我正在尝试将视频拆分为 4 秒的块AVAssetExportSession。初始拆分有效并返回 8mb/4 秒的块。但是当原始视频操作系统只有 18mb 时，第二个返回 12mb 是不正确的。
- (void) splitVideo{
AVURLAsset *vidAsset = [AVURLAsset URLAssetWithURL:output options:nil];
CMTime duration = vidAsset.duration;
NSLog(@"File size is : %.2f MB And Duration: %f",(float)[NSData dataWithContentsOfURL:output].length/1024.0f/1024.0f, CMTimeGetSeconds(duration));
splitArray = [[NSMutableArray alloc]init];
CMTime end = CMTimeMake(4, 1);
CMTimeRange range = CMTimeRangeMake(kCMTimeZero, end);
NSString *outputPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"output0.mp4"];
totalSeconds = 4.0f;
[self cutVideo:output withRange:range withOutput:outputPath];
}
- (void) cutVideo:(NSURL *)url withRange:(CMTimeRange)range withOutput:(NSString*)path{
AVAsset *asset = [[AVURLAsset alloc] initWithURL:url options:nil];
NSArray *compatiblePresets = [AVAssetExportSession exportPresetsCompatibleWithAsset:asset];
if ([compatiblePresets containsObject:AVAssetExportPresetHighestQuality]) {
AVAssetExportSession *exportSession = [[AVAssetExportSession alloc] initWithAsset:asset presetName:AVAssetExportPresetHighestQuality];
NSURL *finalUrl = [NSURL fileURLWithPath:path];
[[NSFileManager defaultManager] removeItemAtURL:finalUrl error:NULL];
exportSession.outputURL = finalUrl;
exportSession.outputFileType = AVFileTypeQuickTimeMovie;
exportSession.shouldOptimizeForNetworkUse = YES;
exportSession.timeRange = range;
NSLog(@"start: %f end: %f", CMTimeGetSeconds(range.start), CMTimeGetSeconds(range.duration));
[exportSession exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
});
if ([exportSession status] == AVAssetExportSessionStatusCompleted){
NSData *videoData = [[NSData alloc]initWithContentsOfURL:exportSession.outputURL];
NSLog(@"DL: %f", (float)videoData.length/1024.0f/1024.0f);
[self makeFile:finalUrl];
AVURLAsset *fullVid = [AVURLAsset URLAssetWithURL:output options:nil];
CMTime start = CMTimeMake(totalSeconds, 1);
totalSeconds = totalSeconds + 4.0f;
CMTime end;
if ((CMTimeGetSeconds(start) + 4) > CMTimeGetSeconds(fullVid.duration)) {
end = fullVid.duration;
}else{
end = CMTimeMake(CMTimeGetSeconds(start) + 4, 1);
}
CMTimeRange range2 = CMTimeRangeMake(start, end);
NSLog(@"%f < %f\n\n", CMTimeGetSeconds(start), CMTimeGetSeconds(fullVid.duration));
if (CMTimeGetSeconds(start) < CMTimeGetSeconds(fullVid.duration)) {
NSString *outputPath = [NSTemporaryDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:@"output%lu.mp4", splitArray.count]];
[self cutVideo:output withRange:range2 withOutput:outputPath];
}else{
[self saveVideo:true];
}
}else if ([exportSession status] == AVAssetExportSessionStatusFailed){
NSLog(@"Export failed: %@", [[exportSession error] localizedDescription]);
}else if ([exportSession status] == AVAssetExportSessionStatusCancelled){
NSLog(@"Export canceled");
}
}];
}
}
文件大小为：18.86 MB 持续时间：9.171667
第一的
开始：0.000000 结束：4.000000
DL: 8.194733
4.000000 < 9.171667
第二
开始：4.000000 结束：8.000000
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