CN109151987A - A kind of method that more room audio groups are played simultaneously in WLAN - Google Patents

The invention discloses the methods that room audio groups more in a kind of WLAN are played simultaneously, it is characterized in that this method comprises: step 1, WIFI mould group decodes Beacon frame, the timing information of AP is extracted from Beacon frame, and the clock counter of WIFI mould group is updated, keep the clock counter of WIFI mould group consistent with AP clock counter；Step 2, the master and slave equipment of audio accesses WIFI mould group clock counter, obtains identical clock reference, realizes that the master and slave equipment room clock reference of audio is identical；Step 3, audio main equipment obtains audio data, is sent to audio in the form of data frames from equipment after coding；Step 4, audio receives data frame from equipment, extracts the temporal information in data frame, and determine whether playing audio-fequency data.The method of the present invention is made clock in WIFI module internal and is synchronized, and avoiding WIFI driving, protocol stack and system transport layer bring influences, and makes isochronous audio broadcasting precision between distinct device that the clock reference synchronization error for being less than 20us may be implemented.

A kind of method that more room audio groups are played simultaneously in WLAN

Technical field

The present invention relates to the methods that room audio groups more in a kind of WLAN are played simultaneously, and belong at computer audio Manage technical field.

Background technique

With the development of technology, people are not content with the audio data that Bluetooth transmission damages, the lossless audio based on WiFi Transmission system is using more and more extensive, in order to obtain better audio, it will usually which multiple wireless sound boxes are combined into room more than one Between audio frequency broadcast system.In more room voice box group sound systems, if each speaker only plays a sound channel, speaker and speaker it Between broadcasting synchronization just seem particularly important.For example, in a music playing system, there are two speakers.Pass through setting Speaker 1 is set to play the L channel of a first stereo music, speaker 2 plays the right channel of same first stereo music, if two sounds Case play time difference be greater than 5ms, human ear can obviously experience play it is asynchronous, largely effect on the experience listened to music.Existing skill Art scheme can achieve higher frequently with hardware and two class implementation of software using hardware realization precise synchronization Precision, but need to increase corresponding hardware module；And the existing scheme using software realization, mostly use Network Time Protocol or Ieee1588 high precision clock synchronous protocol, as shown in Figure 1, synchronous protocol operates in application layer, synchronous protocol operation needs to receive Data packet is sent out, extracts packet time information to run synchronized algorithm, since data packet is handled by WIFI mould group, to driving layer The problem of handling, then handle to protocol layer, encountering many scheduling and cache, is extremely difficult to the error of delicate rank.

Summary of the invention

In view of the deficiencies of the prior art, technical solution of the present invention provides more room audio groups in a kind of WLAN The method being played simultaneously realizes high precision clock reference synchronization technology.

To achieve the above object, the technical solution of the present invention is as follows:

A kind of method that more room audio groups are played simultaneously in WLAN, it is characterised in that this method comprises:

S01, AP broadcast beacon frame, WIFI mould group decode beacon frame, and the timing information of AP is extracted from beacon frame, and update The clock counter of WIFI mould group, while adjusting local clock source running frequency is consistent local time counter with AP；

S02, the master and slave equipment of audio in same local area network accesses WIFI mould group clock counter, when obtaining identical Clock benchmark realizes that the master and slave equipment room clock reference of audio is identical；

S03, audio main equipment obtain audio data, are sent to audio in the form of data frames from equipment after coding；

S04, audio receive data frame from equipment, extract the temporal information in data frame, and determine whether to play audio number According to.

Further, to include main equipment obtain audio number from media server to the method for main equipment coded frame data in S03 According to, it is decoded as PCM format, and data truncation at the data length of a frame frame, header information is added before every frame data, it is described Header information further includes the one or more combined informations for controlling information and version information in addition to including temporal information.

Further, S04 sound intermediate frequency receives data frame from equipment, and extracting the temporal information in data frame is to extract to receive Data frame timestamp.

Further, S04 sound intermediate frequency receives data frame from equipment, extracts the temporal information in data frame, first judges whether Meet broadcast request, if satisfied, then in predetermined time playing audio-fequency data, if not satisfied, then not playing audio in the predetermined time Data.

Further, judge whether that the method for meeting broadcast request includes parsing the data frame received from equipment, extract The clock information on head, compares with local clock, lags behind local clock when data frame packet contains temporal information, then abandons, no Recognize the temporal information provided according to data frame, stamp plays the frame audio data at the appointed time.

Further, the master and slave equipment of S02 sound intermediate frequency accesses WIFI mould group clock counter, obtains identical clock reference It further include that access WIFI mould group clock counter bring shake is eliminated by error correction module.

The invention has the benefit that the present invention tells that equipment updates in local area network by using AP periodic broadcasting beacon frame Timing information, equipment extract beacon frame time information, calculate clocking error and adjust local time counter, equipment access obtains WIFI clock counter, the method for forming equipment room synchronous base, the clock realized in WIFI module internal are synchronized, are avoided WIFI driving, protocol stack and system transport layer bring influence, and isochronous audio broadcasting precision between distinct device may be implemented Clock reference synchronization error less than 20us.

Detailed description of the invention

Fig. 1 show the overview flow chart of embodiment according to the present invention；

Fig. 2 show the flow diagram of main equipment coded frame data of the present invention；

Fig. 3 show the schematic diagram of the master and slave equipment access WIFI mould group clock counter of the present invention；

Fig. 4 show the structure and information transmitting schematic diagram of audio system of the present invention.

Specific embodiment

To make the objectives, technical solutions, and advantages of the present invention clearer, right in the following with reference to the drawings and specific embodiments The present invention is described in detail.

A kind of method that more room audio groups are played simultaneously in WLAN, the flow chart of this method refering to fig. 1, the party Method includes:

S01, AP broadcast beacon frame, WIFI mould group decode beacon frame, and the timing information of AP is extracted from beacon frame, and update The clock counter of WIFI mould group, while adjusting local clock source running frequency is consistent local time counter with AP；

S02, the master and slave equipment of audio in same local area network accesses WIFI mould group clock counter, when obtaining identical Clock benchmark realizes that the master and slave equipment room clock reference of audio is identical；

S03, audio main equipment obtain audio data, are sent to audio in the form of data frames from equipment after coding；

S04, audio receive data frame from equipment, extract the temporal information in data frame, and determine whether to play audio number According to.

The method of main equipment coded frame data includes main equipment from media server acquisition audio data in S03, is decoded as PCM format, and data truncation at the data length of a frame frame, header information, the header information are added before every frame data It further include the one or more combined informations for controlling information and version information, as shown in Figure 2 in addition to including temporal information.

S04 sound intermediate frequency receives data frame from equipment, and extracting the temporal information in data frame is to extract the data frame received Timestamp.

S04 sound intermediate frequency receives data frame from equipment, extracts the temporal information in data frame, first judges whether to meet to play and want It asks, if satisfied, then in predetermined time playing audio-fequency data, if not satisfied, then in predetermined time not playing audio-fequency data.Judgement is The no method for meeting broadcast request includes parsing the data frame that receives from equipment, extracts the clock information on head, with it is local when Clock compares, and lags behind local clock when data frame packet contains temporal information, then abandons, denies the time letter provided according to data frame Breath, stamp plays the frame audio data at the appointed time.

The master and slave equipment of S02 sound intermediate frequency accesses WIFI mould group clock counter, and obtaining identical clock reference further includes passing through Error correction module eliminates access WIFI mould group clock counter bring shake, as shown in Figure 3.

More specific in order to make to illustrate, the present embodiment lists a specific more room audio systems to more room audios The workflow that group is played simultaneously is illustrated, as shown in figure 4, audio main equipment and audio represent sound from the dotted line between equipment Frequency main equipment is transferred to information flow of the audio from equipment after being decoded to audio data.More room audio systems include road By device, an audio main equipment and the first audio are from equipment and the second audio from equipment.Three audio frequency apparatuses are connected by WIFI It is connected to the same router, audio main equipment obtains audio data from media server via router, by audio data Other audios are encoded and then are sent to from equipment.Audio frequency apparatus after wherein encoding includes audio data, control letter The information such as breath, temporal information receive audio data, extracting time information and audio data from equipment, and mention according to temporal information Show, puts audio frame in program request at the same time with main equipment, realize that more equipment are played simultaneously.

In conclusion the method for the present invention tells that equipment updates timing information in local area network by AP periodic broadcasting beacon frame, Equipment extracts beacon frame time information, calculates clocking error and adjusts local time counter, equipment access obtains WIFI clock meter Number device forms equipment room synchronous base, and this method is made clock in WIFI module internal and synchronized, and avoids WIFI driving, protocol stack And system transport layer bring influences, and makes isochronous audio broadcasting precision between distinct device that the clock base for being less than 20us may be implemented Plesiochronous error.

The above, only presently preferred embodiments of the present invention, the invention is not limited to above embodiment, as long as It reaches technical effect of the invention with identical means, all should belong to protection scope of the present invention.In protection model of the invention Its technical solution and/or embodiment can have a variety of different modifications and variations in enclosing.