WO1994010771A1 - Transmission simultanee de signaux sonores et de donnees - Google Patents

Transmission simultanee de signaux sonores et de donnees Download PDF

Info

Publication number
WO1994010771A1
WO1994010771A1 PCT/GB1993/002261 GB9302261W WO9410771A1 WO 1994010771 A1 WO1994010771 A1 WO 1994010771A1 GB 9302261 W GB9302261 W GB 9302261W WO 9410771 A1 WO9410771 A1 WO 9410771A1
Authority
WO
WIPO (PCT)
Prior art keywords
signal
frequency
data
bit stream
auxiliary
Prior art date
Application number
PCT/GB1993/002261
Other languages
English (en)
Inventor
John Robert Emmett
Original Assignee
Thames Television Plc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thames Television Plc filed Critical Thames Television Plc
Priority to EP93924159A priority Critical patent/EP0619928A1/fr
Publication of WO1994010771A1 publication Critical patent/WO1994010771A1/fr

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/28—Arrangements for simultaneous broadcast of plural pieces of information
    • H04H20/33—Arrangements for simultaneous broadcast of plural pieces of information by plural channels
    • H04H20/34—Arrangements for simultaneous broadcast of plural pieces of information by plural channels using an out-of-band subcarrier signal
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G7/00—Volume compression or expansion in amplifiers
    • H03G7/008—Control by a pilot signal

Definitions

  • This invention relates to a method of transmitting an audio signal and data simultaneously over a single transmission channel, ir which method the data is encoded to form an auxiliary signal occupying a predetermined portion of the audible spectrum and the audio and auxiliary signals are combined for transmission.
  • the invention also relates to a transmitter for implementing such a method and to a receiver for data transmitted by such a transmitter.
  • Such a method is known from US-A-4238849.
  • the data is used to modulate one or more pilot signals the frequencies of which lie within the audible range but above the frequency range of the transmitted audio signal.
  • the spectral energy of an incoming sound signal is analysed to determine a threshold of audibility for the pilot signals and their amplitudes are continuously adjusted to lie below this threshold.
  • the transmission rate for the data is constant except when the threshold is determined to be too low to permit satisfactory transmission at this rate; when such a situation occurs the data transmission is interrupted. It is an object of the invention to enable data to be transmitted even when the spectral energy of the incoming sound signal is substantially zero.
  • a method as defined in the first paragraph is characterized in that the audio signal is derived from an incoming sound signal by digitization into a series of multi-bit samples which are compressed according to a floating point technique, in that the auxiliary signal is a bit stream having the form of a carrier signal modulated by the data, the frequency of the carrier signal being one half the sample frequency, and in that the successive bits of the bit stream are substituted for the least significant bits of the frequency component of the audio signal which lies within a frequency range extending from a frequency equal to one half the sample frequency to a given lower frequency.
  • the audio signal is derived from an incoming sound signal by digitization into a series of multibit samples which are compressed according to a floating point technique, for example according to the NICAM standard (see, for example, "Television" March 1988 pages 368 - 369, particularly Fig. 4 on page 368) , and the successive bits of the bit stream are substituted for the least significant bits of a frequency component of this audio signal, the effective level of the auxiliary signal is automatically continuously adapted to the level of the sound signal represented by the audio signal. Furthermore, choosing the said frequency component to be that which lies within a frequency range extending from a frequency equal to one half the sample frequency to a given lower frequency, i.e.
  • the auxiliary signal is a bit stream having the form of a carrier signal modulated by the data, the frequency of the carrier signal being one half the sample frequency, allows use to be made of the fact that the threshold of audibility rises steeply at the top of the audible frequency range; it can be arranged that the effective level of the auxiliary signal remains below the threshold of audibility, allowing data to continue to be transmitted, even when the spectral energy of the incoming sound signal is substantially zero (silence) .
  • said frequency component may be substituted by successive bits of respective bit streams if desired.
  • further data may be transmitted simultaneously with the audio signal over the transmission path, the further data being encoded to form a second auxiliary signal, the second auxiliary signal being a second bit stream having the form of a second carrier signal modulated by the further data, the frequency of the second carrier signal being one half the sample frequency, the successive bits of the second bit stream being substituted for the second-to-least-significant bits of said frequency component of the audio signal.
  • still further data may be also transmitted simultaneously with the audio signal over the transmission path, the still further data being encoded to form a third auxiliary signal, the third auxiliary signal being a third bit stream having the form of a third carrier signal modulated by the still further data, the frequency of the third carrier signal being one half the sample frequency, the successive bits of the third bit stream being substituted for the third- to-least-significant bits of said frequency component of the audio signal.
  • said frequency component is removed from said series of multibit samples by filtering, the successive bits of the or each bit stream are then substituted for the bits of the relevant significance of said frequency components, and the result is added back to the series of multibit samples from which said frequency component has been removed.
  • the invention provides a transmitter for transmitting an audio signal and data simultaneously over a single transmission channel, comprising an encoder for encoding the data to form an auxiliary signal occupying a predetermined portion of the audible spectrum and a signal combiner for combining the audio and auxiliary signals for transmission, characterized in that compression means are provided for compressing an incoming digitally sampled sound signal according to a floating point technique to produce the audio signal, the encoder is arranged to generate the auxiliary signal as a bit stream having the form of a carrier signal modulated by the data, the frequency of the carrier signal being one half the sample frequency, and substitution means are provided for substituting the successive bits of the bit stream for the least significant bits of the frequency component of the audio signal which lies within a frequency range extending from a frequency equal to one half the sample frequency to a given lower frequency.
  • the invention provides a receiver for data transmitted simultaneously with an audio signal over a single transmission path by such a transmitter, comprising a synchronous demodulator for said auxiliary signal, and means for deriving from the transmitted combined audio and auxiliary signals that frequency component thereof which lies within said frequency range and applying the least significant bits of the derived frequency component to said synchronous demodulator.
  • Fig. 1 is a block diagram of part of a transmitter for transmitting an audio signal and data simultaneously over a single transmission channel
  • Fig. 2 is a block diagram of part of a receiver for a signal transmitted by the transmitter of Fig. 1.
  • Fig. 1 an incoming sound signal, for example the left or right channel of a stereo pair, is received at an input 1.
  • This signal is digitized in a sampler 2 into a series of multibit samples which are compressed in a compressor 3 according to a floating point technique, in the present case in accordance with the NICAM standard.
  • the effect of the compression at 3 is that large values of the samples are produced at the output 4 of compressor 3 with relatively coarse resolution whereas small values of the samples are produced with relatively fine resolution.
  • the audio signal comprising the series of samples produced at the output 4 is applied both to a high-pass filter 5 and to a digital subtractor 6.
  • the high-pass filter 5 has a cut-off frequency equal to one quarter the frequency of the samples occurring at the output 4, the latter frequency being in the present example 32KHz.
  • the output signal of the filter 5 consists of the frequency component of the audio signal appearing at the output 4 which lies within the frequency range 8KHz to 16KHz (the sampler 2 incorporating an anti-alias low-pass filter having a cut-off frequency equal to half the sample frequency, i.e. to 16KHz) .
  • the output signal of filter 5 is applied to the subtractor 6 which therefore produces at its output 7 the frequency component of the audio signal which lies below 8KHz.
  • This frequency component is applied to one input of a digital adder 8.
  • the path 10 leads to an accumulator 44 which accumulates the successive stripped least significant bits and, each time the accumulated value becomes equal to the value of the least significant bit of the samples carried on the path 11, applies this value to a second input 14 of adder 13.
  • This value is therefore added to the sample currently applied to the input 12 of adder 13 to compensate for d.c. level changes which occur in the samples carried by the path 11 due to the stripping of the least significant bits in stripper 9.
  • the resulting compensated samples appearing at the output of adder 13 are applied to a second input of adder 8.
  • Data to be transmitted simultaneously with the audio signal is applied serially to an input 15 and thence to a first input 17 of an adder 16 which may take the form of an
  • a signal generator 18 has its output 19 connected to a second input 20 of the adder 16.
  • Generator 18 generates a binary signal the fundamental frequency of which is equal to half the sample frequency, i.e. to 16KHz in the present example.
  • generator 13 may comprise a simple clock signal generator having a frequency equal to 16KHz although in practice some spectral spreading of the output signal thereof is preferred, in which case generator 18 may comprise a maximum length sequence generator (known per se) in the form of a shift register having its output ExORed with the output of another one of its stages and the result fed back to its input, the shift register being clocked at the sample frequency, i.e. at 32KHz in the present example.
  • auxiliary signal appears on the adder output 21, this auxiliary signal being a bit stream having the form of a carrier signal modulated by the data applied to the input 15, this carrier signal having a frequency equal to one half the sample frequency, i.e. to 16KHz in the present example.
  • the bit stream appearing at the output 21 is applied to a third input of the adder 8..
  • the signal appearing at the output 22 of adder 8 therefore consists of a succession of multibit samples, these samples carrying at full resolution the frequency component of the audio signal appearing at the output 4 of compressor 3 which lies below 8KHz, (derived from the output 7 of subtractor 6) and, with one bit less resolution, the frequency component which lies above 8KHz (derived from the adder 13), the least significant bits of the latter component being substituted by the successive bits of the auxiliary signal produced at the output 21 of adder 16.
  • the signal appearing at the output 22 may be further processed at 23 for transmission, for example scrambled according to another aspect of the NICAM standard, the result appearing at an output 24.
  • Many of the operations occurring in the receiver of Fig. 2 are similar to, or the inverse of, operations occurring in the transmitter of Fig. 1.
  • the signal transmitted from the output 24 of the transmitter of Fig. 1 is received at 25 and processed at 26 in a manner which is the inverse of that occurring in the processor 23 of Fig. 1.
  • the resulting samples are applied both to one input of a subtractor 27 and to a high pass filter 28 which has the same characteristic as the filter 5 of Fig. 1.
  • the output signal of filter 28 is applied both to a second input of subtractor 27 and to a bit stripper 29.
  • the output signal of the subtractor 27 therefore consists of a sequence of multibit samples representing the frequency component of the audio signal lying below 8KHz. These samples are applied to one input of an adder 30.
  • the bit stripper 29 diverts the least significant bits of the samples appearing at the output of filter 28 onto a path 31 and supplies the remaining bits of these samples to a path 32.
  • the samples on the path 32 are relatively coarsely quantized representations of the frequency component of the audio signal lying above 8KHz and are added in the adder 30 to the samples produced by subtractor 27, i.e. to the samples representing the frequency component below 8KHz.
  • the output samples of adder 30 are expanded in an expander 33 which operates in an inverse manner to the compressor 3 of Fig.l.
  • the expanded samples produced by expander 33 are converted to analogue form in a D/A converter 34 and applied to an output 35 for reproduction as sound.
  • the least significant bits diverted onto the path 31 are applied to one input of an adder 36 which operates in the same way as the adder 16 of Fig. 1.
  • a second input of the adder 36 is fed from the output of a signal generator 37 which is arranged to generate an output signal which is identical to that generated by the generator 18 of Fig. 1 and is synchronised therewith; synchronism may be achieved by means of a correlator fed with the output of the generator 37 and the bit stream occurring on the path 31 in a manner which is conventional where spread spectrum techniques are employed.
  • Adder 36 in consequence therefore operates as a synchronous demodulator for the auxiliary signal carried by the path 31, supplying a succession of data bits identical to those applied to input 15 of Fig. 1 to an output 38,
  • more than one of the least significant bits of each of the output samples of filter 5 may be replaced by a bit of a respective auxiliary signal if desired, in which case the stripper 9 of Fig. 1 will have to be arranged to strip the appropriate number of bits and the adder 16 together with its data input be duplicated an appropriate number of times, each of the resulting adders then being arranged to generate a stream of bits of the respective significance. If this is the case the data rates carried by the bits of the various significances are preferably lower the greater the significance is, in order to shape the spectrum of the auxiliary signal in such a way that it has a relatively wide bandwidth for auxiliary signals having a relatively low effective amplitude and a relatively narrow bandwidth for auxiliary signals having a relatively high effective amplitude.
  • the data rate transmitted is constant. However, this is not necessarily the case; if desired the data rate can be adaptively adjusted in accordance with what will be audibly masked by the spectral energy in the audio signal.
  • Such adaptation is known per se, for example from conference publication Proc. ICASSP90, Alberquerque, New Mexico, April 3 - 6 1990, pages 1097 - 1100, and may be achieved in the transmitter of Fig. 1 by analysing the spectrum of the output signals of compressor 3 and adjusting both the number of bits which are stripped by stripper 9 and the number of adders similar to 16 which are employed in accordance with the result so that more bits are stripped and more adders are employed the greater the spectral energy which is currently present to mask the auxiliary signals.
  • one or more data bits may simply be arithmetically added to alternate ones of the output samples of adder 13 and arithmetically subtracted from the other alternate ones of these samples. If desired the accumulator 44 and adder 13 of Fig. 1 may be omitted although, as mentioned previously, this may give rise to problems in respect of the average d.c. level of the bit-stripped samples.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Transmission Systems Not Characterized By The Medium Used For Transmission (AREA)

Abstract

Selon cette invention un signal sonore fourni à une entrée (1) est numérisé dans un échantillonneur (2) et comprimé en virgule flottante dans un compresseur (3). Le résultat est divisé en un premier signal qui comprend le constituant spectral dont la fréquence maximale correspond au quart de la fréquence d'échantillonnage et en un deuxième signal comprenant le constituant spectral dont la fréquence se situe entre un quart et une moitié de la fréquence d'échantillonnage, à l'aide d'un filtre (5) et d'une unité de soustraction (6), le premier signal étant directement fourni à une unité (8) d'addition. Le deuxième signal est fourni à l'unité d'addition (8) après que le bit le moins significatif de chacun de ses échantillons constitutifs ait été éliminé dans une unité de suppression (9) de bit. Un signal de données fourni à une deuxième entrée (15) est codé par une unité d'addition (16) et un générateur (18) de signal de porteuse sous forme d'un train de bits ayant la forme d'un signal de porteuse modulé par les données, la fréquence du signal de porteuse étant égale à la moitié de la fréquence d'échantillonnage. Ce train de bits est également fourni à l'unité d'addition de sorte que ces bits remplacent effectivement les bits les moins significatifs éliminés du deuxième signal. Plus d'un des bits les moins significatifs du deuxième signal peut être remplacé de la sorte. Le signal de sortie de l'unité d'addition constitue le signal destiné à la transmission, son constituant de données étant inaudible lorsque le signal sonore est reproduit.
PCT/GB1993/002261 1992-11-03 1993-11-03 Transmission simultanee de signaux sonores et de donnees WO1994010771A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP93924159A EP0619928A1 (fr) 1992-11-03 1993-11-03 Transmission simultanee de signaux sonores et de donnees

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB9222972.3 1992-11-03
GB929222972A GB9222972D0 (en) 1992-11-03 1992-11-03 Transmitting audio and data signals simultaneously

Publications (1)

Publication Number Publication Date
WO1994010771A1 true WO1994010771A1 (fr) 1994-05-11

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Application Number Title Priority Date Filing Date
PCT/GB1993/002261 WO1994010771A1 (fr) 1992-11-03 1993-11-03 Transmission simultanee de signaux sonores et de donnees

Country Status (3)

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EP (1) EP0619928A1 (fr)
GB (1) GB9222972D0 (fr)
WO (1) WO1994010771A1 (fr)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0762417A2 (fr) * 1995-08-25 1997-03-12 Sony Corporation Enregistrement et reproduction de signaux,support d'enregistrement de signaux et transmission et réception de signaux
WO1997037448A2 (fr) * 1996-04-03 1997-10-09 Aris Technologies, Inc. Procede et appareil pour coder et decoder des donnees supplementaires sous forme de signaux analogiques
WO1998003017A1 (fr) * 1996-07-15 1998-01-22 Snell & Wilcox Limited Compression de signaux video
US8838978B2 (en) 2010-09-16 2014-09-16 Verance Corporation Content access management using extracted watermark information
US8869222B2 (en) 2012-09-13 2014-10-21 Verance Corporation Second screen content
US8923548B2 (en) 2011-11-03 2014-12-30 Verance Corporation Extraction of embedded watermarks from a host content using a plurality of tentative watermarks
US9106964B2 (en) 2012-09-13 2015-08-11 Verance Corporation Enhanced content distribution using advertisements
US9117270B2 (en) 1998-05-28 2015-08-25 Verance Corporation Pre-processed information embedding system
US9153006B2 (en) 2005-04-26 2015-10-06 Verance Corporation Circumvention of watermark analysis in a host content
US9189955B2 (en) 2000-02-16 2015-11-17 Verance Corporation Remote control signaling using audio watermarks
US9208334B2 (en) 2013-10-25 2015-12-08 Verance Corporation Content management using multiple abstraction layers
US9251549B2 (en) 2013-07-23 2016-02-02 Verance Corporation Watermark extractor enhancements based on payload ranking
US9262794B2 (en) 2013-03-14 2016-02-16 Verance Corporation Transactional video marking system
US9323902B2 (en) 2011-12-13 2016-04-26 Verance Corporation Conditional access using embedded watermarks
US9547753B2 (en) 2011-12-13 2017-01-17 Verance Corporation Coordinated watermarking
US9571606B2 (en) 2012-08-31 2017-02-14 Verance Corporation Social media viewing system
US9596521B2 (en) 2014-03-13 2017-03-14 Verance Corporation Interactive content acquisition using embedded codes
US9648282B2 (en) 2002-10-15 2017-05-09 Verance Corporation Media monitoring, management and information system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0102608A2 (fr) * 1982-08-30 1984-03-14 Hitachi, Ltd. Circuit d'expansion pour signaux numériques
DE3523809A1 (de) * 1985-05-21 1986-11-27 Polygram Gmbh, 2000 Hamburg Verfahren zur zeitkompression von informationen in digitaler form
EP0359325A1 (fr) * 1988-09-16 1990-03-21 Koninklijke Philips Electronics N.V. Dispositif d'émission de mots de données représentant un signal analogique numérisé et dispositif de réception de mots de données émis
WO1992000637A1 (fr) * 1990-06-30 1992-01-09 Telefunken Fernseh Und Rundfunk Gmbh Procede de transmission d'un parametre de reglage variable dans le temps

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0102608A2 (fr) * 1982-08-30 1984-03-14 Hitachi, Ltd. Circuit d'expansion pour signaux numériques
DE3523809A1 (de) * 1985-05-21 1986-11-27 Polygram Gmbh, 2000 Hamburg Verfahren zur zeitkompression von informationen in digitaler form
EP0359325A1 (fr) * 1988-09-16 1990-03-21 Koninklijke Philips Electronics N.V. Dispositif d'émission de mots de données représentant un signal analogique numérisé et dispositif de réception de mots de données émis
WO1992000637A1 (fr) * 1990-06-30 1992-01-09 Telefunken Fernseh Und Rundfunk Gmbh Procede de transmission d'un parametre de reglage variable dans le temps

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PLENGE, SPIKOFSKI, THEILE: "VARIABELE DYNAMIK- EIN KONZEPT FÜR VERBESSERTE VERSORGUNG IM HöRFUNK UND FERNSEHEN", RUNDFUNKTECHNISCHE MITTEILUNGEN, vol. 30, no. 4, July 1986 (1986-07-01), NORDERSTEDT DE, pages 158 - 167 *
See also references of EP0619928A1 *

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6345146B1 (en) 1995-08-25 2002-02-05 Sony Corporation Signal recording/reproducing method and apparatus, signal record medium and signal transmission/reception method and apparatus
EP0762417A2 (fr) * 1995-08-25 1997-03-12 Sony Corporation Enregistrement et reproduction de signaux,support d'enregistrement de signaux et transmission et réception de signaux
US8301014B2 (en) 1995-08-25 2012-10-30 Sony Corporation Signal recording/reproducing method and apparatus, signal record medium and signal transmission/reception method and apparatus
US7428369B2 (en) 1995-08-25 2008-09-23 Sony Corporation Signal recording/reproducing method and apparatus, signal record medium and signal transmission/reception method and apparatus
US6363209B2 (en) 1995-08-25 2002-03-26 Sony Corporation Signal recording/reproducing method and apparatus, signal record medium and signal
EP0762417A3 (fr) * 1995-08-25 1999-01-27 Sony Corporation Enregistrement et reproduction de signaux,support d'enregistrement de signaux et transmission et réception de signaux
US6345145B1 (en) 1995-08-25 2002-02-05 Sony Corporation Signal recording/reproducing method and apparatus, signal record medium and signal transmission/reception method and apparatus
US5828325A (en) * 1996-04-03 1998-10-27 Aris Technologies, Inc. Apparatus and method for encoding and decoding information in analog signals
WO1997037448A3 (fr) * 1996-04-03 1997-11-13 Aris Technologies Inc Procede et appareil pour coder et decoder des donnees supplementaires sous forme de signaux analogiques
WO1997037448A2 (fr) * 1996-04-03 1997-10-09 Aris Technologies, Inc. Procede et appareil pour coder et decoder des donnees supplementaires sous forme de signaux analogiques
US6674802B2 (en) 1996-07-15 2004-01-06 Snell & Wilcox Limited Video process where part of compressed version of video signal accompanies video signal itself
WO1998003017A1 (fr) * 1996-07-15 1998-01-22 Snell & Wilcox Limited Compression de signaux video
EP2271103A3 (fr) * 1996-07-15 2013-01-16 Amstr. Investments 4 K.G., LLC Compression de signaux vidéo
US9117270B2 (en) 1998-05-28 2015-08-25 Verance Corporation Pre-processed information embedding system
US9189955B2 (en) 2000-02-16 2015-11-17 Verance Corporation Remote control signaling using audio watermarks
US9648282B2 (en) 2002-10-15 2017-05-09 Verance Corporation Media monitoring, management and information system
US9153006B2 (en) 2005-04-26 2015-10-06 Verance Corporation Circumvention of watermark analysis in a host content
US8838977B2 (en) 2010-09-16 2014-09-16 Verance Corporation Watermark extraction and content screening in a networked environment
US9607131B2 (en) 2010-09-16 2017-03-28 Verance Corporation Secure and efficient content screening in a networked environment
US8838978B2 (en) 2010-09-16 2014-09-16 Verance Corporation Content access management using extracted watermark information
US8923548B2 (en) 2011-11-03 2014-12-30 Verance Corporation Extraction of embedded watermarks from a host content using a plurality of tentative watermarks
US9323902B2 (en) 2011-12-13 2016-04-26 Verance Corporation Conditional access using embedded watermarks
US9547753B2 (en) 2011-12-13 2017-01-17 Verance Corporation Coordinated watermarking
US9571606B2 (en) 2012-08-31 2017-02-14 Verance Corporation Social media viewing system
US9106964B2 (en) 2012-09-13 2015-08-11 Verance Corporation Enhanced content distribution using advertisements
US8869222B2 (en) 2012-09-13 2014-10-21 Verance Corporation Second screen content
US9262794B2 (en) 2013-03-14 2016-02-16 Verance Corporation Transactional video marking system
US9251549B2 (en) 2013-07-23 2016-02-02 Verance Corporation Watermark extractor enhancements based on payload ranking
US9208334B2 (en) 2013-10-25 2015-12-08 Verance Corporation Content management using multiple abstraction layers
US9596521B2 (en) 2014-03-13 2017-03-14 Verance Corporation Interactive content acquisition using embedded codes

Also Published As

Publication number Publication date
EP0619928A1 (fr) 1994-10-19
GB9222972D0 (en) 1992-12-16

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