0
我有一個圖像數組可以轉換爲MP4文件。從我所知道的情況來看，似乎並沒有將圖像添加到視頻的視頻幀中，導致視頻中出現零幀。我如何解決這個錯誤，以正確地將圖像轉換爲視頻文件？以下是轉換器的所有代碼和錯誤消息的圖像。將圖像陣列轉換爲MP4文件時遇到問題
- (void) createVideoPlayer:(NSArray *)imagesArray {
NSError *error = nil;
// set up file manager, and file videoOutputPath, remove "test_output.mp4" if it exists...
//NSString *videoOutputPath = @"/Users/someuser/Desktop/test_output.mp4";
NSFileManager *fileMgr = [NSFileManager defaultManager];
NSString *documentsDirectory = [NSHomeDirectory()
stringByAppendingPathComponent:@"Documents"];
NSString *videoOutputPath = [documentsDirectory stringByAppendingPathComponent:@"test_output.mp4"];
//NSLog(@"-->videoOutputPath= %@", videoOutputPath);
// get rid of existing mp4 if exists...
if ([fileMgr removeItemAtPath:videoOutputPath error:&error] != YES)
NSLog(@"Unable to delete file: %@", [error localizedDescription]);
CGSize imageSize = CGSizeMake(640, 853);
////////////// end setup ///////////////////////////////////
NSLog(@"Start building video from defined frames.");
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:videoOutputPath] fileType:AVFileTypeQuickTimeMovie
error:&error];
NSParameterAssert(videoWriter);
NSDictionary* compression = @{
AVVideoAverageBitRateKey:[NSNumber numberWithInt:(960000 * 2)],
AVVideoMaxKeyFrameIntervalKey:[NSNumber numberWithInt:1]
};
AVAssetWriterInput* videoWriterInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:@{
AVVideoCodecKey:AVVideoCodecH264,
AVVideoCompressionPropertiesKey:compression,
AVVideoWidthKey:[NSNumber numberWithInt:imageSize.width],
AVVideoHeightKey:[NSNumber numberWithInt:imageSize.height]
}];
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;
// double FPS = self.numberOfImages/10;
//for(VideoFrame * frm in imageArray)
NSLog(@"**************************************************");
for(UIImage * img in imagesArray)
{
//UIImage * img = frm._imageFrame;
buffer = [self pixelBufferFromCGImage:[img 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,%lu)",frameCount,(unsigned long)[imagesArray count]);
CMTime frameTime = CMTimeMake(frameCount,(int32_t) 10);
append_ok = [adaptor appendPixelBuffer:buffer withPresentationTime:frameTime];
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:0.1];
}
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(@"Write Ended");
AVMutableComposition* mixComposition = [AVMutableComposition composition];
// this is the video file that was just written above, full path to file is in --> videoOutputPath
NSURL *video_inputFileUrl = [NSURL fileURLWithPath:videoOutputPath];
NSLog(@"%@", video_inputFileUrl);
// create the final video output file as MP4
NSString *outputFilePath = [documentsDirectory stringByAppendingPathComponent:@"final_video.mp4"];
NSURL *outputFileUrl = [NSURL fileURLWithPath:outputFilePath];
NSLog(@"%@", outputFileUrl);
if ([[NSFileManager defaultManager] fileExistsAtPath:outputFilePath])
[[NSFileManager defaultManager] removeItemAtPath:outputFilePath 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, a_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:nextClipStartTime error:nil];
AVAssetExportSession* _assetExport = [[AVAssetExportSession alloc] initWithAsset:mixComposition presetName:AVAssetExportPresetHighestQuality];
_assetExport.outputFileType = @"public.mpeg-4";
//NSLog(@"support file types= %@", [_assetExport supportedFileTypes]);
_assetExport.outputURL = outputFileUrl;
theURL = _assetExport.outputURL;
[_assetExport exportAsynchronouslyWithCompletionHandler:
^(void) {
dispatch_async(dispatch_get_main_queue(), ^{
[spinner stopAnimating];
moviePlayer = [[MPMoviePlayerController alloc] initWithContentURL:_assetExport.outputURL];
[moviePlayer.view setFrame:CGRectMake(0, 100, 320, 320)];
[moviePlayer prepareToPlay];
[moviePlayer repeatMode];
moviePlayer.backgroundView.backgroundColor = [UIColor whiteColor];
// And other options you can look through the documentation.
[self.view addSubview:moviePlayer.view];
[moviePlayer play];
});
}
];
NSLog(@"DONE.....outputFilePath--->%@", outputFilePath);
////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////
}
////////////////////////
- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image {
CGSize size = CGSizeMake(640, 853);
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,
kCGImageAlphaNoneSkipFirst);
CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
CGImageGetHeight(image)), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}
