iOS object-c图片帧转视频

images 图片数组
outputURL 视频保存的地址
duration 视频长度

• (void)createVideoFromImages:(NSArray<UIImage *> *)images
  outputURL:(NSURL *)outputURL
  duration:(NSTimeInterval)duration
  completion:(void (^)(BOOL success, NSError *error))completion {

  // 检查参数
  if (images.count == 0 || !outputURL) {
  if (completion) {
  completion(NO, [NSError errorWithDomain:@"VideoCreator"
  code:1001
  userInfo:@{NSLocalizedDescriptionKey: @"无效的参数"}]);
  }
  return;
  }

  // 清理旧文件
  [[NSFileManager defaultManager] removeItemAtURL:outputURL error:nil];

// 获取第一张图片的尺寸
CGSize imageSize = images.firstObject.size;

// 配置视频写入器
NSError *error = nil;
AVAssetWriter *assetWriter = [[AVAssetWriter alloc] initWithURL:outputURL
                                                       fileType:AVFileTypeMPEG4
                                                          error:&error];

if (error) {
    if (completion) {
        completion(NO, error);
    }
    return;
}

// 视频设置
NSDictionary *videoSettings = @{
    AVVideoCodecKey: AVVideoCodecTypeH264,
    AVVideoWidthKey: @(imageSize.width),
    AVVideoHeightKey: @(imageSize.height),
    AVVideoCompressionPropertiesKey: @{
        AVVideoAverageBitRateKey: @(imageSize.width * imageSize.height * 10), // 比特率
        AVVideoProfileLevelKey: AVVideoProfileLevelH264High40,
        AVVideoMaxKeyFrameIntervalKey: @(30)
    }
};

AVAssetWriterInput *writerInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo
                                                                     outputSettings:videoSettings];

// 像素缓冲适配器
NSDictionary *sourcePixelBufferAttributes = @{
    (NSString *)kCVPixelBufferPixelFormatTypeKey: @(kCVPixelFormatType_32ARGB),
    (NSString *)kCVPixelBufferWidthKey: @(imageSize.width),
    (NSString *)kCVPixelBufferHeightKey: @(imageSize.height)
};

AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
                                                 assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
                                                 sourcePixelBufferAttributes:sourcePixelBufferAttributes];

if ([assetWriter canAddInput:writerInput]) {
    [assetWriter addInput:writerInput];
} else {
    if (completion) {
        completion(NO, [NSError errorWithDomain:@"VideoCreator"
                                           code:1002
                                       userInfo:@{NSLocalizedDescriptionKey: @"无法添加视频输入"}]);
    }
    return;
}

// 开始写入
[assetWriter startWriting];
[assetWriter startSessionAtSourceTime:kCMTimeZero];

// 计算每帧的持续时间
CMTime frameTime = CMTimeMakeWithSeconds(duration / images.count, 600);

dispatch_queue_t queue = dispatch_queue_create("video.creation.queue", DISPATCH_QUEUE_SERIAL);

[writerInput requestMediaDataWhenReadyOnQueue:queue usingBlock:^{
    CMTime currentTime = kCMTimeZero;
    
    for (int i = 0; i < images.count; i++) {
        while (!writerInput.readyForMoreMediaData) {
            [NSThread sleepForTimeInterval:0.1];
        }
        
        @autoreleasepool {
            UIImage *image = images[i];
            CVPixelBufferRef pixelBuffer = [self pixelBufferFromCGImage:image.CGImage size:imageSize];
            
            if (pixelBuffer) {
                if (![adaptor appendPixelBuffer:pixelBuffer withPresentationTime:currentTime]) {
                    NSLog(@"无法添加第 %d 帧", i);
                }
                CFRelease(pixelBuffer);
            }
            
            currentTime = CMTimeAdd(currentTime, frameTime);
        }
    }
    
    [writerInput markAsFinished];
    [assetWriter finishWritingWithCompletionHandler:^{
        dispatch_async(dispatch_get_main_queue(), ^{
            if (completion) {
                completion(assetWriter.status == AVAssetWriterStatusCompleted, assetWriter.error);
            }
        });
    }];
}];

}

// 将 CGImage 转换为 CVPixelBuffer

• (CVPixelBufferRef)pixelBufferFromCGImage:(CGImageRef)image size:(CGSize)size {
  NSDictionary *options = @{
  (NSString *)kCVPixelBufferCGImageCompatibilityKey: @YES,
  (NSString *)kCVPixelBufferCGBitmapContextCompatibilityKey: @YES
  };

  CVPixelBufferRef pixelBuffer = NULL;
  CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault,
  size.width,
  size.height,
  kCVPixelFormatType_32ARGB,
  (__bridge CFDictionaryRef)options,
  &pixelBuffer);

  if (status != kCVReturnSuccess) {
  return NULL;
  }

  CVPixelBufferLockBaseAddress(pixelBuffer, 0);
  void *pixelData = CVPixelBufferGetBaseAddress(pixelBuffer);

  CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
  CGContextRef context = CGBitmapContextCreate(pixelData,
  size.width,
  size.height,
  8,
  CVPixelBufferGetBytesPerRow(pixelBuffer),
  rgbColorSpace,
  kCGImageAlphaPremultipliedFirst);

  CGContextDrawImage(context, CGRectMake(0, 0, size.width, size.height), image);

  CGColorSpaceRelease(rgbColorSpace);
  CGContextRelease(context);

  CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

  return pixelBuffer;
  }