我正在尝试使用硬件支持的视频工具包解码器编写视频解码器。但是,如果我像下面发布的示例那样尝试初始化解码会话,调用VTDecompressionSessionCreate时会出现错误-8971。有人可以告诉我在这里做错了什么吗?
谢谢和问候,
Oliver
OSStatus status;
int tmpWidth = sps.EncodedWidth();
int tmpHeight = sps.EncodedHeight();
NSLog(@"Got new Width and Height from SPS - %dx%d", tmpWidth, tmpHeight);
const VTDecompressionOutputCallbackRecord callback = { ReceivedDecompressedFrame, self };
status = CMVideoFormatDescriptionCreate(NULL,
kCMVideoCodecType_H264,
tmpWidth,
tmpHeight,
NULL,
&decoderFormatDescription);
if (status == noErr)
{
// Set the pixel attributes for the destination buffer
CFMutableDictionaryRef destinationPixelBufferAttributes = CFDictionaryCreateMutable(
NULL, // CFAllocatorRef allocator
0, // CFIndex capacity
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
SInt32 destinationPixelType = kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
CFDictionarySetValue(destinationPixelBufferAttributes,kCVPixelBufferPixelFormatTypeKey, CFNumberCreate(NULL, kCFNumberSInt32Type, &destinationPixelType));
CFDictionarySetValue(destinationPixelBufferAttributes,kCVPixelBufferWidthKey, CFNumberCreate(NULL, kCFNumberSInt32Type, &tmpWidth));
CFDictionarySetValue(destinationPixelBufferAttributes, kCVPixelBufferHeightKey, CFNumberCreate(NULL, kCFNumberSInt32Type, &tmpHeight));
CFDictionarySetValue(destinationPixelBufferAttributes, kCVPixelBufferOpenGLCompatibilityKey, kCFBooleanTrue);
// Set the Decoder Parameters
CFMutableDictionaryRef decoderParameters = CFDictionaryCreateMutable(
NULL, // CFAllocatorRef allocator
0, // CFIndex capacity
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
CFDictionarySetValue(decoderParameters,kVTDecompressionPropertyKey_RealTime, kCFBooleanTrue);
// Create the decompression session
// Throws Error -8971 (codecExtensionNotFoundErr)
status = VTDecompressionSessionCreate(NULL, decoderFormatDescription, decoderParameters, destinationPixelBufferAttributes, &callback, &decoderDecompressionSession);
// release the dictionaries
CFRelease(destinationPixelBufferAttributes);
CFRelease(decoderParameters);
// Check the Status
if(status != noErr)
{
NSLog(@"Error %d while creating Video Decompression Session.", (int)status);
continue;
}
}
else
{
NSLog(@"Error %d while creating Video Format Descripttion.", (int)status);
continue;
}