Ben okuma iPod kütüphane assetUrl (kod audioUrl ad)kullanarak şarkı Bu bazı precessing yapabilirim ama...birçok yönden, kesebilir, oynayabilirim Gerçekten bu CMSampleBufferRef ile çizim dalga için veri almak için ne ben ne anlamıyorum! (Belki başka) bu şekilde nasıl alabilirim ibre hakkında bilgi istiyorum?

    AVAssetTrack * songTrack = [audioUrl.tracks objectAtIndex:0];
    AVAssetReaderTrackOutput * output = [[AVAssetReaderTrackOutput alloc] initWithTrack:songTrack outputSettings:nil];
    [reader addOutput:output];
    [output release];

    NSMutableData * fullSongData = [[NSMutableData alloc] init];
    [reader startReading];

    while (reader.status == AVAssetReaderStatusReading){

        AVAssetReaderTrackOutput * trackOutput = 
        (AVAssetReaderTrackOutput *)[reader.outputs objectAtIndex:0];

        CMSampleBufferRef sampleBufferRef = [trackOutput copyNextSampleBuffer];

        if (sampleBufferRef){/* what I gonna do with this? */}

Bana yardım et lütfen!

Benzer bir şey arıyordum ve "benim kendi rulo."karar verdi Bu eski bir yazı olduğunu biliyorum, ama başkasının bu arayışı içinde olması durumunda, burada benim çözümdür. nispeten hızlı ve kirli ve görüntüyü normalleştirir "". tam ölçekli yarattığı görüntüler" UİScrollView koyun veya başka bir görüntü yönetmeniz gerekir yani. "geniş

bu bazı cevaplar this question veriliyor

Örnek Çıktı

DÜZENLEME:Ortalama logaritmik bir sürüm ve oluşturma yöntemleri, alternatif sürümü için bu iletinin sonuna & karşılaştırma çıktıları görmek ekledim. Ben birini algoritması kullanılan artırabilir diye şahsen doğrusal orijinal versiyonu tercih ederim, ama sonrası için karar verdik.

Bu ithalatın gerekir:

#import <MediaPlayer/MediaPlayer.h>
#import <AVFoundation/AVFoundation.h>

İlk olarak, ortalama örnek veriler için bir işaretçi alır genel bir işleme yöntemi
ve döner bir Uİİmage. Bu örnekler, ses örnekleri oynanabilir değildir unutmayın.

-(UIImage *) audioImageGraph:(SInt16 *) samples
                normalizeMax:(SInt16) normalizeMax
                 sampleCount:(NSInteger) sampleCount 
                channelCount:(NSInteger) channelCount
                 imageHeight:(float) imageHeight {

    CGSize imageSize = CGSizeMake(sampleCount, imageHeight);
    UIGraphicsBeginImageContext(imageSize);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
    CGContextSetAlpha(context,1.0);
    CGRect rect;
    rect.size = imageSize;
    rect.origin.x = 0;
    rect.origin.y = 0;

    CGColorRef leftcolor = [[UIColor whiteColor] CGColor];
    CGColorRef rightcolor = [[UIColor redColor] CGColor];

    CGContextFillRect(context, rect);

    CGContextSetLineWidth(context, 1.0);

    float halfGraphHeight = (imageHeight / 2) / (float) channelCount ;
    float centerLeft = halfGraphHeight;
    float centerRight = (halfGraphHeight*3) ; 
    float sampleAdjustmentFactor = (imageHeight/ (float) channelCount) / (float) normalizeMax;

    for (NSInteger intSample = 0 ; intSample < sampleCount ; intSample    ) {
        SInt16 left = *samples  ;
        float pixels = (float) left;
        pixels *= sampleAdjustmentFactor;
        CGContextMoveToPoint(context, intSample, centerLeft-pixels);
        CGContextAddLineToPoint(context, intSample, centerLeft pixels);
        CGContextSetStrokeColorWithColor(context, leftcolor);
        CGContextStrokePath(context);

        if (channelCount==2) {
            SInt16 right = *samples  ;
            float pixels = (float) right;
            pixels *= sampleAdjustmentFactor;
            CGContextMoveToPoint(context, intSample, centerRight - pixels);
            CGContextAddLineToPoint(context, intSample, centerRight   pixels);
            CGContextSetStrokeColorWithColor(context, rightcolor);
            CGContextStrokePath(context); 
        }
    }

    // Create new image
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    // Tidy up
    UIGraphicsEndImageContext();   

    return newImage;
}

Sonraki, bir AVURLAsset alır ve PNG görüntü veri döndüren bir yöntem

- (NSData *) renderPNGAudioPictogramForAsset:(AVURLAsset *)songAsset {

    NSError * error = nil;
    AVAssetReader * reader = [[AVAssetReader alloc] initWithAsset:songAsset error:&error];
    AVAssetTrack * songTrack = [songAsset.tracks objectAtIndex:0];

    NSDictionary* outputSettingsDict = [[NSDictionary alloc] initWithObjectsAndKeys:
                                        [NSNumber numberWithInt:kAudioFormatLinearPCM],AVFormatIDKey,
                                        //     [NSNumber numberWithInt:44100.0],AVSampleRateKey, /*Not Supported*/
                                        //     [NSNumber numberWithInt: 2],AVNumberOfChannelsKey,    /*Not Supported*/
                                        [NSNumber numberWithInt:16],AVLinearPCMBitDepthKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsBigEndianKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsFloatKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsNonInterleaved,
                                        nil];

    AVAssetReaderTrackOutput* output = [[AVAssetReaderTrackOutput alloc] initWithTrack:songTrack outputSettings:outputSettingsDict];

    [reader addOutput:output];
    [output release];

    UInt32 sampleRate,channelCount;

    NSArray* formatDesc = songTrack.formatDescriptions;
    for(unsigned int i = 0; i < [formatDesc count];   i) {
        CMAudioFormatDescriptionRef item = (CMAudioFormatDescriptionRef)[formatDesc objectAtIndex:i];
        const AudioStreamBasicDescription* fmtDesc = CMAudioFormatDescriptionGetStreamBasicDescription (item);
        if(fmtDesc ) {

            sampleRate = fmtDesc->mSampleRate;
            channelCount = fmtDesc->mChannelsPerFrame;

            //    NSLog(@"channels:%u, bytes/packet: %u, sampleRate %f",fmtDesc->mChannelsPerFrame, fmtDesc->mBytesPerPacket,fmtDesc->mSampleRate);
        }
    }

    UInt32 bytesPerSample = 2 * channelCount;
    SInt16 normalizeMax = 0;

    NSMutableData * fullSongData = [[NSMutableData alloc] init];
    [reader startReading];

    UInt64 totalBytes = 0;         
    SInt64 totalLeft = 0;
    SInt64 totalRight = 0;
    NSInteger sampleTally = 0;

    NSInteger samplesPerPixel = sampleRate / 50;

    while (reader.status == AVAssetReaderStatusReading){

        AVAssetReaderTrackOutput * trackOutput = (AVAssetReaderTrackOutput *)[reader.outputs objectAtIndex:0];
        CMSampleBufferRef sampleBufferRef = [trackOutput copyNextSampleBuffer];

        if (sampleBufferRef){
            CMBlockBufferRef blockBufferRef = CMSampleBufferGetDataBuffer(sampleBufferRef);

            size_t length = CMBlockBufferGetDataLength(blockBufferRef);
            totalBytes  = length;

            NSAutoreleasePool *wader = [[NSAutoreleasePool alloc] init];

            NSMutableData * data = [NSMutableData dataWithLength:length];
            CMBlockBufferCopyDataBytes(blockBufferRef, 0, length, data.mutableBytes);

            SInt16 * samples = (SInt16 *) data.mutableBytes;
            int sampleCount = length / bytesPerSample;
            for (int i = 0; i < sampleCount ; i   ) {

                SInt16 left = *samples  ;
                totalLeft   = left;

                SInt16 right;
                if (channelCount==2) {
                    right = *samples  ;
                    totalRight  = right;
                }

                sampleTally  ;

                if (sampleTally > samplesPerPixel) {

                    left  = totalLeft / sampleTally; 

                    SInt16 fix = abs(left);
                    if (fix > normalizeMax) {
                        normalizeMax = fix;
                    }

                    [fullSongData appendBytes:&left length:sizeof(left)];

                    if (channelCount==2) {
                        right = totalRight / sampleTally; 

                        SInt16 fix = abs(right);
                        if (fix > normalizeMax) {
                            normalizeMax = fix;
                        }

                        [fullSongData appendBytes:&right length:sizeof(right)];
                    }

                    totalLeft   = 0;
                    totalRight  = 0;
                    sampleTally = 0;
                }
            }

           [wader drain];

            CMSampleBufferInvalidate(sampleBufferRef);
            CFRelease(sampleBufferRef);
        }
    }

    NSData * finalData = nil;

    if (reader.status == AVAssetReaderStatusFailed || reader.status == AVAssetReaderStatusUnknown){
        // Something went wrong. return nil

        return nil;
    }

    if (reader.status == AVAssetReaderStatusCompleted){

        NSLog(@"rendering output graphics using normalizeMax %d",normalizeMax);

        UIImage *test = [self audioImageGraph:(SInt16 *) 
                         fullSongData.bytes 
                                 normalizeMax:normalizeMax 
                                  sampleCount:fullSongData.length / 4 
                                 channelCount:2
                                  imageHeight:100];

        finalData = imageToData(test);
    }        

    [fullSongData release];
    [reader release];

    return finalData;
}

Gelişmiş Seçenekler: Eğer ses AVAudioPlayer kullanarak oynamak mümkün olmasını istiyorsanız son olarak, önbellek gerekir uygulamalar bu paket önbellek klasörüne. Görüntü veri önbelleği için karar yapıyordum beri ayrıca, Uİİmage bir kategori içine her şeyi tamamladı. this open source offering ses ve here bazı kod bazı arka plan iş parçacığı özellikleri işlemek için ayıklamak için vardır.

ilk olarak, yol adları işlemek için bazı tanımlar ve birkaç genel sınıf yöntemleri vb

//#define imgExt @"jpg"
//#define imageToData(x) UIImageJPEGRepresentation(x,4)

#define imgExt @"png"
#define imageToData(x) UIImagePNGRepresentation(x)

  (NSString *) assetCacheFolder  {
    NSArray  *assetFolderRoot = NSSearchPathForDirectoriesInDomains(NSCachesDirectory, NSUserDomainMask, YES);
    return [NSString stringWithFormat:@"%@/audio", [assetFolderRoot objectAtIndex:0]];
 }

  (NSString *) cachedAudioPictogramPathForMPMediaItem:(MPMediaItem*) item {
    NSString *assetFolder = [[self class] assetCacheFolder];
    NSNumber * libraryId = [item valueForProperty:MPMediaItemPropertyPersistentID];
    NSString *assetPictogramFilename = [NSString stringWithFormat:@"asset_%@.%@",libraryId,imgExt];
    return [NSString stringWithFormat:@"%@/%@", assetFolder, assetPictogramFilename];
}

  (NSString *) cachedAudioFilepathForMPMediaItem:(MPMediaItem*) item {
    NSString *assetFolder = [[self class] assetCacheFolder];

    NSURL    * assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];
    NSNumber * libraryId = [item valueForProperty:MPMediaItemPropertyPersistentID];

    NSString *assetFileExt = [[[assetURL path] lastPathComponent] pathExtension];
    NSString *assetFilename = [NSString stringWithFormat:@"asset_%@.%@",libraryId,assetFileExt];
    return [NSString stringWithFormat:@"%@/%@", assetFolder, assetFilename];
}

  (NSURL *) cachedAudioURLForMPMediaItem:(MPMediaItem*) item {
    NSString *assetFilepath = [[self class] cachedAudioFilepathForMPMediaItem:item];
    return [NSURL fileURLWithPath:assetFilepath];
}

Şimdi ınit yöntemi bu "iş"yapar

- (id) initWithMPMediaItem:(MPMediaItem*) item 
           completionBlock:(void (^)(UIImage* delayedImagePreparation))completionBlock  {

    NSFileManager *fman = [NSFileManager defaultManager];
    NSString *assetPictogramFilepath = [[self class] cachedAudioPictogramPathForMPMediaItem:item];

    if ([fman fileExistsAtPath:assetPictogramFilepath]) {

        NSLog(@"Returning cached waveform pictogram: %@",[assetPictogramFilepath lastPathComponent]);

        self = [self initWithContentsOfFile:assetPictogramFilepath];
        return self;
    }

    NSString *assetFilepath = [[self class] cachedAudioFilepathForMPMediaItem:item];

    NSURL *assetFileURL = [NSURL fileURLWithPath:assetFilepath];

    if ([fman fileExistsAtPath:assetFilepath]) {

        NSLog(@"scanning cached audio data to create UIImage file: %@",[assetFilepath lastPathComponent]);

        [assetFileURL retain];
        [assetPictogramFilepath retain];

        [NSThread MCSM_performBlockInBackground: ^{

            AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:assetFileURL options:nil];
            NSData *waveFormData = [self renderPNGAudioPictogramForAsset:asset]; 

            [waveFormData writeToFile:assetPictogramFilepath atomically:YES];

            [assetFileURL release];
            [assetPictogramFilepath release];

            if (completionBlock) {

                [waveFormData retain];
                [NSThread MCSM_performBlockOnMainThread:^{

                    UIImage *result = [UIImage imageWithData:waveFormData];

                    NSLog(@"returning rendered pictogram on main thread (%d bytes %@ data in UIImage %0.0f x %0.0f pixels)",waveFormData.length,[imgExt uppercaseString],result.size.width,result.size.height);

                    completionBlock(result);

                    [waveFormData release];
                }];
            }
        }];

        return nil;

    } else {

        NSString *assetFolder = [[self class] assetCacheFolder];

        [fman createDirectoryAtPath:assetFolder withIntermediateDirectories:YES attributes:nil error:nil];

        NSLog(@"Preparing to import audio asset data %@",[assetFilepath lastPathComponent]);

        [assetPictogramFilepath retain];
        [assetFileURL retain];

        TSLibraryImport* import = [[TSLibraryImport alloc] init];
        NSURL    * assetURL = [item valueForProperty:MPMediaItemPropertyAssetURL];

         [import importAsset:assetURL toURL:assetFileURL completionBlock:^(TSLibraryImport* import) {
            //check the status and error properties of
            //TSLibraryImport

            if (import.error) {

                NSLog (@"audio data import failed:%@",import.error);

            } else{
                NSLog (@"Creating waveform pictogram file: %@", [assetPictogramFilepath lastPathComponent]);
                AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:assetFileURL options:nil];
                NSData *waveFormData = [self renderPNGAudioPictogramForAsset:asset]; 

                [waveFormData writeToFile:assetPictogramFilepath atomically:YES];

                if (completionBlock) {
                     [waveFormData retain];
                    [NSThread MCSM_performBlockOnMainThread:^{

                        UIImage *result = [UIImage imageWithData:waveFormData];
                        NSLog(@"returning rendered pictogram on main thread (%d bytes %@ data in UIImage %0.0f x %0.0f pixels)",waveFormData.length,[imgExt uppercaseString],result.size.width,result.size.height);

                        completionBlock(result);

                        [waveFormData release];
                    }];
                }
            }

            [assetPictogramFilepath release];
            [assetFileURL release];

        }  ];

        return nil;
    }
}

Bu çağırma örneği :

-(void) importMediaItem {

    MPMediaItem* item = [self mediaItem];

    // since we will be needing this for playback, save the url to the cached audio.
    [url release];
    url = [[UIImage cachedAudioURLForMPMediaItem:item] retain];

    [waveFormImage release];

    waveFormImage = [[UIImage alloc ] initWithMPMediaItem:item completionBlock:^(UIImage* delayedImagePreparation){

        waveFormImage = [delayedImagePreparation retain];
        [self displayWaveFormImage];
    }];

    if (waveFormImage) {
        [waveFormImage retain];
        [self displayWaveFormImage];
    }
}

Ortalama render yöntemleri logaritmik sürümü

#define absX(x) (x<0?0-x:x)
#define minMaxX(x,mn,mx) (x<=mn?mn:(x>=mx?mx:x))
#define noiseFloor (-90.0)
#define decibel(amplitude) (20.0 * log10(absX(amplitude)/32767.0))

-(UIImage *) audioImageLogGraph:(Float32 *) samples
                normalizeMax:(Float32) normalizeMax
                 sampleCount:(NSInteger) sampleCount 
                channelCount:(NSInteger) channelCount
                 imageHeight:(float) imageHeight {

    CGSize imageSize = CGSizeMake(sampleCount, imageHeight);
    UIGraphicsBeginImageContext(imageSize);
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetFillColorWithColor(context, [UIColor blackColor].CGColor);
    CGContextSetAlpha(context,1.0);
    CGRect rect;
    rect.size = imageSize;
    rect.origin.x = 0;
    rect.origin.y = 0;

    CGColorRef leftcolor = [[UIColor whiteColor] CGColor];
    CGColorRef rightcolor = [[UIColor redColor] CGColor];

    CGContextFillRect(context, rect);

    CGContextSetLineWidth(context, 1.0);

    float halfGraphHeight = (imageHeight / 2) / (float) channelCount ;
    float centerLeft = halfGraphHeight;
    float centerRight = (halfGraphHeight*3) ; 
    float sampleAdjustmentFactor = (imageHeight/ (float) channelCount) / (normalizeMax - noiseFloor) / 2;

    for (NSInteger intSample = 0 ; intSample < sampleCount ; intSample    ) {
        Float32 left = *samples  ;
        float pixels = (left - noiseFloor) * sampleAdjustmentFactor;
        CGContextMoveToPoint(context, intSample, centerLeft-pixels);
        CGContextAddLineToPoint(context, intSample, centerLeft pixels);
        CGContextSetStrokeColorWithColor(context, leftcolor);
        CGContextStrokePath(context);

        if (channelCount==2) {
            Float32 right = *samples  ;
            float pixels = (right - noiseFloor) * sampleAdjustmentFactor;
            CGContextMoveToPoint(context, intSample, centerRight - pixels);
            CGContextAddLineToPoint(context, intSample, centerRight   pixels);
            CGContextSetStrokeColorWithColor(context, rightcolor);
            CGContextStrokePath(context); 
        }
    }

    // Create new image
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

    // Tidy up
    UIGraphicsEndImageContext();   

    return newImage;
}

- (NSData *) renderPNGAudioPictogramLogForAsset:(AVURLAsset *)songAsset {

    NSError * error = nil;
    AVAssetReader * reader = [[AVAssetReader alloc] initWithAsset:songAsset error:&error];
    AVAssetTrack * songTrack = [songAsset.tracks objectAtIndex:0];

    NSDictionary* outputSettingsDict = [[NSDictionary alloc] initWithObjectsAndKeys:
                                        [NSNumber numberWithInt:kAudioFormatLinearPCM],AVFormatIDKey,
                                        //     [NSNumber numberWithInt:44100.0],AVSampleRateKey, /*Not Supported*/
                                        //     [NSNumber numberWithInt: 2],AVNumberOfChannelsKey,    /*Not Supported*/

                                        [NSNumber numberWithInt:16],AVLinearPCMBitDepthKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsBigEndianKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsFloatKey,
                                        [NSNumber numberWithBool:NO],AVLinearPCMIsNonInterleaved,
                                        nil];

    AVAssetReaderTrackOutput* output = [[AVAssetReaderTrackOutput alloc] initWithTrack:songTrack outputSettings:outputSettingsDict];

    [reader addOutput:output];
    [output release];

    UInt32 sampleRate,channelCount;

    NSArray* formatDesc = songTrack.formatDescriptions;
    for(unsigned int i = 0; i < [formatDesc count];   i) {
        CMAudioFormatDescriptionRef item = (CMAudioFormatDescriptionRef)[formatDesc objectAtIndex:i];
        const AudioStreamBasicDescription* fmtDesc = CMAudioFormatDescriptionGetStreamBasicDescription (item);
        if(fmtDesc ) {

            sampleRate = fmtDesc->mSampleRate;
            channelCount = fmtDesc->mChannelsPerFrame;

            //    NSLog(@"channels:%u, bytes/packet: %u, sampleRate %f",fmtDesc->mChannelsPerFrame, fmtDesc->mBytesPerPacket,fmtDesc->mSampleRate);
        }
    }

    UInt32 bytesPerSample = 2 * channelCount;
    Float32 normalizeMax = noiseFloor;
    NSLog(@"normalizeMax = %f",normalizeMax);
    NSMutableData * fullSongData = [[NSMutableData alloc] init];
    [reader startReading];

    UInt64 totalBytes = 0; 
    Float64 totalLeft = 0;
    Float64 totalRight = 0;
    Float32 sampleTally = 0;

    NSInteger samplesPerPixel = sampleRate / 50;

    while (reader.status == AVAssetReaderStatusReading){

        AVAssetReaderTrackOutput * trackOutput = (AVAssetReaderTrackOutput *)[reader.outputs objectAtIndex:0];
        CMSampleBufferRef sampleBufferRef = [trackOutput copyNextSampleBuffer];

        if (sampleBufferRef){
            CMBlockBufferRef blockBufferRef = CMSampleBufferGetDataBuffer(sampleBufferRef);

            size_t length = CMBlockBufferGetDataLength(blockBufferRef);
            totalBytes  = length;

            NSAutoreleasePool *wader = [[NSAutoreleasePool alloc] init];

            NSMutableData * data = [NSMutableData dataWithLength:length];
            CMBlockBufferCopyDataBytes(blockBufferRef, 0, length, data.mutableBytes);

            SInt16 * samples = (SInt16 *) data.mutableBytes;
            int sampleCount = length / bytesPerSample;
            for (int i = 0; i < sampleCount ; i   ) {

                Float32 left = (Float32) *samples  ;
                left = decibel(left);
                left = minMaxX(left,noiseFloor,0);
                totalLeft   = left;

                Float32 right;
                if (channelCount==2) {
                    right = (Float32) *samples  ;
                    right = decibel(right);
                    right = minMaxX(right,noiseFloor,0);
                    totalRight  = right;
                }

                sampleTally  ;

                if (sampleTally > samplesPerPixel) {

                    left  = totalLeft / sampleTally; 
                    if (left > normalizeMax) {
                        normalizeMax = left;
                    }

                   // NSLog(@"left average = %f, normalizeMax = %f",left,normalizeMax);

                    [fullSongData appendBytes:&left length:sizeof(left)];

                    if (channelCount==2) {
                        right = totalRight / sampleTally; 

                        if (right > normalizeMax) {
                            normalizeMax = right;
                        }

                        [fullSongData appendBytes:&right length:sizeof(right)];
                    }

                    totalLeft   = 0;
                    totalRight  = 0;
                    sampleTally = 0;
                }
            }

           [wader drain];

            CMSampleBufferInvalidate(sampleBufferRef);
            CFRelease(sampleBufferRef);
        }
    }

    NSData * finalData = nil;

    if (reader.status == AVAssetReaderStatusFailed || reader.status == AVAssetReaderStatusUnknown){
        // Something went wrong. Handle it.
    }

    if (reader.status == AVAssetReaderStatusCompleted){
        // You're done. It worked.

        NSLog(@"rendering output graphics using normalizeMax %f",normalizeMax);

        UIImage *test = [self audioImageLogGraph:(Float32 *) fullSongData.bytes 
                                 normalizeMax:normalizeMax 
                                  sampleCount:fullSongData.length / (sizeof(Float32) * 2) 
                                 channelCount:2
                                  imageHeight:100];

        finalData = imageToData(test);
    }

    [fullSongData release];
    [reader release];

    return finalData;
}

karşılaştırma çıktılar

Başlamak için doğrusal arsa "ısınmak" Acme Swing Şirket tarafından

"O" Acme Swing Şirketi . tarafından ısınmak başlangıç için logaritmik arsa ^/b>