Willi Studer Ag

Sony Corporation

Other

Willi Studer Ag & Sony Corporation

Roger Lagadec

Guy W McNally

Claudia Brandes

Philip S Gaskell

Toshitada Doi

Daniele P Pelloni

Julien Piot

Yukio Fukuju

Robert Muller

Henry O Kunz

Andreas Koch

Method and apparatus for converting an input scanning sequence into an output scanning sequence, where scan values of an input scanning sequence occurring with an input scanning frequency are converted into an output scanning sequence whose scan values occur with an output scanning frequency. To process scanning sequences with alternating scanning frequencies with limited computing and storage capacities, a single one-stage digital filter is provided for processing the input scanning sequence using a limited number of filter coefficients, further filter coefficients supplied thereto by calculation from existing filter coefficients.

Method and apparatus for converting an input scanning sequence into an

To compensate for transmission errors of a non-ideal system for transmitting digital signals, first signal deviations are determined and stored, and then there is a direct processing of the input signals into output signals by combining the input signals with the stored signal deviations. The invention includes both method and apparatus and provides a substantial reduction in equipment costs.

Method and apparatus for reproducing digitized signals

Using the inventive method and apparatus, two scanning sequences can be synchronized with small signal delays and at the smallest possible apparatus expense. The time differences between associated scanning values or signals of the two scanning sequences are compensated by alternatingly delaying relative to each other the scanned values or signals and interpolating between the scanned values or signals of one of the two scanning sequences. The apparatus for carrying out the synchronizing operation comprises a storage for producing the delays and a filtering device for performing the interpolation.

Scanning frequency synchronization method and apparatus

Methods and apparatus for recording and reproducing coded digital signals typically assign values of a signal to 2 categories which are separately coded, delayed differently, and subsequently recorded. In order to reduce the loss of such values in the cases of damage to the recording to the greatest possible extent, the values of the signals are coded at least twice in parallel and recorded onto several tracks. In one of the recordings, the sequence of values is modified in such a way that even major damage to the recording can be accommodated without producing non-correctable errors.

Method and apparatus for recording and reproducing coded digital signals

An input sampling sequence with an input sampling rate is translated into an output sampling sequence with a selectable output sampling rate in a sampling filter. A circuit for forming the time difference of the sampling points forms from the given input sampling rate and the desired output sampling rate a signal corresponding to the time difference and this is used in a translation circuit for converting into data for characterizing the filter coefficients. The sampling filter is conditioned by the selected coefficients from the translation circuit. The invention is suitable for the transmission of sampled data, particularly sampled rates between two systems operating at different clock frequencies.

Process and apparatus for translating the sampling rate of a sampling

In order to equalize different delays between the digital signals of two or more digital signal sequences, additional signals are added to at least one of the digital signal sequences of digital signals. The additional signals are indicative of the momentary temporal relationship between the digital signals of the different digital signal sequences.

Method and apparatus for producing and selectively equalizing a temporal

In a circuit supplying a digital system, the frequency at which the switching device therein is controlled is synchronized to be the same as one or several times half the sampling frequency. In this way, the original frequency spectrum can be kept free from interfering signals.

Method and apparatus for supplying a system for processing electrical

Method of digital signal transmission

Method of recording odd and even words of one channel PCM signals in

For both recording and replay, a digital audio tape (14) is accelerated very rapidly by a motor servo (9), motor (8) and capstan (7) so that the tape speed overshoots nominal speed range before settling back to this range in an oscillatory manner. The digital samples are recorded and replayed via a head (15), a random access memory (16) and input/output electronics (19). During recording, the store (17) is precharged by starting to write in as soon as acceleration is initiated. Read-out to the tape is initiated as soon as the tape first reaches the nominal speed range. Uniformity of samples as recorded on the tape is preserved by clocking a read address generator (21) at a rate proportional to tape speed, signaled by a tachometer (7). The write address generator is clocked at the constant sampling rate. For replay the write address generator is clocked at the tape speed rate while the read address generator (21) is clocked at the constant sample rate. Write in and read out are both initiated when the tape speed first reaches the nominal range. The addresses provided by the generators (20 and 21) are compared by a comparator (22) which provides a reference signal to the servo (9) in an arrangement such as to adjust the tape speed always in the sense to maintain a constant degree of filling of the store (17).

Method and apparatus for recording and replay of digital audio data

In producing an edited tape (31) the lead-in material up to a first edit point is separated from the lead-out material running from a second edit point by a space containing unwanted material and accommodating the actual or notional splice. The unwanted material ensures correct operation of error protection for all of the wanted material on replay. The first and second edit points are marked by codes placed on the tape (31) by a code processor (43) and supplementary head (42). During replay the digital data recovered from the tape by a head (32) is entered into a random access buffer store (34) under control of a write address generator (38) and read out to output electronics (37) under control of a read address generator (39) running at the audio sampling rate. The write address generator (38) normally runs at a rate corresponding to tape speed but the code processor detects the codes for first and second edit points and a control unit (51) stops the write address generator (38) between such points so as to discard the unwanted material. The store is then replenished by speeding up the tape by a comparator (40) and speed control unit (10) in an arrangement which preserves a constant relationship between the read and write addresses, i.e. a constant degree of filling of the memory (34).

Technique for editing interleaved digital audio data

Equidistant timing pulses are counted during the time between the arrival of a first pulse edge of a first signal sequence and the arrival of a following second pulse edge of another signal sequence and are averaged to a mean value with equidistant timing pulses of an immediately preceding count between two pulse edges of the two signal sequences. The continuously formed mean values are accumulated with mean values of preceding cycles and in each case the least significant bit is further processed.

Method and apparatus for measuring the time difference between two

A multitrack tape recorder records and replays digital data on a plurality of data tracks (15) by way of record/replay electronics (7), a record head (5) and a replay head (6). Channels (8) corresponding to the tape track (15) are provided for input to and output from the electronics (7). An additional channel (11) carries auxiliary data related to the signals in the channels (8). This data is formatted during recording by the electronics (7) into a block format compatible with the data format on channels (15) and is recorded on a separate dedicated track (16). The auxiliary information may be formatted in labels each of which has an instruction field and a parameter field. The labels can carry a wide variety of information relating to operation of the system. As one example, a label may contain in the instruction field an instruction to increase the playback gain by an amount contained in the parameter field.

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Rumlang, Switzerland

Roger Lagadec