The following code works, You might have a try. Good luck!///Rotate CMSampleBufferRef to landscape- (void)dealWithSampleBuffer:(CMSampleBufferRef)buffer { CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(buffer); CIImage *ciimage = [CIImage imageWithCVPixelBuffer:pixelBuffer]; size_t width = CVPixelBufferGetWidth(pixelBuffer); size_t height = CVPixelBufferGetHeight(pixelBuffer); CFStringRef RPVideoSampleOrientationKeyRef = (__bridge CFStringRef)RPVideoSampleOrientationKey; NSNumber *orientation = (NSNumber *)CMGetAttachment(buffer, RPVideoSampleOrientationKeyRef,NULL); NSLog(@"info:%@", orientation); CGImagePropertyOrientation cgOrientation = kCGImagePropertyOrientationUp; switch (orientation.unsignedIntValue) { case kCGImagePropertyOrientationUp: cgOrientation = kCGImagePropertyOrientationUp; self.landscape = NO; break; case kCGImagePropertyOrientationRight: cgOrientation = kCGImagePropertyOrientationLeft; width = CVPixelBufferGetHeight(pixelBuffer); height = CVPixelBufferGetWidth(pixelBuffer); self.landscape = YES; break; case kCGImagePropertyOrientationLeft: cgOrientation = kCGImagePropertyOrientationRight; width = CVPixelBufferGetHeight(pixelBuffer); height = CVPixelBufferGetWidth(pixelBuffer); self.landscape = YES; break; default: break; } if (self.lastOritation != orientation.unsignedIntValue) { //init ************ again, Adjust the width and height of the encoding// [self EndVideoToolBox];// [self initVideoToolBox]; NSLog(@"orientation changed"); self.lastOritation = orientation.unsignedIntValue; usleep(5*1000); return; } //Portrait, no need to rotate if (orientation.unsignedIntegerValue == kCGImagePropertyOrientationUp) { //encode buffer by ************// [self encode:buffer]; return ; } // roate ciimage CIImage *wImage = [ciimage imageByApplyingCGOrientation:cgOrientation]; CIImage *newImage = [wImage imageByApplyingTransform:CGAffineTransformMakeScale(0.5, 0.5)]; CVPixelBufferLockBaseAddress(pixelBuffer, 0); NSLog(@"sample width :%ld height :%ld",width,height) float scale = 1.0; CVPixelBufferRef newPixcelBuffer = nil; CVPixelBufferCreate(kCFAllocatorDefault, width * 0.5 * scale, height * 0.5 * scale, kCVPixelFormatType_32BGRA, nil, &newPixcelBuffer); if(!_cicontext) { _cicontext = [CIContext context]; } [_cicontext render:newImage toCVPixelBuffer:newPixcelBuffer]; CVPixelBufferUnlockBaseAddress(pixelBuffer, 0); CMVideoFormatDescriptionRef videoInfo = nil; CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, newPixcelBuffer, &videoInfo); CMTime duration = CMSampleBufferGetDuration(buffer); CMTime presentationTimeStamp = CMSampleBufferGetPresentationTimeStamp(buffer); CMTime decodeTimeStamp = CMSampleBufferGetDecodeTimeStamp(buffer); CMSampleTimingInfo sampleTimingInfo; sampleTimingInfo.duration = duration; sampleTimingInfo.presentationTimeStamp = presentationTimeStamp; sampleTimingInfo.decodeTimeStamp = decodeTimeStamp; // CMSampleBufferRef newSampleBuffer = nil; CMSampleBufferCreateForImageBuffer(kCFAllocatorMalloc, newPixcelBuffer, true, nil, nil, videoInfo, &sampleTimingInfo, &newSampleBuffer); //get a rotated CMSampleBufferRef with newSampleBuffer //encode newSampleBuffer by ************// [self encode:newSampleBuffer]; // release CVPixelBufferRelease(newPixcelBuffer); CFRelease(newSampleBuffer);}