JPS63160437A - Reception reproducing device - Google Patents

Abstract

PURPOSE:To recognize contents of data during reception by decoding a voice data subject to compression processing received from a communication line while it is being stored. CONSTITUTION:When a digital voice data compressed via a line is sent to a communication interface 2, a CPU 3 starts one of a DMA channel of a memory system 4 and the digital voice data compressed from the line 1 is stored in the memory system 4 from a memory cycle steal. When the data is stored by prescribed quantity from the CPU 3 to the memory system 4, a decoding section 6 is driven and the compressed data stored through other DMA channel is read from the memory system 4, decoded to be reproduced at a normal speed and the decoded analog signal is sent to an amplifier 7. After an analog signal is amplified by an amplifier 7, it is outputted through a speaker 8. Thus, the compressed voice data is reproduced and stored tentatively during reception and the content of data is recognized during the reception.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a reception and playback device that receives and plays back compressed audio data.

[Prior Art] Conventionally, this type of device simply performed transmission and reception in accordance with the playback operation, resulting in a problem of line cost.

In addition, for things that are compressed and sent or received, everything is played back after being received and output at normal speed during playback. It had some unknown drawbacks.

[Objective] The present invention was invented for the purpose of eliminating the above-mentioned drawbacks, and provides a reception and playback device that can store received compressed audio data and simultaneously play it back at normal speed. It is something.

[Example] Hereinafter, the present invention will be explained according to preferred embodiments.

FIG. 1 is a block diagram of an embodiment of a receiving and reproducing apparatus to which the present invention is applied, in which 1 is a communication line, 2 is a communication interface, and 3 is a CPU that performs various controls. Further, 4 is a randomly accessible memory system capable of storing data from the communication interface 2 as is, storing data from the magnetic tape device 5 as is, and reading the stored contents. This is a memory system configured to output data from a communication interface 2 to a data input restoration unit 6 using DMA. Reference numeral 5 denotes a magnetic tape device as an external storage means, which operates under the control of the CPU 3 and has the function of storing data from the memory system 4 via the CPU 3, and conversely reading and sending the data to the memory system 4. It is something. 6 is a restoring unit that restores data in the memory system 4 when it is read by DMA in order to reproduce it at normal speed; 7 is an amplifier that amplifies the restored data from the restoring unit 6; Reference numeral 8 denotes a speaker that converts the output of the amplifier 7 into audio. 9 is a program memory for storing control procedures for the CPU 3, and 10 is a keyboard for instructing the CPU 3 to control. Further, 11 is a pass line connecting the CPU 3 and each of the above-mentioned parts.

FIG. 2 is a flowchart showing the operating procedure of the CPU 3 shown in FIG. 1, and this procedure is stored in the program memory 9 in advance.

The operation of the receiving and reproducing apparatus shown in FIG. 1 will be explained below. The audio data such as music sent from the digital communication surface j91 is highly compressed and is compressed to several tenths to several hundredths of the speed of normal audio. For example, set the sampling rate of the original music to 40 per second.
If we consider the case of sending one hour of music data with a dynamic range of 12 bits, if we digitize it as is, 1.7 x 109 (bits) of data out of 40K x 12 x 3600 will be sent, but as mentioned above, the compression is 1 /100 is 1.7×+09 Xi/100=
1.7x107, line speed 128KBit/s
If it is ec, then 1.7X107÷128 and 133 (s
ee) enables transmission. Also, the line speed is a4KBit
/sec, one hour's worth of music can be sent in 266 seconds.

The digital voice data compressed in this manner is sent to the communication ink face 2 via the line 1. When the CPU 3 determines that data has been received to the communication interface 2 (step S1), the
In step S2), the compressed digital audio data from the line 1 is stored in the memory system 4 by memory cycle stealing. When the CPU 3 determines that a predetermined amount of data has been stored in the memory system 4 (step S3), the CPU 3 drives the restoring unit 6 in step S4.
), reads the compressed data stored by the other DMA channels from the memory system 4. The restoring unit 6 restores the read compressed data so as to reproduce it at a normal speed, and sends the restored analog signal to the amplifier 7. The analog signal is amplified by an amplifier 7 and then outputted as audio by a speaker 8. Therefore, while the compressed digital audio data is being temporarily stored in the memory system 4, it is restored by the restoring unit 6 and outputted as audio from the speaker 8.

On the other hand, when the CPtJ3 determines that the restoration of the data stored in the memory system 4 has been completed (step S5), it determines whether or not saving the data has been instructed from the keyboard 10 (step S6). If so, start up the magnetic tape 5 (step S6), read data from the memory system 4, and transfer the compressed digital audio data to the magnetic tape 5 (step S8).
. Then, when the data transfer is completed (step S9
), return the device to its original condition.

As explained above, the compressed digital audio data from the communication line 1 is temporarily stored in the memory system 4, simultaneously reproduced by the speaker 8, and further stored on the magnetic tape 5 as required.

After the data is stored on the magnetic tape 5, the keyboard 1
If there is a reproduction instruction from 0 (310), step Sll to start the memory system 4 and magnetic tape 5;
512), the compressed digital audio data stored on the magnetic tape 5 is transferred to the memory system 4 via the CPU 3 and stored therein (step 513). Then, it can be read out from the memory system 4 by DMA in the same manner as described above, and the restoring unit 6. It is reproduced by an amplifier 7 and a speaker 8.

[Effects] As described above, according to the present invention, compressed audio data can be played back and temporarily stored while being received, and the data contents can be recognized while being received.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of a receiving and reproducing device using the present invention, and FIG. 2 is a flowchart showing the operating procedure of the CPU 3, where 2 is a communication interface, 4 is a memory system, and 6 is a restoring unit. .

Claims (1)

[Claims] A receiving and reproducing device is characterized in that it stores compressed audio data received from a communication line, decompresses it, and outputs the audio data.