上面的图说明的是这个混合的过程，下面放代码：
- (void)mergeAndExportVideos:(NSArray*)videosPathArray withOutPath:(NSString*)outpath{
if (videosPathArray.count == ) {
return;
}
AVMutableComposition *mixComposition = [[AVMutableComposition alloc] init];
AVMutableCompositionTrack *audioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio
preferredTrackID:kCMPersistentTrackID_Invalid];
AVMutableCompositionTrack *videoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID:kCMPersistentTrackID_Invalid];
CMTime totalDuration = kCMTimeZero;
for (int i = ; i < videosPathArray.count; i++) {
AVURLAsset *asset = [AVURLAsset assetWithURL:[NSURL fileURLWithPath:videosPathArray[i]]];
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());
NSURL *mergeFileURL = [NSURL fileURLWithPath:outpath];
AVAssetExportSession *exporter = [[AVAssetExportSession alloc] initWithAsset:mixComposition
presetName:AVAssetExportPreset640x480];
exporter.outputURL = mergeFileURL;
exporter.outputFileType = AVFileTypeMPEG4;
exporter.shouldOptimizeForNetworkUse = YES;
[exporter exportAsynchronouslyWithCompletionHandler:^{
NSLog(@"exporter%@",exporter.error);
}];
下面是方法详解：
- (AVMutableCompositionTrack *)addMutableTrackWithMediaType:(NSString *)mediaType preferredTrackID:(CMPersistentTrackID)preferredTrackID;
参数：
mediaType ：数据类型 AVMediaTypeVideo 视频 AVMediaTypeAudio 音频
preferredTrackID ：可*设定 但建议kCMPersistentTrackID_Invalid也就是0
//向通道内加入音频或者视频
- (BOOL)insertTimeRange:(CMTimeRange)timeRange ofTrack:(AVAssetTrack *)track atTime:(CMTime)startTime error:(NSError * __nullable * __nullable)outError;
参数：
timeRange: 插入视频/音频的的时间段
track ：插入的视频/音频
补充调整视频方向的方法，个人感觉不是很好，希望大家给点建议： 从*查到的具体网址忘了
代码如下：
- (void)startExportVideoWithVideoAsset:(AVURLAsset *)videoAsset completion:(void (^)(NSString *outputPath))completion {
AVAssetExportSession *session = [[AVAssetExportSession alloc]initWithAsset:videoAsset presetName:AVAssetExportPresetHighestQuality];
//
AVMutableVideoComposition *videoComposition = [self fixedCompositionWithAsset:videoAsset];
if (videoComposition.renderSize.width) {
// 修正视频转向
session.videoComposition = videoComposition;
}
//
NSDateFormatter *formater = [[NSDateFormatter alloc] init];
[formater setDateFormat:@"yyyy-MM-dd-HH:mm:ss"];
NSString *outputPath = [NSHomeDirectory() stringByAppendingFormat:@"/tmp/output-%@.mp4", [formater stringFromDate:[NSDate date]]];
session.outputURL = [NSURL fileURLWithPath:outputPath];
// Optimize for network use.
session.shouldOptimizeForNetworkUse = true;
NSArray *supportedTypeArray = session.supportedFileTypes;
if ([supportedTypeArray containsObject:AVFileTypeMPEG4]) {
session.outputFileType = AVFileTypeMPEG4;
} else if (supportedTypeArray.count == 0) {
NSLog(@"No supported file types 视频类型暂不支持导出");
return;
} else {
session.outputFileType = [supportedTypeArray firstObject];
}
if (![[NSFileManager defaultManager] fileExistsAtPath:[NSHomeDirectory() stringByAppendingFormat:@"/tmp"]]) {
[[NSFileManager defaultManager] createDirectoryAtPath:[NSHomeDirectory() stringByAppendingFormat:@"/tmp"] withIntermediateDirectories:YES attributes:nil error:nil];
}
// Begin to export video to the output path asynchronously.
[session exportAsynchronouslyWithCompletionHandler:^(void) {
NSLog(@"%@",[session.error description]);
switch (session.status) {
case AVAssetExportSessionStatusUnknown:
NSLog(@"AVAssetExportSessionStatusUnknown"); break;
case AVAssetExportSessionStatusWaiting:
NSLog(@"AVAssetExportSessionStatusWaiting"); break;
case AVAssetExportSessionStatusExporting:
NSLog(@"AVAssetExportSessionStatusExporting"); break;
case AVAssetExportSessionStatusCompleted: {
NSLog(@"AVAssetExportSessionStatusCompleted");
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion(outputPath);
}
});
} break;
case AVAssetExportSessionStatusFailed:{
dispatch_async(dispatch_get_main_queue(), ^{
if (completion) {
completion(nil);
}
});
NSLog(@"AVAssetExportSessionStatusFailed"); break;
}
default: break;
}
}];
// }
}
/// 获取优化后的视频转向信息
- (AVMutableVideoComposition *)fixedCompositionWithAsset:(AVAsset *)videoAsset {
AVMutableVideoComposition *videoComposition = [AVMutableVideoComposition videoComposition];
// 视频转向
int degrees = [self degressFromVideoFileWithAsset:videoAsset];
if (degrees != 0) {
CGAffineTransform translateToCenter;
CGAffineTransform mixedTransform;
videoComposition.frameDuration = CMTimeMake(1, 30);
NSArray *tracks = [videoAsset tracksWithMediaType:AVMediaTypeVideo];
AVAssetTrack *videoTrack = [tracks objectAtIndex:0];
if (degrees == 90) {
// 顺时针旋转90°
translateToCenter = CGAffineTransformMakeTranslation(videoTrack.naturalSize.height, 0.0);
mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI_2);
videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.height,videoTrack.naturalSize.width);
} else if(degrees == 180){
// 顺时针旋转180°
translateToCenter = CGAffineTransformMakeTranslation(videoTrack.naturalSize.width, videoTrack.naturalSize.height);
mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI);
videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.width,videoTrack.naturalSize.height);
} else if(degrees == 270){
// 顺时针旋转270°
translateToCenter = CGAffineTransformMakeTranslation(0.0, videoTrack.naturalSize.width);
mixedTransform = CGAffineTransformRotate(translateToCenter,M_PI_2*3.0);
videoComposition.renderSize = CGSizeMake(videoTrack.naturalSize.height,videoTrack.naturalSize.width);
}
AVMutableVideoCompositionInstruction *roateInstruction = [AVMutableVideoCompositionInstruction videoCompositionInstruction];
roateInstruction.timeRange = CMTimeRangeMake(kCMTimeZero, [videoAsset duration]);
AVMutableVideoCompositionLayerInstruction *roateLayerInstruction = [AVMutableVideoCompositionLayerInstruction videoCompositionLayerInstructionWithAssetTrack:videoTrack];
[roateLayerInstruction setTransform:mixedTransform atTime:kCMTimeZero];
roateInstruction.layerInstructions = @[roateLayerInstruction];
// 加入视频方向信息
videoComposition.instructions = @[roateInstruction];
}
return videoComposition;
}
/// 获取视频角度
- (int)degressFromVideoFileWithAsset:(AVAsset *)asset {
int degress = 0;
NSArray *tracks = [asset tracksWithMediaType:AVMediaTypeVideo];
if([tracks count] > 0) {
AVAssetTrack *videoTrack = [tracks objectAtIndex:0];
CGAffineTransform t = videoTrack.preferredTransform;
if(t.a == 0 && t.b == 1.0 && t.c == -1.0 && t.d == 0){
// Portrait
degress = 90;
} else if(t.a == 0 && t.b == -1.0 && t.c == 1.0 && t.d == 0){
// PortraitUpsideDown
degress = 270;
} else if(t.a == 1.0 && t.b == 0 && t.c == 0 && t.d == 1.0){
// LandscapeRight
degress = 0;
} else if(t.a == -1.0 && t.b == 0 && t.c == 0 && t.d == -1.0){
// LandscapeLeft
degress = 180;
}
}
return degress;
}