| 主权项 |
1. The method of codec selection in the audio transmission process in the ICT systems between the two transceivers is characterised by the fact that in the first transceiver the electrical signal from the microphone output is fed to the input of an analogue-to-digital converter which converts the signal into digital data, and which is then sent to the input of the microprocessor system, which uses a data encoding programme to encode the digital data, and the encoding programme is assigned a decoding programme wherein both of these programmes constitute a codec, which is assigned an identification number, and all the codecs are saved in the programme memory, and the data obtained from the en-coding process is sent to the input of the microcomputer system, where a packet is created, and this packet comprises, among others, encoder number field, encoded audio data field and codec number for the opposite direction field and this packet is sent, via telecommunication connection channel, to the second transceiver, where it is received from the input by the microcomputer system in which software is used to separate the encoded audio data from the packet, and the encoding programme field is read, and the values of the communication channel parameters, such as throughput, transmission latency delay and fluctuation, are calculated on the basis of a received packet, and then the encoded audio data, the communication channel parameters and the en-coding programme number are sent to the microprocessor system, where, on the basis of the received encoding programme number, a de-coding programme with the same number is picked from programme memory, and the decoding programme decodes the data, and the outcome of the data decoding process consists of the data that is fed to the digital-to-analogue converter at the input of which analogue signal is obtained, which is fed to the loudspeaker, and then the second transceiver starts sending the packet to the first transceiver and this packet includes, in the respective fields and in the form of code for the first transceiver, the information about which codec has been used for audio processing, and the first transceiver, after receiving the packet that stores the information about the used codec from the second transceiver, activates the same codec as in the second transceiver and, after de-coding, sends the sequence of digital samples that constitute the recorded sound to the digital-to-analogue converter and then to the loud-speaker, characterised in that
a certain number of audio programmes are entered into the algorithm encoding memory PAK of the microprocessor system SuP of the first transceiver UN-O-1 and the second transceiver UN-O-2, and the same number of decoding programmes are entered into the algorithm decoding memory PAD, and each encoding and decoding programme is assigned a set of values of the communication channel KTK parameters such as throughput, latency delay and fluctuation, for which a particular encoding and decoding programme is optimal, and a first working register area RR-1 with address space equal to 100 and a second working register area RR-2 with address space equal to 3 are reserved in the data memory PD of the microprocessor system SuP in the first transceiver UN-O-1 and the second transceiver UN-O-2, whereas the second working register area RR-2 is organised in such a manner that the saved value of a new number replaces the oldest entry, and when the micro-computer system uK in the second transceiver UN-O-2 receives a pack-et from the first transceiver UN-O-1, the packet and the programme are used to calculate the values of the current communication channel KTK parameters, and the values of these parameters are transmitted to the microprocessor system SuP, which compares these data with the data from communication channels data stored in the encoding algorithm memory PAK and this comparison allows the system to select an en-coding programme optimal for the given parameters of the communication channel KTK and to assign an identification number of the optimal codec for the direction of the transmission from the first transceiver UN-O-1 to the second transceiver UN-O-2, and subsequently the system saves this number in the first working register area RR-1 and includes it in the packet sent to the first transceiver UN-O-1 in the codec number field for the opposite direction SID, and the first transceiver UN-O-1, after receiving the packet from the second transceiver UN-O-2, reads, from the codec number field for the opposite direction SID, the number of the codec that will be used for processing audio for the transmission direction from the first transceiver UN-O-1 to the second transceiver UN-O-2, and the number of the optimal codec for the transmission direction from the second transceiver UN-O-2 to the first transceiver UN-O-1 is established analogously to the opposite direction, whereas the identification numbers of codecs optimal for the transmission direction from the second transceiver UN-O-2 to the first transceiver UN-O-1 are saved into the working register area RR-1 of the first transceiver UN-O-1, and the process of establishing the number of optimal codec continues throughout the entire transmission of packets between the transceivers until the first working register area RR-1 is full, after which the microprocessor system SuP analyses the content of this area by determining which identification number is most frequent in the registers of this area, and this number is saved into the second working register area RR-2, and when this area is full the microprocessor system SuP analyses the content of this area by selecting an identification number of a codec appears twice in a row within these registers and initiating the procedure of codec change by entering into the packet, in the codec number field of the opposite direction SID, the new codec number, and if no codec appears twice in a row in the second working register area RR-2, the procedure of codec change is not initiated, and the procedure of codec change involves entering the number selected from the second working register area RR-2 into the packet, in the codec number field of the opposite direction SID, and sending it, and when the working register of the first area RR-1 is once again full and the most frequent number is selected, entering it into the working register from the second working register area RR-2. |
