ios - AVPlayer 播放 m3u8 流时如何捕获图像？

Question

我使用 AVPlayer 播放一个 m3u8 文件，我想在这些代码中捕获图像:

AVAssetImageGenerator *gen = [[AVAssetImageGenerator alloc] initWithAsset:self.player.currentItem.asset];
gen.appliesPreferredTrackTransform = YES;
NSError *error = nil;
CMTime actualTime;
CMTime now = self.player.currentTime;
[gen setRequestedTimeToleranceAfter:kCMTimeZero];
[gen setRequestedTimeToleranceBefore:kCMTimeZero];
CGImageRef image = [gen copyCGImageAtTime:now actualTime:&actualTime error:&error];
UIImage *thumb = [[UIImage alloc] initWithCGImage:image];
NSLog(@"%f , %f",CMTimeGetSeconds(now),CMTimeGetSeconds(actualTime));

NSLog(@"%@",error);
if (image) {
    CFRelease(image);
}

但它不起作用。错误是:

Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo=0x7fadf25f59f0 {NSUnderlyingError=0x7fadf25f1670 "The operation couldn’t be completed. (OSStatus error -12782.)", NSLocalizedFailureReason=An unknown error occurred (-12782), NSLocalizedDescription=The operation could not be completed}

我该如何解决？
非常感谢。

Answer 1

AVAssetImageGenerator 可能需要本地资源。将 AVPlayerItemVideoOutput 添加到您的 AVPlayer，寻找所需位置并在 videoOutput 上调用 copyPixelBufferForItemTime:itemTimeForDisplay: 可能会更幸运。