转载: iOS音视频实时采集硬件编码
原文地址：https://blog.csdn.net/u011518723/article/details/49248467 我的demo地址：https://github.com/weiman152/LiveRecordDemo。 其中的swift版的viewcontroller是视频采集部分，供参考。 OC部分包括了音视频的采集以及编码。 感谢作者的分享，下面是原文内容： 使用 AVCaptureSession进行实时采集音视频 通过AVCaptureVideoDataOutputSampleBufferDelegate获取到音视频buffer数据 分别对音视频原始数据进行编码 传输 // // ViewController.h // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import <UIKit/UIKit.h> #import <AVFoundation/AVFoundation.h> #import "AACEncoder.h" #import "H264Encoder.h" @interface ViewController : UIViewController <AVCaptureVideoDataOutputSampleBufferDelegate,AVCaptureAudioDataOutputSampleBufferDelegate,H264EncoderDelegate> @end // // ViewController.m // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import "ViewController.h" #define CAPTURE_FRAMES_PER_SECOND 20 #define SAMPLE_RATE 44100 #define VideoWidth 480 #define VideoHeight 640 @interface ViewController () { UIButton *startBtn; bool startCalled; H264Encoder *h264Encoder; AACEncoder *aacEncoder; AVCaptureSession *captureSession; dispatch_queue_t _audioQueue; AVCaptureConnection* _audioConnection; AVCaptureConnection* _videoConnection; NSMutableData *_data; NSString *h264File; NSFileHandle *fileHandle; } @end @implementation ViewController - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. startCalled = true; _data = [[NSMutableData alloc] init]; captureSession = [[AVCaptureSession alloc] init]; [self initStartBtn]; } #pragma mark #pragma mark - 设置音频 capture - (void) setupAudioCapture { aacEncoder = [[AACEncoder alloc] init]; // create capture device with video input /* * Create audio connection */ AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio]; NSError *error = nil; AVCaptureDeviceInput *audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:&error]; if (error) { NSLog(@"Error getting audio input device: %@", error.description); } if ([captureSession canAddInput:audioInput]) { [captureSession addInput:audioInput]; } _audioQueue = dispatch_queue_create("Audio Capture Queue", DISPATCH_QUEUE_SERIAL); AVCaptureAudioDataOutput* audioOutput = [[AVCaptureAudioDataOutput alloc] init]; [audioOutput setSampleBufferDelegate:self queue:_audioQueue]; if ([captureSession canAddOutput:audioOutput]) { [captureSession addOutput:audioOutput]; } _audioConnection = [audioOutput connectionWithMediaType:AVMediaTypeAudio]; } - (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position { NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo]; for ( AVCaptureDevice *device in devices ) if ( device.position == position ) return device; return nil; } #pragma mark #pragma mark - 设置视频 capture - (void) setupVideoCaprure { h264Encoder = [H264Encoder alloc]; [h264Encoder initWithConfiguration]; NSError *deviceError; AVCaptureDevice *cameraDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; // cameraDevice = [self cameraWithPosition:AVCaptureDevicePositionBack]; // cameraDevice.position = AVCaptureDevicePositionBack; AVCaptureDeviceInput *inputDevice = [AVCaptureDeviceInput deviceInputWithDevice:cameraDevice error:&deviceError]; // make output device AVCaptureVideoDataOutput *outputDevice = [[AVCaptureVideoDataOutput alloc] init]; NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey; NSNumber* val = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange]; NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:val forKey:key]; NSError *error; [cameraDevice lockForConfiguration:&error]; if (error == nil) { NSLog(@"cameraDevice.activeFormat.videoSupportedFrameRateRanges IS %@",[cameraDevice.activeFormat.videoSupportedFrameRateRanges objectAtIndex:0]); if (cameraDevice.activeFormat.videoSupportedFrameRateRanges){ [cameraDevice setActiveVideoMinFrameDuration:CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND)]; [cameraDevice setActiveVideoMaxFrameDuration:CMTimeMake(1, CAPTURE_FRAMES_PER_SECOND)]; } }else{ // handle error2 } [cameraDevice unlockForConfiguration]; // Start the session running to start the flow of data outputDevice.videoSettings = videoSettings; [outputDevice setSampleBufferDelegate:self queue:dispatch_get_main_queue()]; // initialize capture session if ([captureSession canAddInput:inputDevice]) { [captureSession addInput:inputDevice]; } if ([captureSession canAddOutput:outputDevice]) { [captureSession addOutput:outputDevice]; } // begin configuration for the AVCaptureSession [captureSession beginConfiguration]; // picture resolution [captureSession setSessionPreset:[NSString stringWithString:AVCaptureSessionPreset640x480]]; _videoConnection = [outputDevice connectionWithMediaType:AVMediaTypeVideo]; //Set landscape (if required) if ([_videoConnection isVideoOrientationSupported]) { AVCaptureVideoOrientation orientation = AVCaptureVideoOrientationLandscapeRight; //<<<<<SET VIDEO ORIENTATION IF LANDSCAPE [_videoConnection setVideoOrientation:orientation]; } // make preview layer and add so that camera is view is displayed on screen NSFileManager *fileManager = [NSFileManager defaultManager]; NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; h264File = [documentsDirectory stringByAppendingPathComponent:@"test.h264"]; [fileManager removeItemAtPath:h264File error:nil]; [fileManager createFileAtPath:h264File contents:nil attributes:nil]; // Open the file using POSIX as this is anyway a test application //fd = open([h264File UTF8String], O_RDWR); fileHandle = [NSFileHandle fileHandleForWritingAtPath:h264File]; [h264Encoder initEncode:VideoWidth height:VideoHeight]; h264Encoder.delegate = self; } #pragma mark #pragma mark - sampleBuffer 数据 -(void) captureOutput:(AVCaptureOutput*)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection*)connection { CMTime pts = CMSampleBufferGetPresentationTimeStamp(sampleBuffer); double dPTS = (double)(pts.value) / pts.timescale; // NSLog(@"DPTS is %f",dPTS); if (connection == _videoConnection) { [h264Encoder encode:sampleBuffer]; } else if (connection == _audioConnection) { [aacEncoder encodeSampleBuffer:sampleBuffer completionBlock:^(NSData *encodedData, NSError *error) { if (encodedData) { NSLog(@"Audio data (%lu): %@", (unsigned long)encodedData.length, encodedData.description); #pragma mark #pragma mark - 音频数据(encodedData) [_data appendData:encodedData]; } else { NSLog(@"Error encoding AAC: %@", error); } }]; } } #pragma mark #pragma mark - 视频 sps 和 pps - (void)gotSpsPps:(NSData*)sps pps:(NSData*)pps { const char bytes[] = "\x00\x00\x00\x01"; size_t length = (sizeof bytes) - 1; //string literals have implicit trailing '\0' NSData *ByteHeader = [NSData dataWithBytes:bytes length:length]; [fileHandle writeData:ByteHeader]; [fileHandle writeData:sps]; [fileHandle writeData:ByteHeader]; [fileHandle writeData:pps]; } #pragma mark #pragma mark - 视频数据回调 - (void)gotEncodedData:(NSData*)data isKeyFrame:(BOOL)isKeyFrame { NSLog(@"Video data (%lu): %@", (unsigned long)data.length, data.description); if (fileHandle != NULL) { const char bytes[] = "\x00\x00\x00\x01"; size_t length = (sizeof bytes) - 1; //string literals have implicit trailing '\0' NSData *ByteHeader = [NSData dataWithBytes:bytes length:length]; #pragma mark #pragma mark - 视频数据(data) [fileHandle writeData:ByteHeader]; //[fileHandle writeData:UnitHeader]; [fileHandle writeData:data]; } } #pragma mark #pragma mark - 录制 - (void)startBtnClicked { if (startCalled) { [self startCamera]; startCalled = false; [startBtn setTitle:@"Stop" forState:UIControlStateNormal]; } else { [startBtn setTitle:@"Start" forState:UIControlStateNormal]; startCalled = true; [self stopCarmera]; } } - (void) startCamera { [self setupAudioCapture]; [self setupVideoCaprure]; [captureSession commitConfiguration]; [captureSession startRunning]; } - (void) stopCarmera { [h264Encoder End]; [captureSession stopRunning]; //close(fd); [fileHandle closeFile]; fileHandle = NULL; // 获取程序Documents目录路径 NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES); NSString *documentsDirectory = [paths objectAtIndex:0]; NSMutableString * path = [[NSMutableString alloc]initWithString:documentsDirectory]; [path appendString:@"/AACFile"]; [_data writeToFile:path atomically:YES]; } - (void)initStartBtn { startBtn = [UIButton buttonWithType:UIButtonTypeCustom]; startBtn.frame = CGRectMake(0, 0, 100, 30); startBtn.center = self.view.center; [startBtn addTarget:self action:@selector(startBtnClicked) forControlEvents:UIControlEventTouchUpInside]; [startBtn setTitle:@"Start" forState:UIControlStateNormal]; [startBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal]; [self.view addSubview:startBtn]; } - (void)didReceiveMemoryWarning { [super didReceiveMemoryWarning]; // Dispose of any resources that can be recreated. } @end // // AACEncoder.h // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import <Foundation/Foundation.h> #import <AVFoundation/AVFoundation.h> #import <AudioToolbox/AudioToolbox.h> @interface AACEncoder : NSObject @property (nonatomic) dispatch_queue_t encoderQueue; @property (nonatomic) dispatch_queue_t callbackQueue; - (void) encodeSampleBuffer:(CMSampleBufferRef)sampleBuffer completionBlock:(void (^)(NSData *encodedData, NSError* error))completionBlock; @end // // AACEncoder.m // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import "AACEncoder.h" @interface AACEncoder() @property (nonatomic) AudioConverterRef audioConverter; @property (nonatomic) uint8_t *aacBuffer; @property (nonatomic) NSUInteger aacBufferSize; @property (nonatomic) char *pcmBuffer; @property (nonatomic) size_t pcmBufferSize; @end @implementation AACEncoder - (void) dealloc { AudioConverterDispose(_audioConverter); free(_aacBuffer); } - (id) init { if (self = [super init]) { _encoderQueue = dispatch_queue_create("AAC Encoder Queue", DISPATCH_QUEUE_SERIAL); _callbackQueue = dispatch_queue_create("AAC Encoder Callback Queue", DISPATCH_QUEUE_SERIAL); _audioConverter = NULL; _pcmBufferSize = 0; _pcmBuffer = NULL; _aacBufferSize = 1024; _aacBuffer = malloc(_aacBufferSize * sizeof(uint8_t)); memset(_aacBuffer, 0, _aacBufferSize); } return self; } - (void) setupEncoderFromSampleBuffer:(CMSampleBufferRef)sampleBuffer { AudioStreamBasicDescription inAudioStreamBasicDescription = *CMAudioFormatDescriptionGetStreamBasicDescription((CMAudioFormatDescriptionRef)CMSampleBufferGetFormatDescription(sampleBuffer)); AudioStreamBasicDescription outAudioStreamBasicDescription = {0}; // Always initialize the fields of a new audio stream basic description structure to zero, as shown here: ... outAudioStreamBasicDescription.mSampleRate = inAudioStreamBasicDescription.mSampleRate; // The number of frames per second of the data in the stream, when the stream is played at normal speed. For compressed formats, this field indicates the number of frames per second of equivalent decompressed data. The mSampleRate field must be nonzero, except when this structure is used in a listing of supported formats (see “kAudioStreamAnyRate”). outAudioStreamBasicDescription.mFormatID = kAudioFormatMPEG4AAC; // kAudioFormatMPEG4AAC_HE does not work. Can't find `AudioClassDescription`. `mFormatFlags` is set to 0.' outAudioStreamBasicDescription.mFormatFlags = kMPEG4Object_AAC_LC; // Format-specific flags to specify details of the format. Set to 0 to indicate no format flags. See “Audio Data Format Identifiers” for the flags that apply to each format. outAudioStreamBasicDescription.mBytesPerPacket = 0; // The number of bytes in a packet of audio data. To indicate variable packet size, set this field to 0. For a format that uses variable packet size, specify the size of each packet using an AudioStreamPacketDescription structure. outAudioStreamBasicDescription.mFramesPerPacket = 1024; // The number of frames in a packet of audio data. For uncompressed audio, the value is 1. For variable bit-rate formats, the value is a larger fixed number, such as 1024 for AAC. For formats with a variable number of frames per packet, such as Ogg Vorbis, set this field to 0. outAudioStreamBasicDescription.mBytesPerFrame = 0; // The number of bytes from the start of one frame to the start of the next frame in an audio buffer. Set this field to 0 for compressed formats. ... outAudioStreamBasicDescription.mChannelsPerFrame = 1; // The number of channels in each frame of audio data. This value must be nonzero. outAudioStreamBasicDescription.mBitsPerChannel = 0; // ... Set this field to 0 for compressed formats. outAudioStreamBasicDescription.mReserved = 0; // Pads the structure out to force an even 8-byte alignment. Must be set to 0. AudioClassDescription *description = [self getAudioClassDescriptionWithType:kAudioFormatMPEG4AAC fromManufacturer:kAppleSoftwareAudioCodecManufacturer]; OSStatus status = AudioConverterNewSpecific(&inAudioStreamBasicDescription, &outAudioStreamBasicDescription, 1, description, &_audioConverter); if (status != 0) { NSLog(@"setup converter: %d", (int)status); } } - (AudioClassDescription *)getAudioClassDescriptionWithType:(UInt32)type fromManufacturer:(UInt32)manufacturer { static AudioClassDescription desc; UInt32 encoderSpecifier = type; OSStatus st; UInt32 size; st = AudioFormatGetPropertyInfo(kAudioFormatProperty_Encoders, sizeof(encoderSpecifier), &encoderSpecifier, &size); if (st) { NSLog(@"error getting audio format propery info: %d", (int)(st)); return nil; } unsigned int count = size / sizeof(AudioClassDescription); AudioClassDescription descriptions[count]; st = AudioFormatGetProperty(kAudioFormatProperty_Encoders, sizeof(encoderSpecifier), &encoderSpecifier, &size, descriptions); if (st) { NSLog(@"error getting audio format propery: %d", (int)(st)); return nil; } for (unsigned int i = 0; i < count; i++) { if ((type == descriptions[i].mSubType) && (manufacturer == descriptions[i].mManufacturer)) { memcpy(&desc, &(descriptions[i]), sizeof(desc)); return &desc; } } return nil; } static OSStatus inInputDataProc(AudioConverterRef inAudioConverter, UInt32 *ioNumberDataPackets, AudioBufferList *ioData, AudioStreamPacketDescription **outDataPacketDescription, void *inUserData) { AACEncoder *encoder = (__bridge AACEncoder *)(inUserData); UInt32 requestedPackets = *ioNumberDataPackets; //NSLog(@"Number of packets requested: %d", (unsigned int)requestedPackets); size_t copiedSamples = [encoder copyPCMSamplesIntoBuffer:ioData]; if (copiedSamples < requestedPackets) { //NSLog(@"PCM buffer isn't full enough!"); *ioNumberDataPackets = 0; return -1; } *ioNumberDataPackets = 1; //NSLog(@"Copied %zu samples into ioData", copiedSamples); return noErr; } - (size_t) copyPCMSamplesIntoBuffer:(AudioBufferList*)ioData { size_t originalBufferSize = _pcmBufferSize; if (!originalBufferSize) { return 0; } ioData->mBuffers[0].mData = _pcmBuffer; ioData->mBuffers[0].mDataByteSize = _pcmBufferSize; _pcmBuffer = NULL; _pcmBufferSize = 0; return originalBufferSize; } - (void) encodeSampleBuffer:(CMSampleBufferRef)sampleBuffer completionBlock:(void (^)(NSData * encodedData, NSError* error))completionBlock { CFRetain(sampleBuffer); dispatch_async(_encoderQueue, ^{ if (!_audioConverter) { [self setupEncoderFromSampleBuffer:sampleBuffer]; } CMBlockBufferRef blockBuffer = CMSampleBufferGetDataBuffer(sampleBuffer); CFRetain(blockBuffer); OSStatus status = CMBlockBufferGetDataPointer(blockBuffer, 0, NULL, &_pcmBufferSize, &_pcmBuffer); NSError *error = nil; if (status != kCMBlockBufferNoErr) { error = [NSError errorWithDomain:NSOSStatusErrorDomain code:status userInfo:nil]; } //NSLog(@"PCM Buffer Size: %zu", _pcmBufferSize); memset(_aacBuffer, 0, _aacBufferSize); AudioBufferList outAudioBufferList = {0}; outAudioBufferList.mNumberBuffers = 1; outAudioBufferList.mBuffers[0].mNumberChannels = 1; outAudioBufferList.mBuffers[0].mDataByteSize = _aacBufferSize; outAudioBufferList.mBuffers[0].mData = _aacBuffer; AudioStreamPacketDescription *outPacketDescription = NULL; UInt32 ioOutputDataPacketSize = 1; status = AudioConverterFillComplexBuffer(_audioConverter, inInputDataProc, (__bridge void *)(self), &ioOutputDataPacketSize, &outAudioBufferList, outPacketDescription); //NSLog(@"ioOutputDataPacketSize: %d", (unsigned int)ioOutputDataPacketSize); NSData *data = nil; if (status == 0) { NSData *rawAAC = [NSData dataWithBytes:outAudioBufferList.mBuffers[0].mData length:outAudioBufferList.mBuffers[0].mDataByteSize]; NSData *adtsHeader = [self adtsDataForPacketLength:rawAAC.length]; NSMutableData *fullData = [NSMutableData dataWithData:adtsHeader]; [fullData appendData:rawAAC]; data = fullData; } else { error = [NSError errorWithDomain:NSOSStatusErrorDomain code:status userInfo:nil]; } if (completionBlock) { dispatch_async(_callbackQueue, ^{ completionBlock(data, error); }); } CFRelease(sampleBuffer); CFRelease(blockBuffer); }); } /** * Add ADTS header at the beginning of each and every AAC packet. * This is needed as MediaCodec encoder generates a packet of raw * AAC data. * * Note the packetLen must count in the ADTS header itself. * See: http://wiki.multimedia.cx/index.php?title=ADTS * Also: http://wiki.multimedia.cx/index.php?title=MPEG-4_Audio#Channel_Configurations **/ - (NSData*) adtsDataForPacketLength:(NSUInteger)packetLength { int adtsLength = 7; char *packet = malloc(sizeof(char) * adtsLength); // Variables Recycled by addADTStoPacket int profile = 2; //AAC LC //39=MediaCodecInfo.CodecProfileLevel.AACObjectELD; int freqIdx = 4; //44.1KHz int chanCfg = 1; //MPEG-4 Audio Channel Configuration. 1 Channel front-center NSUInteger fullLength = adtsLength + packetLength; // fill in ADTS data packet[0] = (char)0xFF; // 11111111 = syncword packet[1] = (char)0xF9; // 1111 1 00 1 = syncword MPEG-2 Layer CRC packet[2] = (char)(((profile-1)<<6) + (freqIdx<<2) +(chanCfg>>2)); packet[3] = (char)(((chanCfg&3)<<6) + (fullLength>>11)); packet[4] = (char)((fullLength&0x7FF) >> 3); packet[5] = (char)(((fullLength&7)<<5) + 0x1F); packet[6] = (char)0xFC; NSData *data = [NSData dataWithBytesNoCopy:packet length:adtsLength freeWhenDone:YES]; return data; } @end // // H264Encoder.h // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import <Foundation/Foundation.h> #import <AVFoundation/AVFoundation.h> #import <VideoToolbox/VideoToolbox.h> @protocol H264EncoderDelegate <NSObject> - (void)gotSpsPps:(NSData*)sps pps:(NSData*)pps; - (void)gotEncodedData:(NSData*)data isKeyFrame:(BOOL)isKeyFrame; @end @interface H264Encoder : NSObject - (void) initWithConfiguration; - (void) start:(int)width height:(int)height; - (void) initEncode:(int)width height:(int)height; - (void) encode:(CMSampleBufferRef )sampleBuffer; - (void) End; @property (weak, nonatomic) NSString *error; @property (weak, nonatomic) id<H264EncoderDelegate> delegate; @end // // H264Encoder.m // H264AACEncode // // Created by ZhangWen on 15/10/14. // Copyright © 2015年 Zhangwen. All rights reserved. // #import "H264Encoder.h" @implementation H264Encoder { NSString * yuvFile; VTCompressionSessionRef EncodingSession; dispatch_queue_t aQueue; CMFormatDescriptionRef format; CMSampleTimingInfo * timingInfo; BOOL initialized; int frameCount; NSData *sps; NSData *pps; } @synthesize error; - (void) initWithConfiguration { EncodingSession = nil; initialized = true; aQueue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0); frameCount = 0; sps = NULL; pps = NULL; } void didCompressH264(void *outputCallbackRefCon, void *sourceFrameRefCon, OSStatus status, VTEncodeInfoFlags infoFlags, CMSampleBufferRef sampleBuffer ) { // NSLog(@"didCompressH264 called with status %d infoFlags %d", (int)status, (int)infoFlags); if (status != 0) return; if (!CMSampleBufferDataIsReady(sampleBuffer)) { NSLog(@"didCompressH264 data is not ready "); return; } H264Encoder* encoder = (__bridge H264Encoder*)outputCallbackRefCon; // Check if we have got a key frame first bool keyframe = !CFDictionaryContainsKey( (CFArrayGetValueAtIndex(CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, true), 0)), kCMSampleAttachmentKey_NotSync); if (keyframe) { CMFormatDescriptionRef format = CMSampleBufferGetFormatDescription(sampleBuffer); // CFDictionaryRef extensionDict = CMFormatDescriptionGetExtensions(format); // Get the extensions // From the extensions get the dictionary with key "SampleDescriptionExtensionAtoms" // From the dict, get the value for the key "avcC" size_t sparameterSetSize, sparameterSetCount; const uint8_t *sparameterSet; OSStatus statusCode = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(format, 0, &sparameterSet, &sparameterSetSize, &sparameterSetCount, 0 ); if (statusCode == noErr) { // Found sps and now check for pps size_t pparameterSetSize, pparameterSetCount; const uint8_t *pparameterSet; OSStatus statusCode = CMVideoFormatDescriptionGetH264ParameterSetAtIndex(format, 1, &pparameterSet, &pparameterSetSize, &pparameterSetCount, 0 ); if (statusCode == noErr) { // Found pps encoder->sps = [NSData dataWithBytes:sparameterSet length:sparameterSetSize]; encoder->pps = [NSData dataWithBytes:pparameterSet length:pparameterSetSize]; if (encoder->_delegate) { [encoder->_delegate gotSpsPps:encoder->sps pps:encoder->pps]; } } } } CMBlockBufferRef dataBuffer = CMSampleBufferGetDataBuffer(sampleBuffer); size_t length, totalLength; char *dataPointer; OSStatus statusCodeRet = CMBlockBufferGetDataPointer(dataBuffer, 0, &length, &totalLength, &dataPointer); if (statusCodeRet == noErr) { size_t bufferOffset = 0; static const int AVCCHeaderLength = 4; while (bufferOffset < totalLength - AVCCHeaderLength) { // Read the NAL unit length uint32_t NALUnitLength = 0; memcpy(&NALUnitLength, dataPointer + bufferOffset, AVCCHeaderLength); // Convert the length value from Big-endian to Little-endian NALUnitLength = CFSwapInt32BigToHost(NALUnitLength); NSData* data = [[NSData alloc] initWithBytes:(dataPointer + bufferOffset + AVCCHeaderLength) length:NALUnitLength]; [encoder->_delegate gotEncodedData:data isKeyFrame:keyframe]; // Move to the next NAL unit in the block buffer bufferOffset += AVCCHeaderLength + NALUnitLength; } } } - (void) start:(int)width height:(int)height { int frameSize = (width * height * 1.5); if (!initialized) { NSLog(@"H264: Not initialized"); error = @"H264: Not initialized"; return; } dispatch_sync(aQueue, ^{ // For testing out the logic, lets read from a file and then send it to encoder to create h264 stream // Create the compression session OSStatus status = VTCompressionSessionCreate(NULL, width, height, kCMVideoCodecType_H264, NULL, NULL, NULL, didCompressH264, (__bridge void *)(self), &EncodingSession); NSLog(@"H264: VTCompressionSessionCreate %d", (int)status); if (status != 0) { NSLog(@"H264: Unable to create a H264 session"); error = @"H264: Unable to create a H264 session"; return ; } // Set the properties VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_RealTime, kCFBooleanTrue); VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_AllowFrameReordering, kCFBooleanFalse); VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_MaxKeyFrameInterval, 240); VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_ProfileLevel, kVTProfileLevel_H264_High_AutoLevel); // Tell the encoder to start encoding VTCompressionSessionPrepareToEncodeFrames(EncodingSession); // Start reading from the file and copy it to the buffer // Open the file using POSIX as this is anyway a test application int fd = open([yuvFile UTF8String], O_RDONLY); if (fd == -1) { NSLog(@"H264: Unable to open the file"); error = @"H264: Unable to open the file"; return ; } NSMutableData* theData = [[NSMutableData alloc] initWithLength:frameSize] ; NSUInteger actualBytes = frameSize; while (actualBytes > 0) { void* buffer = [theData mutableBytes]; NSUInteger bufferSize = [theData length]; actualBytes = read(fd, buffer, bufferSize); if (actualBytes < frameSize) [theData setLength:actualBytes]; frameCount++; // Create a CM Block buffer out of this data CMBlockBufferRef BlockBuffer = NULL; OSStatus status = CMBlockBufferCreateWithMemoryBlock(NULL, buffer, actualBytes,kCFAllocatorNull, NULL, 0, actualBytes, kCMBlockBufferAlwaysCopyDataFlag, &BlockBuffer); // Check for error if (status != noErr) { NSLog(@"H264: CMBlockBufferCreateWithMemoryBlock failed with %d", (int)status); error = @"H264: CMBlockBufferCreateWithMemoryBlock failed "; return ; } // Create a CM Sample Buffer CMSampleBufferRef sampleBuffer = NULL; CMFormatDescriptionRef formatDescription; CMFormatDescriptionCreate ( kCFAllocatorDefault, // Allocator kCMMediaType_Video, 'I420', NULL, &formatDescription ); CMSampleTimingInfo sampleTimingInfo = {CMTimeMake(1, 300)}; OSStatus statusCode = CMSampleBufferCreate(kCFAllocatorDefault, BlockBuffer, YES, NULL, NULL, formatDescription, 1, 1, &sampleTimingInfo, 0, NULL, &sampleBuffer); // Check for error if (statusCode != noErr) { NSLog(@"H264: CMSampleBufferCreate failed with %d", (int)statusCode); error = @"H264: CMSampleBufferCreate failed "; return; } CFRelease(BlockBuffer); BlockBuffer = NULL; // Get the CV Image buffer CVImageBufferRef imageBuffer = (CVImageBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer); // Create properties CMTime presentationTimeStamp = CMTimeMake(frameCount, 300); //CMTime duration = CMTimeMake(1, DURATION); VTEncodeInfoFlags flags; // Pass it to the encoder statusCode = VTCompressionSessionEncodeFrame(EncodingSession, imageBuffer, presentationTimeStamp, kCMTimeInvalid, NULL, NULL, &flags); // Check for error if (statusCode != noErr) { NSLog(@"H264: VTCompressionSessionEncodeFrame failed with %d", (int)statusCode); error = @"H264: VTCompressionSessionEncodeFrame failed "; // End the session VTCompressionSessionInvalidate(EncodingSession); CFRelease(EncodingSession); EncodingSession = NULL; error = NULL; return; } // NSLog(@"H264: VTCompressionSessionEncodeFrame Success"); } // Mark the completion VTCompressionSessionCompleteFrames(EncodingSession, kCMTimeInvalid); // End the session VTCompressionSessionInvalidate(EncodingSession); CFRelease(EncodingSession); EncodingSession = NULL; error = NULL; close(fd); }); } - (void) initEncode:(int)width height:(int)height { dispatch_sync(aQueue, ^{ // For testing out the logic, lets read from a file and then send it to encoder to create h264 stream // Create the compression session OSStatus status = VTCompressionSessionCreate(NULL, width, height, kCMVideoCodecType_H264, NULL, NULL, NULL, didCompressH264, (__bridge void *)(self), &EncodingSession); NSLog(@"H264: VTCompressionSessionCreate %d", (int)status); if (status != 0) { NSLog(@"H264: Unable to create a H264 session"); error = @"H264: Unable to create a H264 session"; return ; } // Set the properties VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_RealTime, kCFBooleanTrue); VTSessionSetProperty(EncodingSession, kVTCompressionPropertyKey_ProfileLevel, kVTProfileLevel_H264_Main_AutoLevel); // Tell the encoder to start encoding VTCompressionSessionPrepareToEncodeFrames(EncodingSession); }); } - (void) encode:(CMSampleBufferRef )sampleBuffer { dispatch_sync(aQueue, ^{ frameCount++; // Get the CV Image buffer CVImageBufferRef imageBuffer = (CVImageBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer); // Create properties CMTime presentationTimeStamp = CMTimeMake(frameCount, 1000); //CMTime duration = CMTimeMake(1, DURATION); VTEncodeInfoFlags flags; // Pass it to the encoder OSStatus statusCode = VTCompressionSessionEncodeFrame(EncodingSession, imageBuffer, presentationTimeStamp, kCMTimeInvalid, NULL, NULL, &flags); // Check for error if (statusCode != noErr) { NSLog(@"H264: VTCompressionSessionEncodeFrame failed with %d", (int)statusCode); error = @"H264: VTCompressionSessionEncodeFrame failed "; // End the session VTCompressionSessionInvalidate(EncodingSession); CFRelease(EncodingSession); EncodingSession = NULL; error = NULL; return; } // NSLog(@"H264: VTCompressionSessionEncodeFrame Success"); }); } - (void) End { // Mark the completion VTCompressionSessionCompleteFrames(EncodingSession, kCMTimeInvalid); // End the session VTCompressionSessionInvalidate(EncodingSession); CFRelease(EncodingSession); EncodingSession = NULL; error = NULL; } @end
