WO2011067625A1 - Système de traitement de données audio - Google Patents

Système de traitement de données audio Download PDF

Info

Publication number
WO2011067625A1
WO2011067625A1 PCT/IB2009/055442 IB2009055442W WO2011067625A1 WO 2011067625 A1 WO2011067625 A1 WO 2011067625A1 IB 2009055442 W IB2009055442 W IB 2009055442W WO 2011067625 A1 WO2011067625 A1 WO 2011067625A1
Authority
WO
WIPO (PCT)
Prior art keywords
audio
transition
frequency
sampling frequency
audio data
Prior art date
Application number
PCT/IB2009/055442
Other languages
English (en)
Inventor
Santosh Narayan Shilimkar
Original Assignee
Nxp B.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nxp B.V. filed Critical Nxp B.V.
Priority to PCT/IB2009/055442 priority Critical patent/WO2011067625A1/fr
Publication of WO2011067625A1 publication Critical patent/WO2011067625A1/fr

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10527—Audio or video recording; Data buffering arrangements
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10009—Improvement or modification of read or write signals
    • G11B20/10037—A/D conversion, D/A conversion, sampling, slicing and digital quantisation or adjusting parameters thereof
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00007—Time or data compression or expansion
    • G11B2020/00014—Time or data compression or expansion the compressed signal being an audio signal
    • G11B2020/00057—MPEG-1 or MPEG-2 audio layer III [MP3]
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10527—Audio or video recording; Data buffering arrangements
    • G11B2020/10537—Audio or video recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/10527—Audio or video recording; Data buffering arrangements
    • G11B2020/10537—Audio or video recording
    • G11B2020/10546—Audio or video recording specifically adapted for audio data
    • G11B2020/10555—Audio or video recording specifically adapted for audio data wherein the frequency, the amplitude, or other characteristics of the audio signal is taken into account
    • G11B2020/10564—Audio or video recording specifically adapted for audio data wherein the frequency, the amplitude, or other characteristics of the audio signal is taken into account frequency
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B2020/10935—Digital recording or reproducing wherein a time constraint must be met
    • G11B2020/10944—Real-time recording or reproducing, e.g. for ensuring seamless playback of AV data
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B2020/10935—Digital recording or reproducing wherein a time constraint must be met
    • G11B2020/10972—Management of interruptions, e.g. due to editing

Definitions

  • the invention relates to a device for processing audio data.
  • the invention relates to a method of processing audio data.
  • the invention relates to a program element.
  • the invention relates to a computer-readable medium.
  • Audio playback devices become more and more important. Particularly, an increasing number of users buy headphone-based audio players and loudspeaker-based audio surround systems.
  • US 2005/0080500 Al discloses an audio device which includes a DVD player for decoding an input audio signal and for outputting a digital audio signal, an audio amplifier for outputting an analog audio signal based on the digital audio signal, an audio decoder for detecting a change of an audio attribute, a decoding suspension unit for muting an output from the audio amplifier and temporarily suspending an operation of the decoder when the change of the attribute is detected, and a setting changing unit for changing operation conditions of the audio amplifier so as to correspond to the changed audio attribute when a muting part operates.
  • a transition between two audio pieces may still sound artificial for a human listener.
  • a device for processing audio data a method of processing audio data, a program element and a computer-readable medium according to the independent claims are provided.
  • a device for processing audio data comprising a detection unit adapted for detecting a transition between a first piece of audio data having assigned a first sampling frequency and a second piece of audio data having assigned a second sampling frequency (which may differ from the first sampling frequency), and a control unit adapted for disconnecting, during the transition, audio domain clocks (for instance all audio domain clocks of an audio playback system) from a clock frequency relating to the first sampling frequency (for instance a clock frequency being an integer multiple of the first sampling frequency, for instance 256 times the first sampling frequency) and connecting the audio domain clocks to a transition frequency, wherein the control unit is further adapted for disconnecting, after the transition, the audio domain clocks from the transition frequency and connecting the audio domain clocks to a clock frequency relating to the second sampling frequency (for instance a clock frequency being an integer multiple of the second sampling frequency, for instance 256 times the second sampling frequency).
  • the control unit is further adapted for disconnecting, after the transition, the audio domain clocks from the transition frequency and connecting the audio domain clocks to
  • a method of processing audio data comprises detecting a transition between a first piece of audio data having assigned a first sampling frequency and a second piece of audio data having assigned a second sampling frequency, disconnecting, during the transition, audio domain clocks from a clock frequency relating to the first sampling frequency and connecting the audio domain clocks to a transition frequency, and disconnecting, after the transition, the audio domain clocks from the transition frequency and connecting the audio domain clocks to a clock frequency relating to the second sampling frequency.
  • a program element for instance a software routine, in source code or in executable code
  • a processor when being executed by a processor, is adapted to control or carry out a data processing method having the above mentioned features.
  • a computer- readable medium for instance a CD, a DVD, a USB stick, a floppy disk or a harddisk
  • a computer program is stored which, when being executed by a processor, is adapted to control or carry out a data processing method having the above mentioned features.
  • Data processing for audio transition purposes which may be performed according to embodiments of the invention can be realized by a computer program, that is by software, or by using one or more special electronic optimization circuits, that is in hardware, or in hybrid form, that is by means of software components and hardware components.
  • piece of audio data may denote a file or a data collection including data representing acoustic data such as a song, a speech, or the like. Such a piece of audio data may have a quality depending on a sampling frequency (for instance 48 kHz)
  • transition between pieces of audio data may particularly denote a time interval after a previous audio piece has faded out and a subsequent audio piece starts to fade in.
  • an adjustment of clock frequencies (which may be correlated to sampling frequencies) may be necessary which may conventionally result in an annoying audible artefact that may be denoted as an audio "plop”.
  • transition between pieces of audio data may also denote a change between different audio tracks.
  • audio domain clock may particularly denote one or more clocks which are used by an audio playback or audio processing system for driving various components such as an interpolator, a digital to analog converter, etc.
  • One or more audio domain clocks may be generated by a clock factory or clock generation unit (CGU).
  • CGU clock factory or clock generation unit
  • transition frequency may particularly denote an auxiliary frequency, which may be provided by a frequency generator or clock generator such as a fixed oscillator and which has a specific frequency of, for instance, 12 MHz. Such a frequency may be constant with a high precision.
  • clock may denote a sequence of alternating "high” logical values and “low” logical values. Thus, such clocks may define processing speed.
  • an audio plop may be efficiently suppressed by avoiding a stop or break of a clock during a transition between two audio pieces having different sampling frequencies. This may be achieved by bridging a switching period by providing a transition frequency such as a frequency generated by a fixed oscillator between the two pieces of audio data having possibly different sampling frequencies.
  • a transition frequency such as a frequency generated by a fixed oscillator between the two pieces of audio data having possibly different sampling frequencies.
  • an audio processing device may be provided comprising means to prevent a hearable spike (audible "plop”) in case of switching between audio streams of different sampling frequency.
  • a hearable spike audible "plop”
  • An aim according to an exemplary embodiment of the invention is to prevent or suppress an audio plop that can be heard on speakers because of the change in the sampling frequency.
  • embodiments add a software based plop suppression at very low cost.
  • Another disadvantage which may be overcome according to an exemplary embodiment of the invention is that hardware based solutions occupy area on a
  • Embodiments of the invention are software based so that an additional cost is almost zero.
  • the whole audio domain clock (like BCK,
  • WCK, Fs, 256*Fs, 1024*Fs, etc., wherein Fs may denote a sampling frequency) values will be changed as per the new sampling frequency.
  • Fs may denote a sampling frequency
  • Embodiments of the invention actually solve the root cause with a software based technique using the clock system hardware.
  • the detection of the change in the sampling frequency may be done at a software application level.
  • the ID3 tag may provide such information. So in software before the first track ends, a user can already read the ID3 tag of the next song and find out the next audio sampling frequency. So this change detection may be handled completely in software by the software application.
  • the control unit may be adapted for processing the first piece of audio data and the second piece of audio data in such a manner that an audible spike is suppressed during the transition.
  • the clock management may be specifically adjusted to eliminate the audible plop or to at least suppress it efficiently. For this purpose, an uninterrupted supply of clock signals may be guaranteed during sampling frequency switch.
  • the control unit may be adapted for processing the first audio piece of audio data and the second piece of audio data in such a manner that an audio domain clock is prevented from being stopped during the transition.
  • a stop or interruption of a clock i.e. a time interval in which no clock signal is provided, may be a course of an audio plop.
  • the control unit may be adapted for disconnecting, during the transition, the audio domain clocks from an audio phase locked loop (PLL).
  • PLL audio phase locked loop
  • Such an audio phase locked loop may provide a contribution to clock generation.
  • the fixed oscillator may be used for providing a clock signal.
  • the control unit may be adapted for configuring, during the transition, the audio phase locked loop to the second sampling frequency. Therefore, while the transition frequency is active, the system may continue for adapting the system to the sampling frequency of the subsequent audio piece.
  • the control unit may be adapted for reconnecting, after the transition, the audio domain clocks to the audio phase locked loop (PLL).
  • PLL phase locked loop
  • the transition frequency may be deactivated, and the system may continue to work on the basis of the second sampling frequency that may be the base of the generation of all audio clocks.
  • the first sampling frequency may be 44, 1 kHz, which is a characteristic sampling frequency of an MP3 song
  • the second sampling frequency may be a 48 kHz song.
  • the transition frequency may be 12 MHz, which is approximate 2 8 of the sampling frequencies.
  • a sampling frequency may be 44.1 kHz or 48 kHz
  • kHz 12.29MHz
  • transition frequency may be 12MHz
  • the device may comprise a fixed oscillator (such as a quartz oscillator) which may provide a transition frequency.
  • This transition frequency may be a very constant frequency of, for instance, 12 MHz, which may serve for bridging the reconfiguration interval or the transition period between the two audio pieces.
  • the control unit may be adapted for disconnecting the audio domain clocks from the first sampling frequency and connecting the audio domain clocks to the transition frequency when the audio domain clocks are low (or on a falling edge).
  • the clocks are sequences of logical values of "1" and "0", whereas "1" can be indicated with a "high” logic state, whereas the logic state "0” can be assigned to a "low” logic state.
  • control unit may further be adapted for disconnecting the audio domain clocks from the transition frequency and connecting the audio domain clocks to the second sampling frequency when the audio domain clocks are low (or on a falling edge).
  • the reconnection can be performed in the low state of the clock, thereby significantly improving a signal quality and suppressing the audible plop.
  • the device may comprise an audio playback unit adapted for reproducing the processed audio data.
  • a reproduction unit may generate acoustic waves based on the processed audio data, which can be listened to by a human being.
  • Such an audio playback unit may include earpieces, loudspeakers, etc.
  • an embodiment of the invention may be implemented in audiovisual applications like a video player or a home cinema system in which a transition between different audiovisual items (such as music clips or video sequences) takes place.
  • audiovisual items such as music clips or video sequences
  • the device processes combined audio and video data.
  • Video streams may comprise audible portions and image portions. When two video items, such as two music clips, are played back one after the other, an audible plop may occur as well during a transition.
  • the quality of the audiovisual reproduction may be further increased.
  • the device for processing audio data may be realized as at least one of the group consisting of an audio surround system, a mobile phone, a headset, a loudspeaker, a hearing aid, a television device, a video recorder, a monitor, a gaming device, a laptop, an audio player, a DVD player, a CD player, a harddisk-based media player, an internet radio device, a public entertainment device, an MP3 player, a hi-fi system, a vehicle entertainment device, a car entertainment device, a medical communication system, a body-worn device, a speech communication device, a home cinema system, a home theatre system, a flat television, an ambiance creation device, a subwoofer, and a music hall system.
  • Other applications are possible as well.
  • an audio plop may occur due to a sudden change of the sampling frequencies.
  • the sampling frequencies may be an indicator for a quality of an audio piece.
  • the audio plop may be audible as an annoying noise between two pieces because of this limitation.
  • such an audio block may be eliminated. This may be performed with lower costs and more efficiently as compared to conventional solutions involving complex hardware circuits for the suppression of audio plops.
  • the audio data are first decoded and the decoded output is then sampled, for rendering purposes.
  • Rendering may involve components such as an interpolator (which may comprise FIFO buffers pushing audio samples in a forward direction), before these data are supplied to a stereo DAC (digital to analog converter). Subsequently, the audio data may be amplified and played back by speakers.
  • an interpolator which may comprise FIFO buffers pushing audio samples in a forward direction
  • stereo DAC digital to analog converter
  • Each audio component needs clocks for being operated, which clocks may depend on the sampling rate.
  • Clocks may be basically multiples of the sampling frequencies.
  • Using clocks a synchronization of the different components of an audio playback system may be achieved.
  • an interpolator may require clocks for being operated properties.
  • a phase locked loop may generate a clock and may be connected to a crystal oscillator during a transition period.
  • Fig. 1 illustrates a system of processing audio data according to an exemplary embodiment of the invention.
  • Fig. 2 illustrates a flow-chart diagram illustrating a method of processing audio data according to an exemplary embodiment of the invention.
  • Fig. 3 is a block diagram of an audio processor which can be implemented according to an exemplary embodiment of the invention.
  • Fig. 4 illustrates a block diagram of a switch box module of the system shown in Fig. 3.
  • Fig. 5 illustrates a block diagram of an audio playback path in silicon architecture.
  • Fig. 1 illustrates a system 100 for processing audio data according to an exemplary embodiment of the invention.
  • An audio source 120 is provided which can be a harddisk storing different audio pieces, a CD inserted in a reception of a CD player, etc.
  • the audio source 120 may be or may be part of a portable player.
  • the audio playback system 100 further comprises an input/output unit 130 which allows a user to bidirectionally communicate with the various components of the system 100.
  • the input/output unit 130 may comprise input elements such as buttons, a keypad, a joystick, etc. and may include a display element such as a liquid crystal display so that information regarding audio items to be played back may be displayed to a user. Via the input/output unit 130, a user may select audio pieces and a sequence/order of audio pieces stored in the audio source 120 to be played back by the system 100.
  • the input/output unit 130 may communicate with a control unit 104 such as a microprocessor or a CPU (central processing device).
  • the control unit 104 may be supplied with data representing audio pieces stored on the audio source 120 for playback.
  • a scenario will be considered in which a first audio piece (such as a first song) stored on the audio source 120 is played back first, and subsequently a second audio piece (such as a second song) is to be played back which has a different sampling frequency than the first audio piece.
  • a first audio piece such as a first song
  • a second audio piece such as a second song
  • the audio pieces are supplied to a detection unit 102 which may be adapted for detecting a transition between the first piece of audio data having assigned a first sampling frequency and a second piece of audio data having assigned a second sampling frequency.
  • the detection unit 102 analyzes the headers of the respective audio pieces to thereby detect that a transition between a first and a second audio piece will occur soon.
  • This information may be supplied in the form of a control signal from the detection unit 102 to the control unit 104.
  • the control unit 104 is also supplied with the audio data to be played back and allows for an audio processing which can suppress an undesired audio plop in a transition period between the two audio pieces having different sampling frequencies. For that purpose, the control unit 104 disconnects, during the transition, all audio domain clocks from a clock signal which may be adjusted in accordance with the first sampling frequency and connects the audio domain clocks to a fixed transition frequency which may be provided by a fixed oscillator 106 coupled to the control unit 104. Furthermore, after the transition, the control unit 104 disconnects all audio domain clocks from the transition frequency and connects the audio domain clocks to a clock signal which may be adjusted in accordance with the second sampling frequency of the second audio piece provided by the audio data source 120.
  • control unit 104 may control clocks of the various components of the audio playback device 100 in a transition to prevent a clock signal from being stopped during the transition.
  • the processed audio data may then be reproduced by a loudspeaker 108 to generate acoustic waves 150 which can be listened by a human listener without involving undesired audible plops.
  • Fig. 2 shows a flow-chart 200 illustrating a method according to an exemplary embodiment of the invention which can be carried out by the system 100 shown in Fig. 1.
  • a block 205 indicates an end of an MP3 song sampled at a sampling frequency of 44.1 kHz. As can be taken from a block 250, a subsequent song may be played back at a sampling frequency of 48 kHz. Conventionally, the transition between different clocks after the reproduction of the first audio song at the first playback rate of 44.1 kHz and before the reproduction at a second sampling frequency of 48 kHz may result in an annoying audio plop.
  • the audio domain clocks are disconnected from an audio PLL (phase locked loop) and are connected to a fixed oscillator 106 (for instance a crystal oscillator having an oscillation frequency of 12 MHz, using a switch box module which will be explained below in more detail).
  • a fixed oscillator 106 for instance a crystal oscillator having an oscillation frequency of 12 MHz, using a switch box module which will be explained below in more detail.
  • a very short stop may take place.
  • the switch or the disconnection and connection of block 210 may be performed in a clock factory module (see Fig. 3) during a phase when the clock is low.
  • a low pulse of the clock may be used for the switching within the block 210.
  • the system runs on the basis of the 12 MHz crystal frequency. Simultaneously, it is possible to configure the audio PLL (phase locked loop) for the new sampling frequency of 48 kHz.
  • the audio PLL phase locked loop
  • the audio domain clocks are reconnected from the fixed oscillator 106 (that is a 12 MHz clock frequency) and are connected to an audio PLL (phase locked loop) again using the switch box module illustrated below in Fig. 3 and Fig. 4. Also this reconnection and connection may be performed during a low pulse of the clocks or at a falling edge of the clock.
  • a complete (software) flow diagram 200 of an embodiment of the invention is shown in Fig. 2.
  • a 44.1 kHz MP3 song playback is going on and the next song is of 48 kHz sampling frequency.
  • Sampling frequency change needs to be detected in the system by the software. This may be done in the application by reading the stream headers, (for instance ID3 tag information for MP3 files). So whenever the new stream (audio and/or video) has a different audio sampling rate than the previously played stream, the software application can detect this easily. Upon detection the next steps are followed.
  • Each output clock generated by the CGU belongs to one of the system or audio clock domains.
  • Each clock domain is fed by a single base clock that originates from one of the available clock sources.
  • fractional dividers are available to divide the base clock into a lower frequency.
  • the output clocks are again grouped into one or more sub domains. All output clocks within one sub domain are either all generated by the same fractional divider or they are connected directly to the base clock. Therefore all output clocks within one sub domain have the same frequency and all output clocks within one clock domain are synchronous because they originate from the same base clock
  • the CGU has a reference clock (generated by the oscillator) and several external clock inputs.
  • the CGU also has several phase locked loop (PLL) circuits to generate clock signals that can be used for system clocks and/or audio clocks. All clock sources, except the output of the PLLs, can be used as reference input for the PLL.
  • PLL phase locked loop
  • the audio clocks are generated from an audio PLL in the PNX0103 System.
  • the block diagram of the switchbox module is given in Fig. 4.
  • Selection multiplexer switches allow each reference frequency to be passed to each base frequency. Frequency switches allow safe run-time changes of base frequency selection.
  • a two path switch may be used because there are no guaranteed clocks, making the use of state machines difficult.
  • the frequency selector uses two multiplexers on all of the reference frequency inputs, resulting in the frequency fl and f2. Two multiplexers are used to avoid glitches. Glitches can occur either, when multiplexing, or because the two frequencies are asynchronous (which they usually are) and the switching results in pulse- clipping.
  • the switch solves these problems. This is done by selecting the new frequency on the multiplexer towards the switch side that is not activated, then by both removing the enable on one side, and activating the enable on the other side, switching take place.
  • the construction of the switch is such that a base clock (the base frequency) is stopped when its level is low and after (at least) a complete period, at the falling edge of the new frequency, base clock will start to run again with this new frequency.
  • /*User wants to play a audio stream of 44.1 kHz Sampling frequency */ the audio clocks for 44.1 KHz with proper switching */ vhClk_SwitchDomain( VH_CLK_CLK1024FS_BASE7,
  • Fig. 5 illustrates a block diagram 500, which is showing an audio playback path in an integrated architecture.
  • a bold line 502 shows an audio playback path from a memory device 504 providing audio samples to a headphone 506.
  • SAO 510/SAI 508 Simple audio input/ output units are used to stream the audio data from a memory bus to DAO 512/DAI 514. These are kind of hardware FIFOs and work with DMA flow control.
  • DMUX 516 This is used to switch between audio sources. This is a demultiplexer which can select the input signal depending on control setting and connect it to an output.
  • CLASS AB 522 It is the headphone amplifier to drive the
  • MUX 528 Selects one of the input signal depending on the control settings
  • ADC 532 Analog to digital converter.
  • AVC 536 Analog Bypass Modules

Abstract

L'invention concerne un dispositif (100) servant à traiter des données audio, le dispositif (100) comprenant une unité de détection (102) conçue pour détecter une transition entre un premier morceau de données audio auquel est assignée une première fréquence d'échantillonnage et un deuxième morceau de données audio auquel est assignée une deuxième fréquence d'échantillonnage, une unité de commande (104) adaptée pour déconnecter, pendant la transition, les horloges du domaine audio d'une fréquence associée à la première fréquence d'échantillonnage et connecter les horloges du domaine audio à une fréquence de transition, l'unité de commande (104) étant en outre conçue pour déconnecter, après la transition, les horloges du domaine audio de la fréquence de transition et connecter les horloges du domaine audio à une fréquence associée à la deuxième fréquence d'échantillonnage.
PCT/IB2009/055442 2009-12-01 2009-12-01 Système de traitement de données audio WO2011067625A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/IB2009/055442 WO2011067625A1 (fr) 2009-12-01 2009-12-01 Système de traitement de données audio

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/IB2009/055442 WO2011067625A1 (fr) 2009-12-01 2009-12-01 Système de traitement de données audio

Publications (1)

Publication Number Publication Date
WO2011067625A1 true WO2011067625A1 (fr) 2011-06-09

Family

ID=42557485

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2009/055442 WO2011067625A1 (fr) 2009-12-01 2009-12-01 Système de traitement de données audio

Country Status (1)

Country Link
WO (1) WO2011067625A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112201283A (zh) * 2020-09-09 2021-01-08 北京小米松果电子有限公司 音频播放方法及装置

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5155380A (en) * 1991-04-12 1992-10-13 Acer Incorporated Clock switching circuit and method for preventing glitch during switching
EP0840196A2 (fr) * 1996-11-04 1998-05-06 Texas Instruments Inc. Dispositif de commutation entre des sources d'horloge dans un système de traitement de données
JP2002082736A (ja) * 2000-09-11 2002-03-22 Mitsubishi Electric Corp クロック切換回路
US20020047748A1 (en) * 1999-08-12 2002-04-25 Atsushi Fujita Clock control circuit
US6515530B1 (en) * 2001-10-11 2003-02-04 International Business Machines Corporation Dynamically scalable low voltage clock generation system
US20050058158A1 (en) * 2003-08-19 2005-03-17 Sony Corporation Digital transmission system and clock reproducing device
US20050080500A1 (en) 2003-09-10 2005-04-14 Masaru Kimura Audio device and playback method in audio device
US20050091052A1 (en) * 2003-10-14 2005-04-28 Yuh-Chin Chang Variable frequency decoding apparatus for efficient power management in a portable audio device
US7315957B1 (en) * 2003-12-18 2008-01-01 Nvidia Corporation Method of providing a second clock while changing a first supplied clock frequency then supplying the changed first clock

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5155380A (en) * 1991-04-12 1992-10-13 Acer Incorporated Clock switching circuit and method for preventing glitch during switching
EP0840196A2 (fr) * 1996-11-04 1998-05-06 Texas Instruments Inc. Dispositif de commutation entre des sources d'horloge dans un système de traitement de données
US20020047748A1 (en) * 1999-08-12 2002-04-25 Atsushi Fujita Clock control circuit
JP2002082736A (ja) * 2000-09-11 2002-03-22 Mitsubishi Electric Corp クロック切換回路
US6515530B1 (en) * 2001-10-11 2003-02-04 International Business Machines Corporation Dynamically scalable low voltage clock generation system
US20050058158A1 (en) * 2003-08-19 2005-03-17 Sony Corporation Digital transmission system and clock reproducing device
US20050080500A1 (en) 2003-09-10 2005-04-14 Masaru Kimura Audio device and playback method in audio device
US20050091052A1 (en) * 2003-10-14 2005-04-28 Yuh-Chin Chang Variable frequency decoding apparatus for efficient power management in a portable audio device
US7315957B1 (en) * 2003-12-18 2008-01-01 Nvidia Corporation Method of providing a second clock while changing a first supplied clock frequency then supplying the changed first clock

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112201283A (zh) * 2020-09-09 2021-01-08 北京小米松果电子有限公司 音频播放方法及装置

Similar Documents

Publication Publication Date Title
CN107979796B (zh) 用于双信道音频系统中的立体声场域增强的系统及方法
US6681018B1 (en) Audio signal processor and audio device
US8204615B2 (en) Information processing device, information processing method, and program
JP2005027163A (ja) 音声データ処理装置、音声データ処理方法、そのプログラム、および、そのプログラムを記録した記録媒体
WO2020182020A1 (fr) Procédé de lecture de signal audio et dispositif d'affichage
US20190239011A1 (en) Processing method and system of audio multichannel output speaker, and mobile phone
US20110004716A1 (en) Discrete lateral mosfet power amplifier expansion card
JP2013255049A (ja) チャンネルデバイダおよびこれを含む音声再生システム
WO2011067625A1 (fr) Système de traitement de données audio
JP5257288B2 (ja) 音声信号切り換えノイズ低減回路
JP2005509212A (ja) 高精度低電力モードを有する電子装置
EP1968349B1 (fr) Dispositif et procédé pour la mise en forme d'un signal audio numérique
WO2007108301A1 (fr) Appareil et programme de reproduction de son stereophonique
JP4137706B2 (ja) 音声データ処理回路および音声データ処理方法
JP4494470B2 (ja) 音声信号処理装置、音声信号処理方法、そのプログラム、および、そのプログラムを記録した記録媒体
JP4214546B2 (ja) Ａｖシステム
JP2004274374A (ja) マルチチャンネル音響装置
JP2009060336A (ja) 増幅装置
JP2001309499A (ja) 音声出力切替回路
WO2007007469A1 (fr) Dispositif de traitement de signaux vocaux, procédé et programme de traitement de signaux vocaux, et moyen enregistrant ce programme
JP2000092587A (ja) 音響再生装置
TW202211692A (zh) 音訊處理晶片、多聲道系統與音訊處理方法
JP2006014367A (ja) 音声データ処理方法
CN114173274A (zh) 音频处理芯片、多声道系统与音频处理方法
CN101241380A (zh) 模拟数字电路

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09801264

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09801264

Country of ref document: EP

Kind code of ref document: A1