android (10)

 

android (10)

OMX_ERRORTYPE OMX::OnEvent(
        node_id node,
        OMX_IN OMX_EVENTTYPE eEvent,
        OMX_IN OMX_U32 nData1,
        OMX_IN OMX_U32 nData2,
        OMX_IN OMX_PTR pEventData) {
    LOGV("OnEvent(%d, %ld, %ld)", eEvent, nData1, nData2);

    omx_message msg;
    msg.type = omx_message::EVENT;
    msg.node = node;
    msg.u.event_data.event = eEvent;
    msg.u.event_data.data1 = nData1;
    msg.u.event_data.data2 = nData2;

    findDispatcher(node)->post(msg);

    return OMX_ErrorNone;
}

事件处理还是抛到对应的线程来处理

OMX的节点实例有下面的成员

    static OMX_CALLBACKTYPE kCallbacks;

OMX_CALLBACKTYPE OMXNodeInstance::kCallbacks = {
    &OnEvent, &OnEmptyBufferDone, &OnFillBufferDone
};

OMX_ERRORTYPE OMXNodeInstance::OnEvent(
        OMX_IN OMX_HANDLETYPE hComponent,
        OMX_IN OMX_PTR pAppData,
        OMX_IN OMX_EVENTTYPE eEvent,
        OMX_IN OMX_U32 nData1,
        OMX_IN OMX_U32 nData2,
        OMX_IN OMX_PTR pEventData) {
    OMXNodeInstance *instance = static_cast<OMXNodeInstance *>(pAppData);
    if (instance->mDying) {
        return OMX_ErrorNone;
    }
    return instance->owner()->OnEvent(
            instance->nodeID(), eEvent, nData1, nData2, pEventData);
}

最终还是调用owner的方法

再看一下分配节点的方法

    OMX_COMPONENTTYPE *handle;
    OMX_ERRORTYPE err = mMaster->makeComponentInstance(
            name, &OMXNodeInstance::kCallbacks,
            instance, &handle);

将节点实例的时间处理设置进组件了

最终还是调用的OMX的OnEvent方法

OMX_ERRORTYPE OMX::OnEvent(
        node_id node,
        OMX_IN OMX_EVENTTYPE eEvent,
        OMX_IN OMX_U32 nData1,
        OMX_IN OMX_U32 nData2,
        OMX_IN OMX_PTR pEventData) {
    LOGV("OnEvent(%d, %ld, %ld)", eEvent, nData1, nData2);

    omx_message msg;
    msg.type = omx_message::EVENT;
    msg.node = node;
    msg.u.event_data.event = eEvent;
    msg.u.event_data.data1 = nData1;
    msg.u.event_data.data2 = nData2;

    findDispatcher(node)->post(msg);

    return OMX_ErrorNone;
}

抛到对应的消息处理线程中处理了

是谁处理的？

void OMXNodeInstance::onMessage(const omx_message &msg) {
    if (msg.type == omx_message::FILL_BUFFER_DONE) {
        OMX_BUFFERHEADERTYPE *buffer =
            static_cast<OMX_BUFFERHEADERTYPE *>(
                    msg.u.extended_buffer_data.buffer);

        BufferMeta *buffer_meta =
            static_cast<BufferMeta *>(buffer->pAppPrivate);

        buffer_meta->CopyFromOMX(buffer);
    }

    mObserver->onMessage(msg);
}

mObserver。。。。

节点实例的mObserver是从哪来的？

传进来的

OMXClient

申请connect OMX

服务端如果没有OMX就创建一个

OMXMaster

添加插件

void OMXMaster::addVendorPlugin() {
    mVendorLibHandle = dlopen("libstagefrighthw.so", RTLD_NOW);

    if (mVendorLibHandle == NULL) {
        return;
    }

    typedef OMXPluginBase *(*CreateOMXPluginFunc)();
    CreateOMXPluginFunc createOMXPlugin =
        (CreateOMXPluginFunc)dlsym(
                mVendorLibHandle, "_ZN7android15createOMXPluginEv");

    if (createOMXPlugin) {
        addPlugin((*createOMXPlugin)());
    }
}

加载共享库 libstagefrighthw.so，获取_ZN7android15createOMXPluginEv 方法

注意这个函数没有参数

void OMXMaster::addPlugin(OMXPluginBase *plugin) {
    Mutex::Autolock autoLock(mLock);

    mPlugins.push_back(plugin);

    OMX_U32 index = 0;

    char name[128];
    OMX_ERRORTYPE err;
    while ((err = plugin->enumerateComponents(
                    name, sizeof(name), index++)) == OMX_ErrorNone) {
        String8 name8(name);

        if (mPluginByComponentName.indexOfKey(name8) >= 0) {
            LOGE("A component of name '%s' already exists, ignoring this one.",
                 name8.string());

            continue;
        }

        mPluginByComponentName.add(name8, plugin);
    }
    CHECK_EQ(err, OMX_ErrorNoMore);
}

将插件中所有的组件都记录下来

还需要注意组件实例化