/**
* 把视频文件拆成图片保存在沙盒中
*
* @param fileUrl 本地视频文件URL
* @param fps 拆分时按此帧率进行拆分
* @param completedBlock 所有帧被拆完成后回调
*/
- (void)splitVideo:(NSURL *)fileUrl fps:(float)fps completedBlock:(void(^)())completedBlock {
if (!fileUrl) {
return;
}
NSDictionary *optDict = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:NO] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
AVURLAsset *avasset = [[AVURLAsset alloc] initWithURL:fileUrl options:optDict];
CMTime cmtime = avasset.duration; //视频时间信息结构体
Float64 durationSeconds = CMTimeGetSeconds(cmtime); //视频总秒数
NSMutableArray *times = [NSMutableArray array];
Float64 totalFrames = durationSeconds * fps; //获得视频总帧数
CMTime timeFrame;
for (int i = 1; i <= totalFrames; i++) {
timeFrame = CMTimeMake(i, fps); //第i帧 帧率
NSValue *timeValue = [NSValue valueWithCMTime:timeFrame];
[times addObject:timeValue];
}
AVAssetImageGenerator *imgGenerator = [[AVAssetImageGenerator alloc] initWithAsset:avasset];
//防止时间出现偏差
imgGenerator.requestedTimeToleranceBefore = kCMTimeZero;
imgGenerator.requestedTimeToleranceAfter = kCMTimeZero;
NSInteger timesCount = [times count];
[imgGenerator generateCGImagesAsynchronouslyForTimes:times completionHandler:^(CMTime requestedTime, CGImageRef _Nullable image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError * _Nullable error) {
printf("current-----: %lld\n", requestedTime.value);
switch (result) {
case AVAssetImageGeneratorCancelled:
NSLog(@"Cancelled");
break;
case AVAssetImageGeneratorFailed:
NSLog(@"Failed");
break;
case AVAssetImageGeneratorSucceeded: {
if (requestedTime.value == timesCount) {
NSLog(@"completed");
if (completedBlock) { completedBlock();
}
}
}
break;
}
}];
}
