IOS 硬件GPU解码

导入框架和头文件#import <VideoToolbox/VideoToolbox.h>

{//声明的全局变量 NSData *spsData ;    NSData *ppsData;    uint8_t pFrameData[BUFFER_SIZE];    CMVideoFormatDescriptionRef  videoFormatDescription ;    VTDecompressionSessionRef decompressionSession;    VTDecompressionOutputCallback  decompressionSessionDecodeFrameCallback;}-(void)createDecompSession{    VTDecompressionOutputCallbackRecord callBackRecord;    callBackRecord.decompressionOutputCallback = decompressionSessionDecodeFrameCallback;    callBackRecord.decompressionOutputRefCon = (__bridge void *)self;    //attr是传递给decode session的属性词典,两种方式//    NSDictionary *destinationImageBufferAttributes =[NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:NO],(id)kCVPixelBufferOpenGLESCompatibilityKey,//                                                     [NSNumber numberWithInt:kCVPixelFormatType_24RGB],(id)kCVPixelBufferPixelFormatTypeKey,nil];    //kCVPixelFormatType_420YpCbCr8BiPlanarFullRange,kCVPixelFormatType_24RGB    //(__bridge CFDictionaryRef)(destinationImageBufferAttributes)    //attr是传递给decode session的属性词典    CFDictionaryRef attrs = NULL;    //kCVPixelBufferPixelFormatTypeKey，指定解码后的图像格式，必须指定成NV12，苹果的硬解码器只支持NV12。    const void *keys[] = { kCVPixelBufferPixelFormatTypeKey };    //      kCVPixelFormatType_420YpCbCr8Planar is YUV420    //      kCVPixelFormatType_420YpCbCr8BiPlanarFullRange is NV12    uint32_t v = kCVPixelFormatType_420YpCbCr8BiPlanarFullRange;    const void *values[] = { CFNumberCreate(NULL, kCFNumberSInt32Type, &v) };    attrs = CFDictionaryCreate(NULL, keys, values, 1, NULL, NULL);    //创建解码session    OSStatus status =  VTDecompressionSessionCreate(kCFAllocatorDefault,                                                    videoFormatDescription,                                                    NULL,                                                   attrs , // attrs, // NULL                                                    &callBackRecord,                                                    &decompressionSession);}-(void)decodeData:(char*)pFromeData Leng:(int)length{    //去掉开始码,提取sps和pps    int naluType = ((uint8_t)pFromeData[4]&0x1f);//    for (int i=0; i<length; i++) {//        printf("%c",pFromeData[i]);//    }    if ((naluType==7||naluType==8)&&videoFormatDescription ==NULL) {        if (naluType==7) {            spsData = [NSData dataWithBytes:pFromeData + 4 length:length-4];        }        if (naluType==8) {            ppsData = [NSData dataWithBytes:pFromeData+4 length:length-4];        }    }    if(ppsData!=nil&&spsData!=nil){    const uint8_t * const parameterSetPointers[2] = { (const uint8_t*)[spsData bytes], (const uint8_t*)[ppsData bytes] };     const size_t parameterSetSizes[2] = { spsData.length, ppsData.length };    CMVideoFormatDescriptionRef formatDesc = NULL;        //使用CMVideoFormatDescriptionCreateFromH264ParameterSets函数来构建CMVideoFormatDescriptionRef    OSStatus formatCreateResult = CMVideoFormatDescriptionCreateFromH264ParameterSets(kCFAllocatorDefault, 2, parameterSetPointers, parameterSetSizes, 4, &formatDesc);        if (formatCreateResult == noErr) {            videoFormatDescription = formatDesc;            if (decompressionSession == NULL ||                VTDecompressionSessionCanAcceptFormatDescription(decompressionSession, formatDesc) == NO) {                [self createDecompSession];            }        }    }    if ((naluType == 1 || naluType == 5) && videoFormatDescription) {        uint32_t dataLength32 = htonl(length - 4);        memcpy (pFrameData, &dataLength32, sizeof(uint32_t));        NSLog(@"%lu",sizeof(pFromeData));        CMBlockBufferRef blockBuffer = NULL;        //使用CMBlockBufferCreateWithMemoryBlock接口构造CMBlockBufferRef;        OSStatus status = CMBlockBufferCreateWithMemoryBlock(NULL, pFrameData, length, kCFAllocatorNull, NULL, 0, length, kCMBlockBufferAlwaysCopyDataFlag, &blockBuffer);        NSLog(@"%lu",sizeof(blockBuffer));        if (status == kCMBlockBufferNoErr) {            const size_t sampleSize =  CMBlockBufferGetDataLength(blockBuffer);//length; //            CMSampleBufferRef sampBuf = NULL;//            status = CMSampleBufferCreate(kCFAllocatorDefault,//                                          blockBuffer,//                                          true,//                                          NULL,//                                          NULL,//                                          videoFormatDescription,//                                          1,//                                          0,//                                          NULL,//                                          1,//                                          &sampleSize,//                                          &sampBuf);           status = CMSampleBufferCreateReady(kCFAllocatorDefault,                                      blockBuffer,                                      videoFormatDescription,                                      1, 0, NULL, 1, &sampleSize,                                      &sampBuf);            if (status == noErr) {                // 然后根据获取到的buffer画到AVSampleBufferPlayerLayer上即可               // NSLog(@"decode success");                /*                 将CMSampleBuffer数据使用VTDecompressionSessionDecodeFrame接口解码成CVPixelBufferRef数据:                 */                //NSLog(@"%ld",CMSampleBufferGetDataBuffer(sampBuf));                CVPixelBufferRef outputPixelBuffer = NULL;                VTDecodeFrameFlags flags = 0;// kVTDecodeFrame_EnableTemporalProcessing;                VTDecodeInfoFlags flagOut =  0;//kVTDecodeInfo_ImageBufferModifiable;                //将CMSampleBuffer数据使用VTDecompressionSessionDecodeFrame接口解码成CVPixelBufferRef数据:               OSStatus decodeStatus = VTDecompressionSessionDecodeFrame(decompressionSession,                                                  sampBuf,                                                  flags,                                                  &outputPixelBuffer,                                                  &flagOut);                if(decodeStatus == kVTInvalidSessionErr) {                    NSLog(@"IOS8VT: Invalid session, reset decoder session");                } else if(decodeStatus == kVTVideoDecoderBadDataErr) {                    NSLog(@"IOS8VT: decode failed status=%d(Bad data)", decodeStatus);                } else if(decodeStatus != noErr) {                    NSLog(@"IOS8VT: decode failed status=%d ", decodeStatus);                }                if (decodeStatus==noErr) {                    NSLog(@"decode success--------");                }                //将CVPixelBufferRef数据转换成UIImage并显示                CIImage *ciImage = [CIImage imageWithCVPixelBuffer:outputPixelBuffer];                CIContext *temporaryContext = [CIContext contextWithOptions:nil];//required                CGImageRef videoImage = [temporaryContext                                         createCGImage:ciImage                                         fromRect:CGRectMake(0, 0,                                                             CVPixelBufferGetWidth(outputPixelBuffer),                                                             CVPixelBufferGetHeight(outputPixelBuffer))];//required                UIImage *uiImage = [UIImage imageWithCGImage:videoImage];               // NSLog(@"%@",uiImage);                CGImageRelease(videoImage);            }        }    }}