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Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
Texas Instruments Clarity Technologies ABSTRACT This application report describes integration Clarity Acoustic Echo Cancellation (AEC) algorithm Reference Framework (RF3). algorithm considered eXpressDSP-compliant. Reference Frameworks have been developed Texas Instruments provide foundation easy integration eXpressDSP-compliant algorithms DSP/BIOS environment. This report designed tutorial help users Hands-Free (HFK) understand integrate software modules RF3. application report presents first integration Clarity algorithm RF3. Second, report describes modifications required operate system with 16kHz sampling frequency. Contents Introduction Getting Started Acoustic Echo Cancellation Algorithm Integrating Algorithm Using 16kHz Sampling Frequency Conclusion List Figures Figure Block Diagram Acoustic Echo Cancellation Example hfk5407_aec1 Software Applications
Introduction
Hands-Free (HFK) system presented this application report developed open system based DSP/BIOS RF3. This system implemented board that features TMS320C5407 TLV320AIC24 codec from Texas Instruments. This application reports describes integration Clarity eXpressDSP-compliant algorithm RF3. Example1 provided folder used foundation integration algorithm. step-by-step process build Example1 described application report, Hands-Free Kit: Integration AIC24 Driver Reference Framework (SPRA966).
Trademarks property their respective owners.
SPRA969
integration algorithm presented tutorial format help understand process. final result first section this tutorial provided folder \rf3\hfk5407_aec1 SDK. This example will called hfk5407_aec1 documentation. second section tutorial describes operation system with 16kHz sampling frequency. final result second section this tutorial provided folder \rf3\hfk5407_aec2 SDK. This example will called hfk5407_aec2 documentation.
AIC24 driver
McBSP
Clarity
AIC24
McBSP
Figure Block Diagram Example hfk5407_aec1 This tutorial developed using files provided software development Code Composer Studio 2.20. NOTE: Before executing HFK-related code Code Composer Studio, please update chip support library (CSL) Code Composer Studio with provided SDK. located HFK\Src\misc\CSL.
Getting Started
This section will provide necessary steps 8kHz acoustic echo cancellation example, hfk5407_aec1, provided with SDK. Updating libraries libraries have already been updated, skip this section continue step updated libraries header files provided file HFK\Src\misc\CSL\c54xx.zip.
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Unzip file c54xx.zip temporary folder temp. Create temp\include temp\lib directories temporary folder. Inspect folder where current libraries located. libraries installed part Code Composer Studio installation process. default, they located C:\ti\c5400\bios\include C:\ti\c5400\bios\lib. Copy content temp\lib temp\include respective Code Composer Studio folders, C:\ti\c5400\bios\include C:\ti\c5400\bios\lib. Overwrite existing file. replace Code Composer Studio folders with ones temporary folder because Code Composer Studio folders contain additional useful DSP/BIOS libraries. Preparing hardware Connect JTAG cable EVM. Connect player microphone input using audio cable provided HFK. Play audio samples received with folder HFK\Src\AEC\audioSamples. Calibrate player described section Clarity CVC-HFK-sys2.1.0 Software Integration, Testing, Validation (SPRA959). Connect amplified speaker speaker output EVM. Power-up EVM. Running acoustic echo cancellation example hfk5407_aec1 Start Code Composer Studio open project called app.pjt located using Project Open Menu command. Load file provided HFK\Src\GEL. Load executable app.out from .\Debug subdirectory with File Load Program. Start audio source. code: Select Debug from Debug menu press audio signal will heard amplified speaker. audio signal heard should similar signal provided track2 audio samples folder. Inspecting project files project view window left-hand side Code Composer Studio screen examine project. Open source folder examine project files. Open file hfk5407_aic24.c. This file defines functions: HFK5407_AIC24_init() (line 154) used initialize aic24 driver HFK5407_AIC24_DMA_isr() (line 295) aic24 driver interrupt service routine (ISR). Notice that HFK5407_AIC24_DMA_isr(line 328), swiHfkAudio object posted.
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
breakpoint HFK5407_AIC24_DMA_isr() function select Debug Animate from Debug menu, press F12. will called every time there buffers available processing Remove breakpoint close file hfk5407_aic24.c. Open file hfk5407_drvGbl.c. This file defines function HFK5407_audioBuffer_init() (line used initialize aic24 driver buffers. This function called during initialization process. file hfk5407_drvGbl.c, aic24 driver buffers, liMicData[] loSpkData[], defined Determine starting addresses buffers setting cursor first letter name. Write down addresses buffers. They will used later view signal with graph tool. Close file hfk5407_ drvGbl.c From View menu Code Composer Studio window, select View Graph Time/Frequency. Graph Property Dialog window will open. Modify following fields: Start Address: address liMicData[] buffer Acquisition Buffer Size: Display Data Size: Data Type: 16-bit signed integer should something similar
Select
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Graph Window will display content buffer. order update display right-click select Refresh.
first locations represent AIC24 Channel receive buffer next locations through 127) represent AIC24 Channel receive buffer. screen shot above taken point time when there signal Channel1. Open file thrHfkAudio_aec1.c. This file defines functions: thrHfkAudioInit() (line used initialize Audio thread, thrHfkAudioRun() (line thread processing function associated with swiHfkAudio object. thrHfkAudioRun() called DSP/BIOS kernel after swiHfkAudio object posted ISR. example hfk5407_aec1, this function calls algorithm processing function.
Acoustic Echo Cancellation Algorithm
algorithm provided software development available folder HFK\Src\AEC. algorithm includes:
mode near mode libraries
Documentation HFK\Src\AEC\doc XDAIS related files HFK\Src\AEC\ihfk.c HFK\Src\AEC ihfk.h
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Integrating Algorithm
This section describes integrate algorithm RF3. example built application report Hands-Free Kit: Integration AIC24 Driver Reference Framework (SPRA966) used starting point this integration. This example available folder, final project following LAB1 available software development folder, Copy content folder, working folder, RF3_myHFK. Then, copy folder, same directory rename copy hfk5407_aec1. folder will working folder this example. information this section presented that will help understand step step integration process. LAB1: Integrating algorithm RF3. Creating application folder Create folder Copy this folder files HFK\Src\AEC\xdais\ hfkv20100010005_clarity.h HFK\Src\AEC\xdais\ ihfk.c HFK\Src\AEC\xdais\ ihfk.h Adding libraries project Copy files: HFK\Src\AEC\lib\ hfkv20100010005_clarity.l54 HFK\Src\AEC\lib\ hfkv20100010005_clarity.l54f folder: Modifying audio processing thread Open file Make copy this file same folder. Rename copy thrHfkAudio_aec1.c Open file thrHfkAudio_aec1.c Include header file hfkv20100010005_clarity.h
#include #include #include #include #include #include #include #include #include #include <std.h> <utl.h> debug/diagnostics utility functions "appResources.h" application-wide common info "appThreads.h" thread-wide common info "thrHfkAudio.h" definition thrHfkAudio object "hfkv20100010005_clarity.h" include file <hfk5407_drvGbl.h> driver global varaibles <hfk5407.h> hfk5407 board info <hfk5407_aic24.h> aic24 driver info <xdas.h> XDAIS types definition
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
global variables related data memory sections using #pragma DATA_SECTION directive before definition thrHfkAudioInit()function.
Begin Memory Declaration #pragma short #pragma short #pragma short #pragma short #pragma short #pragma short #pragma short cbuf_si[HFK_CLARITY_MEM2_size]; cbuf_ri[HFK_CLARITY_MEM3_size]; cbuf_so[HFK_CLARITY_MEM4_size]; DATA_SECTION(buff0,".HFK_MEM5") buff0[HFK_CLARITY_MEM5_size]; DATA_SECTION(buff1,".HFK_MEM6") buff1[HFK_CLARITY_MEM6_size]; DATA_SECTION(buff2,".HFK_MEM7") buff2[HFK_CLARITY_MEM7_size];
must aligned
global variables IALG_Handle IALG_MemRec
hfk_handle (IALG_Handle) &hfkObject; hfkMem[7];
========= thrHfkAudioInit ======== Initialization data structures thread, called from appThreads.c:thrInit() init time.
thrHfkAudioInit() function, initialize XDAIS object bases memory sections that algorithms requires from framework.
========= thrHfkAudioInit ======== Initialization data structures thread, called from appThreads.c:thrInit() init time. Void thrHfkAudioInit( Void hfkMem[0].base hfkMem[1].base hfkMem[2].base hfkMem[3].base hfkMem[4].base hfkMem[5].base hfkMem[6].base hfk_handle; cbuf_si; cbuf_ri; cbuf_so; buff0; //buffer intermediate result buff1; //buffer intermediate result buff2; //filter buffer
initialize algorithm HFK_CLARITY_initObj(hfk_handle, hfkMem, NULL,(IALG_Params *)&IHFK_PARAMS); HFK5407_AIC24_init(); HFK5407_audioBuffer_init();
thrHfkAudioRun() function, definition pointers that will used with algorithm
Void thrHfkAudioRun( Void XDAS_Int16 *aicSrcBufL, *aicDstBufL; XDAS_Int16 *aicSrcBufR, *aicDstBufR; XDAS_Int16 i,off; related local variables XDAS_Int16 *inRef_Ptr, *inMic_Ptr, *outSnd_Ptr, *outSpkr_Ptr;
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Initialize pointers call processing function.
bufActive*FRAME_SIZE_8K*2; aicSrcBufL &liMicData[off]; //INP3 aicDstBufL &loSpkData[off]; //OUT2 FRAME_SIZE_8K; aicSrcBufR &liMicData[off]; INP2 aicDstBufR &loSpkData[off]; OUT3 Initialize Pointers outSpkr_Ptr aicDstBufL; //OUT3 SPKR outSnd_Ptr aicDstBufR; //OUT2 SEND (processed signal inMic_Ptr aicSrcBufR; //INP3 SEND inRef_Ptr aicSrcBufL; //INP2 Process Frame
Prepare output buffers. Only processed signal will sent out. Save close file
data move. Mask compatibility with those codecs that interpret command flag. FRAME_SIZE_8K; i++) outSnd_Ptr[i] outSnd_Ptr[i] 0xfffe; outSpkr_Ptr[i] inRef_Ptr[i] 0xfffe;
Changing linker command file Open linker command file link.cmd Code Composer Studio Project View window. mode library linker command file.
include config-generated link command file appcfg.cmd include module implementing XDAIS algs. instantiation procedures algrf.l54f include debugging module needed) utl.l54f include library hfkv20100010005_clarity.l54f
memory sections linker command file. Save close linker command file.
SECTIONS .HFK_AUDIO .HFK_MEM1 .HFK_MEM2 .HFK_MEM3 .HFK_MEM4 .HFK_MEM5 .HFK_MEM6 .HFK_MEM7
IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA
PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE
ALIGN ALIGN ALIGN ALIGN
(128) (128) (128)
ALIGN (256)
Changing build options Code Composer Studio menu open Project\Build Options. Select Preprocessor Category. Include Search Path window path folder: .\algHFK;
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Preparing project Remove file thrHfkAudio_aic24.c from project file thrHfkAudio_aec1.c project_ file ihfk.c project Copy file ihfk.h include folder Running code Code Composer Studio menu, select Project\Build build project. Load file provided HFK\Src\Gel folder After loading Gel, menu Code Composer Studio window enables C5407_Configuration functions: CPU_Reset, C5407_Init. These functions should executed each time before loading program. Code Composer Studio menu select File\Load Program. code Connect player microphone input. With player, play audio samples provided with (they located HFK\Src\AEC\ausioSamples folder). This contains real audio stereo samples recorded car. Calibrate player using directions given section application report, Clarity CVC-HFK-sys2.1.0 Software Integration, Testing, Validation (SPRA959). Play track output heard should similar sample output provided track Connect speaker output amplified speaker. Code Composer Studio menu select Debug\Run code.
Using 16kHz Sampling Frequency
order better frequency response, possible 16kHz sampling frequency AIC24 codec. However, since algorithm operates 8kHz, necessary down-sample input signals up-sample output signal. This section application report will provide step step process accomplish that. Example hfk5407_aec1 described previous section will used starting point. Copy content folder working folder RF3_myHFK. Then, folder should copied same directory copy renamed hfk5407_aec2. folder will working folder this example. LAB2: Using 16kHz Sampling Frequency with algorithm order 16kHz sampling frequency must make following changes:
Modify AIC24 configuration 16kHz sampling frequency. Increase size buffers double size. Modify configuration accordingly. decimation interpolation filters.
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
first three modifications affect drivers. These changes have been included drivers available folder: last modification list affects audio thread definition file. Open folder this folder available copy folder Inspecting 16kHz configuration AIC24 configuration AIC24 with 16kHz sampling frequency defined file \drivers\include\ aic24_16kHz.h. sampling frequency AIC24 defined AIC24 control register divider values M,N,P. These values will depend frequency external oscillator available EVM. more information about divider values refer TLV320AIC24 Data Manual (SLAS366A), section 3.1. Increasing size buffers Since value sampling frequency been increased factor two, size buffers needs adjusted accordingly (i.e., increased factor two). file \drivers\drv16kHz_nobsync\ hfk5407_drvGbl_16kHz.c references FRAME_SIZE_8K were commented value FRAME_SIZE_16K used. memory sections 16kHz buffers used.
sections 8KHz buffers used with 16KHz sampling #pragma #pragma #pragma Codec Buffers 16kHz liMicData[FRAME_SIZE_16K*4]; loSpkData[FRAME_SIZE_16K*4]; inMic8KHz[FRAME_SIZE_8K]; inRef8KHz[FRAME_SIZE_8K]; outSnd8KHz[FRAME_SIZE_8K]; Codec Buffers 8kHz //int liMicData[FRAME_SIZE_8K*4]; //int loSpkData[FRAME_SIZE_8K*4];
HFK5407_audioBuffer_init() function been modified:
void HFK5407_audioBuffer_init(void) off_0,i Initialize Global Variables bufActive MUST initialize buffers otherwise will re-program AIC24*/ //for (i=0; FRAME_SIZE_8K*4; i++){ (i=0; FRAME_SIZE_16K*4; i++){ loSpkData[i] Buffers off_0 (unsigned short)&loSpkData[off_0]; (unsigned short)&liMicData[off_0]; off_0 2*FRAME_SIZE_8K; off_0 2*FRAME_SIZE_16K; (unsigned short)&loSpkData[off_0]; (unsigned short)&liMicData[off_0];
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Modifying configuration Open file \drivers\drv16kHz_nobsync\ hfk5407_aic24_16kHz.c. functions HFK5407_AIC24_init() HFK5407_AIC24_DMA_isr(), value FRAME_SIZE_16K used instead FRAME_SIZE_8K. Adding C54x Library project interpolation decimation functions used firdec() firinterp() functions from C54x Library. This library, provided SDK, located HFK\Src\16kHz\dsplib. Copy file Copy file Include 54xdspf.lib linker command file. Since name this library starts with number, quotes required used around name.
include C54x Library "54xdspf.lib"
Adding decimation interpolation filters filter coefficients provided file Copy folder HFK\Src\16kHz\idFilters folder file id_filters.c Code Composer Studio project Copy id_filters.h file project include folder Code Composer Studio menu open Project\Build Options. Select Preprocessor Category. Include Search Path window path: .\.\include; This path will enable file id_filters.c find file TMS320.h that defines DSPLIB data types. Modifying audio processing thread Make copy file same directory, rename thrHfkAudio_aec2.c Open file include file TMS320.h. include file id_filters.h 16kHz versions driver headers
#include <hfk5407_drvGbl.h> #include <hfk5407.h> #include <hfk5407_aic24_16kHz.h> #include "hfkv20100010005_clarity.h" #include <xdas.h> #include <TMS320.h> #include <id_filters.h> driver global varaibles hfk5407 board info aic24 driver info header file XDAIS types definition DSPLIB types definition
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
references filter buffers.
Filter buffers extern DATA dec_buf1[]; extern DATA dec_buf2[]; extern DATA interp_buf1[]; extern const DATA d_coeffs[]; extern const DATA i_coeffs[]; DATA *dp1 dec_buf1; DATA *dp2 dec_buf2; DATA *dp3 interp_buf1;
thrHfkAudioRun() function definition local buffer pointers 8-kHz buffers.
Void thrHfkAudioRun( Void XDAS_Int16 *aicSrcBufL, *aicDstBufL; XDAS_Int16 *aicSrcBufR, *aicDstBufR; XDAS_Int16 i,off; related local variables XDAS_Int16 *inRef_Ptr, *inMic_Ptr, *outSnd_Ptr, *outSpkr_Ptr; 8KHz buffer pointers used with 16KHz related local variables DATA *inMic_Ptr_8Khz, *inRef_Ptr_8Khz, *outSnd_Ptr_8Khz;
function thrHfkAudioRun() comment occurrences FRAME_SIZE_8K replace them with FRAME_SIZE_16K.
bufActive*FRAME_SIZE_8K*2; bufActive*FRAME_SIZE_16K*2; method rotates outputs channel swap Output Channels aicSrcBufR aicDstBufR FRAME_SIZE_8K; FRAME_SIZE_16K; aicSrcBufR aicDstBufR (XDAS_Int16 (XDAS_Int16 &liMicData[off]; (XDAS_Int16 &loSpkData[off]; (XDAS_Int16 &liMicData[off]; &loSpkData[off]; OUT3 //INP3 //OUT2 INP2
Initialize 8-kHz buffer pointers.
inMic_Ptr_8Khz (DATA *)&inMic8KHz[0]; inRef_Ptr_8Khz (DATA *)&inRef8KHz[0]; outSnd_Ptr_8Khz (DATA *)&outSnd8KHz[0]; outSpkr_Ptr outSnd_Ptr inMic_Ptr inRef_Ptr Initialize Pointers aicDstBufL; //OUT3 SPKR aicDstBufR; //OUT2 SEND (processed signal) aicSrcBufR; //INP3 SEND aicSrcBufL; //INP2
thrHfkAudioRun() function calls firdec() firinterp() functions.
16kHz 8kHz inMic buffer 16kHz 8kHz inRef buffer Process Frame with 8Khz buffers 16Hz outSnd buffer 8K,2);
Modify size data move loop.
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Save close file thrHfkAudio_aec2.c.
data move. Mask compatibility with those codecs that interpret command flag. FRAME_SIZE_8K; i++) FRAME_SIZE_16K; i++) outSnd_Ptr[i] outSnd_Ptr[i] 0xfffe; outSpkr_Ptr[i] inRef_Ptr[i] 0xfffe;
Preparing project Remove file thrHfkAudio_aec1.c from project. file thrHfkAudio_aec2.c project. Remove files aic24.c, hfk5407_aic24.c, hfk5407_drvGbl.c from project files hfk5407_drvGbl_16kHz.c project Copy files project include folder Copy file ihfk.h include folder Resetting delay buffers Each instance decimation interpolation function requires delay buffer. Double pointers used point delay buffers. this example dp1,dp3, double pointers used point delay buffers. delay buffers must cleared before functions invoked first time. Clear delay buffers thrHfkAudioInit() function.
Void thrHfkAudioInit( Void hfkMem[0].base hfkMem[1].base hfkMem[2].base hfkMem[3].base hfkMem[4].base hfkMem[5].base hfkMem[6].base hfk_handle; cbuf_si; cbuf_ri; cbuf_so; buff0; //buffer intermediate result buff1; //buffer intermediate result buff2; //filter buffer
clear delay buffers (i=0; i<NUM_DI_COEFFS; i++) dec_buf1[i] dec_buf2[i] interp_buf1[i]
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
SPRA969
Adding filter related memory sections linker command file Open linker command file following filter related memory sections. filter related memory sections require memory alignments because filter buffers used circular buffers. more information about interpolation decimation functions C54x DSPLIB refer TMS320C54x Library Programmer's Reference (SPRU518). firdec() firinterp() functions ones used this project.
SECTIONS .HFK_AUDIO .HFK_MEM1 .HFK_MEM2 .HFK_MEM3 .HFK_MEM4 .HFK_MEM5 .HFK_MEM6 .HFK_MEM7 IDATA PAGE IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA IDATA PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE PAGE ALIGN ALIGN ALIGN ALIGN (128) (128) (128)
ALIGN (256)
Data Interp/Decim Memory .interp_buf1 .dec_buf1 .dec_buf2 .i_coeffs .d_coeffs
ALIGN ALIGN ALIGN ALIGN ALIGN
(64) (64) (64) (64) (64)
Build project code following steps provided (steps 22-29)
Conclusion
This application report described integration Clarity algorithm RF3. integration presented tutorial format order help understand process. modifications required 16kHz signals were also presented. result this integration available folders,
Hands-Free Kit: Integration Clarity Acoustic Echo Cancellation (AEC) Algorithm
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