在iOS上推流 - Helloted Blog

一、编译lib库

1、编译openssl

编译librtmp需要用到openssl，所以先编译openssl，下载脚本OpenSSL。

编译目录下的build-libssl.sh文件，整个编译过程需要一段时间

新建文件夹librtmp，将ssl编译后的两个文件夹lib与include拷入

2、编译

在librtmp目录下，

touch build.sh

将下面的脚本复制进去，注意要修改的地方，SDKVERSION为当前mac上最新的iOS SDK的版本，可以通过得到

ls /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs

#!/bin/sh

###########################################################################
#  Change values here                                                                     
SDKVERSION="11.2"                                                                         
###########################################################################
#                                                                                                              #
# Don't change anything under this line!                                                  #
#                                                                                                              #
###########################################################################

CURRENTPATH=`pwd`  
ARCHS="i386 x86_64 armv7 armv7s arm64"  
LIBRTMPREPO="git://git.ffmpeg.org/rtmpdump"  
BUILDPATH="${CURRENTPATH}/build"  
LIBPATH="${CURRENTPATH}/lib"  
INCLUDEPATH="${CURRENTPATH}/include"  
SRCPATH="${CURRENTPATH}/src"  
LIBRTMP="librtmp.a"  
DEVELOPER=`xcode-select -print-path`

if [ ! -d "$DEVELOPER" ]; then  
  echo "xcode path is not set correctly $DEVELOPER does not exist (most likely because of xcode > 4.3)"
  echo "run"
  echo "sudo xcode-select -switch <xcode path>"
  echo "for default installation:"
  echo "sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer"
  exit 1
fi

# Check whether openssl has already installed on the machine or not.
# libcrypt.a / libssl.a

set -e  
echo 'Check openssl installation'  
if [ -f "${LIBPATH}/libcrypto.a" ] && [ -f "${LIBPATH}/libssl.a" ] && [ -d "${INCLUDEPATH}/openssl" ]; then  
  echo 'Openssl for iOS has already installed, no need to install openssl'
else  
  echo 'Openssl for iOS not found, will install openssl for iOS'
  ./build-libssl.sh
  echo 'Succeeded to install openssl'
fi

# Download librtmp source code from git repository
# We assuem the user already installed git client.
echo 'Clone librtmp git repository'

# Remove the directory if already exist
rm -rf "${SRCPATH}/rtmpdump"

git clone ${LIBRTMPREPO} src/rtmpdump  
cd "${SRCPATH}/rtmpdump/librtmp"

LIBRTMP_REPO=""

for ARCH in ${ARCHS}  
do  
  if [ "${ARCH}" == "i386" ] || [ "${ARCH}" == "x86_64" ];
  then
      PLATFORM="iPhoneSimulator"
  else  
      PLATFORM="iPhoneOS"
  fi

  export CROSS_TOP="${DEVELOPER}/Platforms/${PLATFORM}.platform/Developer"
  export CROSS_SDK="${PLATFORM}${SDKVERSION}.sdk"
  export BUILD_TOOLS="${DEVELOPER}"

  echo "Building librtmp for ${PLATFORM} ${SDKVERSION} ${ARCH}"
  echo "Please wait..."

  # add arch to CC=
  sed -ie "s!AR=\$(CROSS_COMPILE)ar!AR=/usr/bin/ar!" "Makefile"
  sed -ie "/CC=\$(CROSS_COMPILE)gcc/d" "Makefile"
  echo "CC=\$(CROSS_COMPILE)gcc -arch ${ARCH}" >> "Makefile"

  export CROSS_COMPILE="${DEVELOPER}/usr/bin/"  
  export XCFLAGS="-isysroot ${CROSS_TOP}/SDKs/${CROSS_SDK} -miphoneos-version-min=7.0 -I${INCLUDEPATH} -arch ${ARCH}"

  if [ "${ARCH}" == "i386" ] || [ "${ARCH}" == "x86_64" ];
  then
      export XLDFLAGS="-isysroot ${CROSS_TOP}/SDKs/${CROSS_SDK} -miphoneos-version-min=7.0 -L${LIBPATH} -arch ${ARCH}"
  else
      export XLDFLAGS="-isysroot ${CROSS_TOP}/SDKs/${CROSS_SDK} -miphoneos-version-min=7.0 -L${LIBPATH} -arch ${ARCH}"
  fi

  OUTPATH="${BUILDPATH}/librtmp-${PLATFORM}${SDKVERSION}-${ARCH}.sdk"
  mkdir -p "${OUTPATH}"
  LOG="${OUTPATH}/build-librtmp.log"

  make SYS=darwin >> "${LOG}" 2>&1  
  make SYS=darwin prefix="${OUTPATH}" install  >> "${LOG}" 2>&1
  make clean >> "${LOG}" 2>&1

  LIBRTMP_REPO+="${OUTPATH}/lib/${LIBRTMP} "
done

echo "Build universal library..."  
lipo -create ${LIBRTMP_REPO}-output ${LIBPATH}/${LIBRTMP}

mkdir -p ${INCLUDEPATH}  
cp -R ${BUILDPATH}/librtmp-iPhoneSimulator${SDKVERSION}-i386.sdk/include/ ${INCLUDEPATH}/

echo "Building done."  
echo "Cleaning up..."

rm -rf ${SRCPATH}/rtmpdump  
echo "Done."  

保存并且执行

./build.sh

如果报权限错误，则先赋予权限

chmod +x build.sh

最终可以得到librtmp.a以及include文件

二、导入库

1、将include文件夹里的文件就像正常文件一样导入，如下图

2、lib文件夹里的静态库文件则要进行链接

注意除了三个生成的静态库文件，还要导入一个iOS的动态库，libz.tbd，否则运行会报错，导入之后错误消失。

三、推流

因为librtmp用的是C语言，为了方便调用，我用OC封装了一下一个类RTMPPuser。用来推流的代码是

    RTMPPusher *pusher = [[RTMPPusher alloc]init];
    BOOL success = [pusher connectWithURL:@"rtmp://192.168.0.16:1935/zbcs/room"];
    if (success) {
        NSString *htmlFile = [[NSBundle mainBundle]pathForResource:@"demo" ofType:@"flv"];
        NSData *video = [NSData dataWithContentsOfFile:htmlFile];
        [pusher pushFullVideoData:video chunkSize:10 * 5120];
    }
    [pusher closeRTMP];

1、建立连接

- (BOOL)connectWithURL:(NSString *)url{
    _url = url;
    @synchronized (self) {
        _rtmp = [self newRTMP];
        
        char *strUrl = (char *)[url cStringUsingEncoding:NSASCIIStringEncoding];
        if (!RTMP_SetupURL(_rtmp, strUrl)) {
            return NO;
        }
        
        RTMP_EnableWrite(_rtmp);

        if (!RTMP_Connect(_rtmp, NULL) || !RTMP_ConnectStream(_rtmp, 0)) {
            return NO;
        }

        _connected = RTMP_IsConnected(_rtmp);
        return YES;
    }
}

2、切片

- (void)pushFullVideoData:(NSData *)fullVideo chunkSize:(NSUInteger)size{
    NSUInteger length = [fullVideo length];
    NSUInteger chunkSize = 10 * 5120;
    NSUInteger offset = 0;

    // 将整视频切片后推送
    do {
        NSUInteger thisChunkSize = length - offset > chunkSize ? chunkSize : length - offset;
        NSData* chunk = [NSData dataWithBytesNoCopy:(char *)[fullVideo bytes] + offset
                                             length:thisChunkSize
                                       freeWhenDone:NO];
        offset += thisChunkSize;
        [self write:chunk];
        sleep(1);
    } while (offset < length);
}

3、写入推流

- (NSUInteger)write:(NSData *)data{
    @synchronized (self) {
        int sent = -1;
        if (_connected) {
            sent = RTMP_Write(_rtmp, [data bytes], (int)[data length]);
        }
        return sent;
    }
}

以上代码可以在推流Demo下载