TDA4VM: multi_cam_codec demo debug

Hi, team

      we are debugging the multi_cam_codec  demo and  successfully run it.  Now we want to add a API to get h264 stream and push it to our application. I need your help on how to get it. In our  opinion, the h264 stream can get after encode in API decode_display in /ti-processor-sdk-rtos-j721e-evm-08_06_00_12/vision_apps/apps/basic_demos/app_multi_cam_codec/main.c. Is that right?

static vx_status decode_display(AppObj* obj, vx_int32 frame_id)
{
    APP_PRINTF("\ndecode_display: frame %d beginning\n", frame_id);
    vx_status status = VX_SUCCESS;

    TIOVXImgMosaicModuleObj *imgMosaicObj = &obj->imgMosaicObj;
    AppGraphParamRefPool *dec_pool = &obj->dec_pool;

    /* checksum_actual is the checksum determined by the realtime test
        checksum_expected is the checksum that is expected to be the pipeline output */
    uint32_t checksum_actual = 0;

    /* This is the number of frames required for the pipeline AWB and AE algorithms to stabilize
        (note that 15 is only required for the 6-8 camera use cases - others converge quicker) */
    uint8_t stability_frame = 15;

    vx_object_array mosaic_input_arr;
    vx_image mosaic_output_image;
    uint32_t num_refs;

    int8_t pull_status = -2;


    if (status == VX_SUCCESS && obj->decode==1)
    {
        pull_status = appCodecDeqAppSink(obj->appsink_pull_id);
        if (pull_status == 1)
        {
            obj->EOS=1;
            obj->stop_task=1;
            APP_PRINTF("\nCODEC=> EOS Recieved\n");
            goto exit;
        }
        else if (pull_status != 0)
        {
            goto exit;
        }
    }

    if ( frame_id >= dec_pool->bufq_depth )
    {
        if (status == VX_SUCCESS)
        {
            status = vxGraphParameterDequeueDoneRef(obj->display_graph, imgMosaicObj->inputs[0].graph_parameter_index, (vx_reference*)&mosaic_input_arr, 1, &num_refs);
        }
        /************************************
        ****add  code to get h264 stream*****
        
        *************************************/
        if((obj->en_out_img_write == 1) || (obj->test_mode == 1))
        {
            vx_char output_file_name[APP_MAX_FILE_PATH];

            /* Dequeue output */
            if (status == VX_SUCCESS)
            {
                status = vxGraphParameterDequeueDoneRef(obj->display_graph, imgMosaicObj->output_graph_parameter_index, (vx_reference*)&mosaic_output_image, 1, &num_refs);
            }
            if ((status == VX_SUCCESS) && (obj->test_mode == 1) && (frame_id > TEST_BUFFER))
            {
                /* calculate the checksum of the mosaic output */

                if ((app_test_check_image(mosaic_output_image, checksums_expected[obj->sensorObj.sensor_index][obj->sensorObj.num_cameras_enabled-1],
                                        &checksum_actual) != vx_true_e) && (frame_id > stability_frame))
                {
                    test_result = vx_false_e;
                    /* in case test fails and needs to change */
                    populate_gatherer(obj->sensorObj.sensor_index, obj->sensorObj.num_cameras_enabled-1, checksum_actual);
                }
            }

            if (obj->en_out_img_write == 1) {
                appPerfPointBegin(&obj->fileio_perf);
                snprintf(output_file_name, APP_MAX_FILE_PATH, "%s/mosaic_output_%010d_%dx%d.yuv", obj->output_file_path, (frame_id - APP_BUFFER_Q_DEPTH), imgMosaicObj->out_width, imgMosaicObj->out_height);
                if (status == VX_SUCCESS)
                {
                    /* TODO: Correct checksums not added yet.
                     * status = writeMosaicOutput(output_file_name, mosaic_output_image);
                     */
                     status = writeMosaicOutput(output_file_name, mosaic_output_image);
                }
                appPerfPointEnd(&obj->fileio_perf);
            }
        }
    }

    if(status==VX_SUCCESS && obj->decode==1)
    {
        status = assign_array_image_buffers(
                        dec_pool->arr[obj->mosaic_enq_id], 
                        dec_pool->data_ptr[obj->appsink_pull_id],
                        dec_pool->plane_sizes);
    }

    if((obj->en_out_img_write == 1) || (obj->test_mode == 1))
    {
        if (status == VX_SUCCESS)
        {
            status = vxGraphParameterEnqueueReadyRef(obj->display_graph, imgMosaicObj->output_graph_parameter_index, (vx_reference*)&imgMosaicObj->output_image[obj->display_id], 1);
        }
    }
    if (status == VX_SUCCESS)
    {
        status = vxGraphParameterEnqueueReadyRef(obj->display_graph, imgMosaicObj->inputs[0].graph_parameter_index, (vx_reference*)&dec_pool->arr[obj->mosaic_enq_id], 1);
    }

    obj->display_id++;
    obj->display_id         = (obj->display_id  >= APP_BUFFER_Q_DEPTH)? 0 : obj->display_id;
    obj->mosaic_enq_id++;
    obj->mosaic_enq_id      = (obj->mosaic_enq_id  >= dec_pool->bufq_depth)? 0 : obj->mosaic_enq_id;
    obj->appsink_pull_id++;
    obj->appsink_pull_id    = (obj->appsink_pull_id  >= obj->num_codec_bufs)? 0 : obj->appsink_pull_id;

exit:
    if (obj->decode==1)
    {
        appCodecEnqAppSink(obj->appsink_pull_id);
    }

    return status;
}

1. after "status = vxGraphParameterDequeueDoneRef(obj->display_graph, imgMosaicObj->inputs[0].graph_parameter_index, (vx_reference*)&mosaic_input_arr, 1, &num_refs);"

if we can get h264 stream from mosaic_input_arr?

2. how to get stream from vx_reference?

Thinks