KR20180057842A - AVB based SR Speaker System with Adjustable Presentation Time - Google Patents

Abstract

Provided is an AVB-based SR speaker system with an adjustable presentation time (PT). According to an embodiment of the present invention, a PT adjustment method comprises the steps of: receiving transfer times (TTs) of audio data from audio reception devices; adjusting PTs of the audio reception devices using the received TTs; and transmitting the adjusted PTs to an audio transmission device. Therefore, the PT can be adjustable in the speaker system, so audio can be streamed in real time without loss even if speakers located far away from a large space such as a stadium or a concert venue are connected to a daisy chain network.

Description

[0001] AVB-based SR Speaker System with Adjustable PT [0003]

The present invention relates to an SR speaker system, and more particularly, to a speaker system for connecting a speaker located far away in a wide space such as a stadium or a concert hall to a network of a daisy chain structure to stream audio in real time without loss.

AVB (Audio Video Bridging) technology is used to solve the problem of wiring complexity and expensive cost of existing AV (Audio Video) system by using low cost LAN (Local Area Network) As a technology to transmit losslessly to the castle, detailed specifications have been established based on IEEE 802.1BA.

In order to transmit time-sensitive data in a lossless manner in real time in a network environment sharing physical media such as Ethernet to transmit various types of data, all devices belonging to the same domain must be identical You must synchronize the Grand Master to the same time.

Also, in order to prevent the loss of real-time transmission data even in a situation where traffic is concentrated, a resource reservation for a network path from a transmitting apparatus to a receiving apparatus must be preceded before transmitting data.

On the other hand, when speakers located far away from a wide space such as a stadium or a concert venue are connected to a network having a daisy chain structure, there is a problem that synchronization of AV contents is lost and loss occurs.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is an object of the present invention to provide a speaker apparatus and a speaker apparatus, And a speaker system having an adjustable PT (Presentation Time).

According to an aspect of the present invention, there is provided a method of adjusting a PT, comprising: receiving TTs (Transfer Time) of audio data from audio receiving apparatuses; Adjusting a presentation time (PT) of audio receiving apparatuses using received TTs; And delivering the adjusted PT to an audio transmission device.

PT is represented by the following equation, PT = CT (Current Time) +?, Where? Can be determined by the adjustment step.

Further, the adjustment step can determine the maximum TT as?.

Then, TT can be expressed by the following equation.

TT = RT (Receive Time) -PT-alpha

Further, the audio transmitting apparatus and the audio receiving apparatus can be connected to a ring network.

And, the receiving step can receive TTs using a specific field of GET_CONTROL of IEEE1722.1 protocol.

In addition, the transmission step may include transmitting the PT to the SET_CONTROL of the IEEE 1722.1 protocol and transmitting the PT to the audio transmission apparatus.

According to another aspect of the present invention, there is provided an audio system including: an audio transmitting apparatus; Audio receiving devices; And a TT (Transfer Time) of audio data received from the audio receiving apparatuses to adjust the PT (Presentation Time) transmitted from the audio transmitting apparatus together with the audio data to the audio receiving apparatuses, To the management system.

As described above, according to the embodiments of the present invention, it is possible to adjust the PT in the speaker system, so that even when speakers located far away in a wide space such as a stadium or a concert hall are connected to a network of a daisy chain structure, It is possible to stream audio in real time.

1 is a block diagram of an SR speaker,
Figure 2 is a daisy chain connection of SR speakers,
3 shows the maximum / minimum value of the transmission time,
Figure 4 shows the maximum / minimum average transmission time,
5 is a diagram provided for explanation of the PT adjustment method.

Hereinafter, the present invention will be described in detail with reference to the drawings.

1. Overview

In the embodiment of the present invention, an AVB (Audio Video Bridging) based SR speaker system having an adjustable PT (Presentation Time) is presented. It is intended to enable the streaming of audio in real time without loss even when speakers located far away from a large space such as a stadium or a concert hall are connected to a network having a daisy chain structure, which is a ring network structure.

To this end, in the embodiment of the present invention, transmission time and PT are analyzed through transmission measurement or experiment in a network environment, and the PT is adjusted so that the streaming service can be smoothly performed.

2. AVB-based SR speaker transmission time measurement

PT (presentation time) means a time point when a video or audio signal is transmitted through a network, and then reproduced through a display or a speaker after decoding.

In the network, the PT is represented by a time representation defined by the terminals. The PT is reproduced in a multi-part such as a synchronization part of video and audio or audio transmission, PT control is required. The PT is transmitted together with the stream data in the IEEE 1722 frame.

In the embodiment of the present invention, a commercial AVB chip-based SR speaker is proposed for measuring transmission time. 1 is a block diagram of an SR speaker. As shown in FIG. 1, the SR speaker includes two Ethernet ports 101 and 102 to implement a daisy-chain network configuration.

2, the network includes an audio talker 300 as an audio transmitting device and SR speakers 110, 120, 130 and 140 as audio receiving devices (audio listeners) in a daisy chain manner.

In addition, delay testing devices (hubs) 210, 220, 230, and 240 are disposed between the SR speakers 110, 120, 130, and 140 to create a delay situation that may occur in a wide space of the outdoor.

That is, the audio signals transmitted by the SR speakers 110, 120, 130 and 140 are delayed by the delay testing devices 210, 220, 230 and 240.

The delay testing devices 210, 220, 230, and 240 receive the distance, estimate a delay time proportional to the input distance, and delay the received audio signal by the estimated delay time to deliver the delayed audio signal to the SR speakers 110, 120,

1) The distance input to the delay testing device-1 210 is the distance between the audio talker 300 and the SR speaker-1 110,

2) The distance input to the delay device-2 220 is the distance between the SR speaker-1 110 and the SR speaker-2 120,

3) The distance input to the delay testing device-3 230 is the distance between the SR speaker-2 120 and the SR speaker-3 130,

4) The distance input to the delay testing device-4 240 is the distance between the SR speaker-3 (130) and the SR speaker-4 (140).

The audio talker 300 transmits an audio signal, such as 24 bit / 48 kHz PCM 4channel, every 125 microseconds in the form of an IEEE 1722 frame. At this time, the audio talker 300 designates the PT to be one ms later than the frame transmission time. The delay time is more sensitive to the delay, and the network transmission time is usually about 1 ms.

The PC 400 functioning as a manager for network control is a terminal for controlling the connection between the audio talker 300 and the SR speakers 110, 120, 130 and 140 corresponding to the audio listeners.

PC 400 is a Riedel's IEEE 1722.1. Based manager program, but does not exclude other implementations.

When the audio talker 300 displays a PT [= CT (Current Time) +? (1 ms)] to transmit a data packet, the SR speakers 110, 120, 130 and 140 measure RT (Receive Time) TT (Transfer Time) can be calculated by the following equation.

TT = RT-PT-alpha

In the SR speakers 110, 120, 130, and 140, all the packets are observed while 1000 pieces of incoming data are received every 125 microseconds, and the maximum value and the minimum value are outputted and measured. The measurement is performed for 500 times, The transmission time can be derived from the audio talker 300 in the first, second, third, and fourth embodiments.

In FIG. 3, the Direct MIN / MAX is a transmission time measured by removing the delay testing device-1 210 and connecting the audio talker 300 and the SR speaker-1 110 directly. MIN is 1.29 to 1.30 ms, and MAX is 1.39 to 1.40 ms.

In FIG. 3, 2st MIN / MAX indicates the transmission time measured by the SR speaker-2 120 when the delay testing device-1 210, the SR speaker-1 110 and the delay testing device- to be. MIN is between 1.37 and 1.40 ms, and MAX is between 1.46 and 1.51 ms.

In FIG. 3, the 4st MIN / MAX indicates that the delay test device-1 210, the SR speaker -1 110, the delay test device-2 220, the SR speaker- , SR speaker-3 (130), and delay testing device-4 (240) are connected, transmission time measured by the SR speaker-4 (140). MIN is 1.56-1.62 ms, MAX is 1.69-1.73 ms, and audio is interrupted with noise.

FIG. 4 is a result of finding the maximum / minimum average transmission time shown in FIG. 3. As a result, the transmission time becomes longer as the delay elements and the SR speakers increase.

3. PT adjustment method

5 is a diagram provided in a description of a method of adjusting a PT through the IEEE 1722.1 protocol. As shown in Fig. 5, the PT adjustment is performed by the PC 400. Fig.

For PT adjustment, the PC 400, acting as a manager, collects TT measurements from the SR speakers 110, 120, 130, TT measurements can be collected via GET_CONTROL, with the new fields defined in GET_CONTROL.

Next, the PC 400 compares the collected TT measurement values and calculates a proper PT. When the PT adjustment is necessary, the PC 400 issues a PT adjustment instruction to the audio talker 300. [ The PT adjustment command can be transmitted to the audio talker 300 by recording the appropriate PT in SET_CONTROL.

The audio talker 300, which has received the command, can adjust the PT, specifically, "?" In the above equation to prevent audio loss due to transmission delay. It is preferable to adjust "?" To 1.73 ms or more in an environment where a transmission delay occurs as shown in Figs. 3 and 4, but the adjustment is not necessarily limited to such adjustment.

4. Variations

A preferred embodiment has been described in detail for a technique for allowing the IEEE1772.1 manager to confirm the transmission delay occurring when real-time streaming is performed in an AVB-based audio system and to adjust the PT of the audio talker.

In the above embodiment, an AVB-based audio system is assumed, which is merely an example. It goes without saying that the technical idea of the present invention can also be applied to audio systems of other standards / structures.

It goes without saying that the technical idea of the present invention can also be applied to a computer-readable recording medium having a computer program for performing the functions of the apparatus and method according to the present embodiment. In addition, the technical idea according to various embodiments of the present invention may be embodied in computer-readable code form recorded on a computer-readable recording medium. The computer-readable recording medium is any data storage device that can be read by a computer and can store data. For example, the computer-readable recording medium may be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical disk, a hard disk drive, or the like. In addition, the computer readable code or program stored in the computer readable recording medium may be transmitted through a network connected between the computers.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present invention.

110,120,130,140: SR speaker
210, 220, 230, 240:
300: Audio Talker
400: PC

Claims (8)

Receiving TTs (Transfer Time) of audio data from audio receiving devices;
Adjusting a presentation time (PT) of audio receiving apparatuses using received TTs;
And transmitting the adjusted PT to an audio transmission apparatus.
The method according to claim 1,
PT is expressed by the following equation,
PT = CT (Current Time) + alpha
and? is determined by an adjustment step.
The method of claim 2,
In the adjustment step,
And the maximum TT is determined as?.
The method of claim 2,
TT = RT (Receive Time) -PT-alpha
TT is expressed by the above equation.
The method according to claim 1,
The audio transmitting apparatus and the audio receiving apparatus,
Wherein the PT is connected to a ring network.
The method of claim 5,
In the receiving step,
Wherein the TTs are received using a specific field of GET_CONTROL of the IEEE 1722.1 protocol.
The method of claim 5,
In the delivery step,
The PT is stored in the SET_CONTROL of the IEEE 1722.1 protocol, and the PT is transmitted to the audio transmission apparatus.
An audio transmission device;
Audio receiving devices; And
(TT) of the audio data received from the audio receiving apparatus, adjusts the PT (Presentation Time) transmitted by the audio transmitting apparatus together with the audio data to the audio receiving apparatus, and transmits the adjusted PT to the audio transmitting apparatus And a management system for delivering the audio data.

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