implementing camera using ndk camera api, getting error [ImageReader-4208x3120f23u3m3-8785-0](id:225100000000,api:4,p:832,c:8785) connect: already connected (cur=4 req=2)

[Ashish2000L]

ndk version : 25

I am trying to implement the preview of camera using ndk camera cpp api but I am unable to lock the window to set the preview.
Here are the logs I am getting

below is the code where I am trying to lock the screen:-

void CameraWorkManager::Camera::renderToNativeWindow(uint8_t *rgbData, int width, int height) {
    if (nativeWindow == nullptr) {
        LOGE("Native window is null, cannot render!");
        return;
    }

    int geometryStatus = ANativeWindow_setBuffersGeometry(nativeWindow, width, height, WINDOW_FORMAT_RGBA_8888);
    if (geometryStatus != 0) {
        LOGE("Failed to set buffer geometry! Status: %d", geometryStatus);
        return;
    }

    ANativeWindow_Buffer buffer;
    int lockStatus = ANativeWindow_lock(nativeWindow, &buffer, nullptr);
    LOGI("Native window buffer width: %d, height: %d", buffer.width, buffer.height);
    LOGI("Expected width: %d, height: %d", width, height);
    if (lockStatus != 0) {
        LOGE("Failed to lock native window! Status: %d", lockStatus);
        return;
    }
        if (buffer.width != width || buffer.height != height) {
            LOGE("Buffer dimensions do not match the rendered image!");
            ANativeWindow_unlockAndPost(nativeWindow);
            return;
        }

        uint8_t* dst = (uint8_t*)buffer.bits;

        if (buffer.format != WINDOW_FORMAT_RGBA_8888) {
            LOGE("Unexpected window format!");
            ANativeWindow_unlockAndPost(nativeWindow);
            return;
        }

        for (int y = 0; y < height; y++) {
            memcpy(dst + y * buffer.stride, rgbData + y * width * 4, width * 4);
        }

        ANativeWindow_unlockAndPost(nativeWindow);
}

below is the step I am trying to perform after receiving frames:-

void CameraWorkManager::Camera::onImageAvaiable(void *context, AImageReader *reader) {
    AImage* image = nullptr;
    LOGW("entered onImageAvailable");
    while (AImageReader_acquireNextImage(reader, &image) == AMEDIA_OK) {
        LOGD("Getting frames");
        if (image != nullptr) {
            int width = 0, height = 0;
            AImage_getWidth(image, &width);
            AImage_getHeight(image, &height);

            uint8_t* yPlane = nullptr;
            uint8_t* uPlane = nullptr;
            uint8_t* vPlane = nullptr;
            int yStride = 0;
            int uvStride = 0;

            if (AImage_getPlaneData(image, 0, &yPlane, &yStride) != AMEDIA_OK ||
                AImage_getPlaneData(image, 1, &uPlane, &uvStride) != AMEDIA_OK ||
                AImage_getPlaneData(image, 2, &vPlane, &uvStride) != AMEDIA_OK ||
                    AImage_getPlaneRowStride(image,0,&yStride)!=AMEDIA_OK ||
                    AImage_getPlaneRowStride(image,1,&uvStride)!=AMEDIA_OK) {
                LOGE("Failed to get plane data");
                AImage_delete(image);
                continue; // Skip this image
            }

            int rgbSize = width * height * 4;
            uint8_t* rgbData = (uint8_t*) malloc(rgbSize);
            if (!rgbData) {
                LOGE("Failed to allocate memory for RGB image");
                AImage_delete(image);
                continue; 
            }

            YUVtoRGB(yPlane, uPlane, vPlane, yStride, uvStride, rgbData, width, height);

            LOGI("Conversion complete");

            //addRandomLines(rgbData, width/5, height/3);
            AImage_delete(image);

            LOGI("Lines drawn");

            renderToNativeWindow(rgbData, width, height);
            LOGI("clean up");

            free(rgbData);
            LOGI("Frame deleted");
        }
    }
}

please help me with the same getting stuck to this since long time.

#UPDATE

please find the discussion for this problem here:- https://issuetracker.google.com/u/1/issues/372873691

[DanAlbert]

If you're looking for help from a Googler, the folks that know the APIs don't monitor this forum. I've sent the link on to one of them so hopefully they'll be along soon, but in general the best way to get the attention of the API experts is to file a framework bug via http://b.android.com.

[DanAlbert]

Paraphrasing what the camera API expert told me over DM:

That error happens when more than one thing writes to the same surface. cur =4 means it's connected to camera, and you're trying to draw into it via CPU (2). You're trying to draw into something that the camera is already drawing into. This is probably an architectural flaw in your app, but there's not enough context here to say much for certain.

[Ashish2000L]

if I share you the code can you make something out of it?

[DanAlbert]

I certainly can't. Like I said in the other post, if you need to talk to camera experts you should file a bug against the frameworks on http://b.android.com.

[DanAlbert]

Ah, it looks like you have: https://issuetracker.google.com/372873691. I sent that along to the camera folks.