GameAnywhere代码结构
GameAnywhere 是一个开源的云游戏平台，由 Chun-Ying Huang 在2013年开发，最开始是毕业论文研究使用，近期随着云游戏风口正盛，这个项目关注度又有起色，本文介绍GameAnywhere代码构成。GameAnywhere 的License为 BSD3，可以修改代码后闭源，但是项目依赖的开源组件较多，需要注意 License。
代码构成
目录结构
├─bin
│├─config
││└─common
│├─data
│├─log
│└─mod
├─deps.pkg.win32#依赖组件的windows包
│├─bin
│├─NvCodec
│└─NVENC
├─deps.posix#依赖组件的unix包
│└─lib
├─deps.src#依赖组件的源码
│└─patches
├─deps.win32#依赖组件的Windows头文件与库
│├─bin
│├─include
││├─include
││├─lib
││├─libavcodec
││├─libavdevice
││├─libavfilter
││├─libavformat
││├─libavutil
││├─libpostproc
││├─libswresample
││├─libswscale
││├─live555
││├─NVENC
││└─SDL2
│└─lib
├─docs
└─ga
├─android# android客户端
├─client# windows客户端
├─core# 公共依赖部分
├─module# 各个功能模块
│├─asource-system# apple 平台的音频抓取
│├─ctrl-sdl# 键盘输入
│├─encoder-audio# 音频编码
│├─encoder-mfx
│├─encoder-nvenc# NVIDIA 硬编码
│├─encoder-video# FFmpeg 软编码
│├─encoder-x264# 编码x264库
│├─filter-rgb2yuv# rgb转yuv库，编码前预处理
│├─server-ffmpeg# FFmpeg库
│├─server-live555# live555 项目，承载 rtsp 协议
│└─vsource-desktop# DirectX GDI 抓图
├─server
│├─event-driven# 键盘鼠标输入windows平台实现
│├─event-posix# 键盘鼠标输入posix平台实现
│└─periodic# 可执行文件 Main 函数，依赖 ga/core
└─vs2010#Visual Studio工程
├─BasicUsageEnvironment
├─CloudGameDM_Installer
├─encoder-nvenc
├─ga-client
├─ga-hook
├─ga-server-event-driven
├─ga-server-periodic
├─groupsock
├─ipch
├─libga
├─liveMedia
├─module-asource-system
├─module-ctrl-sdl
├─module-encoder-audio
├─module-encoder-video
├─module-encoder-x264
├─module-filter-rgb2yuv
├─module-server-ffmpeg
├─module-server-live555
├─module-vsource-desktop
├─module-vsource-desktop-d3d
├─module-vsource-desktop-dfm
└─UsageEnvironment服务端
Main: server\ga\server\periodic\ga-server-periodic.cpp Server 端的功能：图像采集、图像预处理、声音采集、键盘输入、音视频编码、封包、传输功能，这些功能分别由对应GameAnywhere定义的模块实现。
//
if (load_modules() < 0) {
write_log("error, load_modules error ! \n");
return -1;
}
if (init_modules() < 0) {
write_log("error, init_modules error ! \n");
return -1;
}
if (run_modules() < 0) {
write_log("error, run_modules error ! \n");
return -1;
}
GameAnywhere 模块类型定义: server\ga\core\ga-module.h
/**
* Enumeration for types of a module.
*/
enum ga_module_types {
GA_MODULE_TYPE_NULL = 0,/**< Not used */
GA_MODULE_TYPE_CONTROL,/**< Is a controller module */
GA_MODULE_TYPE_ASOURCE,/**< Is an audio source module */
GA_MODULE_TYPE_VSOURCE,/**< Is an video source module */
GA_MODULE_TYPE_FILTER,/**< Is a filter module */
GA_MODULE_TYPE_AENCODER,/**< Is an audio encoder module */
GA_MODULE_TYPE_VENCODER,/**< Is a video encoder module */
GA_MODULE_TYPE_ADECODER,/**< Is an audio decoder module */
GA_MODULE_TYPE_VDECODER,/**< Is a video decoder module */
GA_MODULE_TYPE_SERVER/**< Is a server module */
};
GameAnywhere 模块定义: server\ga\core\ga-module.h
/**
* Data strucure to represent a module.
*/
typedef struct ga_module_s {
HMODULEhandle;
/**< Handle to a module */
int type;
/**< Type of the module */
char *name;
/**< Name of the module */
char *mimetype;
/**< MIME-type of the module */
int (*init)(void *arg);
/**< Pointer to the init function */
int (*start)(void *arg);
/**< Pointer to the start function */
//void * (*threadproc)(void *arg);
int (*stop)(void *arg);
/**< Pointer to the stop function */
int (*deinit)(void *arg);
/**< Pointer to the deinit function */
int (*ioctl)(int command, int argsize, void *arg);
/**< Pointer to ioctl function */
int (*notify)(void *arg);
/**< Pointer to the notify function */
void * (*raw)(void *arg, int *size);
/**< Pointer to the raw function */
int (*send_packet)(const char *prefix, int channelId, AVPacket *pkt, int64_t encoderPts, struct timeval *ptv);
/**< Pointer to the send packet function: sink only */
void * privdata;
/**< Private data of this module */
}ga_module_t;
模块生命周期动作: server\ga\core\ga-module.h
EXPORT ga_module_t * ga_load_module(const char *modname, const char *prefix);
EXPORT void ga_unload_module(ga_module_t *m);
EXPORT int ga_init_single_module(const char *name, ga_module_t *m, void *arg);
EXPORT void ga_init_single_module_or_quit(const char *name, ga_module_t *m, void *arg);
EXPORT int ga_run_single_module(const char *name, void * (*threadproc)(void*), void *arg);
EXPORT void ga_run_single_module_or_quit(const char *name, void * (*threadproc)(void*), void *arg);
// module function wrappers
EXPORT int ga_module_init(ga_module_t *m, void *arg);
EXPORT int ga_module_start(ga_module_t *m, void *arg);
EXPORT int ga_module_stop(ga_module_t *m, void *arg);
EXPORT int ga_module_deinit(ga_module_t *m, void *arg);
EXPORT int ga_module_ioctl(ga_module_t *m, int command, int argsize, void *arg);
EXPORT int ga_module_notify(ga_module_t *m, void *arg);
EXPORT void * ga_module_raw(ga_module_t *m, void *arg, int *size);
EXPORT int ga_module_send_packet(ga_module_t *m, const char *prefix, int channelId, AVPacket *pkt, int64_t encoderPts, struct timeval *ptv);
图像采集模块: server\ga\module\vsource-desktop 此模块提供桌面级别图像采集功能，未提供进程级别图像采集。提供
DirectX与GDI两种图像采集实现。ga_module_t *
module_load() {
static ga_module_t m;
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_VSOURCE;
m.name = strdup("vsource-desktop");
m.init = vsource_init;
m.start = vsource_start;
m.stop = vsource_stop;
m.deinit = vsource_deinit;
m.ioctl = vsource_ioctl;
return &m;
}图像预处理模块: server\ga\module\filter-rgb2yuv\filter-rgb2yuv.cpp 【GameAnywhere代码结构】此模块提供将抓取到的RGB格式图片转换为YUV格式。
ga_module_t *
module_load() {
static ga_module_t m;
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_FILTER;
m.name = strdup("filter-RGB2YUV");
m.init = filter_RGB2YUV_init;
m.start = filter_RGB2YUV_start;
m.stop = filter_RGB2YUV_stop;
m.deinit = filter_RGB2YUV_deinit;
//m.threadproc = filter_RGB2YUV_threadproc;
return &m;
}NVIDIA硬编码模块: server\ga\module\encoder-nvenc\encoder-nvenc.cpp
ga_module_t *
module_load() {
static ga_module_t m;
struct RTSPConf *rtspconf = rtspconf_global();
//
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_VENCODER;
m.name = strdup("nvenc-video-encoder");
m.mimetype = strdup("video/H264");
m.init= nvenc_init;
m.deinit= nvenc_deinit;
m.start = nvenc_start;
m.ioctl = nvenc_ioctl;
m.stop= nvenc_stop;
return &m;
}软编码模块(ffmpge实现): server\ga\module\encoder-video\encoder-video.cpp
ga_module_t *
module_load() {
static ga_module_t m;
//struct RTSPConf *rtspconf = rtspconf_global();
char mime[64];
//
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_VENCODER;
m.name = strdup("ffmpeg-video-encoder");
if(ga_conf_readv("video-mimetype", mime, sizeof(mime)) != NULL) {
m.mimetype = strdup(mime);
}
m.init = vencoder_init;
m.start = vencoder_start;
//m.threadproc = vencoder_threadproc;
m.stop = vencoder_stop;
m.deinit = vencoder_deinit;
//
m.raw = vencoder_raw;
m.ioctl = vencoder_ioctl;
return &m;
}软编码模块(x264实现): server\ga\module\encoder-x264\encoder-x264.cpp
ga_module_t *
module_load() {
static ga_module_t m;
//
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_VENCODER;
m.name = strdup("x264-video-encoder");
m.mimetype = strdup("video/H264");
m.init = vencoder_init;
m.start = vencoder_start;
//m.threadproc = vencoder_threadproc;
m.stop = vencoder_stop;
m.deinit = vencoder_deinit;
//
m.raw = vencoder_raw;
m.ioctl = vencoder_ioctl;
return &m;
}音频采集模块: server\ga\module\asource-system\asource-system.cpp 在windows操作系统上，使用微软的 IAudioClient API 采集声音。
ga_module_t *
module_load() {
static ga_module_t m;
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_ASOURCE;
m.name = strdup("asource-system");
m.init = asource_init;
m.start = asource_start;
//m.threadproc = asource_threadproc;
m.stop = asource_stop;
m.deinit = asource_deinit;
return &m;
}音频编码模块: server\ga\module\encoder-audio\encoder-audio.cpp 使用 ffmpeg 封装的API编码音频，编码格式支持 LAME/OPUS 。
ga_module_t *
module_load() {
static ga_module_t m;
struct RTSPConf *rtspconf = rtspconf_global();
char mime[64];
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_AENCODER;
m.name = strdup("ffmpeg-audio-encoder");
if(ga_conf_readv("audio-mimetype", mime, sizeof(mime)) != NULL) {
m.mimetype = strdup(mime);
}
m.init = aencoder_init;
m.start = aencoder_start;
//m.threadproc = aencoder_threadproc;
m.stop = aencoder_stop;
m.deinit = aencoder_deinit;
return &m;
}媒体传输模块(ffmpge-server): server\ga\module\server-ffmpeg\server-ffmpeg.cpp 此模块不再使用。
ga_module_t *
module_load() {
static ga_module_t m;
//
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_SERVER;
m.name = strdup("ffmpeg-rtsp-server");
m.init = ff_server_init;
m.start = ff_server_start;
m.stop = ff_server_stop;
m.deinit = ff_server_deinit;
m.send_packet = ff_server_send_packet;
//
encoder_register_sinkserver(&m);
//
return &m;
}音视频传输模块(live555): server\ga\module\server-live555\server-live555.cpp 当前使用此模块。Live555 存在性能优化空间，网上资料较多，可参考。
ga_module_t *
module_load() {
static ga_module_t m;
//
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_SERVER;
m.name = strdup("live555-rtsp-server");
m.init = live_server_init;
m.start = live_server_start;
m.stop = live_server_stop;
m.deinit = live_server_deinit;
m.send_packet = live_server_send_packet;
//
encoder_register_sinkserver(&m);
//
return &m;
}控制指令输入模块 此模块支持键盘、鼠标事件输入，基于 SDL 实现。
ga_module_t *
module_load() {
static ga_module_t m;
bzero(&m, sizeof(m));
m.type = GA_MODULE_TYPE_CONTROL;
m.name = strdup("control-SDL");
m.init = sdlmsg_replay_init;
m.deinit = sdlmsg_replay_deinit;
return &m;
}Android 客户端
客户端由C/C++ Native库与Java App组成。
- C/C++ Native: 提供触控指令传输、媒体流接收、解码、播放功能。
- Java App: 提供触控指令采集、以及云游戏App功能。
- 初始化
JNIEXPORT jboolean JNICALL Java_org_gaminganywhere_gaclient_GAClient_initGAClient(
JNIEnv *env, jobject thisObj, jobject weak_this);
- 配置参数
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_resetConfig(
JNIEnv *env, jobject thisObj);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setProtocol(
JNIEnv *env, jobject thisObj, jstring proto);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setHost(
JNIEnv *env, jobject thisObj, jstring host);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setPort(
JNIEnv *env, jobject thisObj, jint port);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setObjectPath(
JNIEnv *env, jobject thisObj, jstring objpath);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setRTPOverTCP(
JNIEnv *env, jobject thisObj, jboolean enabled);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setCtrlEnable(
JNIEnv *env, jobject thisObj, jboolean enabled);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setCtrlProtocol(
JNIEnv *env, jobject thisObj, jboolean tcp);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_setCtrlPort(
JNIEnv *env, jobject thisObj, jint port);
JNIEXPORT void JNICALL
Java_org_gaminganywhere_gaclient_GAClient_setBuiltinAudioInternal(
JNIEnv *env, jobject thisObj, jboolean enable);
JNIEXPORT void JNICALL
Java_org_gaminganywhere_gaclient_GAClient_setBuiltinVideoInternal(
JNIEnv *env, jobject thisObj, jboolean enable);
JNIEXPORT void JNICALL
Java_org_gaminganywhere_gaclient_GAClient_setAudioCodec(
JNIEnv *env, jobject thisObj,
/*jstring codecname,*/ jint samplerate, jint channels);
JNIEXPORT void JNICALL
Java_org_gaminganywhere_gaclient_GAClient_setDropLateVideoFrame(JNIEnv *env, jobject thisObj, jint ms);
- 发送键盘鼠标事件
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendKeyEvent(
JNIEnv *env, jobject thisObj, jboolean pressed, jint scancode, jint sym, jint mod, jint unicode);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseKey(
JNIEnv *env, jobject thisObj, jboolean pressed, jint button, jint x, jint y);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseMotion(
JNIEnv *env, jobject thisObj, jint x, jint y, jint xrel, jint yrel, jint state, jboolean relative);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseWheel(
JNIEnv *env, jobject thisObj, jint dx, jint dy);
- 媒体解码与播放
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendKeyEvent(
JNIEnv *env, jobject thisObj, jboolean pressed, jint scancode, jint sym, jint mod, jint unicode);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseKey(
JNIEnv *env, jobject thisObj, jboolean pressed, jint button, jint x, jint y);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseMotion(
JNIEnv *env, jobject thisObj, jint x, jint y, jint xrel, jint yrel, jint state, jboolean relative);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_sendMouseWheel(
JNIEnv *env, jobject thisObj, jint dx, jint dy);
GameAnywhere 对视频使用软解码(猜测出于兼容性考虑)，相比较硬解码性能较差，可替换为硬解码。
- 媒体流连接请求
JNIEXPORT jboolean JNICALL Java_org_gaminganywhere_gaclient_GAClient_rtspConnect(
JNIEnv *env, jobject thisObj);
JNIEXPORT void JNICALL Java_org_gaminganywhere_gaclient_GAClient_rtspDisconnect(
JNIEnv *env, jobject thisObj);
媒体流传输客户端(Live555 客户端): server\ga\android\jni\src\rtspclient.cpp 媒体流传输客户端是一个RTSP客户端，依赖 Live555 的库 (BasicUsageEnvironment, UsageEnvironment, groupsock, liveMedia)。
RTSP 客户端启动一个线程，通过
BasicTaskScheduler.SingleStep() 方法不断从服务端读取音视频数据，然后解码、播放。读数据:
void *
rtsp_thread(void *param) {
RTSPClient *client = NULL;
BasicTaskScheduler0 *bs = BasicTaskScheduler::createNew();
...
while(rtspParam->quitLive555 == 0) {
bs->SingleStep(1000000);
}
...
}如果是视频数据，回调
play_video 函数：static void
play_video(int channel, unsigned char *buffer, int bufsize, struct timeval pts, bool marker) {
struct decoder_buffer *pdb = &db[channel];
int left;
//
if(bufsize <= 0 || buffer == NULL) {
rtsperror("empty buffer?\n");
return;
}
#ifdef ANDROID
if(rtspconf->builtin_video_decoder != 0) {
//////// Work with built-in decoders
if(video_codec_id == AV_CODEC_ID_H264) {
if(android_decode_h264(rtspParam, buffer, bufsize, pts, marker) < 0)
return;
} else if(video_codec_id == AV_CODEC_ID_VP8) {
if(android_decode_vp8(rtspParam, buffer, bufsize, pts, marker) < 0)
return;
}
image_rendered = 1;
} else {
//////// Work with ffmpeg
#endif
...
}如果是音频数据，回调
play_audio 函数:static void
play_audio(unsigned char *buffer, int bufsize, struct timeval pts) {
#ifdef ANDROID
if(rtspconf->builtin_audio_decoder != 0) {
android_decode_audio(rtspParam, buffer, bufsize, pts);
} else {
////////////////////////////////////////
#endif
...
}媒体流解码与播放: server\ga\android\jni\src\android-decoders.cpp 具体的媒体流解码逻辑在
android-decoders.cpp 中实现。 包括配置解码器参数，启动解码器，解码一帧视频。int android_prepare_audio(RTSPThreadParam *rtspParam, const char *mime, bool builtinDecoder);
int android_decode_audio(RTSPThreadParam *rtspParam, unsigned char *buffer, int bufsize, struct timeval pts);
int android_config_h264_sprop(RTSPThreadParam *rtspParam, const char *sprop);
int android_decode_h264(RTSPThreadParam *rtspParam, unsigned char *buffer, int bufsize, struct timeval pts, bool marker);
int android_decode_vp8(RTSPThreadParam *rtspParam, unsigned char *buffer, int bufsize, struct timeval pts, bool marker);
指令传输: server\ga\android\jni\src\controller.cpp Java App层发送的指令，被保存到队列中，由
controller.cpp 实现的线程将队列中指令发送给服务端。指令通道是一条独立通道。Java App Java App 相对简单，提供界面与采集用户输入。
Reference GameAnywhere On Github
GameAnyhwere Offical Site
更多云最佳实践 https://best.practices.cloud
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