News Column

Patent Issued for Video Decoder

May 7, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- A patent by the inventor Munnan, Ravindranath Ramalingaiah (Bengaluru, IN), filed on September 30, 2011, was published online on April 22, 2014, according to news reporting originating from Alexandria, Virginia, by VerticalNews correspondents.

Patent number 8704952 is assigned to STMicroelectronics International N.V. (Amsterdam, NL).

The following quote was obtained by the news editors from the background information supplied by the inventors: "Analog video signals define image data stored by the use of an analog modulation on an electrical signal. There are many established color analog video formats. One such color analog video system specifies the video image in terms of the luminance or luma (Y) and chrominance or chroma (C) of the image.

"An analog video decoder can receive in a single channel or signal a color analog encoded video signal, for example, from a composite video input or from a television broadcast encoded analog signal. The luma and chroma components of the analog video signal can then be separated in such a way that they can then be presented on a screen or display.

"Analog video is used in both consumer and professional applications and is found in many terrestrial television broadcast systems. For example, composite video, a format of analog television picture (picture only) signals, contains all the required video information, including color, in a single line level signal. Composite video is sometimes known as CVBS (composite video broadcast signal). The composite signal is a composite of three source signals Y (luma), U and V (representing hue and saturation or chrominance). Composite video signals can be found, for example, in many standard formats such as NTSC (National Television System Committee), PAL (Phase Alternating Line), and SECAM (Sequential Color with Memory) as well as the various sub-standards of these standards such as PAL-M, PAL-N, NTSC443, PAL-60.

"A typical analog video decoder receives the composite video signal and separates these into the three source signals. However, in order to apply correct color decoding techniques to separate the luma and chroma to produce the correct image output, detecting the correct mode and/or standard of the modulation/encoding allows a more efficient decoding operation to be performed. Some standards can, for example, be detected by their synchronization timings; however, some cannot. For example, the PAL and SECAM standards have closely matched color burst frequencies and synchronization timings.

"Furthermore, determining the color burst position in CVBS is similarly important in accurate video mode detection; under poor broadcast conditions the color burst position can be located in positions other than the designated or expected position on the back porch region of the signal."

In addition to the background information obtained for this patent, VerticalNews journalists also obtained the inventor's summary information for this patent: "Embodiments of the present application aim to address the above problems.

"There is provided according to the disclosure a video decoder comprising: a hue and saturation separator configured to demodulate from a component video signal chroma signal a hue signal and a saturation signal; and a video signal determiner configured to determine at least one video signal characteristic of the component video signal dependent on the hue and saturation signal.

"The video signal determiner may comprise a mode determiner configured to determine the encoding standard of the video signal.

"The mode determiner may comprise: a signal lock detector configured to determine when a phase alternating line phase lock occurs between the hue signal and saturation signal; a sequence matcher configured to receive the video signal chroma signal and determine when the D.sub.b and D.sub.r sequence from the chroma signal match; and an encoding mode selector configured to output an encoding standard indicator dependent on the signal lock detector and sequence matcher.

"The encoding mode selector may be configured to output a phase alternating line encoding standard indicator when the signal lock detector determines the hue signal and the saturation signal are phase locked.

"The encoding mode selector may be configured to output a SECAM encoding standard indicator when the signal lock detector fails to determine the hue signal and the saturation signal are phase locked and the sequence matcher determines the D.sub.b and D.sub.r sequence from the chroma signal match.

"The encoding mode selector may be configured to output an unknown encoding standard indicator when the signal lock detector fails to determine the hue signal and the saturation signal are phase locked and the sequence matcher fails to determine the D.sub.b and D.sub.r sequence from the chroma signal match.

"The video signal determiner may comprise a color burst determiner configured to determine a location of a color burst signal within the video signal.

"The color burst determiner may comprise: an absolute value determiner configured to sum the modulus values for the saturation and hue signals; and a burst position determiner configured to determine the color burst location dependent on the summed modulus values for the saturation and hue signals.

"The color burst determiner may further comprise a burst position indicator generator configured to output an indicator value relative to a horizontal synchronization signal.

"The burst position determiner may comprise a comparator configured to compare the sum of the modulus values for the saturation and hue signals against a threshold value and return a comparison indicator value.

"The comparator may be configured to output the comparison indicator dependent on a backporch indicator signal.

"The burst position determiner may be configured to receive a backporch indicator signal configured to indicate when the video signal is in the backporch region.

"The burst position determiner may comprise a threshold determiner configured to determine the threshold value.

"The threshold determiner may be configured to determine the threshold value as half the maximum value of the sum the modulus values for the saturation and hue signal.

"The burst position determiner may further comprise: a splitter configured to split the comparator comparison indicator value signal into a determined number of parts; and a counter configured to examine at least one part comparator comparison indicator value signal and generate a counter value output.

"The counter may be further configured to: increment the counter value output when the comparator comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is greater than the threshold for a greater portion of the part; and decrement the counter value output when the comparator comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is less than the threshold for a greater portion of the part.

"The degree of change of the counter value output for at least one part may be dependent on the ratio of the occurrence of the sum of the modulus values for the saturation and hue signals is greater than or less than the threshold.

"The burst position determiner may further comprise a local maximum determiner configured to determine the location of a color burst signal at a local maximum counter value output.

"According to a second aspect there is provided a method for video decoding comprising: demodulating from a component video signal chrome signal a hue signal and a saturation signal; and determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal.

"Determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise determining the encoding standard of the video signal.

"Determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise: determining when a phase alternating line phase lock occurs between the hue signal and saturation signal; receiving the video signal chrome signal and determining when a D.sub.b and D.sub.r sequence from the chrome signal match; and outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match.

"Outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise outputting a phase alternating line encoding standard indicator when the hue signal and the saturation signal are phase locked.

"Outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise outputting a SECAM encoding standard indicator when the hue signal and the saturation signal are not phase locked and the D.sub.b and D.sub.r sequence from the chroma signal match.

"Outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise outputting an unknown encoding standard indicator when the hue signal and the saturation signal are not phase locked and the D.sub.b and D.sub.r sequence from the chroma signal are not matched.

"Determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise determining a location of a color burst signal within the video signal.

"Determining the location of a color burst signal within the video signal may comprise: summing the modulus values for the saturation and hue signals, and determining the color burst location dependent on the summed modulus values for the saturation and hue signals.

"Determining the location of a color burst signal within the video signal further may comprise outputting a color burst indicator value relative to a horizontal synchronization signal.

"Determining the location of a color burst signal within the video signal may comprise: comparing the sum of the modulus values for the saturation and hue signals against a threshold value; and returning a comparison indicator value.

"Returning a comparison indicator value may comprise outputting the comparison indicator dependent on a backporch indicator signal.

"Determining the location of a color burst signal may comprise receiving a backporch indicator signal configured to indicate when the video signal is in the backporch region.

"Determining the location of a color burst signal may comprise determining the threshold value.

"Determining the threshold value may comprise determining the threshold value as half the maximum value of the sum the modulus values for the saturation and hue signal.

"Determining the location of a color burst signal may further comprise: splitting the comparison indicator value signal into a determined number of parts; and examining at least one part comparison indicator value signal to generate a counter value output.

"Examining at least one part comparison indicator value signal to generate a counter value output may comprise: incrementing the counter value output when the comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is greater than the threshold for a greater portion of the part; and decrementing the counter value output when the comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is less than the threshold for a greater portion of the part.

"A degree of change of the incrementing the counter value output or decrementing the counter value output for at least one part may be dependent on the ratio of the occurrence of the of the sum of the modulus values for the saturation and hue signals is greater than or less than the threshold.

"The determining the location of a color burst signal may further comprise determining the location of the color burst signal at a local maximum counter value output.

"According to a third aspect there is provided a chipset comprising the video decoder as discussed herein.

"According to a fourth aspect there is provided a television receiver comprising the video decoder as discussed herein.

"According to a fifth aspect there is provided an integrated circuit comprising the video decoder as discussed herein.

"According to a sixth aspect there is provided a video player comprising the video decoder as discussed herein.

"According to a seventh aspect there is provided a processor-readable medium encoded with instructions that, when executed by a processor, perform a method for decoding video as discussed herein.

"According to an eighth aspect there is provided apparatus comprising at least one processor and at least one memory, including computer code, for one or more programs, the at least one memory and the computer code configured to, with the at least one processor, cause the apparatus to at least perform a method as discussed herein.

"According to a ninth aspect there is provided a video decoder comprising: means for demodulating from a component video signal chroma signal a hue signal and a saturation signal; and means for determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal.

"The means for determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise means for determining the encoding standard of the video signal.

"The means for determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise: means for determining when a phase alternating line phase lock occurring between the hue signal and saturation signal; means for receiving the video signal chroma signal and determining when a D.sub.b and D.sub.r sequence from the chrome signal match; and means for outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match.

"The means for outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise means for outputting a phase alternating line encoding standard indicator when the hue signal and the saturation signal are phase locked.

"The means for outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise means for outputting a SECAM encoding standard indicator when the hue signal and the saturation signal are not phase locked and the D.sub.b and D.sub.r sequence from the chroma signal match.

"The means for outputting an encoding standard indicator dependent on the condition of the signal lock and sequence match may comprise means for outputting an unknown encoding standard indicator when the hue signal and the saturation signal are not phase locked and the D.sub.b and D.sub.r sequence from the chroma signal are not matched.

"The means for determining at least one video signal characteristic of the component video signal dependent on the hue and saturation signal may comprise means for determining a location of a color burst signal within the video signal.

"The means for determining the location of a color burst signal within the video signal may comprise: means for summing the modulus values for the saturation and hue signals; and means for determining the color burst location dependent on the summed modulus values for the saturation and hue signals.

"The means for determining the location of a color burst signal within the video signal may further comprise means for outputting a color burst indicator value relative to a horizontal synchronization signal.

"The means for determining the location of a color burst signal within the video signal may comprise: means for comparing the sum of the modulus values for the saturation and hue signals against a threshold value; and means for returning a comparison indicator value.

"The means for returning a comparison indicator value may comprise means for outputting the comparison indicator dependent on a backporch indicator signal.

"The means for determining the location of a color burst signal may comprise means for receiving a backporch indicator signal configured to indicate when the video signal is in the backporch region.

"The means for determining the location of a color burst signal may comprise means for determining the threshold value.

"The means for determining the threshold value may comprise means for determining the threshold value as half the maximum value of the sum the modulus values for the saturation and hue signal.

"The means for determining the location of a color burst signal may further comprise: means for splitting the comparison indicator value signal into a determined number of parts; and means for examining at least one comparison indicator value signal to generate a counter value output.

"The means for examining each comparison indicator value signal to generate a counter value output may comprise: means for incrementing the counter value output when the comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is greater than the threshold for a greater portion of the part; and means for decrementing the counter value output when the comparison indicator value signal indicates that the occurrence of the sum of the modulus values for the saturation and hue signals is less than the threshold for a greater portion of the part.

"A degree of change of the counter value by the means for incrementing the counter value output and the means for decrementing the counter value output for at least one part is dependent on the ratio of the occurrence of the of the sum of the modulus values for the saturation and hue signals being greater than or less than the threshold.

"The means for determining the location of a color burst signal may further comprise: means for determining the location of the color burst signal at a local maximum counter value output."

URL and more information on this patent, see: Munnan, Ravindranath Ramalingaiah. Video Decoder. U.S. Patent Number 8704952, filed September 30, 2011, and published online on April 22, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=61&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=3026&f=G&l=50&co1=AND&d=PTXT&s1=20140422.PD.&OS=ISD/20140422&RS=ISD/20140422

Keywords for this news article include: STMicroelectronics International N.V.

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Source: Electronics Newsweekly


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