摘要:
A watermark signal provider comprises a time-frequency-domain waveform provider to provide time-domain waveforms for a plurality of frequency subbands. The time-frequency-domain waveform provider is configured to map a given value of a time-frequency-domain representation onto a bit shaping function, a temporal extension of which is longer than a bit interval, such that there is a temporal overlap between bit shaped functions provided for temporally subsequent values of the time-frequency-domain representation of the same frequency subband. A time-domain waveform of a given frequency subband contains a plurality of bit shaped functions provided for temporally subsequent values of the time-frequency-domain representation. The water mark signal provider further has a time-domain waveform combiner.
摘要:
A watermark signal provider provides a watermark signal suitable for being hidden in an audio signal when the watermark signal is added to the audio signal, such that the watermark signal represents watermark data. The watermark signal provider includes a psychoacoustical processor for determining a masking threshold of the audio signal; and a modulator for generating the watermark signal from a superposition of sample-shaping functions spaced apart from each other at a sample time interval of a time-discrete representation of the watermark data, each sample-shaping function being amplitude-weighted with a respective sample of the time-discrete representation, multiplied by a respective amplitude weight depending on the masking threshold, the modulator being configured such that the sample time interval is shorter than a time extension of the sample-shaping functions; and the respective amplitude weight also depends on samples of the time-discrete representation neighboring the respective sample in time.
摘要:
A watermark generator for providing a watermark signal in dependence on binary message data includes an information processor configured to provide, in dependence on information units of the binary message data, a first time-frequency domain representation, values of which represent the binary message data. The watermark generator also includes a differential encoder configured to derive a second time-frequency domain representation from the first time-frequency-domain representation, such that the second time-frequency-domain representation includes a plurality of values, wherein a difference between two values of the second time-frequency-domain representation represents a corresponding value of the first time-frequency-domain representation, in order to obtain a differential encoding of the values of the first time-frequency-domain representation. The watermark generator also includes a watermark signal provider configured to provide the watermark signal on the basis of the second time-frequency-domain representation.
摘要:
A watermark decoder includes a time-frequency-domain representation provider, a memory unit, a synchronization determiner and a watermark extractor. The time-frequency-domain representation provider provides a frequency-domain representation of the watermarked signal for a plurality of time blocks. The memory unit stores the frequency-domain representation of the watermarked signal for a plurality of time blocks. Further, the synchronization determiner identifies an alignment time block based on the frequency-domain representation of the watermarked signal of a plurality of time blocks. The watermark extractor provides binary message data based on stored frequency-domain representations of the watermarked signal of time blocks temporally preceding the identified alignment time block considering a distance to the identified alignment time block.
摘要:
A watermark generator for providing a watermark signal in dependence on binary message data, the watermark generator has an information spreader configured to spread an information unit to a plurality of time-frequency-domain values, to obtain a spread information representation. The watermark generator also has a synchronization inserter configured to multiplicatively combine the spread information representation with a synchronization sequence to obtain a combined information-synchronization representation. The watermark generator also has a watermark signal provider configured to provide the watermark signal on the basis of the combined information-synchronization representation. A watermark decoder, methods and computer programs are also described.
摘要:
A watermark generator for providing a watermark signal in dependence on binary message data includes an information processor configured to provide, in dependence on a single message bit of the binary message data, a 2-dimensional spread information representing the message bit in the form of a set of time-frequency-domain values. The watermark generator also includes a watermark signal provider configured to provide the watermark signal on the basis of the 2-dimensional spread information.A watermark detector, methods and computer programs are also described.
摘要:
An audio encoder, an audio decoder or an audio processor includes a filter for generating a filtered audio signal, the filter having a variable warping characteristic, the characteristic being controllable in response to a time-varying control signal, the control signal indicating a small or no warping characteristic or a comparatively high warping characteristic. Furthermore, a controller is connected for providing the time-varying control signal, which depends on the audio signal. The filtered audio signal can be introduced to an encoding processor having different encoding algorithms, one of which is a coding algorithm adapted to a specific signal pattern. Alternatively, the filter is a post-filter receiving a decoded audio signal.
摘要:
An audio encoder has a common preprocessing stage, an information sink based encoding branch such as spectral domain encoding branch, a information source based encoding branch such as an LPC-domain encoding branch and a switch for switching between these branches at inputs into these branches or outputs of these branches controlled by a decision stage. An audio decoder has a spectral domain decoding branch, an LPC-domain decoding branch, one or more switches for switching between the branches and a common post-processing stage for post-processing a time-domain audio signal for obtaining a post-processed audio signal.
摘要:
An audio signal synthesizer generates a synthesis audio signal having a first frequency band and a second synthesized frequency band derived from the first frequency band and comprises a patch generator, a spectral converter, a raw signal processor and a combiner. The patch generator performs at least two different patching algorithms, each patching algorithm generating a raw signal. The patch generator is adapted to select one of the at least two different patching algorithms in response to a control information. The spectral converter converts the raw signal into a raw signal spectral representation. The raw signal processor processes the raw signal spectral representation in response to spectral domain spectral band replication parameters to obtain an adjusted raw signal spectral representation.
摘要:
An audio encoder, an audio decoder or an audio processor includes a filter for generating a filtered audio signal, the filter having a variable warping characteristic, the characteristic being controllable in response to a time-varying control signal, the control signal indicating a small or no warping characteristic or a comparatively high warping characteristic. Furthermore, a controller is connected for providing the time-varying control signal, which depends on the audio signal. The filtered audio signal can be introduced to an encoding processor having different encoding algorithms, one of which is a coding algorithm adapted to a specific signal pattern. Alternatively, the filter is a post-filter receiving a decoded audio signal.