IOS-recording function

Initialize AVAudioRecorder and set the recording parameters and storage address:

// Set recording * recordsetting = [[audio alloc] init] autorelease]; // set the recording format avformatidkey = kaudioformatlinearpcm [recordsetting setvalue: [nsnumber numberwithint: Encrypted] forkey: avformatidkey]; // sets the recording sampling rate (HZ), for example, avsampleratekey = 8000/44100/96000 (affects audio quality) [recordsetting setvalue: [nsnumber numberwithfloat: 44100] forkey: avsampleratekey]; // Number of recording channels 1 or 2 [recordsetting setvalue: [nsnumber numberwithint: 1] forkey: avnumberofchannelskey]; // Number of linear sampling digits 8, 16, 24, 32 [recordsetting setvalue: [nsnumber numberwithint: 16] forkey: audio]; // recording quality [recordsetting setvalue: [nsnumber numberwithint: avaudioqualityhigh] forkey: weight]; nsstring * strurl = [nsdocumentdirectory, nsuserdomainmask, yes) lastobject]; nsurl * url = [nsurl fileurlwithpath: [nsstring stringwithformat: @ "% @/lll. AAC ", strurl]; urlplay = URL; nserror * error; // initialize recorder = [[avaudiorecorder alloc] initwithurl: URL settings: recordsetting error: & error]; // enable the Volume Detection recorder. meteringenabled = yes; recorder. delegate = self;

Identify the volume size to display different images to show fluctuations in the volume chart

[Recorder updatemeters]; // refresh the volume data // obtain the average volume [Recorder averagepowerforchannel: 0]; // The maximum volume [Recorder peakpowerforchannel: 0]; double lowpassresults = POW (10, (0.05 * [Recorder peakpowerforchannel: 0]); nslog (@ "% lf", lowpassresults ); // up to 50 0 // small image-large if (0 <lowpassresults <= 0.06) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_01.png"];} else if (0.06 <lowpassresults <= 0.13) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_02.png"];} else if (0.13 <lowpassresults <= 0.20) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_03.png"];} else if (0.20 <lowpassresults <= 0.27) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_04.png"];} else if (0.27 <lowpassresults <= 0.34) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_05.png"];} else if (0.34 <lowpassresults <= 0.41) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_06.png"];} else if (0.41 <lowpassresults <= 0.48) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_07.png"];} else if (0.48 <lowpassresults <= 0.55) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_08.png"];} else if (0.55 <lowpassresults <= 0.62) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_09.png"];} else if (0.62 <lowpassresults <= 0.69) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_10.png"];} else if (0.69 <lowpassresults <= 0.76) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_11.png"];} else if (0.76 <lowpassresults <= 0.83) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_12.png"];} else if (0.83 <lowpassresults <= 0.9) {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_13.png"];} else {[self. imageview setimage: [uiimage imagenamed: @ "record_animate_14.png"];}

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