摘要:
The process is characterized in that it comprises: a step of reading tags recorded together with the packets, these tags defining the instants of arrival of the data packets to be recorded, on the basis of a tagging clock (8), a step of comparing the tags with values counted (9) on the basis of a transfer clock (8) for determining the instants of transfer on the bus of the data read from the record carrier, the frequencies of operation of the said tagging and transfer clocks being such that the maximum deviation between these frequencies, added to the maximum drift of the MPEG system clock, is, in proportion to the nominal values, of the order of or less than the drift of the system clock specified in the standard. Application to the storage of MPEG data.
摘要:
The present invention relates to a sending device able to send packets in a network comprising at least two stations, the said device comprising means for extracting image pips on the basis of a synchronization signal, initializing an image counter on the basis of the image pips, initializing a counter every “m” zero-crossings of the image counter, the counter being regulated by a clock produced by the image counter, sampling the counter every period Tsmp, where Tsmp emanates from a time base synchronized on all the stations of the said network; and sending packets containing the samples of the counter in the network. According to the invention, it comprises means for receiving packets containing samples sent by a station of the network as echo to the samples and when samples are received for: evaluating a duration of propagation of samples over an outward-return trip between the said device and the said station; determining a phase shift value Δφ on the basis of the duration of propagation; sending the phase shift value Δφ in the network.
摘要:
The present invention relates to a device able to receive packets circulating in a packet communication network, said device comprising: the means to receive packets from said network, said packets comprising samples coming from a sampling of a counting ramp having a range EX according to a sampling clock, said counting ramp being timed by a clock with a period of T_VID, said means extracting said samples from received packets, the means to regenerate counting ramps with a range EX, the means (PLL) receiving the samples and also delivering local samples of counting ramps realised according to sampling clock and a reconstituted clock with a period T_VID, the counting ramps being timed by the clock, the means to produce counting ramps timed by the clock and having a range EX_I where EX=m.EX_I, m being a whole number necessarily greater than 1, the counting ramps being set to zero at each passage of the counting ramp by a fixed whole number M where 0
摘要:
The present invention relates to the domain of video equipment. It relates to a phase-locked loop able to recover the timing of a synchronization signal comprising a temporal discontinuity of a maximum amplitude equal to PCR_Modulus, the loop comprising:a sample comparator comparing the samples and the local samples of a synthesised signal,means for producing the synthesised signal from a corrected signal,a corrector receiving a comparison result delivered by the comparison means and delivering the corrected signal, According to the invention, the comparison means comprises the means to determine a difference in value between the local samples and the samples of the synchronisation signal and in that the comparison result has a value that depends on the value ε and on the difference between the value ε and the value PCR_Modulus/2.
摘要:
The present invention relates to a reception device able to receive packets in a communication network comprising at least two stations. The device comprises means for: receiving packets containing samples of the network which originate from data sampled every period Tsmp, where Tsmp emanates from a time base synchronized on all the stations of the said network; regenerating a counting ramp with the aid of a loop receiving the samples and furthermore delivering local samples every period Tsmp and a clock; the phase-locked loop comprises: a samples comparator comparing the samples and the local samples and delivering an error signal; a corrector receiving the signal and delivering a corrected error signal, the corrector having a static gain equal to 1; a digital oscillator receiving the corrected error signal and delivering the clock, which has a frequency dependent on the signal and is proportional to a gain. According to the invention, the phase-locked loop comprises, furthermore, a gain adjustment device which determines a gain value as a function of the error signal.
摘要:
A synchronization aid device is part of receiving communication equipment of an IP network, having a primary clock signal consisting of primary clock pulses spaced apart by a first period. This device comprises i) a required to increment its value by one unit on each primary clock pulse and reset its value to zero each time it reaches a value M, ii) detection means required to generate a secondary clock pulse each time the value of the counter is zero, the secondary clock pulses forming a secondary clock signal having a second period equal to M times the first period, and iii) control means required, each time the receiving equipment receives a packet containing at least one first bit having a first value, to initialize the counter with a chosen value.
摘要:
The invention concerns a device able for receiving packets in a packet communication network comprising at least two stations, characterized in that it includes: phase-locked loop, as well as means for: receiving packets containing samples of said network, said samples being derived from data sampled every Tech period, where Tech is derived from a time base synchronized on all the stations of said network and said samples being associated with incremental values predicting at least one sample, calculating, in case of interruption of packet reception, a prediction of a sample that should have been received, by adding an increment value to a received sample value. The invention also concerns a device for transmitting packets in a packet communication network.
摘要:
A method for restoring a service reservation booking system in a network after a failure, that comprises a first step of invalidating at least a portion of the bookings which cannot be seen anymore by the service booking system due to the failure, a second step of recalculating the bookings which cannot be seen anymore by the service booking system by validating the bookings which are valid in the network topology after the failure and by cancelling the bookings which are invalid in the network topology after the failure. Advantageously, the method of the present invention further includes a third step during which the nodes of the network disappear from the service booking system. The present invention also includes to a service booking system in a network.
摘要:
The present invention relates to the domain of video equipment. It relates to a phase-locked loop able to recover the timing of a synchronization signal comprising a temporal discontinuity of amaximum amplitude equal to PCR_Modulus, the loop comprising: a sample comparator comparing the samples and the local samples of a synthesized signal, means for producing the synthesized signal from a corrected signal, a corrector receiving a comparison result delivered by the comparison means and delivering the corrected signal, According to the invention, the comparison means comprises the means to determine a difference in value between the local samples and the samples of the synchronization signal and in that the comparison result has a value that depends on the value ε and on the difference between the value ε and the value PCR_Modulus/2.
摘要:
A synchronization aid device is part of receiving communication equipment of an IP network, having a primary clock signal consisting of primary clock pulses spaced apart by a first period. This device comprises i) a required to increment its value by one unit on each primary clock pulse and reset its value to zero each time it reaches a value M, ii) detection means required to generate a secondary clock pulse each time the value of the counter is zero, the secondary clock pulses forming a secondary clock signal having a second period equal to M times the first period, and iii) control means required, each time the receiving equipment receives a packet containing at least one first bit having a first value, to initialize the counter with a chosen value.