GPUImageWriter间歇性崩溃

Question

我正在使用GPUImage框架来录制视频。但是，在录制时，我希望能够停止录制，开始录制和重复录制。我的代码如下：

-(void) startRecording {
NSLog(@"begin recording ");
dispatch_async(recordingQ, ^{
    @autoreleasepool {
        _assetURL = [self mediaURLAsVideo:YES];
        _movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:[self mediaURLAsVideo:YES] size:CGSizeMake(640, 480)];
        [_overlay addTarget:_movieWriter];
        [_movieWriter startRecording];
    }
});

}

-(void) stopRecording {
NSLog(@"stop recording");
dispatch_sync(recordingQ, ^{
    [_overlay removeTarget:_movieWriter];
    [_movieWriter finishRecording];
});
}

偶尔，我会看到这次崩溃：

*** Assertion failure in -[GPUImageMovieWriter createDataFBO], /Users/.../Pods/GPUImage/framework/Source/iOS/GPUImageMovieWriter.m:548

我不确定为什么会这样，但任何帮助都会受到赞赏。

还有第二个问题。有时，控制台会记录

Couldn't write a frame
Couldn't write a frame
Couldn't write a frame
Couldn't write a frame