llama.cpp/examples/llava/llava.cpp

#include "clip.h"
#include "common.h"
#include "llama.h"
#include "llava.h"

#include <cstdio>
#include <cstdlib>
#include <vector>

#include "base64.hpp"

static bool encode_image_with_clip(clip_ctx * ctx_clip, int n_threads, const clip_image_u8 * img, float * image_embd, int * n_img_pos) {
    clip_image_f32 * img_res = clip_image_f32_init();
    if (!clip_image_preprocess(ctx_clip, img, img_res, /*pad2square =*/ true)) {
        fprintf(stderr, "%s: unable to preprocess image\n", __func__);
        clip_image_f32_free(img_res);
        return false;
    }

    *n_img_pos = clip_n_patches(ctx_clip);

    const int64_t t_img_enc_start_us = ggml_time_us();
    bool encoded = clip_image_encode(ctx_clip, n_threads, img_res, image_embd);
    clip_image_f32_free(img_res);
    if (!encoded) {
        fprintf(stderr, "Unable to encode image\n");

        return false;
    }

    const int64_t t_img_enc_end_us = ggml_time_us();
    float t_img_enc_ms = (t_img_enc_end_us - t_img_enc_start_us) / 1000.0;

    printf("\n%s: image encoded in %8.2f ms by CLIP (%8.2f ms per image patch)\n", __func__, t_img_enc_ms, t_img_enc_ms / *n_img_pos);

    return true;
}

bool llava_validate_embed_size(const llama_context * ctx_llama, const clip_ctx * ctx_clip) {
        // make sure that the correct mmproj was used, i.e., compare apples to apples
    int n_llama_embd = llama_n_embd(llama_get_model(ctx_llama));
    auto n_image_embd = clip_n_mmproj_embd(ctx_clip);
    if (n_image_embd != n_llama_embd) {
        printf("%s: embedding dim of the multimodal projector (%d) is not equal to that of LLaMA (%d). Make sure that you use the correct mmproj file.\n", __func__, n_image_embd, n_llama_embd);
        return false;
    }
    return true;
}

static bool llava_image_embed_make_with_clip_img(clip_ctx * ctx_clip, int n_threads, const clip_image_u8 * img, float ** image_embd_out, int * n_img_pos_out) {
    float * image_embd = (float *)malloc(clip_embd_nbytes(ctx_clip));
    if (!image_embd) {
        fprintf(stderr, "Unable to allocate memory for image embeddings\n");
        free(image_embd);
        return false;
    }

    int n_img_pos;
    if (!encode_image_with_clip(ctx_clip, n_threads, img, image_embd, &n_img_pos)) {
        fprintf(stderr, "%s: cannot encode image, aborting\n", __func__);
        free(image_embd);
        return false;
    }
    *image_embd_out = image_embd;
    *n_img_pos_out = n_img_pos;

    return true;
}

bool llava_eval_image_embed(llama_context * ctx_llama, const struct llava_image_embed * image_embed, int n_batch, int * n_past) {
    int n_embd  = llama_n_embd(llama_get_model(ctx_llama));

    for (int i = 0; i < image_embed->n_image_pos; i += n_batch) {
        int n_eval = image_embed->n_image_pos - i;
        if (n_eval > n_batch) {
            n_eval = n_batch;
        }
        llama_batch batch = {int32_t(n_eval), nullptr, (image_embed->embed+i*n_embd), nullptr, nullptr, nullptr, nullptr, *n_past, 1, 0, };
        if (llama_decode(ctx_llama, batch)) {
            fprintf(stderr, "%s : failed to eval\n", __func__);
            return false;
        }
        *n_past += n_eval;
    }
    return true;
}

LLAVA_API struct llava_image_embed * llava_image_embed_make_with_bytes(struct clip_ctx * ctx_clip, int n_threads, const unsigned char * image_bytes, int image_bytes_length) {
    clip_image_u8 * img = clip_image_u8_init();
    if (!clip_image_load_from_bytes(image_bytes, image_bytes_length, img)) {
        clip_image_u8_free(img);
        fprintf(stderr, "%s: can't load image from bytes, is it a valid image?", __func__);
        return NULL;
    }

    float* image_embed = NULL;
    int n_image_pos = 0;
    bool image_embed_result = llava_image_embed_make_with_clip_img(ctx_clip, n_threads, img, &image_embed, &n_image_pos);
    if (!image_embed_result) {
        clip_image_u8_free(img);
        fprintf(stderr, "%s: coulnd't embed the image\n", __func__);
        return NULL;
    }

    clip_image_u8_free(img);
    auto result = (llava_image_embed*)malloc(sizeof(llava_image_embed));
    result->embed = image_embed;
    result->n_image_pos = n_image_pos;
    return result;
}

static bool load_file_to_bytes(const char* path, unsigned char** bytesOut, long *sizeOut) {
    auto file = fopen(path, "rb");
    if (file == NULL) {
        fprintf(stderr, "%s: can't read file %s\n", __func__, path);
        return false;
    }

    fseek(file, 0, SEEK_END);
    auto fileSize = ftell(file);
    fseek(file, 0, SEEK_SET);

    auto buffer = (unsigned char *)malloc(fileSize); // Allocate memory to hold the file data
    if (buffer == NULL) {
        fprintf(stderr, "%s: failed to alloc %ld bytes for file %s\n", __func__, fileSize, path);
        perror("Memory allocation error");
        fclose(file);
        return false;
    }
    errno = 0;
    size_t ret = fread(buffer, 1, fileSize, file); // Read the file into the buffer
    if (ferror(file)) {
        die_fmt("read error: %s", strerror(errno));
    }
    if (ret != (size_t) fileSize) {
        die("unexpectedly reached end of file");
    }
    fclose(file); // Close the file

    *bytesOut = buffer;
    *sizeOut = fileSize;
    return true;
}

LLAVA_API struct llava_image_embed * llava_image_embed_make_with_filename(struct clip_ctx * ctx_clip, int n_threads, const char * image_path) {
    unsigned char* image_bytes;
    long image_bytes_length;
    auto loaded = load_file_to_bytes(image_path, &image_bytes, &image_bytes_length);
    if (!loaded) {
        fprintf(stderr, "%s: failed to load %s\n", __func__, image_path);
        return NULL;
    }

    auto embed = llava_image_embed_make_with_bytes(ctx_clip, n_threads, image_bytes, image_bytes_length);
    free(image_bytes);

    return embed;
}

LLAVA_API void llava_image_embed_free(struct llava_image_embed * embed) {
    free(embed->embed);
    free(embed);
}