java - 在Android Gstreamer SDK中使用ANativeWindow_lock返回错误-22

大家，

现在我正在使用Android Gstreamer SDK通过修改http://docs.gstreamer.com/display/GstSDK/Android+tutorial+3%3A+Video这个项目来实现流传输，
我想在流式传输时捕获图像，所以我添加了JNI函数来渲染帧，
这是我的以下功能:

void gst_native_render_image(JNIEnv *env, jobject thiz, jobject surface){

CustomData *data = GET_CUSTOM_DATA (env, thiz, custom_data_field_id);
         if (!data)
             return;

         GST_DEBUG ("Releasing Native Window %p", data->native_window);

         ANativeWindow_Buffer buffer;
         //ANativeWindow *window = ANativeWindow_fromSurface(env, surface);
         render_window = ANativeWindow_fromSurface(env, surface);
         ANativeWindow_acquire(render_window);
         //ANativeWindow *window = data->native_window;
         GST_DEBUG("Got window %p", render_window);

         if(render_window > 0){
                 int width = ANativeWindow_getWidth(render_window);
                 int height = ANativeWindow_getHeight(render_window);

                 GST_DEBUG("Got window %d %d", width,height);

                 ANativeWindow_setBuffersGeometry(render_window, width, height, WINDOW_FORMAT_RGBA_8888);

                 memset((void*)&buffer,0,sizeof(buffer));

                 int lockResult = 0;

                 lockResult = ANativeWindow_lock(render_window, &buffer, NULL);
                 if (lockResult == 0) {
                         GST_DEBUG("GStreamer: ANativeWindow_locked");
                         memcpy(buffer.bits, g_buffer,  640*320);
                         ANativeWindow_unlockAndPost(render_window);
                 }
                 else{
                         GST_DEBUG("GStreamer: ANativeWindow_lock failed error %d",lockResult);
                 }

                 GST_DEBUG("Releasing window");

                 ANativeWindow_release(render_window);
                 (*env)->CallVoidMethod(env, thiz, surface_pixel_render_id); // call JAVA method to save the pixel data....oranhuang
         }else {
                 GST_DEBUG("surface is null");
         }
}

但我总是使用ANativeWindow_lock()收到返回错误-22。

还有什么我需要做的或者以错误的方式使用ANativeWindow_lock()吗？？？？

因为几乎没有关于ANativeWindow_lock()的讨论，
我不知道如何修正错误讯息。

最佳答案

我遇到了类似的问题，这也花了我数千个小时。然而，解决方案非常简单，这是ANativeWindow_fromSurface的注释中的引文:
/*...This acquires a reference on the ANativeWindow that is returned; be sure to use ANativeWindow_release() ...*/
因此，窗口对象将在ANativeWindow_fromSurface上锁定。不只是ANativeWindow_acquire!因此，答案是:如果您在锁定窗口之前已经调用过ANativeWindow_release，则必须调用ANativeWindow_acquire将其释放为 TWICE 。