GPU 踩的幾個坑

GPUimage
前幾幀是黑色的；
背景色是藍色的；
靜音錄製崩潰；
push 的時間延遲；

前幾幀是黑色的，
https://github.com/BradLarson/GPUImage/issues/1255
static BOOL allowWriteAudio = NO;

- (void)startRecording;
{
  ...
  allowWriteAudio = NO;
}

- (void)processAudioBuffer:(CMSampleBufferRef)audioBuffer;
{
  if (!allowWriteAudio) {
    return;
  }
  ...
}

- (void)newFrameReadyAtTime:(CMTime)frameTime atIndex:(NSInteger)textureIndex;
{
  ...
  if (![assetWriterPixelBufferInput appendPixelBuffer:pixel_buffer withPresentationTime:frameTime])
    NSLog(@"Problem appending pixel buffer at time: %@", CFBridgingRelease(CMTimeCopyDescription(kCFAllocatorDefault, frameTime)));

  allowWriteAudio = YES;   //< add this
  ...
}

push 的時間延遲bug
            //只有一段視頻
            [KJUtility hideProgressDialog];
            NSDictionary *dict = self.kj_videoArray.firstObject;
            self.kj_outPath = dict[@"path"];



            [self saveVideoToLibrary];
            WS(weakSelf)
            if (self.kjFileDelegate && [self.kjFileDelegate respondsToSelector:@selector(kj_videoFileCompleteLocalPath:)]) {
                NSLog(@"一段視頻：.........%@",self.kj_outPath);
                [self.kjFileDelegate kj_videoFileCompleteLocalPath:self.kj_outPath];
            } else {
                [self saveVideoToLibrary];
            }

藍邊的bug
//        kj_movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:videoURL size:CGSizeMake(SCREEN_WIDTH, SCREEN_HEIGHT)];

        kj_movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:videoURL size:CGSizeMake(floor(1080), floor(1920))];

https://github.com/BradLarson/GPUImage/issues/1276

靜音的bug
AVURLAsset *kj_videoAsset = [[AVURLAsset alloc] initWithURL:tmpUrl options:kj_options];
        if ([[kj_videoAsset tracksWithMediaType:AVMediaTypeAudio] count] > 0){
            kj_movieComposition.audioEncodingTarget = kj_movieWriter;
        } else {//no audio
            kj_movieComposition.audioEncodingTarget = nil;
        }
//        kj_movieComposition.audioEncodingTarget = kj_movieWriter;

if ([[anAsset tracksWithMediaType:AVMediaTypeAudio] count] > 0){
            _movieFile.audioEncodingTarget = _movieWriter;
        } else {//no audio
            _movieFile.audioEncodingTarget = nil;
        }