dnn/openvino: add log error message

Signed-off-by: Ting Fu <ting.fu@intel.com>

libavfilter/dnn/dnn_backend_openvino.c

@@ -28,7 +28,12 @@
 #include "libavutil/avassert.h"
 #include <c_api/ie_c_api.h>
 
+typedef struct OVContext {
+    const AVClass *class;
+} OVContext;
+
 typedef struct OVModel{
+    OVContext ctx;
     ie_core_t *core;
     ie_network_t *network;
     ie_executable_network_t *exe_network;
@@ -36,6 +41,14 @@ typedef struct OVModel{
     ie_blob_t *input_blob;
 } OVModel;
 
+static const AVClass dnn_openvino_class = {
+    .class_name = "dnn_openvino",
+    .item_name  = av_default_item_name,
+    .option     = NULL,
+    .version    = LIBAVUTIL_VERSION_INT,
+    .category   = AV_CLASS_CATEGORY_FILTER,
+};
+
 static DNNDataType precision_to_datatype(precision_e precision)
 {
     switch (precision)
@@ -51,6 +64,7 @@ static DNNDataType precision_to_datatype(precision_e precision)
 static DNNReturnType get_input_ov(void *model, DNNData *input, const char *input_name)
 {
     OVModel *ov_model = (OVModel *)model;
+    OVContext *ctx = &ov_model->ctx;
     char *model_input_name = NULL;
     IEStatusCode status;
     size_t model_input_count = 0;
@@ -58,25 +72,33 @@ static DNNReturnType get_input_ov(void *model, DNNData *input, const char *input
     precision_e precision;
 
     status = ie_network_get_inputs_number(ov_model->network, &model_input_count);
-    if (status != OK)
+    if (status != OK) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to get input count\n");
         return DNN_ERROR;
+    }
 
     for (size_t i = 0; i < model_input_count; i++) {
         status = ie_network_get_input_name(ov_model->network, i, &model_input_name);
-        if (status != OK)
+        if (status != OK) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to get No.%d input's name\n", (int)i);
             return DNN_ERROR;
+        }
         if (strcmp(model_input_name, input_name) == 0) {
             ie_network_name_free(&model_input_name);
             status |= ie_network_get_input_dims(ov_model->network, input_name, &dims);
             status |= ie_network_get_input_precision(ov_model->network, input_name, &precision);
-            if (status != OK)
+            if (status != OK) {
+                av_log(ctx, AV_LOG_ERROR, "Failed to get No.%d input's dims or precision\n", (int)i);
                 return DNN_ERROR;
+            }
 
             // The order of dims in the openvino is fixed and it is always NCHW for 4-D data.
             // while we pass NHWC data from FFmpeg to openvino
             status = ie_network_set_input_layout(ov_model->network, input_name, NHWC);
-            if (status != OK)
+            if (status != OK) {
+                av_log(ctx, AV_LOG_ERROR, "Input \"%s\" does not match layout NHWC\n", input_name);
                 return DNN_ERROR;
+            }
 
             input->channels = dims.dims[1];
             input->height   = dims.dims[2];
@@ -88,12 +110,14 @@ static DNNReturnType get_input_ov(void *model, DNNData *input, const char *input
         ie_network_name_free(&model_input_name);
     }
 
+    av_log(ctx, AV_LOG_ERROR, "Could not find \"%s\" in model\n", model_input_name);
     return DNN_ERROR;
 }
 
 static DNNReturnType set_input_ov(void *model, DNNData *input, const char *input_name)
 {
     OVModel *ov_model = (OVModel *)model;
+    OVContext *ctx = &ov_model->ctx;
     IEStatusCode status;
     dimensions_t dims;
     precision_e precision;
@@ -129,6 +153,7 @@ err:
         ie_blob_free(&ov_model->input_blob);
     if (ov_model->infer_request)
         ie_infer_request_free(&ov_model->infer_request);
+    av_log(ctx, AV_LOG_ERROR, "Failed to create inference instance or get input data/dims/precision/memory\n");
     return DNN_ERROR;
 }
 
@@ -147,6 +172,7 @@ DNNModel *ff_dnn_load_model_ov(const char *model_filename, const char *options)
     ov_model = av_mallocz(sizeof(OVModel));
     if (!ov_model)
         goto err;
+    ov_model->ctx.class = &dnn_openvino_class;
 
     status = ie_core_create("", &ov_model->core);
     if (status != OK)
@@ -188,25 +214,34 @@ DNNReturnType ff_dnn_execute_model_ov(const DNNModel *model, DNNData *outputs, c
     precision_e precision;
     ie_blob_buffer_t blob_buffer;
     OVModel *ov_model = (OVModel *)model->model;
+    OVContext *ctx = &ov_model->ctx;
     IEStatusCode status = ie_infer_request_infer(ov_model->infer_request);
-    if (status != OK)
+    if (status != OK) {
+        av_log(ctx, AV_LOG_ERROR, "Failed to start synchronous model inference\n");
         return DNN_ERROR;
+    }
 
     for (uint32_t i = 0; i < nb_output; ++i) {
         const char *output_name = output_names[i];
         ie_blob_t *output_blob = NULL;
         status = ie_infer_request_get_blob(ov_model->infer_request, output_name, &output_blob);
-        if (status != OK)
+        if (status != OK) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to get model output data\n");
             return DNN_ERROR;
+        }
 
         status = ie_blob_get_buffer(output_blob, &blob_buffer);
-        if (status != OK)
+        if (status != OK) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to access output memory\n");
             return DNN_ERROR;
+        }
 
         status |= ie_blob_get_dims(output_blob, &dims);
         status |= ie_blob_get_precision(output_blob, &precision);
-        if (status != OK)
+        if (status != OK) {
+            av_log(ctx, AV_LOG_ERROR, "Failed to get dims or precision of output\n");
             return DNN_ERROR;
+        }
 
         outputs[i].channels = dims.dims[1];
         outputs[i].height   = dims.dims[2];