JPH02265340A - Music information processing system - Google Patents

Abstract

PURPOSE:To reproduce music information processed into plural packets consecutively by dividing a CPU memory into plural number storing a packet and replacing a reception function and a reproduction function of each memory at each end of the reproduction of one packet so as to apply reception and reproduction processing in real time. CONSTITUTION:Music information is extracted from a database 1 by a request at a terminal equipment side, processed into a packet with a prescribed size by a packet switching exchange 2 and sent to a communication line 3. The packet is restored by a packet exchange 2, at the triennial equipment side and outputted to a terminal equipment 4 via a MODEM 9. The packet outputted to the terminal equipment 4 is stored in a memory 1 of the CPU 5 one by one packet each, and subject to reproduction processing by the CPU 5. The succeeding packet sent during that time is stored into another memory 2 of the CPU 5 receiving an interrupt signal. When the processing is finished, the CPU 5 restores to the reproduction processing of the memory having implemented and when the processing is finished, the packet stored in the other memory is subject to reproduction processing and the packet received succeedingly is stored in the memory 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a music information processing system that can perform processing without interruption when transmitting and reproducing packetized digital music information.

[Conventional technology]

In general, packet communication divides the size of data to be transmitted into relatively short packet units, attaches address information and transmission control information to each packet, and transmits each packet in the correct order in a time-sharing manner. It was designed to do so. Therefore, since the communication line is not monopolized,
It is much more efficient than switching circuits such as telephones, where the line remains occupied until the user turns it off, and the communication costs are lower.Also, error detection/correction information can be added to the packets. Data can be transmitted more accurately.In addition, the difference in data transmission charges determined by the communication distance is smaller than that of normal lines, which is especially advantageous for long-distance transmission. , the usage rate of the above packet communication is increasing.

[Problem to be solved by the invention]

However, when digitized music information is stored as a database on the host computer, transmitted via packet communication, and used as BGM on the terminal side,
It is necessary to use packets divided into playback times of appropriate length, but compared to the packet transmission time, the time it takes to play music based on the signal is long, so there is a time lag between reception and playback. occurs. However, since packets are constantly being sent out, it is technically difficult to match them, and many issues remain to be resolved in order to provide high-quality music playback using packet communications.

In the present invention, the memory for storing packets is divided into multiple parts, and one
A processing system that can continuously play multiple packetized music information by swapping the reception function and playback function of each memory every time the playback of a packet is completed and performs reception and playback processing in real time. The purpose is to provide.

[Means for solving the problem] Binary-encoded music information is packetized into multiple pieces, these packets are transmitted over a communication line, each packet signal is restored to its original state by a packet switch, and then sent to a terminal device. A music information processing system that outputs data to a CPU, in which the memory of the CPU is divided into a plurality of memories each capable of storing one packet, and the playback function of one memory and the reception function of another memory are performed alternately by interrupt signals. With,
A means for sequentially switching the playback and reception functions of each of the above memories was adopted.

In addition, the playback time is longer than the packet signal reception time,
We also adopted a method that uses these time differences as the packet transmission interval.

[For production]

The music information in the database is packetized into a predetermined size by a packet switch and transmitted sequentially at predetermined intervals. The transmitted packets are restored to their original state by the packet switch on the terminal side and stored in the memory of CPU 1, and are reproduced by the CPU. The next packet sent during this time is stored in another memory by the CPU that received the interrupt signal. When this process is finished, CP
U returns to the memory playback process that was being performed up to that point, and when this process is finished, it immediately plays back the packet stored in the other memory, and then the received packet is
store in memory. By alternately switching the two memories to the playback function and the reception function in this way, music information for one song consisting of several packets is continuously played back.

〔Example〕

Hereinafter, the configuration of the present invention will be described in more detail based on the embodiment shown in the drawings. 1 is a host computer that controls a database in which music information such as BGM is binary encoded and stored; 2 and 2 are A packet switching device (PAD) installed on the host computer side and the terminal side packetizes the music information into approximately 8 bytes in size and connects it to the communication line 3.
While the packetized music information is stored in the terminal device 4, it is also outputted to the terminal device 4. 5 is a CPU of the above-mentioned terminal device, and a memory divided into two for storing the above-mentioned packets (
1) and (2), and alternately switches to the packet signal reception/reproduction function upon receiving an interrupt signal. 6 is an output device, and the music information processed by the CPU 5 is reproduced and performed by an amplifier 7, a speaker 8, etc.

Note that 9 in the figure indicates a modem with a communication speed of 2400 bps, but when using 15DN as a communication line, direct digital communication can be performed, so an interface is used instead of the modem.

Next, the operation of the music information processing system will be described.

The above-mentioned music information is preformatted for packetization into a database, and is extracted from this database at the request of the terminal side, and is packetized by the packet switch 2. Address information and transmission control are added to each packet. It is sent to the communication line 3 with information etc.' added thereto. The transmitted packet is restored to its original state by the packet switch 2 on the terminal side, that is, with address information and transmission control information removed, and then sent to the terminal device 4 via the modem 9.
is output to.

The packets outputted to the terminal device 4 are stored one by one in the memo of the CPU 5. Note that since the size of one packet is fixed, one packet can be determined based on a predefined length. Whether the stored packet is at the beginning of the song is determined based on the packet status information provided at the time of formatting, and if it is not at the beginning, playback is not performed and the process waits for the next packet to be received.

On the other hand, if it is determined that the packet is the beginning of the song, the music information of the first packet is played back, but the next packet is sent even during this playback process, so this packet It is necessary to receive the first packet and reproduce the first packet in real time. Therefore, when receiving data, the modem 9 issues an interrupt request signal for each byte, and when the CPU 5 receives this interrupt signal, it immediately stores the second packet in the memory (2) and writes 1 to the storage location. to add. Also, when this process is finished, the CPU 5 returns to the playback process that was being performed up to that point.
Repeat the operation for each byte. In this case, while the interrupt signal is stored in the memory (2), the playback of the packet in Memo (January 1) is interrupted, but even with an 8-bit CPU, the playback ends within 1 millisecond, so the music does not sound audible. There is no interruption (in fact, there is almost no effect.

If the reception time of one packet is set to around 30 seconds, if a song consists of several packets, the data production will be arranged so that the playback time of one packet is longer than the reception time. . Specifically, avoid making frequent use of "changes in frequency after the start of pronunciation" or "frequency modulation" in music information.

In short, when receiving and reproducing packets, the reception time is made shorter than the reproduction time.

As soon as the above memo (January 1) finishes playing, the memory (
The packet stored in 2) is played back from the beginning, and the next received packet is stored in memory (1). By alternately switching the memo (January 1) and the memory (2) to the playback function and the reception function in this way, music information of a plurality of packets can be continuously played back.

Note that the packet switching device 2 sends packets at fixed time intervals. This is because if a transmission interval (waiting time) is not set, the playback time will be longer than the reception (transmission) time as described above, so if reception and playback are repeated in order, the reception processing will precede by the time difference. This is because a new signal will be saved in the memory that is being played back, destroying the necessary playback memory and causing confusion in the processing. Therefore, it is necessary to set the transmission interval by using a time shorter than the playback time as a waiting time. That is, the interval between packets sent from the information center and reproduction have the following relationship.

Wt=T-Receiving time Wt: Transmission interval T: Playback time specified in advance for the packet If the next reception process is performed while maintaining such a time interval, destruction of the playback memory can be prevented. Furthermore, the greater the difference between the reception time and the playback time, the greater the number of packets to be transmitted, so it is possible to make BGM multi-channel.

In this embodiment, the memory is divided into two parts, but the memory is not limited to this, and can be divided into three parts or more, and the function of the memory can be increased accordingly.

〔Effect of the invention〕

The music information processing system of the present invention processes the data by alternately switching the memory of the CPU that stores the packets between the reception function and the playback function. There is no time lag, and music information consisting of multiple packets can be played continuously without interruption.

Therefore, according to the present invention, a system is provided that can not only provide music such as high-quality BGM, but also make maximum use of the advantages of packet communication, such as improving communication line usage efficiency and, in particular, reducing long-distance communication costs. It becomes possible to provide.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an outline of the system of the present invention. In addition, in the figure 1... host computer, 2.2"...
Baquerato exchange, 3... communication line, 4... terminal device,... CPU, 6... output device, 9... modem. Below

Claims (1)

[Claims] 1. Binary encoded music information is packetized into a plurality of pieces,
In a music information processing system that transmits these packets through a communication line, restores each packet signal to its original state using a packet switch, and outputs it to a CPU of a terminal device, the memory of the CPU is configured to have multiple memories each capable of storing one packet. 1. A music information processing system characterized in that the music information processing system is divided into two memories, alternately performs the playback function of one memory and the reception function of another memory by an interrupt signal, and sequentially switches the playback and reception functions of each of the memories. 2. Make the playback time longer than the packet signal reception time,
2. The music information processing system according to claim 1, wherein these time differences are used as packet transmission intervals.