Patent Application
20150015782
None
Various embodiments relate to coding used in devices such as video decoders for video signals.
Video encoding has become an important issue for modern video processing devices. Robust encoding algorithms allow video signals to be transmitted with reduced bandwidth and stored in less memory. However, the accuracy of these encoding methods face the scrutiny of users that are becoming accustomed to greater resolution and higher picture quality. Standards have been promulgated for many encoding methods including the H.264 standard that is also referred to as MPEG-4, part 10 or Advanced Video Coding, (AVC). While this standard sets forth many powerful techniques, further improvements are possible to improve the performance and speed of implementation of such methods. The video signal encoded by these encoding methods must be similarly decoded for playback on most video display devices.
An ultra high-definition television (UHDTV) standard has been set that defines a picture with a minimum resolution of 3840×2160 pixels. This format has four times the number of pixels than a 1080p high definition signal. The higher data content in UHDTV requires greater data rates to transmit. Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of ordinary skill in the art through comparison of such systems with the present invention.
In an embodiment of the present invention, the received signal 98 is a broadcast video signal, such as an ultra high definition (UHD) television signal, high definition television signal, enhanced definition television signal or other broadcast video signal that has been transmitted over a wireless medium, either directly or through one or more satellites or other relay stations or through a cable network, optical network or other transmission network. In addition, received signal 98 can be generated from a stored video file, played back from a recording medium such as a magnetic tape, magnetic disk or optical disk, and can include a streaming video signal that is transmitted over a public or private network such as a local area network, wide area network, metropolitan area network or the Internet.
A/V signal 110 can include a digital video signal complying with a digital video codec standard such as H.265 high efficiency video coding (HEVC), H.264 MPEG-4 Part 10 Advanced Video Coding (AVC) including a SVC signal, an encoded stereoscopic video signal having a base layer that includes a 2D compatible base layer and an enhancement layer generated by processing in accordance with an MVC extension of MPEG-4 AVC, or another digital format such as a Motion Picture Experts Group (MPEG) format (such as MPEG1, MPEG2 or MPEG4), Quicktime format, Real Media format, Windows Media Video (WMV) or Audio Video Interleave (AVI), video coding one (VC-1), etc.
In an embodiment, the A/V signal 110 can include a digital audio signal, such as a PCM coded audio signal that is has been compressed via audio compression. In addition, the A/V signal 110 can include encryption data, metadata and/or other control information.
Video display devices 104 can include a television, monitor, computer, handheld device or other video display device that creates an optical image stream either directly or indirectly, such as by projection, based on the processed A/V signal 112 either as a streaming video signal or by playback of a stored digital video file.
The home digital media interface 142 and the home digital media interface 154 have differing data formats. For example, HDMI 142 may be compliant with the 1.4b standard and HDMI 154 can be compliant with a 2.0 or higher standard. Further, while described in context of HDMI standards, HDMI 142 and 154 can be implemented via other signal interfaces with differing data formats. It should be noted that the HDMI 142 and 154 each include corresponding transmit and receive portions that implement physical layer signaling and other coding and formatting in accordance with their respective standards.
In one example of operation, A/V signal 110 contains an ultra HD signal such as a 3840×2160p 50 Hz or 60 Hz, 10 bit signal that is encoded via H.265, H.264, VC1 or other video compression standard and also is encrypted. With full blanking, the signal is 4400×2160. The decoding device 140 operates to decrypt and decode the A/V signal 110 to produce the decoded A/V signal 146 as a 3840×2160p 50 Hz or 60 Hz, 10 bit 4:2:0 signal—with reduced horizontal and vertical resolution for chroma values. In addition, the decoded A/V signal 146 is formatted with reduced blanking such as 4000×2160 or 4 k×2 k instead of full 4400×2160. The decoded A/V signal is optionally unencrypted and formatted for transmission via HDMI 142 in compliance with the 1.4b HDMI standard.
For example, the table below describes two reduced blanking modes to support 4 k×2 k within a 340 MHz TMDS clock rate. The parameters are shown for the 8-bit case as is customary in the HDMI standards even though this mode is intended mainly for 10-bit.
The mapping of the 10-bit video data onto the 8-bit channels could be the same as the standard deep color pixel packing in section 6.5.2 of HDMI 1.4b standard. A comparison of the 4:2:0 and 4:4:4 mapping is shown below.
4:4:4 Mapping:
4:2:0 Mapping:
The VIC code can be 0x7d for 60 Hz frame rates and 0x7e for 50 Hz frame rates. The
HDMI video format field of the VSIF can be 0b001.
The decoding device 140 and reformatting device 150 can each be implemented using a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, co-processors, a micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on operational instructions that are stored in a memory. This memory may be a single memory device or a plurality of memory devices. Such a memory device can include a hard disk drive or other disk drive, read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that when the decoding device 140 and reformatting device 150 implement one or more of their functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry.
Consider the example presented in conjunction with
In this diagram a signal in 4:2:0 format with full luma pixel resolution and ½ horizontal and vertical chroma resolution is upsampled to generate a signal in 4:2:2 format. In particular, the scaling 200 includes a 2:1 vertical upsampling of chroma values.
In this diagram a signal in 4:2:0 format with full luma pixel resolution and ½ horizontal and vertical chroma resolution is upsampled to generate a signal in 4:4:4 format. In particular, the scaling 202 includes a 2:1 vertical and horizontal upsampling of chroma values.
In this diagram a signal in 4:2:0 format with full luma pixel resolution and ½ horizontal and vertical chroma resolution is upsampled to generate a signal in 4:1:1 format. In particular, the scaling 204 includes a 2:1 vertical upsampling and a horizontal downsampling of chroma values.
In an embodiment, the decoded A/V signal includes a 3840×2160p, 60 Hz, 10 bit reduced blanking 4:2:0 signal. The compressed A/V signal can include an ultra HD signal. The first home digital media interface can be HDMI 1.4b compliant and the second home digital media interface can be HDMI 2.0 compliant. The decoded A/V signal can be unencrypted. The decoded A/V signal can be scaled by at least one of: a vertical upscaling, a horizontal upscaling, a vertical downscaling and a horizontal downscaling.
While particular combinations of various functions and features of the present invention have been expressly described herein, other combinations of these features and functions are possible that are not limited by the particular examples disclosed herein are expressly incorporated in within the scope of the present invention.
As may also be used herein, the term(s) “operably coupled to”, “coupled to”, and/or “coupling” includes direct coupling between items and/or indirect coupling between items via an intervening item (e.g., an item includes, but is not limited to, a component, an element, a circuit, and/or a module) where, for indirect coupling, the intervening item does not modify the information of a signal but may adjust its current level, voltage level, and/or power level. As may further be used herein, inferred coupling (i.e., where one element is coupled to another element by inference) includes direct and indirect coupling between two items in the same manner as “coupled to”. As may even further be used herein, the term “operable to” or “operably coupled to” indicates that an item includes one or more of power connections, input(s), output(s), etc., to perform, when activated, one or more its corresponding functions and may further include inferred coupling to one or more other items. As may still further be used herein, the term “associated with”, includes direct and/or indirect coupling of separate items and/or one item being embedded within another item.
As may also be used herein, the terms “processing module”, “processing circuit”, and/or “processing unit” may be a single processing device or a plurality of processing devices. Such a processing device may be a microprocessor, micro-controller, digital signal processor, microcomputer, central processing unit, field programmable gate array, programmable logic device, state machine, logic circuitry, analog circuitry, digital circuitry, and/or any device that manipulates signals (analog and/or digital) based on hard coding of the circuitry and/or operational instructions. The processing module, module, processing circuit, and/or processing unit may be, or further include, memory and/or an integrated memory element, which may be a single memory device, a plurality of memory devices, and/or embedded circuitry of another processing module, module, processing circuit, and/or processing unit. Such a memory device may be a read-only memory, random access memory, volatile memory, non-volatile memory, static memory, dynamic memory, flash memory, cache memory, and/or any device that stores digital information. Note that if the processing module, module, processing circuit, and/or processing unit includes more than one processing device, the processing devices may be centrally located (e.g., directly coupled together via a wired and/or wireless bus structure) or may be distributedly located (e.g., cloud computing via indirect coupling via a local area network and/or a wide area network). Further note that if the processing module, module, processing circuit, and/or processing unit implements one or more of its functions via a state machine, analog circuitry, digital circuitry, and/or logic circuitry, the memory and/or memory element storing the corresponding operational instructions may be embedded within, or external to, the circuitry comprising the state machine, analog circuitry, digital circuitry, and/or logic circuitry. Still further note that, the memory element may store, and the processing module, module, processing circuit, and/or processing unit executes, hard coded and/or operational instructions corresponding to at least some of the steps and/or functions illustrated in one or more of the Figures. Such a memory device or memory element can be included in an article of manufacture.
The present invention has been described above with the aid of method steps illustrating the performance of specified functions and relationships thereof. The boundaries and sequence of these functional building blocks and method steps have been arbitrarily defined herein for convenience of description. Alternate boundaries and sequences can be defined so long as the specified functions and relationships are appropriately performed. Any such alternate boundaries or sequences are thus within the scope and spirit of the claimed invention. Further, the boundaries of these functional building blocks have been arbitrarily defined for convenience of description. Alternate boundaries could be defined as long as the certain significant functions are appropriately performed. Similarly, flow diagram blocks may also have been arbitrarily defined herein to illustrate certain significant functionality. To the extent used, the flow diagram block boundaries and sequence could have been defined otherwise and still perform the certain significant functionality. Such alternate definitions of both functional building blocks and flow diagram blocks and sequences are thus within the scope and spirit of the claimed invention. One of average skill in the art will also recognize that the functional building blocks, and other illustrative blocks, modules and components herein, can be implemented as illustrated or by discrete components, application specific integrated circuits, processors executing appropriate software and the like or any combination thereof.
The present invention may have also been described, at least in part, in terms of one or more embodiments. An embodiment of the present invention is used herein to illustrate the present invention, an aspect thereof, a feature thereof, a concept thereof, and/or an example thereof. A physical embodiment of an apparatus, an article of manufacture, a machine, and/or of a process that embodies the present invention may include one or more of the aspects, features, concepts, examples, etc. described with reference to one or more of the embodiments discussed herein. Further, from figure to figure, the embodiments may incorporate the same or similarly named functions, steps, modules, etc. that may use the same or different reference numbers and, as such, the functions, steps, modules, etc. may be the same or similar functions, steps, modules, etc. or different ones.
Unless specifically stated to the contra, signals to, from, and/or between elements in a figure of any of the figures presented herein may be analog or digital, continuous time or discrete time, and single-ended or differential. For instance, if a signal path is shown as a single-ended path, it also represents a differential signal path. Similarly, if a signal path is shown as a differential path, it also represents a single-ended signal path. While one or more particular architectures are described herein, other architectures can likewise be implemented that use one or more data buses not expressly shown, direct connectivity between elements, and/or indirect coupling between other elements as recognized by one of average skill in the art.
The term “module” is used in the description of the various embodiments of the present invention. A module includes a processing module, a functional block, hardware, and/or software stored on memory for performing one or more functions as may be described herein. Note that, if the module is implemented via hardware, the hardware may operate independently and/or in conjunction software and/or firmware. As used herein, a module may contain one or more sub-modules, each of which may be one or more modules.
While particular combinations of various functions and features of the present invention have been expressly described herein, other combinations of these features and functions are likewise possible. The present invention is not limited by the particular examples disclosed herein and expressly incorporates these other combinations.
