Patent Application
20130308056
1. Field
Example embodiments of the present disclosure relate to an Unequal Error Protection (UEP) method and apparatus for transmitting various types of uncompressed video signals in a broadband high frequency wireless system, and more particularly, to a UEP method and apparatus for transmitting and receiving various types of uncompressed video signals, which are immune to radio channel errors, according to a priority of the video signals while maintaining a high transmission/reception speed.
2. Description of the Related Art
Unlike general data information in which priorities of all data information bits are the same, video information may have different priorities of video information bits. For example, upper bits of pixel bytes displaying images may be more important than lower bits thereof, and luminance information bits of an image may be more important than chrominance information bits of the image. Also, in an RGB chromatic system being comprised of Red elements, Green elements, and Blue elements, the Green elements are more important.
In general, the video information may be required to be transmitted at a high speed because an amount of the video information is significantly greater than that of the general data information and the video information requires real-time performance in information transmission. In addition, channel errors may occur in a radio channel due to various factors, resulting in transformation of transmitted information. To minimize the transformation of the information due to the radio channel errors, supplementary information (hereinafter, referred to as channel error correction code) may be added to information intended to be transmitted in a transmission terminal, and transformed information may be restored in a reception terminal using the added channel error correction code. However, the channel error correction code information may reduce a transmission speed of a channel.
Concerning the priority of the video information and characteristics of the radio channel, a recent ‘high transmission speed radio system through an ultra-wideband high frequency band’ may categorize upper bits and lower bits of pixel information bytes being comprised of image information, and use more channel error correction code information in the upper bits and use less channel error correction code information in the lower bits, thereby preventing transformation of important information, and improving image quality. As described above, adapting unequal error correction schemes according to a priority of signals may be referred to as an Unequal Error Protection (UEP) scheme.
However, the above-mentioned UEP scheme may display the priority using common bit position of three element information (RGB information or YCbCr information) being comprised of a pixel. Also, according to the above-mentioned UEP scheme, a case where each of the three element information is displayed as identical 8-bits may be considered. That is, since the priority may be classified only using common bit positions of the pixel information, a priority difference between luminance information (corresponding to Y in a YCbCr system) and chrominance information (corresponding to CbCr in the YCbCr system), and a priority difference between Green information and Red/Blue information in the RGB chromatic system may not be used. Also, the above-mentioned UEP scheme may not support pixel information displayed as various depths such as 8-bits/16-bits/32-bits and the like, because the color depth is required to be separated into 8-bits/8-bits when being displayed as 16-bit color space information, however, when the color depth is separated into a 4-bit unit as illustrated in
One or more example embodiments may provide an Unequal Error Protection (UEP) method and apparatus for transmitting various types of uncompressed video signals in a broadband high frequency wireless system.
One or more example embodiments may also provide a method and apparatus which may reflect various bit fields of elements being comprised of a pixel in uncompressed video information, and support a priority difference (Y>Cb or Cr, G>R or B) between components while maintaining, as is, a priority discrimination scheme through an existing bit field separation.
According to example embodiments, an Unequal Error Protection (UEP) transmission apparatus may be provided. The UEP transmission apparatus may include: a UEP transmission controller to verify a bit separation point of separating a color depth and priority for each pixel element being composed of a video data pixel when video data is inputted, and to control an error correction coding of correcting relatively many errors to be used in information with a high priority for each pixel element; a bit separator to separate the video data pixel through a control of the UEP transmission controller based on the priority for each pixel element; and a channel coding unit to use a corresponding error correction coding through the control of the UEP transmission controller based on the priority for each pixel element.
According to other example embodiments, a UEP reception apparatus may be provided. The UEP reception apparatus may include: a UEP reception controller to verify a bit separation point of separating a color depth and priority for each pixel element being composed of a pixel; a demodulation unit to perform a corresponding demodulation according to priority information of UEP video data included in a header of the UEP video data when UEP video data is received; a channel decoding unit to perform an error correction coding, which is separated according to the priority information, on the demodulated data according to the priority information; and a bit combiner to combine, through a control of the UEP reception controller, the data on which the error correction coding is performed according to the priority information based on the color depth and bit separation point.
According to other example embodiments, a UEP method in a transmission apparatus may be provided. The UEP method may include: verifying a bit separation point for separating a bit field size and priority for each pixel element being comprised of a pixel of video data; classifying the pixel of the video data based on the priority for each pixel element; and performing an error correction coding for correcting relatively many errors occurring in information having a high priority for each pixel element.
According to other example embodiments, a UEP method in a reception apparatus may be provided. The UEP method may include: verifying a bit separation point for separating a bit field size and priority for each pixel element being comprised of a pixel; performing a demodulation on UEP video data according to priority information of the UEP video data included in a header of the UEP video data when the UEP video data is received; performing an error correction coding with respect to the UEP video data on which the demodulation is performed according to the priority information, the error correction coding being classified according to the priority information; and combining, for each pixel element, the data on which the error correction coding is performed based on the bit field size and bit separating point.
Additional aspects and/or advantages will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the example embodiments.
These and/or other aspects, features, and advantages of example embodiments will become apparent and more readily appreciated from the following description, taken in conjunction with the accompanying drawings of which:
Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. Example embodiments are described below to explain the present disclosure by referring to the figures.
The present disclosure relates to an Unequal Error Protection (UEP) method and apparatus for transmitting various types of uncompressed video signals in a broadband high frequency wireless system.
The video data input interface 101 may be an apparatus receiving various types of uncompressed video signals, so while the present specification may describe only R/G/B and Y/Cb/Cr types, other uncompressed video signals may be received.
R/G/B color image may be comprised of pixels constituting Red (R), Green (G), and Blue (B) elements, and Y/Cb/Cr color image may be comprised of pixels constituting a luminance (Y) element and chrominance elements (Cb and Cr).
These pixel elements may be displayed as various color depths such as 8-bits, 16-bits, and the like. The video data input interface 101 may inform the UEP transmission controller 110 of inputted uncompressed video information 102, and transmit, to the video signal bit separator 160, the inputted uncompressed video information 102 for each pixel information.
The UEP Tx controller 110 may receive, from the video data input interface 101, the video information 102 including a pixel type constituting video images, a bit field size of the pixel, a bit separation point of separating a priority of the pixel, and the like, transmit a negotiation request message 120a of the UEP scheme to a UEP reception controller, which will be described in detail below, so as to transmit the corresponding video image in the UEP scheme, and receive a UEP response message 120b with respect to the negotiation request message 120a.
Also, the UEP Tx controller 110 may control a series of procedures associated with video image transmission using UEP information 111 and 112 which are negotiated through an exchange between the messages 120a and 120b. The bit separator 160 may receive, from the video data input interface 101, video data of a series of bit type for each pixel information (R/G/B or Y/Cb/Cr).
The bit separator 160 may receive, from the UEP Tx controller 110, the color depth and bit separation point for each pixel information to configure frames each having a high priority or low priority by separating video data bits inputted for each pixel information in a scheme, which will be described in detail in
The multiplexing and buffer unit 181 may sequentially multiplex and store the frame with the high priority and the frame with the low priority each being outputted for each pixel information from the bit separator 160, and singly output the multiplexed and stored frames.
The header generation unit 182 may assign a sequence number and a priority (two-level priorities are provided in the present specification, however, multi-level priorities may be provided) to the frames outputted from the multiplexing and buffer unit 181, and may receive demodulation information and channel decoding information that is included in modulation and coding scheme (MCS) information 112 required for receiving the frames from the UEP Tx controller 112 to thereby supplement a header.
The channel coding unit 183 may unequally insert channel error correction information depending on a priority of frame data inputted from the header generation unit 182 using channel coding information included in the MCS information 112 provided from the UEP Tx controller 110. Specifically, greater channel error correction information may be inserted in a case of the frame with a high priority, and less channel error correction information may be inserted or no channel error correction information may be inserted in a case of the frame with a low priority.
The symbol mapping and modulation unit 184 may map, in a symbol, bits of the frame outputted from the channel coding unit 183, and modulate the mapped bits according to a modulation scheme for each frame priority provided from the UEP Tx controller 110 to transmit the modulated bits to the reception apparatus.
The UEP reception apparatus 200 includes: a de-modulation and symbol de-mapping device 220 to modulate received radio frequency (RF) signals and extract bit information from a modulated symbol; a channel decoding unit 230 to correct error generation bits from the inserted channel error correction information; a header parsing unit 240 to parse information of a received header and transmit demodulation and channel decoding information of video data and priority and sequencing information received based on the parsed information; a buffer and de-multiplexing unit 250 to store a received video frame and inputting related frame information to a bit combiner 260 depending on the sequencing information and priority information; the bit combiner 260 including a plurality of bit combiners 260a, 260b, and 260c to extract bits for each pixel information from the received video frames; a video data output interface 270; and a UEP receiving controller 210 (hereinafter, referred to as UEP Rx controller).
The UEP Rx controller 210 may receive the negotiation request message 120a of the UEP scheme from the UEP Tx controller 110, and transmit the UEP response message 120b with respect to the negotiation request message 120a. Also, the UEP Rx controller 210 may control a series of procedures associated with receiving a video image using UEP information 211 negotiated through an exchange between the messages 120a and 120b.
The de-modulation and symbol de-mapping device 220, the channel decoding unit 230, and the header parsing unit 240 may receive header information according to a predetermined transmitting/receiving scheme of the header information to sequentially process the received header information. The header parsing unit 240 having parsed the header information may transmit, to the de-modulation and symbol de-mapping device 220 and the channel decoding unit 230, demodulation and channel decoding information of video data signals intended to be received. In this instance, a type of the transmitted information may be MCS index information, which will be described in detail below.
The de-modulation and symbol de-mapping device 220 and the channel decoding unit 230 may appropriately process the received video data signals using the demodulation and channel decoding information transmitted from the header parsing unit 240, and transmit the processed signals to the buffer and de-multiplexing unit 250. In this instance, the header parsing unit 240 may also transmit the sequencing information and priority information obtained from corresponding header information to the buffer and de-multiplexing unit 250.
The buffer and de-multiplexing unit 250 may readily extract a frame with a high priority and a frame with a low priority using the sequencing information and priority information inputted together with the video frame data, and input these frames to the bit combiner 260.
The bit combiner 260 may receive, from the buffer and de-multiplexing unit 250, the frames with high priority and low priority for each pixel information, and also receive, from the UEP Rx controller 210, the color depth and bit separation point for each pixel information to re-configure original pixel information. The re-configured pixel information may be transmitted to the video data output interface 270.
The UEP negotiation request message 120a transmitted from the UEP Tx controller 110 to the UEP Rx controller 210, and the UEP negotiation response message 120b transmitted from the UEP Rx controller 210 to the UEP Tx controller 110 may have an identical structure as illustrated in
A command type field 121 may be a field indicating the UEP negotiation request message or the UEP negotiation response message. A length field 122 may be a field indicating a length of the UEP negotiation request message or the UEP negotiation response message. A UEP type field 123 may be a field indicating a UEP type separated in a conventional art, and may not be limited as a specific value because the present invention is completely compatible with the conventional art.
MCS fields 124a to 124n may be fields indicating MCS types supported for a UEP stream by the UEP Tx controller 110 and UEP Rx controller 210, and may be displayed as a 6-bit (2 bits not being used) index value. In this instance, specific MCS-related parameters corresponding to the index value may be assumed to be shared between the MCS fields.
According to the present invention, to support various color depths indicating pixel information and support a control of a priority for each pixel information, field information, which will be described below, may be supplemented in a structure of the UEP negotiation message. A color format field 130 describing a color video displaying scheme may be displayed in a 1-byte size, and indicate various color types such as RGB, YCbCr, and the like. Specifically, the color format field 130 may be pixel component information indicating pixel components. A color depth field 140 may indicate a bit-field-size value of three pixel elements.
In
A bit separation point field 150 may be supplemented in the structure of the UEP negotiation message, and separate, into bits with a high priority and bits with a low priority, pixel component information being composed of the color depth determined for each pixel element by the color depth field 140.
As an example, as illustrated in
A second byte (b8 to b15) may designate bit point values used when separating pixel elements having a bit field of Y into two levels according to a corresponding priority, and a third byte (b16 to b23) may designate bit point values used when separating pixel elements having a bit field of Z into two levels according to a corresponding priority.
Accordingly, when a byte value is designated as ‘0’, all bits of the corresponding pixel elements may be included in a higher priority frame (displayed as a most significant bit (MSB) frame in
When the byte value designates an arbitrary n value that is greater than ‘0’ and smaller than the color depth values (that is, X, Y, and Z), all n-bits of 0th bit to a (n−1)-th bit in bits indicating the corresponding pixel elements may be included in the LSB frame, and an n-bit to a (color depth value-1)-th bit may be included in the MSB frame.
As described above, as an example of separately controlling the priority for each pixel element, the bit separation point is designated as 0, 8, and 8, respectively, in a YCbCr system having a color depth value of 8:8:8, whereby all bits used to indicate Y may be included in the MSB frame, and all bits used to indicate the CbCr may be included in the LSB frame. As a result, Y signals that are more sensitive to a sense of sight of a human being may be processed to be immune to channel errors in comparison to CbCr signals that are more insensitive to the sense of sight.
An example of R or Y pixel elements whose color depth value is Dx, and whose bit separation point value is Px will be herein described in detail. The bit separator 160a of the UEP Tx apparatus 100 may receive, from the video data input interface 101, the R or Y pixel elements in a series of bit types to thereby separate the received pixel elements in a Dx bit unit. Next, the bit separator 160a of the UEP Tx apparatus 100 may enable 0th bit to (Px−1)th bit of the separated Dx bits to be included in the LSB frame 162, that is, the lower priority frame, and also enable Px th bit to (Dx−1)th bit thereof to be included in the MSB frame 161, that is, the higher priority frame.
When frames having a certain size are configured, the MSB frame 161 and the LSB frame 162 may be processed in the procedure as described in
In particular, according to the present example embodiment, other implemented examples of the present invention may be suggested, in which the color depth and bit separation point of the pixel may be transmitted through the UEP negotiation message as described with reference to
In
A field display-bit length of the color format field 130, the color depth field 140, and the bit separation point field 150 may be adjusted, as necessary. The fields 130, 140, and 150 may be applied to all sub-packets included in an identical data structure.
An individual sub-packet may be the configured MSB frame or LSB frame as described with reference to
The sub-packet type field 810 may be applied in another case other than the MSB/LSB frame separation method described with reference to
As described above, according to the UEP apparatus and UEP method of the present disclosure, more important pixel information may be more strongly protected, thereby preventing significant deterioration of image quality occurring in transmission channel errors in a reception end. Also, an error control may be focused on more important signal elements, thereby improving a transmission speed.
Although a few example embodiments have been shown and described, the present disclosure is not limited to the described example embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these example embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined by the claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2008-0024741 | Mar 2008 | KR | national |
| 10-2008-0041165 | May 2008 | KR | national |
| 10-2008-0127924 | Dec 2008 | KR | national |
This application is a continuation application of U.S. Ser. No. 12/406,329, filed Mar. 18, 2009 now allowed, which claims the benefit of Korean Patent Application Nos. 10-2008-0024741 filed on Mar. 18, 2008, 10-2008-0041165 filed on May 2, 2008 and 10-2008-0127924 filed on Dec. 16, 2008 in the Korean Intellectual Property Office, the disclosures of all of which are incorporated herein by reference.
