US 6,788,347 B1 · HDTV downconversion system

Abstract

A video decoder compliant with the Advanced Television Systems Standard (ATSC) includes circuitry which decodes an ATSC encoded image and employs a downconversion process to produce a standard definition video signal. The video decoder includes a frequency-domain filter to reduce the resolution of the ATSC encoded signal. The video decoder downconversion system also includes a formatting section having vertical and horizontal filters, as well as resampling processing, to format the decoded and downconverted video image for a particular display and aspect ratio. The decoder senses the display format of the encoded video signal and changes the processing provided by the decoder to produce a standard definition output signal regardless of the display format of the encoded input signal. The system also includes a format converter which may be programmed to use a plurality of methods to convert the aspect ratio of the input signal for display on a display device having a different aspect ratio. In one mode, the system sequences through the possible methods to allow the user to select one method.

Claims18

Dependent claims

A digital video signal conversion system for decoding and reformatting a baseband encoded digital video signal which sequentially represents first and second video display formats to produce a decoded video signal suitable for display in a predetermined video display format, each video display format having an aspect ratio and a resolution, the system comprising:

a digital video signal decoder including:
an input terminal coupled to receive the encoded digital video signal;
data retrieval circuitry which extracts from the encoded digital video signal an indication of the video display format for the decoded video signal;
and
signal processing circuitry which decodes the encoded digital video signal to produce an output video signal, wherein the decoder is responsive to a control signal to process the encoded digital video signal according to respective first and second down conversion processes to produce an output signal in the predetermined video display format from encoded digital video signals in the respective first and second video display formats;
and
a controller, coupled to receive data which identifies the extracted video display format, the controller producing control signals for the digital video signal decoder which cause the decoder to convert the encoded digital video signal corresponding to the extracted display format into the output video signal having the predetermined video display format in both the first and second intervals;
wherein the encoded digital video signal is encoded using a frequency-domain transform operation and the digital video signal decoder includes a low-pass filter which operates on the frequency domain coefficient of the frequency-domain transformed digital video signal to cause the digital video signal decoder to produce a decoded digital video signal having a resolution less than a resolution specified by the extracted video display format.

5 more elements

A digital video signal conversion system for decoding and reformatting a baseband encoded digital video signal, which is encoded using a frequency-domain transform operation and which may represent a plurality of video display formats, to produce a decoded video signal, each video display format having an aspect ratio and a resolution, the system comprising;

a display device having a predetermined video display format;
a digital video signal decoder including:
an input terminal coupled to receive the encoded digital video signal;
data retrieval circuitry which extracts from the encoded digital video signal an indication of the video display format for the decoded video signal;
a low-pass filter, responsive to a first control signal, which operates on frequency domain coefficients of the frequency-domain transformed digital video signal to selectivity cause the digital video signal decoder to produce a decoded digital video signal having a resolution less than the resolution of the extracted video display format;
and
signal processing circuitry, responsive to a second control signal, which decodes the filtered frequency domain encoded digital video signal to produce an output video signal;
and
a controller, coupled to receive data which identifies the predetermined video display format and the extracted video display format, the controller producing the control signals for the digital video signal decoder which cause the decoder to convert the encoded digital video signal corresponding to the extracted display format into the output video signal having the predetermined video display format.

6 more elements

A digital video signal conversion system for decoding and reformatting a baseband encoded digital video signal which is encoded using a frequency domain transform operation and which represents a video display format having a first aspect ratio to produce a decoded video signal suitable for display in a predetermined video display format having a second aspect ratio, different from the first aspect ratio, the system comprising:

a digital video signal decoder including:
an input terminal coupled to receive the encoded digital video signal;
data retrieval circuitry which extracts from the encoded digital video signal an indication of the aspect ratio for the decoded video signal;
and
signal processing circuitry which decodes the encoded digital video signal to produce an output video signal, wherein the decoder is responsive to a control signal to process the encoded digital video signal according to respective first and second down conversion processes, each of the first and second down conversion processes including a low-pass filter which operates on frequency domain coefficient of the frequency-domain encoded video signal to produce an output signal in the predetermined video display format having respective first and second conversions between the first aspect ratio and the second aspect ratio;
and
a controller, coupled to receive data which identifies the extracted video display format, the controller producing control signals for the digital video signal decoder which cause the decoder to sequentially convert the decoded video signal having the first aspect ratio into a first and second output signals having, respectively, the first and second conversions between the first aspect ratio and the second aspect ratio.

4 more elements

Dependencies are inferred from the claim text.

HDTV downconversion system

Life of this patent

HDTV downconversion system

Life of this patent

Abstract

Claims18