Question

大家，

现在我正在使用Android Gstreamer SDK来实现流媒体，通过修改http://docs.gstreamer.com/display/GstSDK/Android+tutorial+3%3A+Video这个项目，我想在流式传输时捕获图像，所以我添加了一个JNI函数来渲染一个帧，以下是我的功能：

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");
         }
}

但我总是在ANativeWindow_lock()时收到错误-22。

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

'原因只有很少与ANativeWindow_lock()在线讨论，我不知道如何修复我的错误信息..

Answer 1

我遇到了类似的问题，这也花了我几千个小时。然而，解决方案结果非常简单，这里引用了/*... This acquires a reference on the ANativeWindow that is returned; be sure to use ANativeWindow_release() ...*/的评论：

ANativeWindow_fromSurface

因此ANativeWindow_acquire上的窗口对象将被锁定。不只是ANativeWindow_release！因此，答案是：如果您在锁定窗口之前已经调用ANativeWindow_acquire一次，则必须致电{{1}}将其释放 TWICE 。

使用Android Gstreamer SDK使用ANativeWindow_lock返回错误-22

1 个答案: