常规获取MP4某一帧画面的方法对m3u8流媒体而言并不适用,如果有需求中需要获取m3u8流媒体截图的小伙伴可以看一下这个方法。

首先，用AVPlayer创建一个视频播放器，并且对AVPlayerItem添加观察者，具体代码不在这里啰嗦了。

流媒体的某一帧在流媒体播放时才能获取，所以我们在KVO中去调用获取画面的方法：

-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{    AVPlayerItem *playerItem=object;    if ([keyPath isEqualToString:@"status"]) {        AVPlayerStatus status= [[change objectForKey:@"new"] intValue];        if(status==AVPlayerStatusReadyToPlay){            NSLog(@"正在播放...，视频总长度:%.2f",CMTimeGetSeconds(playerItem.duration));            //image即为获取到的视频帧截图            UIImage *image = [self getPixelBufferForItem:playerItem];        }    }}复制代码

获取视频帧的代码：

//获取m3u8视频帧画面- (UIImage *)getPixelBufferForItem:(AVPlayerItem *)playerItem{    AVPlayerItemVideoOutput *output = [[AVPlayerItemVideoOutput alloc] init];    [playerItem addOutput:output];    CVPixelBufferRef ref =[output copyPixelBufferForItemTime:CMTimeMake(1000, 60) itemTimeForDisplay:nil];    UIImage *image = [self CVImageToUIImage:ref];    return image;}复制代码

copyPixelBufferForItemTime: itemTimeForDisplay:这个方法获取到的视频帧是CVPixelBufferRef类型,我们需要将CVPixelBufferRef类型转化为UIImage类型

//CVPixelBufferRef转UIImage- (UIImage *)CVImageToUIImage:(CVPixelBufferRef)imageBuffer{    CVPixelBufferLockBaseAddress(imageBuffer, 0);    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);    size_t width = CVPixelBufferGetWidth(imageBuffer);    size_t height = CVPixelBufferGetHeight(imageBuffer);    size_t bufferSize = CVPixelBufferGetDataSize(imageBuffer);    size_t bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 0);        CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();    CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, baseAddress, bufferSize, NULL);        CGImageRef cgImage = CGImageCreate(width, height, 8, 32, bytesPerRow, rgbColorSpace, kCGImageAlphaNoneSkipFirst|kCGBitmapByteOrder32Little, provider, NULL, true, kCGRenderingIntentDefault);            UIImage *image = [UIImage imageWithCGImage:cgImage];        CGImageRelease(cgImage);    CGDataProviderRelease(provider);    CGColorSpaceRelease(rgbColorSpace);        NSData* imageData = UIImageJPEGRepresentation(image, 1.0);    image = [UIImage imageWithData:imageData];    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);    return image;}复制代码