文件名称：Linux Audio for Android
文件大小：627KB
文件格式：ZIP
更新时间：2023-09-26 08:47:11
wolfson audio wolfson公司音 wolfson公司音
wolfson公司音频芯片的ppt介绍，将音频开发的大致流程和关键点都写出来了，新手值得一看。V. wolfson Android audio stack Applications MediaPlayer Media Recorder Audio Flinger iaudio 3@2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V. wolfson Modern smartphone audio subsystems HDM CPU Earpiece Speaker Mixing DSP Headset Dock Cellular Bluetooth modem 4@ 2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V. wolfson Flexibility and complexity zua Lrm l t H LD1 CHARGE PUMP CB INlLNO 一IN2 LNDMICDAT1 CHPOUT1L IN2LPVRXP IN1RNO oHPOUT1R INIRP t-IN2RNDMICDAT2 HI HEADPHONE HPOUT1FB RIVERS IN2RPNRXNO 4 Digital MIC CHPOUT2P POUT2N → Channels E ERVER CUTPL ANALOGUE PKOUTLP ARc MULTHCHANNEL DIGITA MIXER dSPKOUTLN INTERFACE ADCL H FILTERS MIXING osPKOUTRP MPUT JsPKOUTRN MERS RrTurcMabik LOUDSPEAKER P限 AMIETRKC EQUALISE FILTERE DRTERS VOLIME 口 FNAMIC RANGE COONTROL VCLUME凵DAc LINEOUT1P RECORD CD STEREO EXPYNSICN 4 MIC OLINEOUTIN DMICDAT1 DIGITAL MIG CHANNELS HIGH ASYNCHRONOU DMICDAT2 PASS R八 TE CONVERS|N NTERFAGE QLINEOUT2P DMICCLKO4 FILT-R5 DLINEOUT2N MICDET ACCESSORY MIC AcUNy derect GPiO RECORD DETECT LINE CRIERS LINEOUTFB MICBIAS10* FLL1 12S/PCM#1 12SPCM #2 12S/PCM#3 INTERFACE MICBIAS2O+ 5 02011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V. wolfson Traditional driver model Memory Processing Analogue 6 O2011 Wolfson Microelectronics plo April2011www.wolfsonmicro.com V. wolfson Traditional driver model Monolithic driver for each card No structure for managing off-CPU hardware Very little reuse Tight coupling between application and kernel code Per-use case register settings Detailed register level knowledge of components Time consuming 7@2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V. wolfson The Linux solution ASoC embedded audio framework Merged since 2.6.21, April 2007 e Provides standard aLSA interface to applications Reusable drivers for each chip Minimal per-system drivers Use case configuration done by userspace Automatic and transparent power management More reuse, less coupling g 8@2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V. wolfson Dynamic Audio Power Management Looks for audio paths connecting inputs to outputs Powers only components in an active path Automatically activates DACs and ADCs DAC Speaker Mixer FM radio Headset 9 C 2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com V wolfson ASoC coDEC drivers Four classes of control Audio processing controls(eg, volume, effects) Audio routing controls(DAPM controls and routes Power controls(DAPM widgets, bias Stream control (Digital audio streaming) Mostly direct mapping into register map SOC DOUBlE R TLV DACI Volume WM8994 DAC1 LEFT VOLUME WM8994 DACI RIGHT VOLUME 1, 96,0, digital tlv 10@ 2011 Wolfson Microelectronics plc April2011www.wolfsonmicro.com
【文件预览】：
sepnic-3783997-Linux Audio for Android_1599289219
----sepnic-3783997-Linux Audio for Android.pdf(693KB)