whisper.cpp/src/openvino/whisper-openvino-encoder.cpp

#include "openvino/whisper-openvino-encoder.h"
#include "ggml.h"
#include <openvino/openvino.hpp>
#include <iostream>

struct whisper_openvino_context {
    ov::InferRequest inferRequest;
};

struct whisper_openvino_context * whisper_openvino_init(const char* path_model,
    const char* device,
    const char* cache_dir)
{
    if (!path_model || !device) {
        fprintf(stderr, "%s: path_model and/or device is null\n", __func__);
        return nullptr;
    }

    fprintf(stderr, "%s: path_model = %s, device = %s, cache_dir = %s\n",
        __func__, path_model, device, cache_dir ? cache_dir : "(not set)");

	whisper_openvino_context *context = new whisper_openvino_context;
    try {
        ov::Core core;

        if (cache_dir) {
            // enables caching of device-specific 'blobs' during core.compile_model
            // routine. This speeds up calls to compile_model for successive runs.
            core.set_property(ov::cache_dir(cache_dir));
        }

        //Read the OpenVINO encoder IR (.xml/.bin) from disk, producing an ov::Model object.
        std::shared_ptr<ov::Model> model = core.read_model(path_model);

        // Produce a compiled-model object, given the device ("CPU", "GPU", etc.)
        auto compiledModel = core.compile_model(model, device);

        // From the compiled model object, create an infer request. This is the thing that we
        //  we will use later on to trigger inference execution.
        context->inferRequest = compiledModel.create_infer_request();
    }
    catch (const std::exception& error) {
        std::cout << "in openvino encoder compile routine: exception: " << error.what() << std::endl;
        delete context;
        context = nullptr;
    }

    return context;
}

void whisper_openvino_free(struct whisper_openvino_context * ctx) {
    if( ctx ) {
        delete ctx;
    }
}

int whisper_openvino_encode(
    whisper_openvino_context* ctx,
    ggml_tensor* mel,
    ggml_tensor* out) {

    if (!ctx || !mel || !out) {
        fprintf(stderr, "%s: Error! ctx / mel / out is null\n", __func__);
        return 0;
    }

    if (ggml_n_dims(mel) != 2) {
        fprintf(stderr, "%s: Error! mel ggml_tensor expected to have n_dims=2, but it has n_dims=%d\n",
            __func__, ggml_n_dims(mel));
        return 0;
    }

    if (ggml_n_dims(out) != 2) {
        fprintf(stderr, "%s: Error! out ggml_tensor expected to have n_dims=2, but it has n_dims=%d\n",
            __func__, ggml_n_dims(out));
        return 0;
    }

    try {

        //wrap the passed-in mel ggml_tensor as an OpenVINO Tensor object, and set as input tensor to infer request
        {
            // note, we populate shape & stride dimensions in opposite order from how they are listed in ne / nb arrays
            ov::Shape input_shape = { 1, (unsigned long long)mel->ne[1], (unsigned long long)mel->ne[0] };
            ov::Strides input_strides = { mel->nb[2], mel->nb[1], mel->nb[0] };
            ov::Tensor input_tensor(ov::element::f32, input_shape, mel->data, input_strides);
            ctx->inferRequest.set_input_tensor(input_tensor);
        }

        //wrap the passed-in out ggml_tensor as an OpenVINO Tensor object, and set as output tensor to infer request
        {
            // note, we populate shape & stride dimensions in opposite order from how they are listed in ne / nb arrays
            ov::Shape output_shape = { 1, (unsigned long long)out->ne[1], (unsigned long long)out->ne[0] };
            ov::Strides output_strides = { out->nb[2], out->nb[1], out->nb[0] };
            ov::Tensor out_tensor(ov::element::f32, output_shape, out->data, output_strides);
            ctx->inferRequest.set_output_tensor(out_tensor);
        }

        //run inference
        ctx->inferRequest.infer();
    }
    catch (const std::exception& error) {
        std::cout << "in openvino encode inference execution routine: exception: " << error.what() << std::endl;
        return 0;
    }

    return 1;
}