Question

我需要修剪很多视频，然后显示他们的编辑预览。用户可以编辑每个视频的开始时间和结束时间，并使用代码显示当前视频的预览（当用户修剪时）：

AVPlayer *player = [AVPlayer playerWithURL:[NSURL URLWithString:video.fileURL]];
int32_t timeScale = player.currentItem.asset.duration.timescale;
float startTime = video.startTime;
float endTime = video.endTime > 0 ? video.endTime : video.duration;
player.currentItem.forwardPlaybackEndTime = CMTimeMakeWithSeconds(endTime, timeScale);
[player seekToTime:CMTimeMakeWithSeconds(startTime, timeScale)
   toleranceBefore:kCMTimeZero
    toleranceAfter:kCMTimeZero
 completionHandler:^(BOOL finished) {
     if (finished) {
         [self.player play];
     }
 }];

我使用AVMutableComposition进行编译预览，因为我需要单个AVPlayerItem用于GPUImage。我的代码：

AVMutableComposition *composition = [[AVMutableComposition alloc] init];
for (Video *video in videos) {
    AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:[NSURL URLWithString:video.fileURL] options:nil];
    int32_t timeScale = asset.duration.timescale;
    CMTime startTime = CMTimeMakeWithSeconds(video.startTime, timeScale);
    CMTime duration = CMTimeMakeWithSeconds(
            (video.endTime > 0 ? video.endTime : video.duration) - video.startTime,
            timeScale);

    [composition insertTimeRange:CMTimeRangeMake(startTime, duration)
                         ofAsset:asset
                          atTime:composition.duration error:nil];
}

AVPlayerItem *playerItem = [[AVPlayerItem alloc] initWithAsset:[composition copy]];

我在屏幕上看到不同范围的视频。我哪里错了？

Answer 1

Swift 5.1

您必须从AVMutableComposition获取最新的timeRange，并在范围的末尾插入新的AVAset：

self.mutableComposition.tracks.last?.timeRange.end

这将返回您的AVMutableComposition持续时间，以及如果您想添加新用途：

try mutableComposition.insertTimeRange(CMTimeRange(start: .zero, duration: media.duration), of: media, at: duration ?? .zero)

AVMutableComposition insertTimeRange：使用错误的范围

1 个答案:

Swift 5.1