Method and system for assessing, at reception level, the quality of a digital signal, such as a digital audio/video signal
AssigneeTelediffusion de France
InventorsDenis Masse, Jamal Baina
Life of this patent
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Abstract
The invention concerns a method and a system for assessing the quality of a broadcast digital signal. A reference signal (sref) is generated (1001) from an initial signal (so) and jointly broadcast (1002) with a digital signal (sn). At reception level, the broadcast digital signal and reference signal received (snr, sref) are synchronized (2001) and a value D of the distance between the reference signal and the digital signal (snr, sref) is computed (2002) for assigning (2003) a quality value Q. The invention is applicable to the broadcast of audio and/or video digital signals.
Claims16
A method of evaluating on reception the quality of a broadcast digital signal emitted from an initial signal, wherein said method comprises the steps of:
- (a) on emission,
- generating a reference signal representative of said initial signal;
- and
- broadcasting said digital signal and said reference signal jointly;
- and
- (b) on reception,
- synchronizing said broadcast digital signal received and said broadcast reference signal received;
- computing a distance value, as the variance from identity, separating said broadcast digital signal received from said broadcast reference signal received;
- and
- assigning, on the basis of a value criterion of said distance value, a quality value of said digital signal on reception.
In a transmission network for broadcasting a broadcast digital audio signal emitted from an initial signal, said transmission network including, upstream of a device for emitting a broadcast digital audio signal, means for coding said initial signal to produce a coded digital signal, a system for evaluating the quality of said broadcast digital audio signal on reception, comprising at least, upstream:
- means for generating a reference signal representing said initial signal and means for receiving said coded digital audio signal and said reference signal, and
- means for inserting said reference signal in the digital stream of said coded digital signal in order to create a coded emission signal allowing said broadcast digital audio signal to be generated.
In a transmission network for broadcasting a broadcast digital audio signal emitted from an initial signal, said broadcast digital signal being formed from a coded digital signal in which a reference signal representative of said initial signal is inserted, said transmission network including a device for receiving said broadcast digital signal which issues a digital stream formed by a coded digital signal received and a reference signal received, a system for evaluating the quality of said broadcast digital signal on reception comprising, downstream of said device for receiving:
- auxiliary means for decoding said coded digital signal received which receives said coded digital signal received and issues a decoded-coded digital signal;
- means for extracting said broadcast reference signal received which receives said digital stream and issues a control reference signal;
- and
- means for evaluating the transmission quality of said broadcast digital signal which receives said decoded-coded digital signal and said control reference signal and for delivering by applying the distance value criterion, as the variance from identity separating said decoded-coded digital signal from said control reference signal, a signal representative of a quality value on reception a posteriori of said digital signal.
An in-service, real-time picture quality analysis method of measuring degradation of a test digital signal at a test point with respect to a reference signal, said method comprising the steps of:
- generating from the reference signal a set of parameters that characterize the reference signal;
- inserting the set of parameters into a transport stream containing an encoded version of the reference signal for transmission to the test point;
- extracting at the test point the set of parameters from the transport stream;
- generating at the test point from the test signal a corresponding set of parameters, the test signal being a decoded version of the reference signal derived from the transport stream;
- synchronizing at the test point the set of parameters representing the reference signal and the set of parameters representing the test signal;
- and
- comparing the two sets of parameters to produce a picture quality rating that represents the degradation of the test signal with respect to the reference signal.
Dependencies are inferred from the claim text.