音視頻開發之pcm、yuv、rgb數據存儲

pcm數據流存儲到.pcm音頻文件

//數據源枚舉
@interface AudioSample : NSObject
@property (nonatomic, assign) long dataPtr;
@property (nonatomic, assign) int numOfSamples;
@property (nonatomic, assign) int bytesPerSample;
@property (nonatomic, assign) int numOfChannels;
@property (nonatomic, assign) int samplesPerSec;
@end

//文件管理器
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *path = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/pcm/"];
    if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {  //如果沒有路徑則創建
        [fileManager createDirectoryAtPath:path withIntermediateDirectories:YES attributes:nil error:nil];
    }
    
    NSString * dataPath = [path stringByAppendingPathComponent:@"pub_audio.pcm"];

    int bufferSize = audioSample.numOfSamples * audioSample.bytesPerSample * audioSample.numOfChannels;
    void *audioSampleBufferPtr = NULL;

    if(bufferSize) {
        audioSampleBufferPtr = malloc(bufferSize);
        if(audioSampleBufferPtr) {
            memcpy(audioSampleBufferPtr, (void *)audioSample.dataPtr, bufferSize);
        }
    }

    FILE *file = fopen([dataPath UTF8String], "ab");

    fwrite(audioSampleBufferPtr, 1, bufferSize, file);
    fclose(file);
    
    if (audioSampleBufferPtr) {
        free(audioSampleBufferPtr);
        audioSampleBufferPtr = NULL;
    }

yuv數據流存儲到.yuv視頻文件

      uint8_t *outputData = NULL;
      int32_t w = videoSample.width;
      int32_t h = videoSample.height;
      if (outputData == NULL) 
          outputData = (uint8_t*)malloc(w*h*3/2);
      }

      memcpy(outputData, (uint8_t*)videoSample.dataYPtr,w*h*3/2);
      memcpy(outputData + w*h, (uint8_t*)videoSample.dataUPtr, w*h/4);
      memcpy(outputData + w*h*5/4, (uint8_t*)videoSample.dataVPtr, w*h/4);

      fwrite(outputData, 1, w*h*3/2, file);
        
      if (outputData) {
          free(outputData);
          outputData = NULL;
      }

rgb數據存儲爲圖片

            UIImage *image = [self imageFromRGBData:(void *)videoSample.dataPtr width:videoSample.width height:videoSample.height];
            NSString *filePath =[NSHomeDirectory() stringByAppendingPathComponent:@"Documents/rgb.jpg"];
            NSData *data = UIImageJPEGRepresentation(image, 0.1);
            [data writeToFile:filePath atomically:YES];


- (UIImage *)imageFromRGBData:(void *)data width:(int)width height:(int)height {
    CGColorSpaceRef rgbSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(data, width, height, 8, width*4, rgbSpace, kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little );
    CGImageRef imageRef = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    UIImage *image = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);   
    return image;
    
}