iOS 基于实时音视频 SDK 实现屏幕共享功能——2
这里的核心思想是拿到屏幕共享的数据之后，先进行压缩，当压缩完成后会通过回调上报给当前类。既而通过 clientSend 方法，发给主 App。发给主 App 的数据中自定义了一个头部，头部添加了一个前缀和一个每次发送字节的长度，当接收端收到数据包后解析即可。
- (void)clientSend:(NSData *)data {
//data length
NSUInteger dataLength = data.length;
// data header struct
DataHeader dataH;
memset((void *)&dataH, 0, sizeof(dataH));
// pre
PreHeader preH;
memset((void *)&preH, 0, sizeof(preH));
preH.pre[0] = '&';
preH.dataLength = dataLength;
dataH.preH = preH;
// buffer
int headerlength = sizeof(dataH);
int totalLength = dataLength + headerlength;
// srcbuffer
Byte *src = (Byte *)[data bytes];
// send buffer
char *buffer = (char *)malloc(totalLength * sizeof(char));
memcpy(buffer, &dataH, headerlength);
memcpy(buffer + headerlength, src, dataLength);
// to send
[self sendBytes:buffer length:totalLength];
free(buffer);
}1.4 接收屏幕共享数据
//
// RongRTCServerSocket.m
// SealRTC
//
// Created by Sun on 2020/5/7.
// Copyright © 2020 RongCloud. All rights reserved.
//
#import "RongRTCServerSocket.h"
#import <arpa/inet.h>
#import <netdb.h>
#import <sys/types.h>
#import <sys/socket.h>
#import <ifaddrs.h>
#import <UIKit/UIKit.h>
#import "RongRTCThread.h"
#import "RongRTCSocketHeader.h"
#import "RongRTCVideoDecoder.h"
@interface RongRTCServerSocket() <RongRTCCodecProtocol>
{
pthread_mutex_t lock;
int _frameTime;
CMTime _lastPresentationTime;
Float64 _currentMediaTime;
Float64 _currentVideoTime;
dispatch_queue_t _frameQueue;
}
@property (nonatomic, assign) int acceptSocket;
/**
data length
*/
@property (nonatomic, assign) NSUInteger dataLength;
/**
timeData
*/
@property (nonatomic, strong) NSData *timeData;
/**
decoder queue
*/
@property (nonatomic, strong) dispatch_queue_t decoderQueue;
/**
decoder
*/
@property (nonatomic, strong) RongRTCVideoDecoder *decoder;
@end
@implementation RongRTCServerSocket
- (BOOL)createServerSocket {
if ([self createSocket] == -1) {
return NO;
}
[self setReceiveBuffer];
[self setReceiveTimeout];
BOOL isB = [self bind];
BOOL isL = [self listen];
if (isB && isL) {
_decoderQueue = dispatch_queue_create("cn.rongcloud.decoderQueue", NULL);
_frameTime = 0;
[self createDecoder];
[self receive];
return YES;
} else {
return NO;
}
}
- (void)createDecoder {
self.decoder = [[RongRTCVideoDecoder alloc] init];
self.decoder.delegate = self;
RongRTCVideoEncoderSettings *settings = [[RongRTCVideoEncoderSettings alloc] init];
settings.width = 720;
settings.height = 1280;
settings.startBitrate = 300;
settings.maxFramerate = 30;
settings.minBitrate = 1000;
[self.decoder configWithSettings:settings onQueue:_decoderQueue];
}
- (void)receiveData {
struct sockaddr_in rest;
socklen_t rest_size = sizeof(struct sockaddr_in);
self.acceptSocket = accept(self.socket, (struct sockaddr *) &rest, &rest_size);
while (self.acceptSocket != -1) {
DataHeader dataH;
memset(&dataH, 0, sizeof(dataH));
if (![self receiveData:(char *)&dataH length:sizeof(dataH)]) {
continue;
}
PreHeader preH = dataH.preH;
char pre = preH.pre[0];
if (pre == '&') {
// rongcloud socket
NSUInteger dataLenght = preH.dataLength;
char *buff = (char *)malloc(sizeof(char) * dataLenght);
if ([self receiveData:(char *)buff length:dataLenght]) {
NSData *data = [NSData dataWithBytes:buff length:dataLenght];
[self.decoder decode:data];
free(buff);
}
} else {
NSLog(@"pre is not &");
return;
}
}
}
- (BOOL)receiveData:(char *)data length:(NSUInteger)length {
LOCK(lock);
int receiveLength = 0;
while (receiveLength < length) {
ssize_t res = recv(self.acceptSocket, data, length - receiveLength, 0);
if (res == -1 || res == 0) {
UNLOCK(lock);
NSLog(@"receive data error");
break;
}
receiveLength += res;
data += res;
}
UNLOCK(lock);
return YES;
}
- (void)didGetDecodeBuffer:(CVPixelBufferRef)pixelBuffer {
_frameTime += 1000;
CMTime pts = CMTimeMake(_frameTime, 1000);
CMSampleBufferRef sampleBuffer = [RongRTCBufferUtil sampleBufferFromPixbuffer:pixelBuffer time:pts];
// Check to see if there is a problem with the decoded data. If the image appears, you are right.
UIImage *image = [RongRTCBufferUtil imageFromBuffer:sampleBuffer];
[self.delegate didProcessSampleBuffer:sampleBuffer];
CFRelease(sampleBuffer);
}
- (void)close {
int res = close(self.acceptSocket);
self.acceptSocket = -1;
NSLog(@"shut down server: %d", res);
[super close];
}
- (void)dealloc {
NSLog(@"dealoc server socket");
}
@end主 App 通过 Socket 会持续收到数据包，再将数据包进行解码，将解码后的数据通过代理 didGetDecodeBuffer 代理方法回调给 App 层。App 层就可以通过融云 RongRTCLib 的发送自定义流方法将视频数据发送到对端。
