簡單介紹
2020/04 已重構(gòu) 支持cocoapod
這篇文章是自己做短視頻功能這幾個(gè)月的一個(gè)總結(jié)，以下文字或代碼有任何不妥的地方希望各位積極指出錯(cuò)誤，并給出建議。
從短視頻拍攝基本功能來說，我想應(yīng)該有以下，美顏磅网，水印，斷點(diǎn)拍攝筷屡，編輯功能涧偷，編輯功能包含，濾鏡添加毙死，背景音樂添加燎潮，貼圖貼紙?zhí)砑樱哔|(zhì)量壓縮（視頻降低碼率）扼倘。針對這些功能跟啤，我會(huì)逐一介紹其實(shí)現(xiàn)方法。
使用到的第三方庫：TZImagePickerController，GPUImage隅肥，SDAVAssetExportSession
demo效果圖
文章末尾會(huì)附上demo地址
預(yù)覽畫面支持美顏切換竿奏，前后相機(jī)切換
錄制中
暫停錄制，支持?jǐn)帱c(diǎn)回刪
濾鏡選擇共8重
選擇音樂
貼紙選擇腥放，可隨意調(diào)整貼紙位置
預(yù)覽發(fā)布頁面泛啸，按各自實(shí)際app需求調(diào)整
錄制功能實(shí)現(xiàn)
錄制功能是基于GPUImageVideoCamera實(shí)現(xiàn)的：
相機(jī)初始化
videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPreset1280x720 cameraPosition:AVCaptureDevicePositionBack];
給相機(jī)添加濾鏡
filter = [[LFGPUImageEmptyFilter alloc] init]; //這個(gè)濾鏡是一個(gè)空濾鏡
filteredVideoView = [[GPUImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; //創(chuàng)建預(yù)覽畫面
[videoCamera addTarget:filter];
[filter addTarget:filteredVideoView];
開起預(yù)覽
[videoCamera startCameraCapture]; //啟動(dòng)相機(jī)
切換至美顏濾鏡
[videoCamera removeAllTargets]; //移除其它濾鏡
filter = [[GPUImageBeautifyFilter alloc] init];//美顏濾鏡
[videoCamera addTarget:filter];
[filter addTarget:filteredVideoView];
視頻錄制以及斷點(diǎn)續(xù)拍
斷點(diǎn)續(xù)拍的實(shí)質(zhì)就是把多個(gè)視頻合并成同一視頻
開始錄制
movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(720.0, 1280.0)];
movieWriter.isNeedBreakAudioWhiter = YES;
movieWriter.encodingLiveVideo = YES;
movieWriter.shouldPassthroughAudio = YES;
[filter addTarget:movieWriter];
videoCamera.audioEncodingTarget = movieWriter;
[movieWriter startRecording];
暫停錄制
暫停錄制就是把視頻先保存起來，并將視頻地址保存在數(shù)組中秃症，這樣就能實(shí)現(xiàn)斷點(diǎn)續(xù)拍候址。
[movieWriter finishRecording];
[filter removeTarget:movieWriter];
[urlArray addObject:[NSURL URLWithString:[NSString stringWithFormat:@"file://%@",pathToMovie]]];
拍攝完成后的合成操作以及水印添加
創(chuàng)建音視頻合成體，以及視頻通道容器种柑，音頻通道容器
[[AVMutableComposition alloc] init];
[mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio
preferredTrackID:kCMPersistentTrackID_Invalid];
[mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
用AVAsset取出素材岗仑，并且分別取出音頻軌道 與視頻軌道按時(shí)間措添加至 上面創(chuàng)建的音視頻容器中
AVAsset* asset = [AVURLAsset URLAssetWithURL:videosPathArray[i] options:options];
//獲取AVAsset中的音頻 或者視頻
AVAssetTrack *assetAudioTrack = [[asset tracksWithMediaType:AVMediaTypeAudio] firstObject];
//向通道內(nèi)加入音頻或者視頻
BOOL ba = [audioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, asset.duration)
ofTrack:assetAudioTrack
atTime:totalDuration
error:&erroraudio];
//向通道內(nèi)加入視頻步驟與上面音頻的添加差不多
視頻水印的添加，創(chuàng)建layer 聚请，并將layer 添加AVMutableVideoComposition 這個(gè)對象中
視頻導(dǎo)出荠雕，創(chuàng)建AVAssetExportSession 對象 ，并為其設(shè)置videoComposition屬性驶赏，以此添加水印
//視頻導(dǎo)出工具
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
presetName:AVAssetExportPreset1280x720];
exporter.videoComposition = videoComp;
導(dǎo)出方法 - (void)exportAsynchronouslyWithCompletionHandler:(void (^)(void))handler;
導(dǎo)出成功后進(jìn)入下一個(gè)視頻編輯頁面
視頻濾鏡處理
創(chuàng)建視頻預(yù)覽炸卑，使用GPUImageMovie工具 并結(jié)合avPlayer
mainPlayer = [[AVPlayer alloc] init];
playerItem = [[AVPlayerItem alloc] initWithURL:videoURL];
[mainPlayer replaceCurrentItemWithPlayerItem:playerItem];
playerLayer = [AVPlayerLayer playerLayerWithPlayer:mainPlayer];
movieFile = [[GPUImageMovie alloc] initWithPlayerItem:playerItem];
movieFile.runBenchmark = YES; movieFile.playAtActualSpeed = YES;
//新建一個(gè)空白濾鏡添加至 movieFile
filter = [[LFGPUImageEmptyFilter alloc] init];
_filtClassName = @"LFGPUImageEmptyFilter";
[movieFile addTarget:filter];
//視頻預(yù)覽容器view
_filterView = [[GPUImageView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:_filterView];
[filter addTarget:_filterView];
開始預(yù)覽方法：- (void)startProcessing;
//avplay開始播放
[mainPlayer play];
[movieFile startProcessing];
切換濾鏡效果
[movieFile removeAllTargets];
//新建一個(gè)新的濾鏡文件
filter = [[NSClassFromString(_filtClassName) alloc] init];
//將濾鏡添加至 movieFile上
[movieFile addTarget:filter];
//重新添加預(yù)覽容器view
[filter addTarget:_filterView];
生成帶濾鏡處理后的視頻
//1.新建用于導(dǎo)出的MovieFile
endMovieFile = [[GPUImageMovie alloc] initWithURL:sampleURL];
endMovieFile.runBenchmark = YES;
endMovieFile.playAtActualSpeed = NO;
//2.給MovieFile添加濾鏡
endFilter = [[NSClassFromString(_filtClassName) alloc] init];
[endMovieFile addTarget:endFilter];
//3.新建GPUImageMovieWriter寫入類
movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(720.0, 1280.0)];
[endFilter addTarget:movieWriter];
movieWriter.shouldPassthroughAudio = YES;
endMovieFile.audioEncodingTarget = movieWriter;
[endMovieFile enableSynchronizedEncodingUsingMovieWriter:movieWriter];
//4.開始寫入
[movieWriter startRecording];
[endMovieFile startProcessing];
[movieWriter setCompletionBlock:^{
//.完成后的邏輯處理
}];
音樂合成處理/貼圖合成處理
此處方法原理 與第一頁視頻合成，水印處理基本相同煤傍。前者就是將音頻素材 添加到音頻軌道中盖文， 后者還是視頻layer上加layer；
視頻的壓縮處理
NSDictionary* options = @{AVURLAssetPreferPreciseDurationAndTimingKey:@YES};
AVAsset* asset = [AVURLAsset URLAssetWithURL:inputVideoUrl options:options];
NSArray* keys = @[@"tracks",@"duration",@"commonMetadata"];
[asset loadValuesAsynchronouslyForKeys:keys completionHandler:^{
SDAVAssetExportSession *compressionEncoder = [SDAVAssetExportSession.alloc initWithAsset:asset]; // provide inputVideo Url Here
compressionEncoder.outputFileType = AVFileTypeMPEG4;//文件輸出格式
compressionEncoder.outputURL = outputVideoUrl; //文件輸出地址
//視頻參數(shù)配置
compressionEncoder.videoSettings = @
{
AVVideoCodecKey: AVVideoCodecH264,//編碼方式
AVVideoWidthKey: @720, //視頻寬
AVVideoHeightKey: @1280, //視頻高
AVVideoCompressionPropertiesKey: @
{
//2000*1000 建議800*1000-5000*1000
// AVVideoAverageBitRateKey: @2500000, // Give your bitrate here for lower size give low values
AVVideoAverageBitRateKey: _bit,//比特lv
AVVideoProfileLevelKey: AVVideoProfileLevelH264HighAutoLevel,
AVVideoAverageNonDroppableFrameRateKey: _frameRate,//fps
},
};
//音頻參數(shù)配置
compressionEncoder.audioSettings = @
{
AVFormatIDKey: @(kAudioFormatMPEG4AAC),//編碼方式
AVNumberOfChannelsKey: @2,//通道蚯姆，雙通道
AVSampleRateKey: @44100,//菜樣率
AVEncoderBitRateKey: @128000,//編碼比特lv
};
[compressionEncoder exportAsynchronouslyWithCompletionHandler:^
{
//處理成功
}];
}];
