초록 ▼

Packet transfer apparatus transmits/receives event sequence data such as audio data and music data over a fast serial network to which a plurality of devices are connected. The input section sequentially inputs event sequence data, which is sampled at a double rate by a sampling clock signal having

Packet transfer apparatus transmits/receives event sequence data such as audio data and music data over a fast serial network to which a plurality of devices are connected. The input section sequentially inputs event sequence data, which is sampled at a double rate by a sampling clock signal having a half period of the input clock signal. The input section can switch between a fast sampling mode where the event sequence data is sampled at a double rate by a sampling clock signal having a half period of the input clock signal and a regular sampling mode where the event sequence data is sampled at a regular rate by another sampling clock signal having the same period as the input clock signal, and further a regular packetizing section operates under the regular sampling mode for generating a packet of the inputted event sequence data in response to only one of the leading edge and the trailing edge of the input clock signal and adds the timestamp every time the predetermined number of data blocks are packetized by the regular packetizing section.

대표청구항 ▼

1. A packet transmitting apparatus for packetizing inputted one or more event sequence data into a packet, and transmitting the packet to one or more receiving node located on a network, the packet transmitting apparatus comprising: an input section that inputs the event sequence data; a transmittin

1. A packet transmitting apparatus for packetizing inputted one or more event sequence data into a packet, and transmitting the packet to one or more receiving node located on a network, the packet transmitting apparatus comprising: an input section that inputs the event sequence data; a transmitting buffer that stores the inputted event sequence data; a packetizing section that packetizes the stored event sequence data; and a switching section that switches between a first mode and a second mode,wherein under the first mode, the input section operates in response to a first sampling frequency for inputting 2N (N is a natural number) number of event sequence data at one period of the first sampling frequency such that the 2N number of the event sequence data have the same sampling time, the transmitting buffer stores the event sequence data inputted by the input section, and the packetizing section reads out the event sequence data from the transmitting buffer and makes every 2N number of the read event sequence data into one data block so that the 2N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by a predetermined isochronous cycle period while a timestamp is added per every M number (M is a natural number) of the data blocks, and wherein under the second mode, the input section operates in response to a second sampling frequency, which is twice as fast as the first sampling frequency, for inputting N number of event sequence data at one period of the second sampling frequency such that the N number of the event sequence data have the same sampling time, the transmitting buffer stores the event sequence data inputted by the input section, and the packetizing section reads out the event sequence data from the transmitting buffer and makes every N number of the read event sequence data into one data block so that the N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by the predetermined isochronous cycle period while a timestamp is added per every 2M number of the data blocks. 2. A packet receiving apparatus for receiving a packet from one or more transmitting node located on a network, then retrieving one or more event sequence data from the received packet, and outputting the event sequence data, the packet receiving apparatus comprising: an unpacketizing section that unpacketizes the received packet into one or more data block of the event sequence data; a receiving buffer that stores the data blocks; a clock section that generates a reproduction sampling clock signal; an output section that outputs the event sequence data from the receiving buffer in response to the reproduction sampling clock signal; and a switching section that switches between a first mode and a second mode,wherein under the first mode, the unpacketizing section receives a first packet containing one or more data blocks such that each data block is composed of 2N (N is a natural number) number of event sequence data which have been sampled at one period of a first sampling frequency and therefore have the same sampling time while a timestamp is added per every M number (M is a natural number) of the data blocks, and retrieves the data blocks from the received first packet together with the timestamps, the receiving buffer sequentially stores the data blocks retrieved by the unpacketizing section, the clock section outputs a reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, the output section reads Out the data blocks each composed of the 2N number of the event sequence data from the receiving buffer and outputs the 2N number of the event sequence data by a period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted from the clock section and the timestamps outputted from the unpacketizing section, and wherein under the second mode, the unpacketizing section receives a second packet containing one or more data blocks such that each data block is composed of N number of event sequence data which have been sampled at one period of a second sampling frequency twice as fast as the first sampling frequency and therefore which have the same sampling time while a timestamp is added per every 2M number of the data blocks, and retrieves the data blocks from the received second packet together with the timestamps, the receiving buffer sequentiallystores the data blocks retrieved by the unpacketizing section, the clock section outputs the reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, and the output section reads out the data blocks each composed of the N number of the event sequence data from the receiving buffer and sequentially outputs the N number of the event sequence data by half a period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted from the clock section and the timestamps outputted from the unpacketizing section. 3. A packet transmitting method of packetizing inputted one or more event sequence data into a packet, and transmitting the packet to one or more receiving nodes located on a network, the packet transmitting method comprising: an input step of inputting the event sequence data; a storing step of storing the inputted event sequence data in a transmitting buffer; a packetizing step of packetizing the stored event sequence data; and a switching step of switching between a first mode and a second mode,wherein under the first mode, the input step inputs, in response to a first sampling frequency, 2N (N is a natural number) number of event sequence data at one period of the first sampling frequency such that the 2N number of the event sequence data have the same sampling time, the storing step stores the event sequence data inputted by the input step in the transmitting buffer, and the packetizing step reads out the event sequence data from the transmitting buffer and makes every 2N number of the read event sequence data into one data block so that the 2N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by a predetermined isochronous cycle period while a timestamp is added per every M number (M is a natural number) of the data blocks, and wherein under the second mode, the input step inputs, in response to a second sampling frequency which is twice as fast as the first sampling frequency, N number of event sequence data at one period of the second sampling frequency such that the N number of the event sequence data have the same sampling time, the storing step stores the event sequence data inputted by the input step in the transmitting buffer, and the packetizing step reads out the event sequence data from the transmitting buffer and makes every N number of the read event sequence data into one data block so that the N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by the predetermined isochronous cycle period while a timestamp is added per every 2M number of the data blocks. 4. A packet receiving method of receiving a packet from one or more transmitting nodes located on a network, then retrieving one or more event sequence data from the receiving packet, and outputting the event sequence data, the packet receiving method comprising: an unpacketizing step of unpacketizing the received packet into one or more data blocks of the event sequence data;a storing step of storing the data blocks in a receiving buffer; a clock step of generating a reproduction sampling clock signal; an output step of outputting the event sequence data from the receiving buffer in response to the reproduction sampling clock signal; and a switching step of switches between a first mode and second mode, wherein under the first mode, the unpacketizing step receives a first packet containing one or more data blocks such that each data block is composed of 2N (N is a natural number) number of event sequence data which have been sampled at one period of a first sampling frequency and therefore have the same sampling time while a timestamp is added per every M number (M is a natural number) of the data blocks, and retrieves the data blocks from the received first packet together with the timestamps, the storing step sequentially stores the data blocks retrieved by the unpacketizing step in the receiving buffer, the clock step outputs a reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, the output step reads out the data blocks each composed of the 2N number of the event sequence data from the receiving buffer and outputs the 2N number of the event sequence data by a period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted by the clock step and the timestamps outputted by the unpacketizing step, and wherein under the second mode, the unpacketizing step receives a second packet containing one or more data blocks such that each data block is composed of N number of event sequence data which have been sampled at one period of a second sampling frequency twice as fast as the first sampling frequency and therefore which have the same sampling time while a timestamp is added per every 2M number of the data blocks, and retrieves the data blocks from the received second packet together with the timestamps, the storing step sequentially stores the data blocks retrieved by the unpacketizing step in the receiving buffer, the clock step outputs the reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, and the output step reads out the data blocks each composed of the N number of the event sequence data from the receiving buffer and sequentially outputs the N number of the event sequence data by half a period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted by the clock step and the timestamps outputted by the unpacketizing step. 5. A medium for use in a packet transmitting machine having a CPU for packetizing inputted one or more event sequence data into a packet, and transmitting the packet to one or more receiving nodes located on a network, wherein the medium contains program instructions executable by the CPU for causing the packet transmitting machine under either of a first mode and a second mode to perform a process comprising: an input step of inputting the event sequence data; a storing step of storing the inputted event sequence data in a transmitting buffer; and a packetizing step of packetizing the stored event sequence data,wherein under the first mode, the input step inputs, in response to a first sampling frequency, 2N (N is a natural number) number of event sequence data at one period of the first sampling frequency such that the 2N number of the event sequence data have the same sampling time, the storing step stores the event sequence data inputted by the input step in the transmitting buffer, and the packetizing step reads out the event sequence data from the transmitting buffer and makes every 2N number of the read event sequence data into one data block so that the 2N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by a predetermined isochronous cycle period while a timestamp is added per every M number (M is a natural number) of the data blocks, and wherein under the second mode, the input step inputs, in response to a second sampling frequency which is twice as fast as the first sampling frequency, N number of event sequence data at one period of the second sampling frequency such that the N number of the event sequence data have the same sampling time, the storing step stores the event sequence data inputted by the input step in the transmitting buffer, and the packetizing step reads out the event sequence data from the transmitting buffer and makes every N number of the read event sequence data into one data block so that the N number of the event sequence data in one data block have the same sampling time, and packetizes one or more of the data blocks into one packet by the predetermined isochronous cycle period while a timestamp is added per every 2M number of the data blocks. 6. A medium for use in a packet receiving machine having a CPU for receiving a packet from one or more transmitting nodes located on a network, then retrieving one or more event sequence data from the received packet, and outputting the event sequence data, wherein the medium contains program instructions executable by the CPU for causing the packet receiving machine under either of a first mode and a second mode to perform a process comprising: an unpacketizing step of unpacketizing the received packet into one or more data blocks of the event sequence data; a storing step of storing the data blocks in a receiving buffer; a clock step of generating a reproduction sampling clock signal; and an output step of outputting the event sequence data from the receiving buffer in response to the reproduction sampling clock signal,wherein under the first mode, the unpacketizing step receives a first packet containing one or more data blocks such that each data block is composed of 2N (N is a natural number) number of event sequence data which have been sampled at one period of a first sampling frequency and therefore have the same sampling time while a timestamp is added per every M number (M is a natural number) of the data blocks, and retrieves the data blocks from the received first packet together with the timestamps, the storing step sequentially stores the data blocks retrieved by the unpacketizing step in the receiving buffer, the clock step outputs a reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, the output step reads out the data blocks each composed of the 2N number of the event sequence data from the receiving buffer and outputs the 2N number of the event sequence data by a period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted by the clock step and the timestanips outputted by the unpacketizing step, and wherein under the second mode, the unpacketizing step receives a second packet containing one or more data blocks such that each data block is composed of N number of event sequence data which have been sampled at one period of a second sampling frequency twice as fast as the first sampling frequency and therefore which have the same sampling time while a timestamp is added per every 2M number of the data blocks, and retrieves the data blocks from the received second packet together with the timestamps, the storing step sequentially stores the data blocks retrieved by the unpacketizing step in the receiving buffer, the clock step outputs the reproduction sampling clock signal of the first sampling frequency which is synchronized among nodes of the network, and the output step reads out the data blocks each composed of the N number of the event sequence data from the receiving buffer and sequentially outputs the N number of the event sequence data by half period of the sampling reproduction clock signal at a timing which is determined according to the reproduction sampling clock signal outputted by the clock step and the timestamps outputted by the unpacketizing step.