appendPixelBuffer 调用在 3GS 设备 (IOS 4.1) 上返回 NO,但在 iPhone 4 设备上运行良好。
以下对 appendPixelBuffer 的调用是问题的根源:
CVPixelBufferRef buffer = NULL;
buffer = [self pixelBufferFromCGImage:[[UIImage imageNamed:@"frame1.png"] CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
if (result == NO) //failes on 3GS, but works on iphone 4
NSLog(@"failed to append buffer");
完整代码:
-(void)writeImagesAsMovie:(NSArray *)array toPath:(NSString*)path {
NSLog(path);
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
error:&error];
if(error) {
NSLog(@"error creating AssetWriter: %@",[error description]);
}
错误(ONLY ON 3GS, iphone 4 is fine)是
Error Domain=AVFoundationErrorDomain Code=-11800 "The operation couldn’t be completed. (AVFoundationErrorDomain error -11800.)" UserInfo=0x4970530 {NSUnderlyingError=0x496d2c0 "The operation couldn’t be completed. (OSStatus error -12908.)"}
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:frameSize.width], AVVideoWidthKey,
[NSNumber numberWithInt:frameSize.height], AVVideoHeightKey,
nil];
AVAssetWriterInput* writerInput = [[AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings] retain];
NSMutableDictionary *attributes = [[NSMutableDictionary alloc]init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.width] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.height] forKey:(NSString*)kCVPixelBufferHeightKey];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:attributes];
[videoWriter addInput:writerInput];
// fixes all errors
writerInput.expectsMediaDataInRealTime = YES;
//Start a session:
BOOL start = [videoWriter startWriting];
NSLog(@"Session started? %d", start);
[videoWriter startSessionAtSourceTime:kCMTimeZero];
CVPixelBufferRef buffer = NULL;
buffer = [self pixelBufferFromCGImage:[[UIImage imageNamed:@"frame1.png"] CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
if (result == NO) //failes on 3GS, but works on iphone 4
NSLog(@"failed to append buffer");
if(buffer)
CVBufferRelease(buffer);
[NSThread sleepForTimeInterval:0.05];
//for (int i = 1;i<[array count]; i++)
for (int i = 1;i<20; i++)
{
if (adaptor.assetWriterInput.readyForMoreMediaData)
{
NSLog(@"inside for loop %d",i);
CMTime frameTime = CMTimeMake(1, 15);
CMTime lastTime=CMTimeMake(i, 15);
CMTime presentTime=CMTimeAdd(lastTime, frameTime);
NSString *imgName = [NSString stringWithFormat:@"frame%d.png",i];
UIImage *imgFrame = [UIImage imageNamed:imgName] ;
buffer = [self pixelBufferFromCGImage:[imgFrame CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
if (result == NO) //failes on 3GS, but works on iphone 4
{
NSLog(@"failed to append buffer");
NSLog(@"The error is %@", [videoWriter error]);
}
if(buffer)
CVBufferRelease(buffer);
[NSThread sleepForTimeInterval:0.05];
}
else
{
NSLog(@"error");
i--;
}
}
//Finish the session:
[writerInput markAsFinished];
[videoWriter finishWriting];
CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
[videoWriter release];
[writerInput release];
NSLog(@"Movie created successfully");
}
- (CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image
{
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;
CVPixelBufferCreate(kCFAllocatorDefault, self.view.frame.size.width,
self.view.frame.size.height, kCVPixelFormatType_32ARGB, (CFDictionaryRef) options,
&pxbuffer);
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, self.view.frame.size.width,
self.view.frame.size.height, 8, 4*self.view.frame.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;
}
最佳答案
检查设备管理器中的控制台登录。 我在 Ipod 2nd Gen 上遇到了同样的错误并报告了控制台日志
com.apple.mediaserverd[18]:VTSelectAndCreateVideoEncoderInstance:找不到“avc1”的视频编码器
确切地说,这意味着仍在努力,但它为我指明了方向。
关于iphone - 使用 AVAssetWriter 从图像创建电影在 3GS 设备上无法正常工作,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/5681927/