轉載:iOS音視訊實時採集硬體編碼
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是視訊採集部分，供參考。
OC部分包括了音視訊的採集以及編碼。
感謝作者的分享，下面是原文內容：
使用 AVCaptureSession進行實時採集音視訊
通過AVCaptureVideoDataOutputSampleBufferDelegate獲取到音視訊buffer資料
分別對音視訊原始資料進行編碼
傳輸
//
// 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 - 設定音訊 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 - 設定視訊 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 資料
-(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 - 音訊資料(encodedData)
[_data appendData:encodedData];
} else {
NSLog(@"Error encoding AAC: %@", error);
}
}];
}
}
#pragma mark
#pragma mark - 視訊 sps 和 pps
- (void)gotSpsPps:(NSData*)sps pps:(NSData*)pps
{
const char bytes[] = "x00x00x00x01";
size_t length = (sizeof bytes) - 1; //string literals have implicit trailing ` `
NSData *ByteHeader = [NSData dataWithBytes:bytes length:length];
[fileHandle writeData:ByteHeader];
[fileHandle writeData:sps];
[fileHandle writeData:ByteHeader];
[fileHandle writeData:pps];
}
#pragma mark
#pragma mark - 視訊資料回撥
- (void)gotEncodedData:(NSData*)data isKeyFrame:(BOOL)isKeyFrame
{
NSLog(@"Video data (%lu): %@", (unsigned long)data.length, data.description);
if (fileHandle != NULL)
{
const char bytes[] = "x00x00x00x01";
size_t length = (sizeof bytes) - 1; //string literals have implicit trailing ` `
NSData *ByteHeader = [NSData dataWithBytes:bytes length:length];
#pragma mark
#pragma mark - 視訊資料(data)
[fileHandle writeData:ByteHeader];
//[fileHandle writeData:UnitHeader];
[fileHandle writeData:data];
}
}
#pragma mark
#pragma mark - 錄製
- (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;
// 獲取程式Documents目錄路徑
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
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