although the embodiment has been described above, the embodiment is just an example and should not limit the scope of the invention. The novel embodiment may be practiced in other various forms, and part of it may be omitted, replaced by other elements, or changed in various manners without departing from the spirit and scope of the invention. For example, although HDMI Specification has been exemplified in the embodiment, the embodiment may be applied to other communication methods than the HDMI Specification. These modifications will also fall within the scope of Claims and its equivalents
Claims
1. An electronic apparatus configured to communicate via a HDMI cable with an external apparatus, the electronic apparatus comprising:
- input circuitry configured to receive first encoded video data of a first format, wherein the first encoded video data comprises a first pixel, a second pixel, a third pixel, and a fourth pixel, the second pixel is adjacent to the first pixel, the third pixel is adjacent to the second pixel, and the fourth pixel is adjacent to the third pixel;
- processor circuitry configured to: decode the first encoded video data to generate a first decoded video data; and encode the first decoded video data to generate a second encoded video data of a second format, wherein the second format comprises YCbCr 4:2:0, and the second encoded video data comprises (1) a first luminance value of the first pixel, (2) a second luminance value of the second pixel, (3) a third luminance value of the third pixel, (4) a fourth luminance value of the fourth pixel, (5) a first color difference value, and (6) a second color difference value; and
- a terminal configured to transmit the second encoded video data via channels 0, 1, and 2 of the HDMI cable by transmitting the first color difference value and the second color difference value via the channel 0 within a period, and transmitting the first luminance value, the second luminance value, the third luminance value, and the fourth luminance value via the channels 1 and 2 within the period.
2. The electronic apparatus of claim 1,
- wherein the processor circuitry is further configured to determine whether the external apparatus indicates support for the second format,
- wherein the terminal configured to transmit the second encoded video data to the external apparatus, if the external apparatus indicates support for the second format, and
- wherein the terminal configured not to transmit the second encoded video data to the external apparatus, if the external apparatus does not indicate support for the second format.
3. The electronic apparatus of claim 2,
- wherein the processor circuitry is further configured to determine whether the external apparatus indicates support for the second format based on EDID (Extended Display Identification Data) of the external apparatus.
4. The electronic apparatus of claim 1,
- wherein the period is determined in accordance with at least one cycle of a TMDS (Transition Minimized Differential Signaling) clock.
5. The electronic apparatus of claim 1, further comprising
- storage configured to store the first encoded video data,
- wherein the input circuitry configured to receive the first encoded video data stored in the storage.
6. The electronic apparatus of claim 1, further comprising
- an optical disc drive configured to read the first encoded video data stored in an optical disc.
7. The electronic apparatus of claim 1,
- wherein the input circuitry is further configured to receive the first encoded video data via a network.
8. The electronic apparatus of claim 1,
- wherein the first encoded video data comprises 4K2K video.
9. The electronic apparatus of claim 1,
- wherein the first encoded video data comprises a 3D video comprising a right-eye frame and a left-eye frame.
10. The electronic apparatus of claim 1, further comprising
- a tuner to receive a television broadcasting signal of a television program.
11. The electronic apparatus of claim 1, further comprising
- a display configured to a video of the first encoded video data.
12. An electronic apparatus configured to communicate via a HDMI cable with an external apparatus, the electronic apparatus comprising:
- a terminal configured to receive encoded video data via channels 0, 1, and 2 of the HDMI cable; and
- processor circuitry configured to: receive the encoded video data conforming to YCbCr 4:2:0 via the terminal, if the electronic apparatus indicates support for YCbCr 4:2:0, wherein the encoded video data comprises (1) a first luminance value of a first pixel, (2) a second luminance value of a second pixel, (3) a third luminance value of a third pixel, (4) a fourth luminance value of a fourth pixel, (5) a first color difference value, and (6) a second color difference value, the second pixel is adjacent to the first pixel, the third pixel is adjacent to the second pixel, and the fourth pixel is adjacent to the third pixel; and decode the encoded video data to generate a decoded video data;
- a display configured to display the video of the decoded video data,
- wherein the first color difference value and the second color difference value are received via the channel 0 within a period, and
- wherein the first luminance value, the second luminance value, the third luminance value, and the fourth luminance value are received via the channels 1 and 2 within the period
13. The electronic apparatus of claim 12,
- wherein whether the electronic apparatus indicates support for YCbCr 4:2:0 is determined based on EDID (Extended Display Identification Data) of the electronic apparatus.
14. The electronic apparatus of claim 12,
- wherein the period is determined in accordance with at least one cycle of a TMDS (Transition Minimized Differential Signaling) clock.
15. The electronic apparatus of claim 12,
- wherein the encoded video data comprises 4K2K video.
16. The electronic apparatus of claim 12,
- wherein the encoded video data comprises a 3D video comprising a right-eye frame and a left-eye frame.
17. The electronic apparatus of claim 12, further comprising:
- a tuner configured to receive a television broadcasting signal of a television program; and
- a selector configured to select either one of an output from the tuner and an output from the processor circuitry and provide the selected output to the display.
18. A method for communicating with an external apparatus via an HDMI cable, the method comprising:
- inputting first encoded video data of a first format, wherein the first encoded video data comprises a first pixel, a second pixel, a third pixel, and a fourth pixel, the second pixel is adjacent to the first pixel, the third pixel is adjacent to the second pixel, and the fourth pixel is adjacent to the third pixel;
- decoding the first encoded video data to generate a first decoded video data;
- encoding the first decoded video data to generate a second encoded video data of a second format, wherein the second format comprises YCbCr 4:2:0, and the second encoded video data comprises (1) a first luminance value of the first pixel, (2) a second luminance value of the second pixel, (3) a third luminance value of the third pixel, (4) a fourth luminance value of the fourth pixel, (5) a first color difference value, and (6) a second color difference value; and
- transmitting the second encoded video data via channels 0, 1, and 2 of the HDMI cable by transmitting the first color difference value and the second color difference value via the channel 0 within a period, and transmitting the first luminance value, the second luminance value, the third luminance value, and the fourth luminance value via the channels 1 and 2 within the period.
19. The method of claim 18, further comprising
- determining whether the external apparatus indicates support for the second format,
- wherein the transmitting the second encoded video data is performed, if the external apparatus indicates support for the second format, and
- wherein the transmitting the second encoded video data is not performed, if the external apparatus does not indicate support for the second format.
20. The method of claim 19, further comprising
- determining whether the external apparatus indicates support for the second format based on EDID (Extended Display Identification Data) of the external apparatus.
21. The method of claim 18,
- wherein the period is determined in accordance with at least one cycle of a TMDS (Transition Minimized Differential Signaling) clock.
22. The method of claim 18, further comprising
- reading the first encoded video data from a storage,
- wherein the storage stores the first encoded video data.
23. The method of claim 18, further comprising
- reading, by an optical disc drive, the first encoded video data from an optical disc.
24. The method of claim 18, further comprising
- receiving the first encoded video data via a network.
25. The method of claim 18,
- wherein the first encoded video data comprises 4K2K video.
26. The method of claim 18,
- wherein the first encoded video data comprises a 3D video comprising a right-eye frame and a left-eye frame.
27. The method of claim 18, further comprising
- receiving a television broadcasting signal of a television program by a tamer.
28. The method of claim 18, further comprising
- displaying a video of the first encoded video data on a screen.
29. A method for communicating with an external apparatus via an HDMI cable, the method comprising:
- inputting encoded video data via channels 0, 1, and 2 of the HDMI cable; and wherein the second format comprises YCbCr 4:2:0, the encoded video data comprises (1) a first luminance value of a first pixel, (2) a second luminance value of a second pixel, (3) a third luminance value of a third pixel, (4) a fourth luminance value of a fourth pixel, (5) a first color difference value, and (6) a second color difference value, the second pixel is adjacent to the first pixel, the third pixel is adjacent to the second pixel, and the fourth pixel is adjacent to the third pixel; and
- decoding the encoded video data to generate a decoded video data;
- displaying the video of the decoded video data,
- wherein the first color difference value and the second color difference value are received via the channel 0 within a period, and
- wherein the first luminance value, the second luminance value, the third luminance value, and the fourth luminance value are received via the channels 1 and 2 within the period
30. The method of claim 28, further comprising
- determining whether support for YCbCr 4:2:0 is indicated based on EDID (Extended Display Identification Data).
31. The method of claim 28,
- wherein the period is determined in accordance with at least one cycle of a TMDS (Transition Minimized Differential Signaling) clock.
32. The method of claim 28,
- wherein the encoded video data comprises 4K2K video.
33. The method of claim 28,
- wherein the encoded video data comprises a 3D video comprising a right-eye frame and a left-eye frame.
34. The method of claim 28, further comprising
- receiving a television broadcasting signal of a television program by a tuner,
- wherein the displaying is performed based on the television broadcasting data or the encoded video data, whichever is selected.
Type: Application
Filed: Jun 7, 2017
Publication Date: Sep 21, 2017
Inventors: Nobuaki SUZUKI (Akishima-shi), Makoto SATO (Hino-shi), Masahiko MAWATARI (Yokohama-shi)
Application Number: 15/616,789