以下是从 CMSampleBufferRef 创建 NSData 对象的方法:
在接口 (.h) 文件中,将示例缓冲区引用添加为属性,同时转换为对象:
@property (nonatomic, strong) __attribute__((NSObject)) CMSampleBufferRef sampleBuffer;
在实现文件 (.m) 中:
CMSampleBufferRef sampleBuffer = (CMSampleBufferRef)[(AVAssetReaderTrackOutput *)[assetReader 输出][0] copyNextSampleBuffer];
NSPurgeableData *sampleBufferData = (NSPurgeableData *)[self imageToBuffer:sampleBuffer];
要从 NSData 对象访问样本缓冲区,只需使用强制转换:
(CMSampleBufferRef)sampleBufferData;
这是另一种方式:
- (NSData *) imageToBuffer:(CMSampleBufferRef)source {
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(source);
CVPixelBufferLockBaseAddress(imageBuffer,0);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);
void *src_buff = CVPixelBufferGetBaseAddress(imageBuffer);
NSData *data = [NSData dataWithBytes:src_buff length:bytesPerRow * height];
CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
return data;
}