llm-ocr/main.cpp

538 lines
15 KiB
C++

#include "ggml.h"
#include "llama.h"
#include "mtmd-helper.h"
#include "mtmd.h"
#include <cinttypes>
#include <cmath>
#include <csignal>
#include <cstdio>
#include <cstdlib>
#include <getopt.h>
#include <string>
#include <sys/stat.h>
#include <thread>
#include <unistd.h>
#include <vector>
static volatile bool g_interrupted = false;
static void noop_log(const ggml_log_level level, const char *text,
void *user_data) {
(void)level;
(void)text;
(void)user_data;
}
static void sigint_handler(const int signo) {
(void)signo;
g_interrupted = true;
}
static void batch_clear(llama_batch &batch) { batch.n_tokens = 0; }
static void batch_add(llama_batch &batch, const llama_token id,
const llama_pos pos,
const std::vector<llama_seq_id> &seq_ids,
const bool logits) {
batch.token[batch.n_tokens] = id;
batch.pos[batch.n_tokens] = pos;
batch.n_seq_id[batch.n_tokens] = static_cast<int32_t>(seq_ids.size());
for (size_t i = 0; i < seq_ids.size(); ++i) {
batch.seq_id[batch.n_tokens][i] = seq_ids[i];
}
batch.logits[batch.n_tokens] = logits ? 1 : 0;
batch.n_tokens++;
}
static std::string token_to_piece(const llama_vocab *vocab,
const llama_token token) {
std::string piece;
piece.resize(256);
int32_t n = llama_token_to_piece(
vocab, token, &piece[0], static_cast<int32_t>(piece.size()), 0, false);
if (n < 0) {
piece.resize(-n);
n = llama_token_to_piece(vocab, token, &piece[0],
static_cast<int32_t>(piece.size()), 0, false);
}
piece.resize(std::max(0, n));
return piece;
}
static std::string json_escape(const std::string &s) {
std::string out;
out.reserve(s.size() + 2);
for (const char c : s) {
switch (c) {
case '"':
out += "\\\"";
break;
case '\\':
out += "\\\\";
break;
case '\n':
out += "\\n";
break;
case '\r':
out += "\\r";
break;
case '\t':
out += "\\t";
break;
default:
out += c;
break;
}
}
return out;
}
static std::vector<unsigned char> read_clipboard() {
const char *cmd;
if (getenv("WAYLAND_DISPLAY")) {
cmd = "wl-paste 2>/dev/null";
} else {
cmd = "xclip -selection clipboard -t image/png -o 2>/dev/null";
}
std::vector<unsigned char> data;
FILE *pipe = popen(cmd, "re");
if (!pipe)
return data;
unsigned char buf[65536];
size_t n;
while ((n = fread(buf, 1, sizeof(buf), pipe)) > 0) {
data.insert(data.end(), buf, buf + n);
}
const int st = pclose(pipe);
if (st != 0 || data.empty()) {
data.clear();
// fallback for X11: try without explicit target
if (!getenv("WAYLAND_DISPLAY")) {
pipe = popen("xclip -selection clipboard -o 2>/dev/null", "re");
if (pipe) {
while ((n = fread(buf, 1, sizeof(buf), pipe)) > 0)
data.insert(data.end(), buf, buf + n);
pclose(pipe);
}
}
}
return data;
}
static std::string capture_screenshot(bool quiet) {
const char *tmpdir = getenv("TMPDIR");
if (!tmpdir)
tmpdir = "/tmp";
std::string path = std::string(tmpdir) + "/ocr_screenshot.png";
if (!quiet)
fprintf(stderr, "Select a screen region to OCR...\n");
auto check = [&]() -> bool {
struct stat st {};
return stat(path.c_str(), &st) == 0 && st.st_size > 0;
};
// 1. gnome-screenshot (blocks until selection complete)
unlink(path.c_str());
if (system(("gnome-screenshot --area -f " + path + " >/dev/null 2>&1")
.c_str()) == 0 &&
check())
return path;
// 2. spectacle (KDE, blocks)
unlink(path.c_str());
if (system(
("spectacle --region -b -o " + path + " >/dev/null 2>&1").c_str()) ==
0 &&
check())
return path;
// 3. flameshot (writes raw PNG to stdout, blocks)
unlink(path.c_str());
if (system(("flameshot gui -r > " + path + " 2>/dev/null").c_str()) == 0 &&
check())
return path;
// 4. maim (lightweight X11, blocks)
unlink(path.c_str());
if (system(("maim -s " + path + " 2>/dev/null").c_str()) == 0 && check())
return path;
// 5. slurp + grim (Sway/Wayland, blocks)
unlink(path.c_str());
if (system(("slurp | grim -g - " + path + " 2>/dev/null").c_str()) == 0 &&
check())
return path;
return "";
}
static void print_usage(const char *prog) {
fprintf(
stderr,
"Usage: %s -m <model> --mmproj <mmproj> [options] [<image_path>]\n"
"\n"
"Options:\n"
" -m, --model <path> model file path (GGUF)\n"
" --mmproj <path> mmproj file path\n"
" -p <text> OCR prompt (default: OCR)\n"
" -t <n> number of threads (default: cpu cores)\n"
" --ngl <n> GPU layers (-1 = all, default: -1)\n"
" -c <n> context size (default: 8192)\n"
" --temp <f> sampling temperature (0 = greedy, default: 0)\n"
" -s <seed> random seed\n"
" --json output in JSON format\n"
" --chat-template <name> chat template (default: auto from model)\n"
" --screenshot interactively select screen region to OCR\n"
" -q, --quiet suppress info logs, show only OCR result\n"
" -h show this help\n"
"\n"
"If <image_path> is omitted, reads image from clipboard.\n"
"Requires wl-paste (Wayland) or xclip (X11) for clipboard support.\n"
"\n"
"Examples:\n"
" %s -m model.gguf --mmproj mmproj.gguf -p \"OCR\" image.png\n"
" %s -m model.gguf --mmproj mmproj.gguf # use clipboard image\n"
" %s -m model.gguf --mmproj mmproj.gguf --screenshot # select "
"region\n",
prog, prog, prog, prog);
}
int main(int argc, char **argv) {
std::string model_path;
std::string mmproj_path;
std::string image_path;
std::string prompt = "OCR";
std::string chat_template;
bool screenshot_mode = false;
int n_threads = static_cast<int>(std::thread::hardware_concurrency());
int n_gpu_layers = -1;
int n_ctx = 8192;
float temp = 0.0f;
uint32_t seed = LLAMA_DEFAULT_SEED;
bool json_output = false;
bool quiet = false;
while (true) {
static option long_opts[] = {
{"temp", required_argument, nullptr, 0},
{"json", no_argument, nullptr, 1},
{"mmproj", required_argument, nullptr, 2},
{"ngl", required_argument, nullptr, 3},
{"model", required_argument, nullptr, 'm'},
{"chat-template", required_argument, nullptr, 4},
{"screenshot", no_argument, nullptr, 5},
{"quiet", no_argument, nullptr, 6},
{"help", no_argument, nullptr, 'h'},
{nullptr, 0, nullptr, 0}};
int idx = 0;
int c = getopt_long(argc, argv, "m:p:t:c:s:qh", long_opts, &idx);
if (c == -1)
break;
switch (c) {
case 0:
temp = std::stof(optarg);
break;
case 1:
json_output = true;
break;
case 2:
mmproj_path = optarg;
break;
case 3:
n_gpu_layers = std::stoi(optarg);
break;
case 4:
chat_template = optarg;
break;
case 5:
screenshot_mode = true;
break;
case 6:
case 'q':
quiet = true;
break;
case 'm':
model_path = optarg;
break;
case 'p':
prompt = optarg;
break;
case 't':
n_threads = std::stoi(optarg);
break;
case 'c':
n_ctx = std::stoi(optarg);
break;
case 's':
seed = static_cast<uint32_t>(std::stoul(optarg));
break;
case 'h':
print_usage(argv[0]);
return 0;
default:
print_usage(argv[0]);
return 1;
}
}
if (model_path.empty() || mmproj_path.empty()) {
fprintf(stderr, "ERROR: -m/--model and --mmproj are required\n");
return 1;
}
if (screenshot_mode) {
image_path = capture_screenshot(quiet);
if (image_path.empty()) {
fprintf(stderr,
"ERROR: no screenshot tool found. Install gnome-screenshot, "
"flameshot, spectacle, maim, or slurp+grim.\n");
return 1;
}
} else if (optind < argc) {
image_path = argv[optind];
}
signal(SIGINT, sigint_handler);
int64_t t_start_us = ggml_time_us();
llama_backend_init();
if (quiet) {
llama_log_set(noop_log, nullptr);
mtmd_helper_log_set(noop_log, nullptr);
}
llama_model_params mparams = llama_model_default_params();
mparams.n_gpu_layers = n_gpu_layers;
llama_model *model = llama_model_load_from_file(model_path.c_str(), mparams);
if (!model) {
fprintf(stderr, "ERROR: failed to load model from %s\n",
model_path.c_str());
return 1;
}
llama_context_params cparams = llama_context_default_params();
cparams.n_ctx = static_cast<uint32_t>(n_ctx);
cparams.n_batch = 512;
cparams.n_ubatch = 512;
llama_context *lctx = llama_init_from_model(model, cparams);
if (!lctx) {
fprintf(stderr, "ERROR: failed to create context\n");
llama_model_free(model);
return 1;
}
llama_set_n_threads(lctx, n_threads, n_threads);
const llama_vocab *vocab = llama_model_get_vocab(model);
mtmd_context_params mtmd_params = mtmd_context_params_default();
mtmd_params.use_gpu = (n_gpu_layers != 0);
mtmd_params.n_threads = n_threads;
mtmd_context *ctx_vision =
mtmd_init_from_file(mmproj_path.c_str(), model, mtmd_params);
if (!ctx_vision) {
fprintf(stderr, "ERROR: failed to load mmproj from %s\n",
mmproj_path.c_str());
llama_free(lctx);
llama_model_free(model);
return 1;
}
int64_t t_loaded_us = ggml_time_us();
mtmd_bitmap *bmp;
if (!image_path.empty()) {
bmp = mtmd_helper_bitmap_init_from_file(ctx_vision, image_path.c_str());
if (!bmp) {
fprintf(stderr, "ERROR: failed to load image from %s\n",
image_path.c_str());
if (screenshot_mode)
unlink(image_path.c_str());
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
return 1;
}
} else {
if (!quiet)
fprintf(stderr, "Reading image from clipboard...\n");
auto clip = read_clipboard();
if (clip.empty()) {
fprintf(stderr,
"ERROR: clipboard is empty or no image found.\n"
"Make sure wl-paste (Wayland) or xclip (X11) is installed.\n");
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
return 1;
}
bmp =
mtmd_helper_bitmap_init_from_buf(ctx_vision, clip.data(), clip.size());
if (!bmp) {
fprintf(stderr, "ERROR: failed to decode clipboard image.\n");
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
return 1;
}
}
// Build user message with image marker placeholder
std::string user_content = std::string(mtmd_default_marker()) + prompt;
// Apply chat template for any model
std::string full_prompt;
const char *tmpl = chat_template.empty()
? llama_model_chat_template(model, nullptr)
: chat_template.c_str();
if (tmpl) {
llama_chat_message msg[1] = {{"user", user_content.c_str()}};
char buf[8192];
int32_t n = llama_chat_apply_template(tmpl, msg, 1, true, buf, sizeof(buf));
if (n > 0) {
full_prompt = std::string(buf, n);
}
}
// Fallback: use chatml format for models without recognizable template
if (full_prompt.empty()) {
full_prompt = "<|im_start|>user\n" + user_content +
"<|im_end|>\n<|im_start|>assistant\n";
}
// Template output already includes role markers and special tokens (e.g.
// [gMASK]<sop>) So we don't add BOS separately — add_special=false
mtmd_input_chunks *chunks = mtmd_input_chunks_init();
mtmd_input_text in_text;
in_text.text = full_prompt.c_str();
in_text.add_special = false;
in_text.parse_special = true;
const mtmd_bitmap *bitmaps[1] = {bmp};
int32_t res = mtmd_tokenize(ctx_vision, chunks, &in_text, bitmaps, 1);
if (res != 0) {
fprintf(stderr, "ERROR: mtmd_tokenize failed (%d)\n", res);
mtmd_input_chunks_free(chunks);
mtmd_bitmap_free(bmp);
if (screenshot_mode)
unlink(image_path.c_str());
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
return 1;
}
llama_pos n_past = 0;
res = mtmd_helper_eval_chunks(ctx_vision, lctx, chunks, n_past, 0, 512, true,
&n_past);
if (res != 0) {
fprintf(stderr, "ERROR: mtmd_helper_eval_chunks failed (%d)\n", res);
mtmd_input_chunks_free(chunks);
mtmd_bitmap_free(bmp);
if (screenshot_mode)
unlink(image_path.c_str());
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
return 1;
}
mtmd_input_chunks_free(chunks);
mtmd_bitmap_free(bmp);
if (screenshot_mode)
unlink(image_path.c_str());
llama_sampler *smpl;
if (temp <= 0.0f) {
llama_sampler_chain_params sparams = llama_sampler_chain_default_params();
smpl = llama_sampler_chain_init(sparams);
llama_sampler_chain_add(smpl, llama_sampler_init_greedy());
} else {
llama_sampler_chain_params sparams = llama_sampler_chain_default_params();
smpl = llama_sampler_chain_init(sparams);
llama_sampler_chain_add(smpl, llama_sampler_init_top_k(40));
llama_sampler_chain_add(smpl, llama_sampler_init_top_p(0.9f, 1));
llama_sampler_chain_add(smpl, llama_sampler_init_temp(temp));
llama_sampler_chain_add(smpl, llama_sampler_init_dist(seed));
}
llama_batch batch = llama_batch_init(1, 0, 1);
int64_t t_infer_start_us = ggml_time_us();
std::string ocr_text;
int n_generated = 0;
for (int i = 0; i < 2048; i++) {
if (g_interrupted)
break;
llama_token token_id = llama_sampler_sample(smpl, lctx, -1);
llama_sampler_accept(smpl, token_id);
if (llama_vocab_is_eog(vocab, token_id))
break;
std::string piece = token_to_piece(vocab, token_id);
ocr_text += piece;
if (!json_output) {
printf("%s", piece.c_str());
fflush(stdout);
}
batch_clear(batch);
batch_add(batch, token_id, n_past++, {0}, true);
if (llama_decode(lctx, batch) != 0) {
fprintf(stderr, "\nERROR: llama_decode failed\n");
break;
}
n_generated++;
}
int64_t t_end_us = ggml_time_us();
if (!json_output) {
printf("\n");
}
llama_batch_free(batch);
llama_sampler_free(smpl);
mtmd_free(ctx_vision);
llama_free(lctx);
llama_model_free(model);
llama_backend_free();
if (json_output) {
printf("{\n");
printf(" \"text\": \"%s\",\n", json_escape(ocr_text).c_str());
printf(" \"meta\": {\n");
printf(" \"model\": \"%s\",\n", json_escape(model_path).c_str());
printf(" \"mmproj\": \"%s\",\n", json_escape(mmproj_path).c_str());
printf(" \"prompt\": \"%s\",\n", json_escape(prompt).c_str());
printf(" \"n_prompt_tokens\": %" PRId64 ",\n",
static_cast<int64_t>(n_past));
printf(" \"n_generated\": %d,\n", n_generated);
printf(" \"timings_ms\": {\n");
printf(" \"load\": %" PRId64 ",\n", (t_loaded_us - t_start_us) / 1000);
printf(" \"inference\": %" PRId64 "\n",
(t_end_us - t_infer_start_us) / 1000);
printf(" }\n");
printf(" }\n");
printf("}\n");
}
return g_interrupted ? 130 : 0;
}