主要功能（有示例代码）：
1.基于GPUImage自定义美颜滤镜 2.基于GPUImage添加文本水印及动态水印 3.录制过程中各种滤镜随意切换，及文本水印动态水印随意切换可以加载gif图作为水印 4.录制过程中可以暂停并继续录制 5.使用AVFoundation框架进行视频拼接 6.获取短视频第一帧图片，示例代码中有方法 录制页面：
暂停功能：
由于音视频同步过程中需要用到时间戳，视频录制过程中有时间戳，暂停过程如果只是停止编码是不行的，暂停后开始编码时间戳就有问题，不连续了。于是就采用暂停录制就录制成为一段完成视频，结束录制时再把录制的所有视频拼接起来。
美颜滤镜：
不想下载示例代码可以到这里看： iOS GPUImage 自定义美颜滤镜
动态水印功能：
这个动态水印就像抖音的抖动水印一样，可以加载gif图，没有使用第三方框架加载gif图，是把gif图当中的所有图片提取出来，然后动态替换水印图片，直接使用UIImageView的animation加载图片没有效果，就在GPUImage的回调当中进行动态改变水印图片：
///gif
NSString *path = [[NSBundle mainBundle] pathForResource:@"video.gif" ofType:nil] ;
NSData *imageData = [NSData dataWithContentsOfFile:path];
NSArray * arrImage = [YHHelp changeGifToImage:imageData];
UIImageView * imageV = [[UIImageView alloc]initWithFrame:CGRectMake(80, 0, 100, 80)];
imageV.image = arrImage[0];
//创建滤镜 GPUImageDissolveBlendFilter
gifFilter = [[GPUImageAlphaBlendFilter alloc] init];
// GPUImageGaussianBlurFilter *filter = [[GPUImageGaussianBlurFilter alloc] init];
gifFilter.mix = 0.8;
//创建水印图形
UIView* watermarkView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 180, 380)];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 80, 80)];
label.text = @"Record";
label.textColor = [UIColor whiteColor];
label.textAlignment = NSTextAlignmentCenter;
label.font = [UIFont systemFontOfSize:20 weight:UIFontWeightBold];
[watermarkView addSubview:imageV];
[watermarkView addSubview:label];
GPUImageUIElement *uiElement = [[GPUImageUIElement alloc] initWithView:watermarkView];
videoFilter = [[GPUImageFilter alloc] init];
[videoFilter addTarget:gifFilter];
[uiElement addTarget:gifFilter];
__block NSInteger imageIndex = 0;
__block GPUImageUIElement *weakElement = uiElement;
__block NSInteger timeCount = 0;
[videoFilter setFrameProcessingCompletionBlock:^(GPUImageOutput *output, CMTime time) {
NSInteger tempCount = time.value/(time.timescale/1000);
//控制水印图片刷新速率
if (tempCount - timeCount > 100) {
imageIndex ++;
dispatch_async(dispatch_get_main_queue(), ^{
imageV.image = arrImage[imageIndex];
});
if (imageIndex == arrImage.count -1) {
imageIndex = 0;
}
timeCount = tempCount;
}
[weakElement update];
}];
视频拼接，使用AVMutableComposition进行拼接：
- (void)mergeAndExportVideos:(NSArray*)videosPathArray withOutPath:(NSString*)outpath{
if (videosPathArray.count == 0) {
[YHToastHUD showToast:@"没有可处理视频文件！"];
return;
}
//音频视频合成体
AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
//创建音频通道容器
AVMutableCompositionTrack *audioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
//创建视频通道容器
AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime totalDuration = kCMTimeZero;
for (int i = 0; i < videosPathArray.count; i++) {
// AVURLAsset *asset = [AVURLAsset assetWithURL:[NSURL URLWithString:videosPathArray[i]]];
NSDictionary* options = @{AVURLAssetPreferPreciseDurationAndTimingKey:@YES};
AVAsset* asset = [AVURLAsset URLAssetWithURL:videosPathArray[i] options:options];
NSError *erroraudio = nil;
//获取AVAsset中的音频 或者视频
AVAssetTrack *assetAudioTrack = [[asset tracksWithMediaType:AVMediaTypeAudio] firstObject];
//向通道内加入音频或者视频
BOOL ba = [audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
ofTrack:assetAudioTrack
atTime:totalDuration
error:&erroraudio];
NSLog(@"erroraudio:%@%d",erroraudio,ba);
NSError *errorVideo = nil;
AVAssetTrack *assetVideoTrack = [[asset tracksWithMediaType:AVMediaTypeVideo]firstObject];
BOOL bl = [videoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
ofTrack:assetVideoTrack
atTime:totalDuration
error:&errorVideo];
NSLog(@"errorVideo:%@%d",errorVideo,bl);
totalDuration = CMTimeAdd(totalDuration, asset.duration);
}
NSLog(@"%@",NSHomeDirectory());
CGSize videoSize = [videoTrack naturalSize];
AVMutableVideoComposition* videoComp = [AVMutableVideoComposition videoComposition];
videoComp.renderSize = videoSize;
videoComp.frameDuration = CMTimeMake(1, 30);
AVMutableVideoCompositionInstruction *instruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
instruction.timeRange = CMTimeRangeMake(kCMTimeZero, [mixComposition duration]);
AVAssetTrack *mixVideoTrack = [[mixComposition tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableVideoCompositionLayerInstruction *layerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:mixVideoTrack];
instruction.layerInstructions = [NSArray arrayWithObject:layerInstruction];
videoComp.instructions = [NSArray arrayWithObject: instruction];
NSURL *mergeFileURL = [NSURL fileURLWithPath:outpath];
//视频导出工具
#pragma mark 录制分辨率设置
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetMediumQuality];
exporter.videoComposition = videoComp;
exporter.outputURL = mergeFileURL;
exporter.outputFileType = AVFileTypeMPEG4;
exporter.shouldOptimizeForNetworkUse = YES;
__weak typeof(self) weak_self = self;
[exporter exportAsynchronouslyWithCompletionHandler:^{
dispatch_async(dispatch_get_main_queue(), ^{
[YHToastHUD showToast:@"处理完毕...." completion:^{
[weak_self dismissViewControllerAnimated:YES completion:nil];
}];
});
}];
}
示例代码调试文件查看：
视频录制文件保存到了document目录下面了，这个目录会被iTunes同步，所以可以使用iTunes把视频保存目录Video给直接导出（拖出即可），或者直接Window->Devices and Simulators 找到相应设备及app导出沙盒里面的内容查看。 test.mp4为最终合成文件。
示例代码：https://github.com/huizai0705/VideoRecorder_iOS
