android 4.0 Stagefright中的OpenMax

}
status_t OMX::allocateNode(const char *name, const sp<IOMXObserver> &observer, node_id *node) {
Mutex::Autolock autoLock(mLock);
*node = 0; //1.new OMXNodeInstance
OMXNodeInstance *instance = new OMXNodeInstance(this, observer);
OMX_COMPONENTTYPE *handle; OMX_ERRORTYPE err = mMaster->makeComponentInstance(name, &OMXNodeInstance::kCallbacks, instance, &handle); *node = makeNodeID(instance); mDispatchers.add(*node, new CallbackDispatcher(instance)); instance->setHandle(*node, handle); mLiveNodes.add(observer->asBinder(), instance); observer->asBinder()->linkToDeath(this);
String8 name8(name); mPluginByComponentName.add(name8, plugin); } }
三．Component 的创建
1. 创建流程
2.具体实现 sp<MediaSource> OMXCodec::Create(
const sp<IOMX> &omx, const sp<MetaData> &meta, bool createEncoder, const sp<MediaSource> &source, const char *matchComponentName, uint32_t flags, const sp<ANativeWindow> &nativeWindow) { ……. const char *mime; // 获取之前设定了编码算法 // enc_meta->setCString(kKeyMIMEType, MEDIA_MIMETYPE_VIDEO_AVC); bool success = meta->findCString(kKeyMIMEType, &mime); CHECK(success);
return OK; }
mMaster->makeComponentInstance
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TIOMXPlugin 的函数
2. OMXPluginBase *Ti_plugin = (*createOMXPlugin)()；//创建 TIPlugIn 对象 3. 再次调用 addPlugIn 2 addPlugin((*createOMXPlugin)()); }
OMX_BuildComponentTable, 根据 tComponentName 初始化全局变量 CompTab typedef struct _ComponentTable { OMX_STRING name;//Componet 名称，无标准 OMX_U16 nRoles;//Componet 中 Roles 的数量,标准 //Role 名称指针数值 OMX_STRING pRoleArray[MAX_ROLES];
-----------------------------------------------------------------\frameworks\base\media\libmediaplayerservice\MediaPlayerService.cpp sp<IOMX> MediaPlayerService::getOMX() {
}ComponentTable; -----------------------------------------------------------------//对 VenderPlugIn 和 softPlugIn 都调用该函数 void OMXMaster::addPlugin(OMXPluginBase *plugin) { mPlugins.push_back(plugin); char name[128]; while ((err = plugin->enumerateComponents(name, sizeof(name), index++)) == OMX_ErrorNone) {
-----------------------------------------------------------------a void OMXMaster::addPlugin(const char *libname)
{ 1． 从 libstagefrighthw.so 中动态装载 createOMXPlugin ，这里也就是找到 new
TIOMXPlugin.makeComponentInstance
|| SoftOMXPlugin::makeComponentInstance
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在函数 status_t StagefrightRecorder::setupVideoEncoder 中 OMXClient client; //通过 MediaPlayerService binder 获取 OMX binder CHECK_EQ(client.connect(),OK); -----------------------------------------------------------------\frameworks\base\media\libstagefright\OMXClient.cpp
status_t OMXClient::connect() { sp<IServiceManager> sm = defaultServiceManager(); sp<IBinder> binder = sm->getService(String16("media.player")); sp<IMediaPlayerService> service = interface_cast<IMediaPlayerService>(binder); CHECK(service.get() != NULL); mOMX = service->getOMX(); CHECK(mOMX.get() != NULL); return OK; }
// OMX.google.前缀， 没有前缀的也是为 soft // OMX.前缀的为硬编码 /***************************************************************** findMatchingCodecs(mime, createEncoder, matchComponentName, flags, &matchingCodecs);
Vector<String8> matchingCodecs;
//1.查找有哪些 Component 支持 MEDIA_MIMETYPE_VIDEO_AVC /************************************************************
查找结果如下，flag 可以指定选用软编码或者硬编码 { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.TI.DUCATI1.VIDEO.H264E" }, { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.qcom.7x30.video.encoder.avc" }, { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.qcom.video.encoder.avc" }, { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.TI.Video.encoder" }, { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.Nvidia.h264.encoder" }, { MEDIA_MIMETYPE_VIDEO_AVC, "OMX.SEC.AVC.Encoder" }, { MEDIA_MIMETYPE_VIDEO_AVC, "AVCEncoder" },软编码
sp<MediaSource> softwareCodec = InstantiateSoftwareEncoder(componentName, source, meta); } ……………………… //4.创建依据 componentName 的值，依次创建 Node，第一个创建成功的就返回 status_t err = omx->allocateNode(componentName, observer, &node);
{}
-----------------------------------------------------------------OMXMaster::OMXMaster()