Fault detection using embedded watermarks
View Patent ↗Detection of faults in a transmitted signal stream occurs by recovering, from the information stream, a water mark embedded in the stream prior to transmission. The embedded watermark has data characteristic of stream quality. Thereafter, the at least one watermark property is analyzed to detect faults in the received information stream.
1. A method comprising the steps of:
recovering, from a received information stream, a watermark embedded in the stream, the watermark having data that is characteristic of stream quality; the watermark data including a program identifier that identifies a program within the information stream and wherein the watermark data includes a successively increasing count which identifies a video frame in which the watermark data is embedded; and
analyzing the watermark to establish the quality of the received information stream by (a) comparing the program identifier to a reference program identifier and (b) comparing the successively increasing count of successively recovered watermarks to a previous watermark count to determine whether the count has increased.
2. The method according to claim 1 wherein the watermark is recovered from a baseband portion of received information stream following compression transcoding of the stream.
3. The method according to claim 1 wherein the watermark is recovered from the received information stream prior to compression transcoding of the stream.
4. Apparatus comprising:
a receiver for receiving an information stream having a watermark embedded in the stream, the watermark having data that is characteristic of stream quality the watermark data including a program identifier that identifies a program within the information stream and wherein the watermark data includes a successively increasing count which identifies a video frame in which the watermark data is embedded;
a watermark detector for extracting the data from the watermark; and
a fault detector for analyzing the extracted data to detect whether a fault exists in the received information stream by comparing (a) the program identifier to a reference program identifier and (b) comparing the successively increasing count of successively recovered watermarks to a previous watermark count to determine whether the count has increased.