typedef struct appdata {
//…
    int width;
    int height;
    media_packet_h mediaPcktPtr;
//…
} appdata_s;

int finalize_callback(media_packet_h packet, int err, void* userdata)
{
    return MEDIA_PACKET_FINALIZE;
}

Evas_Event_Flags on_click_convert_colorspace_start(void *data, void *event_info)
{
    appdata_s *ad = (appdata_s *)data;
    void* src_ptr;
    media_format_h fmt;
    media_packet_h src;
    transformation_h handle;

    image_util_transform_create(&handle);

    unsigned char *img_source = NULL;
    int width = 0, height = 0;
    unsigned int size_decode = 0;

    image_util_decode_jpeg( ad->array[ad->curIndex], (image_util_colorspace_e)IMAGE_UTIL_COLORSPACE_RGB888, &img_source, &width, &height, &size_decode);

    ad->width =width;
    ad->height =height;
    unsigned int buffer_size;
    image_util_calculate_buffer_size(ad->width,ad->height, IMAGE_UTIL_COLORSPACE_NV12,&buffer_size);

    media_format_create(&fmt);
    media_format_set_video_mime(fmt, MEDIA_FORMAT_RGB888);
    media_format_set_video_width(fmt, width);
    media_format_set_video_height(fmt, height);
    media_packet_create_alloc(fmt, finalize_callback, NULL, &src);

    image_util_transform_set_colorspace(handle, IMAGE_UTIL_COLORSPACE_NV12);

    media_packet_get_buffer_data_ptr(src, &src_ptr);
    memcpy(src_ptr, img_source, size_decode);
    free(img_source);

    image_util_transform_run(handle, src , (image_util_transform_completed_cb)completed_convert_colorspace_callback, ad);

    ad->mediaPcktPtr = src;
    image_util_transform_destroy(handle);
    return EVAS_EVENT_FLAG_NONE;
}

static void completed_convert_colorspace_callback(media_packet_h *dst, int error_code, void *user_data)
{
    appdata_s *ad = (appdata_s *)user_data;
    void * ptr;

    media_packet_get_buffer_data_ptr(*dst, &ptr);
    int ret=image_util_encode_jpeg((unsigned char*)ptr, ad->width, ad->height
                                                  , IMAGE_UTIL_COLORSPACE_NV12, 50, "/opt/usr/media/conv_color.jpg");
    media_packet_destroy(*dst);
    media_packet_destroy(ad->mediaPcktPtr);
}