JP4930207B2 - Information processing device - Google Patents

Description

  The present invention relates to an information processing apparatus, and more particularly to an information processing apparatus capable of streaming and transferring audio data in real time.

  In recent years, for example, Bluetooth (registered trademark) is known as a wireless communication technology that can be applied to, for example, electronic devices. By using this Bluetooth wireless communication technology, audio data can be transferred from a portable information terminal such as a mobile phone or a portable music player to an opposite device such as a headset without using an audio cable.

  As profiles for transmitting audio data, for example, “Advanced Audio Distribution Profile (A2DP)” (Non-Patent Document 1) and “Generic Audio / Video Distribution Profile” (Non-Patent Document 2) are known. These are standards for performing streaming transfer of audio data in real time between devices connected via Bluetooth.

For example, in portable information terminals such as mobile phones and portable music players, audio data is compressed in a format such as SBC (Sub Band Coding), MP3 (MPEG1 Audio Layer-3), or ATRAC (Advanced Transform Acoustic Coding) 3. Transfer in packets. On the other hand, an opposing device such as a speaker or a headset does not wait for all packets to be received and reproduces them simultaneously with reception of data. As a result, the user can listen to the sound from the portable information terminal, portable music player, etc. in an almost real time on the opposite device such as a speaker or a headset.
Advanced Audio Distribution Profile (Bluetooth SIG) Generic Audio / Video Distribution Profile (Bluetooth SIG)

  When the mobile phone and the headset as the opposite device are connected by A2DP, if the distance between the mobile phone and the headset is increased, a link loss that is a state in which the connection with the headset is lost occurs. In general, when this link loss occurs during transmission of a media packet containing music content for streaming playback, the transmission processing of the media packet from the mobile phone is stopped.

  However, there is a problem that if the transmission process of the media packet is simply stopped just because a link loss occurs, the media packet overflows on the mobile phone side. Of course, the implementation of stopping the music player playback process itself as a higher-level application program is also conceivable. On the other hand, even if a link loss occurs, the music player plays the sound while continuing the music player playback process. In some cases, the media packet overflow as described above may occur.

  The present invention has been made in view of such circumstances, and provides an information processing apparatus that can suitably prevent overflow of a media packet even if a link loss occurs during media packet transmission. Objective.

  In order to solve the above-described problem, the information processing apparatus according to the present invention transmits audio data or audio data encoded in advance by a predetermined encoding method to an opposite device via wireless communication. A cutout unit that cuts out audio data in frame units, a generation unit that generates a packet to be transferred to the opposite device based on audio data or audio data in frame units cut out by the cutout unit, and a packet generated by the generation unit Detection that detects whether or not a link loss has occurred between the holding unit temporarily holding, the transmission unit that transmits the packets held by the holding unit to the opposite device every predetermined amount, and the opposite device And a link between the detection device and the opposite device during transmission of the packet to the opposite device by the transmission means. If the scan is detected to have occurred, transmitting means is characterized by discarding a packet to be transmitted is held by the holding means.

  In order to solve the above-described problem, the information processing apparatus according to the present invention decodes audio data or audio data previously encoded by a predetermined encoding method using a decoding method corresponding to the predetermined codec method. Means, encoding means for encoding audio data or voice data decoded by the decoding means by different encoding methods, and audio data or voice data encoded by the encoding means opposed to each other via wireless communication A cutout unit that cuts out audio data or audio data in frame units when transferring to a device, and a generation unit that generates a packet to be transferred to the opposite device based on the audio data or audio data in frame units cut out by the cutout unit Holding means for temporarily holding the packet generated by the generating means; A transmission means for transmitting packets held by the means to the opposite device every predetermined amount, and a detection means for detecting whether or not a link loss has occurred between the opposite devices. When it is detected that a link loss has occurred with the opposite device during transmission of the packet to the opposite device by the means, the encoding means stops and the audio data or voice data already decoded by the decoding means It is characterized by destroying.

  In the information processing apparatus of the present invention, when audio data or audio data encoded in advance by a predetermined encoding method is transferred to the opposite device via wireless communication, the audio data or audio data is cut out in units of frames. Based on the extracted audio data or audio data in units of frames, a packet to be transferred to the opposite device is generated, the generated packet is temporarily held, and the held packet is stored for each predetermined amount. It is detected whether or not a link loss has occurred with the opposite device, and is retained when it is detected that a link loss has occurred with the opposite device during packet transmission to the opposite device. A packet to be transmitted is discarded.

  In the information processing apparatus of the present invention, audio data or audio data encoded in advance by a predetermined encoding method is decoded by a decoding method corresponding to the predetermined codec method, and the decoded audio data or audio data Is encoded with a different encoding method, and when the encoded audio data or audio data is transferred to the opposite device via wireless communication, the audio data or audio data is extracted in frame units, and the extracted frame units Based on the audio data or audio data of the device, a packet to be transferred to the opposite device is generated, the generated packet is temporarily held, and the held packets are transmitted to the opposite device every predetermined amount. Whether or not a link loss has occurred between the If the link loss with the device is detected to have occurred, with coding means to stop the audio data or voice data already decoded are discarded.

  According to the present invention, even if a link loss occurs during media packet transmission, overflow of the media packet can be suitably prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, in the vicinity of a mobile phone 1, a headset 2 that can be applied as a counter device according to the present invention is arranged. The headset 2 can receive audio data transferred from the mobile phone 2 using wireless communication (for example, Bluetooth) and reproduce it in real time. In addition to the headset 2, an in-vehicle device (not shown) may be used as the opposing device.

  FIG. 2 shows an internal configuration of the mobile phone 1 of FIG. As shown in FIG. 2, the mobile phone 1 includes a control unit 11, a display unit 12, an input unit 13, a storage unit 14, a radio telephone communication unit 15, a signal processing unit 16, a PCM codec 17, a microphone 18, a speaker 19, A media player control unit 20, a content processing unit 21, and a short-range wireless communication unit 22 are connected to each other via a bus 23.

  The control unit 11 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The CPU is loaded into the RAM from a program stored in the ROM or the storage unit 14. Various processes are executed in accordance with various application programs, and various control signals are generated and supplied to each unit to control the mobile phone 1 in an integrated manner. The RAM appropriately stores data necessary for the CPU to execute various processes.

  The display unit 12 includes, for example, an LCD (Liquid Crystal Display), and the input unit 13 includes operation keys and operation buttons (not shown).

  The radio telephone communication unit 15 receives a radio signal transmitted from a base station (not shown) via an antenna (not shown), down-converts the received radio signal to obtain an intermediate frequency signal, and further performs orthogonal demodulation. Processing, despreading and combining processing of each path by a RAKE receiver (not shown) are performed. Thereafter, the received packet data output from the RAKE receiver is input to the signal processing unit 16.

  The signal processing unit 16 includes, for example, a DSP (Digital Signal Processor) and the like, and includes a speech codec that performs encoding / decoding of an audio signal transmitted / received via the wireless telephone communication unit 15. The digital audio signal obtained by such decoding processing is PCM decoded by the PCM codec 17, amplified and output from the speaker 19. On the other hand, the audio signal input from the microphone 18 is modulated into a digital audio signal by the PCM codec 17 and input to the speech codec.

  The media player unit 20 executes a music player function for reproducing audio data, for example. Of course, the mobile phone 1 is provided with a terrestrial digital one seg / radio receiver, for example, various functions such as a terrestrial digital one seg player function by executing an application program when receiving a terrestrial digital one seg broadcast wave. A media player may be executed.

  The content processing unit 21 includes a decoder 24 and an encoder 25. When the media player unit 20 controls the music player function, for example, the decoder 24 performs encoding using an encoding method such as AAC, aacPlus, MP3, ATRAC, or SBC. The encoded (encoded) audio data is once decoded (decoded) by a decoding method corresponding to the encoding method. Then, the encoder 25 of the content processing unit 21 performs re-encoding processing or the like on the analog audio data decoded (decoded) by the decoder 24 using another encoding method.

  In addition, when the media player unit 20 executes the one-segment player function, in addition to the audio data encoding / decoding process such as the AAC, MPEG4 or H.264 is performed. The encoding and decoding processes may be performed using an encoding method and a decoding method such as H.264.

  The short-range wireless communication unit 22 includes, for example, a module that performs wireless communication using Bluetooth (registered trademark), and performs wireless communication with the headset 2 that exists in the vicinity of the mobile phone 1. Of course, wireless communication other than Bluetooth (for example, infrared communication) may be used. The short-range wireless communication unit 22 includes a frame cutout unit 26, a packet generation unit 27, a transmission buffer 28, a packet transmission unit 29, a link loss detection unit 30, and the like.

  The frame cutout unit 26 sequentially reads out the audio data stored in the storage unit 14 or the audio data after being re-encoded by the content processing unit 21, and reads out the read-out audio data using a codec method (for example, an encoding method such as AAC). For each frame suitable for (), and the audio data of the cut frame unit is supplied to the packet generation unit 27.

  The packet generation unit 27 generates a packet to be transferred to the headset based on the audio data in units of frames extracted by the frame extraction unit 26, and sequentially supplies the generated packets to the transmission buffer 28. The transmission buffer 28 is configured in, for example, a FIFO (First In First Out) format, and sequentially buffers (temporarily stores) packets supplied from the packet generation unit 27.

  The packet transmission 29 sequentially reads the packets buffered in the transmission buffer 28 and wirelessly transmits the read packets to the headset 2 at a predetermined amount at a predetermined timing.

  The link loss detection unit 30 is a headset 2 that is generated when the distance between the mobile phone 1 and the headset 2 increases when the mobile phone 1 and the headset 2 as the opposite device are connected by A2DP. Link loss is detected in which the connection with is lost.

  Next, the audio data transfer process in the mobile phone 1 of FIG. 2 will be described with reference to the flowchart of FIG. This audio data transfer process is performed when the negotiation is initiated from the headset 2, which is the opposite device (SNK) that receives the audio data, to start streaming transfer, or the device that holds the audio data. This is executed when negotiation is initiated by the mobile phone 1 which is (SRC) to start streaming transfer.

  In step S <b> 1, the mobile phone 1 establishes a control session with the headset 2 using the short-range wireless communication unit 22, and controls a service for transmitting a packet (media packet) to the headset 2. Establish a logical channel.

  After the control session is established, the headset 2 requests the acquisition of parameter information, which is information relating to parameters supported by the mobile phone 1 (for example, codec type, sampling rate, bit rate, etc.). Parameter information supported by the mobile phone 1 is acquired.

  In step S2, the short-range wireless communication unit 22 performs parameters (for example, the type of codec, the sampling rate, and the like) according to the audio data to be transmitted to the headset 2 as the opposite device via wireless communication according to a predetermined data transfer procedure. Negotiate with headset 2 for bit rate etc.

  In step S <b> 3, the short-range wireless communication unit 22 acquires a parameter specified at the time of negotiation from the headset 2 regarding a parameter for transferring audio data to the headset 2, and uses the acquired parameter to reset the headset. 2 is initialized with parameters for transferring audio data.

  After that, an open request (“Open” command) is made from the headset 2 via wireless communication, and a transport logic for transmitting a packet (media packet) between the mobile phone 1 and the headset 2. A channel is established. In step S4, the state between the mobile phone 1 and the headset 2 is changed to the streaming state by the above-described data transfer procedure by the short-range wireless communication unit 22.

  Thereafter, the media player unit 20 executes the music player, selects a song according to the operation by the user, and makes an open request to the short-range wireless communication unit 22 via wireless communication. In addition, the short-range wireless communication unit 22 checks parameters appropriate for audio data to be transmitted to the headset 2.

  In step S <b> 5, the media player unit 20 executes a music player and starts audio data transfer processing via the short-range wireless communication unit 22. In step S6, the decoder 24 of the content processing unit 21 is encoded (encoded) with an encoding method such as AAC, aacPlus, MP3, ATRAC, or SBC when the media player unit 20 executes the music player function. Audio data is read from the storage unit 14, and is once decoded (decoded) in step S7 by a decoding method corresponding to the encoding method. In step S8, the encoder 25 of the content processing unit 21 performs re-encoding processing (re-encoding) on the analog audio data decoded (decoded) by the decoder 24 using another encoding method.

  In step S9, the frame cutout unit 26 of the short-range wireless communication unit 22 sequentially reads and reads the audio data after re-encoding (after re-encoding) of the content processing unit 21 after the establishment of the transport logical channel. The extracted audio data is cut out for each frame suitable for a codec method (for example, an encoding method such as AAC), and the audio data of the cut frame unit is supplied to the packet generation unit 27.

  In step S10, the packet generation unit 27 of the short-range wireless communication unit 22 generates a packet to be transferred to the headset based on the frame-unit audio data extracted by the frame extraction unit 26, and transmits the generated packet for transmission. Sequentially supplied to the buffer 28. In step S11, the transmission buffer 28 sequentially buffers (temporarily stores) the packets supplied from the packet generator 27.

  In step S12, the packet transmission unit 26 sequentially reads the packets buffered in the transmission buffer 28, and sequentially transmits the read packets to the headset 2 by wireless communication.

  In step S13, the link loss detection unit 30 occurs when the distance between the mobile phone 1 and the headset 2 increases when the mobile phone 1 and the headset 2 as the opposite device are connected by A2DP. A link loss is detected in which the connection with the headset 2 is lost.

  If a link loss, which is a state in which the connection with the headset 2 is lost in step S13, is not detected, the process returns to step S6, and the processes after step S6 are repeatedly executed. That is, audio data is sequentially transferred from the mobile phone 1 to the headset 2 in predetermined amounts at predetermined timing.

  On the other hand, if a link loss in which the connection with the headset 2 is lost is detected in step S13, the link loss detection unit 30 determines that the link loss in the state in which the connection with the headset 2 has been lost. The packet transmission unit 29 is notified of the fact that it has been detected. Thereafter, in the processes of steps S14 to S19, the re-encoded audio data is cut out in units of frames in the same manner as in the processes of steps S6 to S11, and packets are generated based on the cut out audio data in units of frames. The transmitted packet is buffered in the transmission buffer 28. In step S <b> 20, the packet transmission unit 29 temporarily stores the current transmission buffer 28 in accordance with the notification from the link loss detection unit 30 that the link loss in which the connection with the headset 2 has been detected has been detected. Discard (hold) packets to be transmitted (media packets).

  In step S21, the packet transmission unit 29 calculates a performance time corresponding to the packet amount discarded by the packet discarding process in step S20. For example, if the number of packets discarded by the packet discarding process is five and if 45 ms of audio data is stored in each packet, the performance time corresponding to the amount of packets discarded by the packet discarding process is 225 ms ( 45 ms + 45 ms + 45 ms + 45 ms + 45 ms = 225 ms) is calculated. In addition, when 45 ms of audio data is stored in four packets out of the five packets and 42 ms of audio data is stored in the remaining one packet, this corresponds to the amount of packets discarded by the packet discarding process. 222 ms (45 ms + 45 ms + 45 ms + 45 ms + 42 ms = 222 ms) is calculated as the performance time. Of course, the performance time corresponding to the amount of packets discarded by the packet discarding process may be calculated using other calculation methods.

  In step S22, the packet transmitter 29 recognizes the time after the performance time corresponding to the discarded packet amount as the next transmission time from the current transmission time. In step S23, the link loss detection unit 30 has recovered (recovered) from the link loss in which the connection with the headset 2 that occurs when the distance between the mobile phone 1 and the headset 2 increases. Detect whether or not. If it is detected in step S23 that the connection with the headset 2 has not been lost from the link loss, the process returns to step S14, and the processes after step S14 are repeatedly executed. As a result, the packets buffered in the transmission buffer 28 are repeatedly discarded during the link loss.

  On the other hand, when it is detected in step S23 that the connection with the headset 2 has been lost, the link loss detection unit 30 detects that (the link with the connection with the headset 2 has been lost). The media player control unit 20 is notified of the fact that it has returned from the loss. In step S <b> 24, the media player unit 20 executes the music player function again, and resumes the audio data transfer process via the short-range wireless communication unit 22 at the transmission time recognized by the packet transmission unit 29. Thereafter, the process returns to step S6, and the processes after step S6 are repeatedly executed. Thereby, even when the packet to be transmitted is discarded, the audio data transfer process can be resumed at an appropriate transmission time after recovering from the link loss once generated.

  In the embodiment of the present invention, the case where the music player function is executed by the media player unit 20 has been described. However, the present invention is also applied to the case where various media player functions such as a terrestrial digital one-segment player are executed. You may make it do.

  In the embodiment of the present invention, when audio data encoded in advance by a predetermined codec method is transferred to the headset 2 via wireless communication, the audio data is cut out in units of frames, and the audio in units of the cut out frames is recorded. Based on the data, a packet to be transferred to the headset 2 is generated, the generated packet is temporarily held, and the held packet is transmitted to the headset 2 by a predetermined amount. Then, it is detected whether or not a link loss has occurred between the mobile phone 1 and the headset 2, and a link loss has occurred with the headset 2 during transmission of a packet to the headset 2 which is the opposite device. When a link loss occurs, the currently held packet to be transmitted is continuously discarded, and the time after the performance time corresponding to the discarded packet amount is It can be recognized that it is the transmission time.

  As a result, when a link loss occurs between the mobile phone 1 and the headset 2, even if the transmission processing of the media packet is stopped, the currently held packet to be transmitted is continuously discarded at the same time. Therefore, the occurrence of overflow of the media packet can be prevented. In addition, since the time after the performance time corresponding to the discarded packet amount has elapsed is recognized as the next transmission time after discarding the packet, between the mobile phone 1 and the headset 2. Even if the transfer process of audio data is resumed when the link loss that has occurred is resumed, the transfer process of audio data can be resumed at an appropriate transmission time after the return from the link loss that has occurred once. In particular, for example, when the present invention is applied to the case where the media player control unit 20 controls the terrestrial digital one-seg player, the performance time of the moving image displayed on the display unit 12 is voiced due to the occurrence of link loss. Although it may be possible to proceed ahead of the (audio data) performance time, after discarding the packet, the time after the performance time corresponding to the discarded packet amount has elapsed is recognized as the next transmission time. In this way, it is possible to avoid the inconsistency of the audio performance time with the performance time of the moving image. Therefore, even if a link loss occurs during media packet transmission, overflow of the media packet can be suitably prevented.

In the audio data transfer process described with reference to the flowchart of FIG.
When it is detected that a link loss has occurred with the headset 2 during transmission of the packet to the headset 2 as the opposite device, the currently held packet to be transmitted is discarded. For example, the encoder 25 of the content processing unit 21 may be temporarily stopped and analog audio data that has already been decoded (decoded) by the decoder may be discarded. The audio data transfer process using this method will be described below.

  With reference to the flowchart of FIG. 4, another audio data transfer process in the mobile phone 1 of FIG. 2 will be described. The processes in steps S31 to S43 and steps S46 to S47 in FIG. 4 are the same as those in steps S1 to S13 and steps S23 to S24 in FIG.

  If a link loss in which the connection with the headset 2 is lost is detected in step S43, the link loss detection unit 30 detects that fact (a link loss in a state in which the connection with the headset 2 is lost). To the content processing unit 21. In step S44, the content processing unit 21 executes the music player function according to the notification from the link loss detection unit 30 that the link loss, which is the state in which the connection with the headset 2 has been detected, has been detected. The encoder 25 used for this is temporarily stopped.

  In step S45, when the media player unit 20 controls the music player function, the content processing unit 21 discards analog audio data that has already been decoded (decoded) by the decoder 24 until the link loss occurs.

  As a result, when a link loss occurs between the mobile phone 1 and the headset 2, the encoder 25 used when the media player unit 20 controls the music player function without stopping the media packet transmission process. Since the analog audio data that has already been decoded (decoded) by the decoder 24 before the loss of the link is discarded by the decoder 24, the occurrence of overflow of the media packet can be prevented. Therefore, even if a link loss occurs during media packet transmission, overflow of the media packet can be suitably prevented. Moreover, the power consumption in the mobile phone 1 can be suppressed by stopping the encoder 25.

  The present invention can be applied to a PDA (Personal Digital Assistant), a personal computer, a portable game machine, a portable music player, a portable video player, and other information processing information processing apparatuses in addition to the cellular phone 1. can do.

  The series of processes described in the embodiments of the present invention can be executed by software, but can also be executed by hardware.

  Furthermore, in the embodiment of the present invention, the steps of the flowchart show an example of processing performed in time series in the order described, but parallel or individual execution is not necessarily performed in time series. The processing to be performed is also included.

1 is a diagram showing a schematic configuration of an information exchange system according to the present invention. 1 is a block diagram showing an internal configuration of a mobile phone applicable to an information processing apparatus of the present invention. 3 is a flowchart for explaining audio data transfer processing in the mobile phone of FIG. The flowchart explaining the other audio data transfer process in the mobile telephone of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Mobile telephone, 2 ... Headset, 11 ... Control part, 12 ... Display part, 13 ... Input part, 14 ... Memory | storage part, 15 ... Radio telephone communication part, 16 ... Signal processing part, 17 ... PCM codec, 18 ... Microphone, 19 ... speaker, 20 ... media player unit, 21 ... content processing unit, 22 ... short-range wireless communication unit, 23 ... bus, 24 ... decoder, 25 ... encoder, 26 ... frame cutout unit, 27 ... packet generation unit, 28... Transmission buffer, 29... Packet transmission unit, 30.

Claims (3)

When transferring audio data or audio data encoded in advance by a predetermined encoding method to the opposite device via wireless communication, a clipping means for cutting out the audio data or audio data in units of frames;
Generating means for generating a packet to be transferred to the opposite device based on the audio data or audio data in units of frames cut out by the cut-out means;
Holding means for temporarily holding the packet generated by the generating means;
Transmitting means for transmitting the packet held by the holding means to the opposite device for each predetermined amount;
Detecting means for detecting whether or not a link loss has occurred with the opposite device,
When it is detected by the detecting means that a link loss has occurred with the opposing device during transmission of the packet to the opposing device by the transmitting means, the transmitting means is held by the holding means. An information processing apparatus, wherein the packet to be transmitted is discarded.   The transmission means discards the packet to be transmitted held by the holding means, and the time after the performance time or performance time corresponding to the discarded packet amount is the next transmission time The information processing apparatus according to claim 1, wherein Decoding means for decoding audio data or audio data encoded in advance by a predetermined encoding method by a decoding method corresponding to the predetermined codec method;
Encoding means for encoding the audio data or audio data decoded by the decoding means with different encoding methods;
Further comprising
It said cut-out means, the information processing apparatus according to claim 1, wherein the score cut out the audio data or voice data encoded in units of frames by the encoding means.

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