我试图在我的3s视频的开头添加1s音轨（＆＃34; dummy_recording.m4a＆＃34;）。但是我现在得到的结果是6s长的视频。它以黑色背景录制开始，然后仅显示黑色背景，然后在结尾显示视频。我在这做错了什么？我只是希望音频从头开始重叠我的视频。
-(void) addAudioToFileAtPath:(NSString *) filePath toPath:(NSString *)outFilePath completion:( void ( ^ ) () )completion
{
NSString *audioFilePath = [[NSBundle mainBundle] pathForResource:@"dummy_recording"
ofType:@"m4a"];
NSDictionary *audioInfoDictionary = @{@"audioFilePath": audioFilePath, @"audioDuration": [NSNumber numberWithFloat:1.0]};
NSArray *audioInfoArray = @[audioInfoDictionary];
NSError * error = nil;
AVMutableComposition * composition = [AVMutableComposition composition];
AVURLAsset * videoAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:filePath] options:nil];
AVAssetTrack * videoAssetTrack = [[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0];
AVMutableCompositionTrack *compositionVideoTrack = [composition addMutableTrackWithMediaType:AVMediaTypeVideo
preferredTrackID: kCMPersistentTrackID_Invalid];
NSLog(@"videoAsset.duration... value: %lld, timescale: %d, seconds: %lld", videoAsset.duration.value, videoAsset.duration.timescale, videoAsset.duration.value / videoAsset.duration.timescale);
[compositionVideoTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero, videoAsset.duration) ofTrack:videoAssetTrack atTime:kCMTimeZero
error:&error];
CMTime audioStartTime = kCMTimeZero;
for (NSDictionary * audioInfo in audioInfoArray)
{
NSString * pathString = [audioInfo objectForKey:@"audioFilePath"];
AVURLAsset * urlAsset = [AVURLAsset URLAssetWithURL:[NSURL fileURLWithPath:pathString] options:nil];
AVAssetTrack * audioAssetTrack = [[urlAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0];
AVMutableCompositionTrack *compositionAudioTrack = [composition addMutableTrackWithMediaType:AVMediaTypeAudio
preferredTrackID: kCMPersistentTrackID_Invalid];
NSLog(@"urlAsset.duration... value: %lld, timescale: %d, seconds: %lld", urlAsset.duration.value, urlAsset.duration.timescale, urlAsset.duration.value / urlAsset.duration.timescale);
[compositionAudioTrack insertTimeRange:CMTimeRangeMake(kCMTimeZero,urlAsset.duration) ofTrack:audioAssetTrack atTime:audioStartTime error:&error];
audioStartTime = CMTimeAdd(audioStartTime, CMTimeMake((int) (([[audioInfo objectForKey:@"audioDuration"] floatValue] * RECORDING_FPS) + 0.5), RECORDING_FPS));
}
NSLog(@"composition.duration... value: %lld, timescale: %d, seconds: %lld", composition.duration.value, composition.duration.timescale, composition.duration.value / composition.duration.timescale);
AVAssetExportSession* assetExport = [[AVAssetExportSession alloc] initWithAsset:composition presetName:AVAssetExportPresetHighestQuality];
assetExport.outputFileType = AVFileTypeMPEG4;
assetExport.outputURL = [NSURL fileURLWithPath:outFilePath];
[assetExport exportAsynchronouslyWithCompletionHandler:
^(void ) {
switch (assetExport.status)
{
case AVAssetExportSessionStatusCompleted:
// export complete
NSLog(@"Export Complete");
completion();
break;
case AVAssetExportSessionStatusFailed:
NSLog(@"Export Failed");
NSLog(@"ExportSessionError: %@", [assetExport.error localizedDescription]);
// export error (see exportSession.error)
break;
case AVAssetExportSessionStatusCancelled:
NSLog(@"Export Failed");
NSLog(@"ExportSessionError: %@", [assetExport.error localizedDescription]);
// export cancelled
break;
}
}];
}
这是记录持续时间的语句的结果。这个作品的长度是3s，这就是我想要的，但它仍然错误地输出到6s长：
videoAsset.duration... value: 1840, timescale: 600, seconds: 3
urlAsset.duration... value: 87040, timescale: 44100, seconds: 1
composition.duration... value: 1840, timescale: 600, seconds: 3
我从静止图像创建了3s视频文件。这是代码：
NSString *documentsFolder = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)
objectAtIndex:0];
NSString *path = [documentsFolder stringByAppendingPathComponent:@"test_video.mp4"];
DDLogInfo(@"path: %@", path);
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *removeItemError;
BOOL success = [fileManager removeItemAtPath:path error:&removeItemError];
if (success) {
NSLog(@"removed file");
}
else
{
NSLog(@"Could not delete file -:%@ ",[removeItemError localizedDescription]);
}
NSString *path2 = [documentsFolder stringByAppendingPathComponent:@"test_video_with_audio.mp4"];
DDLogInfo(@"path2: %@", path);
NSError *removeItemError2;
BOOL success2 = [fileManager removeItemAtPath:path2 error:&removeItemError2];
if (success2) {
NSLog(@"removed file");
}
else
{
NSLog(@"Could not delete file -:%@ ",[removeItemError2 localizedDescription]);
}
//1. Wire the writer.
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:path] fileType:AVFileTypeMPEG4
error:&error];
NSParameterAssert(videoWriter);
self.videoWriter = videoWriter;
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:640], AVVideoWidthKey,
[NSNumber numberWithInt:640], AVVideoHeightKey,
nil];
AVAssetWriterInput* writerInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings]; //retain should be removed if ARC
NSParameterAssert(writerInput);
NSParameterAssert([videoWriter canAddInput:writerInput]);
[videoWriter addInput:writerInput];
NSMutableDictionary *attributes = [[NSMutableDictionary alloc] init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:640] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:640] forKey:(NSString*)kCVPixelBufferHeightKey];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:attributes];
//2. Start a session
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero]; //use kCMTimeZero if unsure
UIImage *image = [UIImage imageNamed:@"dummy_square.jpg"];
CGImageRef cgImage = image.CGImage;
//3. Write some samples
//CVPixelBufferRef pixelBuffer = [self newPixelBufferFromCGImage:cgImage];
CVPixelBufferRef pixelBuffer = [self pixelBufferFromCGImage:cgImage];
BOOL result = [adaptor appendPixelBuffer:pixelBuffer withPresentationTime:CMTimeMakeWithSeconds(3.0, RECORDING_FPS)];
if (result == NO)
NSLog(@"failed to append buffer");
else
NSLog(@"appended buffer!");
if(pixelBuffer)
{
CVBufferRelease(pixelBuffer);
}
//4. Finish the session
[writerInput markAsFinished];
//[videoWriter endSessionAtSourceTime:…]; //optional can call finishWriting without specifiying endTime
self.library = [[ALAssetsLibrary alloc] init];
__weak ALAssetsLibrary *lib = self.library;
[videoWriter finishWritingWithCompletionHandler:^{
[self addAudioToFileAtPath:path toPath:path2 completion:^{
NSString *albumName = @"Test Album";
NSURL *pathUrl = [[NSURL alloc] initWithString:path2];
[lib addAssetsGroupAlbumWithName:albumName resultBlock:^(ALAssetsGroup *group) {
///checks if group previously created
if(group == nil){
//enumerate albums
[lib enumerateGroupsWithTypes:ALAssetsGroupAlbum
usingBlock:^(ALAssetsGroup *g, BOOL *stop)
{
//if the album is equal to our album
if ([[g valueForProperty:ALAssetsGroupPropertyName] isEqualToString:albumName]) {
[lib writeVideoAtPathToSavedPhotosAlbum:pathUrl completionBlock:^(NSURL *assetURL, NSError *error) {
//then get the image asseturl
[lib assetForURL:assetURL
resultBlock:^(ALAsset *asset) {
//put it into our album
[g addAsset:asset];
} failureBlock:^(NSError *error) {
}];
}];
}
}failureBlock:^(NSError *error){
}];
}else{
[lib writeVideoAtPathToSavedPhotosAlbum:pathUrl completionBlock:^(NSURL *assetURL, NSError *error) {
//then get the image asseturl
[lib assetForURL:assetURL
resultBlock:^(ALAsset *asset) {
//put it into our album
[group addAsset:asset];
} failureBlock:^(NSError *error) {
}];
}];
}
} failureBlock:^(NSError *error) {
}];
}];
}];
答案 0 :(得分：2)
这里我告诉你，如何从图像阵列转换并将音乐添加到视频
NSError *error = nil;
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *documentsDirectory12 = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
NSString *videoOutputPath = [documentsDirectory12 stringByAppendingPathComponent:@"test_output.mp4"];
if ([fileMgr removeItemAtPath:videoOutputPath error:&error] != YES)
NSLog(@"Unable to delete file: %@", [error localizedDescription]);
CGSize imageSize = CGSizeMake(480, 320);
NSUInteger fps = 1;
NSLog(@"Start building video from defined frames.");
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:videoOutputPath] fileType:AVFileTypeQuickTimeMovie
error:&error];
NSParameterAssert(videoWriter);
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:imageSize.width], AVVideoWidthKey,
[NSNumber numberWithInt:imageSize.height], AVVideoHeightKey,
nil];
AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput
sourcePixelBufferAttributes:nil];
NSParameterAssert(videoWriterInput);
NSParameterAssert([videoWriter canAddInput:videoWriterInput]);
videoWriterInput.expectsMediaDataInRealTime = YES;
[videoWriter addInput:videoWriterInput];
//Start a session:
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];
CVPixelBufferRef buffer = NULL;
//convert uiimage to CGImage.
int frameCount = 0;
//NSLog(@"fps :%f",(60.0-finalSec)/(float)[photoAlbumImages count]);
float numberOfSecondsPerFrame =60.0/(float)[photoAlbumImages count];
//NSLog(@"total fps :%f",numberOfSecondsPerFrame);
float frameDuration = fps * numberOfSecondsPerFrame;
NSLog(@"frame duration :%f",frameDuration);
//for(VideoFrame * frm in imageArray)
NSLog(@"**************************************************");
for(UIImage * img12 in photoAlbumImages)
{
//UIImage * img = frm._imageFrame;
buffer = [self pixelBufferFromCGImage:[img12 CGImage]];
BOOL append_ok = NO;
int j = 0;
while (!append_ok && j < 30) {
if (adaptor.assetWriterInput.readyForMoreMediaData) {
//print out status:
NSLog(@"Processing video frame (%d,%d)",frameCount,[photoAlbumImages count]);
CMTime frameTime12 = CMTimeMake(frameCount*frameDuration,fps);
// NSLog(@"%@",frameTime12);
NSLog(@"seconds = %f", CMTimeGetSeconds(frameTime12));
append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime12];
CVPixelBufferRelease(buffer);
if(!append_ok){
NSError *error = videoWriter.error;
if(error!=nil) {
NSLog(@"Unresolved error %@,%@.", error, [error userInfo]);
}
}
}
else {
printf("adaptor not ready %d, %d\n", frameCount, j);
[NSThread sleepForTimeInterval:0.3];
}
j++;
}
if (!append_ok) {
printf("error appending image %d times %d\n, with error.", frameCount, j);
}
frameCount++;
}
NSLog(@"**************************************************");
//Finish the session:
[videoWriterInput markAsFinished];
[videoWriter finishWritingWithCompletionHandler:^(){
NSLog (@"finished writing");
}];
NSLog(@"Write Ended");
////////////////////////////////////////////////////////////////////////////
////////////// OK now add an audio file to move file /////////////////////
AVMutableComposition* mixComposition = [AVMutableComposition composition];
NSString *bundleDirectory = [[NSBundle mainBundle] bundlePath];
// audio input file...
AVURLAsset* audioAsset;
if(pathURL==NULL){
NSString *audio_inputFilePath = [bundleDirectory stringByAppendingPathComponent:@"30secs.mp3"];
NSURL *audio_inputFileUrl = [NSURL fileURLWithPath:audio_inputFilePath];
audioAsset = [[AVURLAsset alloc]initWithURL:audio_inputFileUrl options:nil];
}
// this is the video file that was just written above, full path to file is in --> videoOutputPath
NSURL *video_inputFileUrl = [NSURL fileURLWithPath:videoOutputPath];
// create the final video output file as MOV file - may need to be MP4, but this works so far...
NSString *str=[NSString stringWithFormat:@"project1/imgtovid%@.mov",[self getCurrentDateTimeAsNSString]];
NSString *outputFilePath = [documentsDirectory stringByAppendingPathComponent:str];
// NSString* webStringURL = [outputFilePath stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSURL *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
NSURL *outputFileUrl1;
if(outputFileUrl!=nil){
NSString* webStringURL = [outputFilePath stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
outputFileUrl1 = [NSURL URLWithString:webStringURL];
[self.project1Array addObject:[NSString stringWithFormat:@"file://localhost%@",outputFileUrl1]];
[positionArray addObject:[NSString stringWithFormat:@"file://localhost%@",outputFileUrl1]];
}
if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
[[NSFileManager defaultManager] removeItemAtPath:outputFilePath error:nil];
CMTime nextClipStartTime = kCMTimeZero;
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:video_inputFileUrl options:nil];
// NSLog(@"duration - %f",videoAsset.duration);
CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[a_compositionVideoTrack insertTimeRange:video_timeRange ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:nextClipStartTime error:nil];
CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
AVMutableCompositionTrack *b_compositionAudioTrack12 = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
if(pathURL==NULL){
[b_compositionAudioTrack12 insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil];
}else{
[b_compositionAudioTrack12 insertTimeRange:audio_timeRange ofTrack:[[addAudioAsset1 tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:nextClipStartTime error:nil];
}
AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
_assetExport.outputFileType = @"public.mpeg-4";
_assetExport.outputURL = outputFileUrl;
NSLog(@"duration = %f", CMTimeGetSeconds(videoAsset.duration));
_assetExport.timeRange=CMTimeRangeMake(kCMTimeZero, videoAsset.duration);
[_assetExport exportAsynchronouslyWithCompletionHandler:
^(void ) {
}
这里是imagebuffer from image
- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef)photimage {
CGSize size = CGSizeMake(480, 320);
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;
CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault,
size.width,
size.height,
kCVPixelFormatType_32ARGB,
(__bridge CFDictionaryRef) options,
&pxbuffer);
if (status != kCVReturnSuccess){
NSLog(@"Failed to create pixel buffer");
}
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, size.width,
size.height, 8, 4*size.width, rgbColorSpace,
kCGImageAlphaPremultipliedFirst);
//kCGImageAlphaNoneSkipFirst);
CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
CGContextDrawImage(context, CGRectMake(0, 0, size.width,
size.height), photimage);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}
如果您需要更多帮助，请随时联系
答案 1 :(得分：1)
我对从图像和声音制作电影有同样的要求。我用这种方法添加电影和音频。
-(void)CompileFilesToMakeMovie
{
AVMutableComposition* mixComposition = [AVMutableComposition composition];
//AUDIO FILE PATH
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"final_%@.m4a",appDelegate.storyName]];
NSURL* audio_inputFileUrl = [NSURL fileURLWithPath:path];
//VIDEO FILE PATH
NSString* path1 = [documentsDirectory stringByAppendingPathComponent:@"temp.mp4"];
NSURL* video_inputFileUrl = [NSURL fileURLWithPath:path1];
//FINAL VIDEO PATH
NSString* path2 = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"outputFile_%@.mp4",appDelegate.storyName]];
NSURL* outputFileUrl = [NSURL fileURLWithPath:path2];
NSLog(@"%@",path2);
if ([[NSFileManager defaultManager] fileExistsAtPath:path2])
[[NSFileManager defaultManager] removeItemAtPath:path2 error:nil];
CMTime nextClipStartTime = kCMTimeZero;
AVURLAsset* videoAsset = [[AVURLAsset alloc]initWithURL:video_inputFileUrl options:nil];
CMTimeRange video_timeRange = CMTimeRangeMake(kCMTimeZero,videoAsset.duration);
AVMutableCompositionTrack *a_compositionVideoTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeVideo preferredTrackID:kCMPersistentTrackID_Invalid];
[a_compositionVideoTrack insertTimeRange:video_timeRange ofTrack:[[videoAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] atTime:nextClipStartTime error:nil];
//nextClipStartTime = CMTimeAdd(nextClipStartTime, video_timeRange.duration);
AVURLAsset* audioAsset = [[AVURLAsset alloc]initWithURL:audio_inputFileUrl options:nil];
CMTimeRange audio_timeRange = CMTimeRangeMake(kCMTimeZero, audioAsset.duration);
AVMutableCompositionTrack *b_compositionAudioTrack = [mixComposition addMutableTrackWithMediaType:AVMediaTypeAudio preferredTrackID:kCMPersistentTrackID_Invalid];
[b_compositionAudioTrack insertTimeRange:audio_timeRange ofTrack:[[audioAsset tracksWithMediaType:AVMediaTypeAudio] objectAtIndex:0] atTime:CMTimeMake(2,1) error:nil];
AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPreset640x480];
_assetExport.outputFileType = @"com.apple.quicktime-movie";
_assetExport.outputURL = outputFileUrl;
[_assetExport exportAsynchronouslyWithCompletionHandler:
^(void ) {
//VIDEO COMPLETED
}
];
}
对不起，代码有点乱，但我认为它会起作用。如果我需要解释一下，请告诉我。
修改电影制作代码
#pragma mark - Movie Making Code
-(void)makeMovie{
//making movie and audio code ll be here
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,
NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString* path = [documentsDirectory stringByAppendingPathComponent:[NSString stringWithFormat:@"temp.mp4"]];
NSLog(@"%@",path);
if ([[NSFileManager defaultManager] fileExistsAtPath:path])
[[NSFileManager defaultManager] removeItemAtPath:path error:nil];
CGSize sz = CGSizeMake(480, 320);
[self writeImageAsMovie:appDelegate.imageArray toPath:path size:sz];
}
- (void)writeImageAsMovie:(NSMutableArray *)image toPath:(NSString*)path size:(CGSize)size
{
//last screen adding
UIImage *tempImg=[UIImage imageNamed:@"powered_by.png"];
[image addObject:tempImg];
//last screen adding end
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
error:&error];
NSParameterAssert(videoWriter);
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:size.width], AVVideoWidthKey,
[NSNumber numberWithInt:size.height], AVVideoHeightKey,
nil];
AVAssetWriterInput* writerInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:nil];
NSParameterAssert(writerInput);
NSParameterAssert([videoWriter canAddInput:writerInput]);
[videoWriter addInput:writerInput];
writerInput.expectsMediaDataInRealTime = YES;
//Start a session:
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];
//Write samples:
/* CVPixelBufferRef buffer = [self pixelBufferFromCGImage:image.CGImage size:size];
[adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
[adaptor appendPixelBuffer:buffer withPresentationTime:CMTimeMake(duration-1, 2)];
*/
float nxttime=0;
float time=0;
CVPixelBufferRef buffer=nil;
@autoreleasepool {
for(int i=0;i<image.count;i++)
{
NSLog(@"%d",image.count);
if([writerInput isReadyForMoreMediaData])
{
if(i!=0 && i!=4)
{
NSLog(@"AUDIO DURATION:%@",appDelegate.audioDuration);
nxttime=nxttime+time;
time=([[appDelegate.audioDuration objectAtIndex:i-1] floatValue])+1;
}
else if(i==0)
{
nxttime=0;
time=3;
}
else if(i==4)
{
nxttime=nxttime+5;
}
buffer = [self pixelBufferFromCGImage:[[image objectAtIndex:i] CGImage] size:size];
CMTime frameTime = CMTimeMake(time, 1 );
CMTime lastTime=CMTimeMake(nxttime, 1);
CMTime presentTime=CMTimeAdd(lastTime, frameTime);
// NSLog(@"%d: ft:%@ Lt:%@ PT:%@",i,frameTime,lastTime,presentTime);
[adaptor appendPixelBuffer:buffer withPresentationTime:lastTime];
}
else
{
i=i-1;
}
}
}
//Finish the session:
[writerInput markAsFinished];
[self latestCombineVoices];
[videoWriter finishWriting];
}
- (CVPixelBufferRef) pixelBufferFromCGImage:(CGImageRef)image size:(CGSize)size
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;
CVReturn status = CVPixelBufferCreate(kCFAllocatorDefault, size.width,
size.height, kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef)options,
&pxbuffer);
status=status;//Added to make the stupid compiler not show a stupid warning.
NSParameterAssert(status == kCVReturnSuccess && pxbuffer != NULL);
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
NSParameterAssert(pxdata != NULL);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, size.width,
size.height, 8, 4*size.width, rgbColorSpace,
kCGImageAlphaNoneSkipFirst);
NSParameterAssert(context);
// CGContextTranslateCTM(context, 0, CGImageGetHeight(image));
//CGContextScaleCTM(context, 1.0, -1.0);//Flip vertically to account for different origin
CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
CGImageGetHeight(image)), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}
在我的情况下例如：有img1，img2，img3和sound1，sound2，sound3所以我制作一部电影，其中img1将为sound1_duration显示，依此类推。