fix: set VAE conv scale for all SDXL variants

* feat: add basic sdapi support to sd-server

Compatible with AUTOMATIC1111 / Forge.

* fix img2img with no mask

* add more parameter validation

* eliminate MSVC warnings

---------

Co-authored-by: leejet <leejet714@gmail.com>

docs/distilled_sd.md

@@ -1,8 +1,8 @@
-# Running distilled models: SSD1B and SDx.x with tiny U-Nets
+# Running distilled models: SSD1B, Vega and SDx.x with tiny U-Nets
 
 ## Preface 
 
-These models feature a reduced U-Net architecture. Unlike standard SDXL models, the SSD-1B U-Net contains only one middle block and fewer attention layers in its up- and down-blocks, resulting in significantly smaller file sizes. Using these models can reduce inference time by more than 33%. For more details, refer to Segmind's paper: https://arxiv.org/abs/2401.02677v1.
+These models feature a reduced U-Net architecture. Unlike standard SDXL models, the SSD-1B and Vega U-Net contains only one middle block and fewer attention layers in its up- and down-blocks, resulting in significantly smaller file sizes. Using these models can reduce inference time by more than 33%. For more details, refer to Segmind's paper: https://arxiv.org/abs/2401.02677v1.
 Similarly, SD1.x- and SD2.x-style models with a tiny U-Net consist of only 6 U-Net blocks, leading to very small files and time savings of up to 50%. For more information, see the paper: https://arxiv.org/pdf/2305.15798.pdf.
 
 ## SSD1B
@@ -17,7 +17,17 @@ Useful LoRAs are also available:
  * https://huggingface.co/seungminh/lora-swarovski-SSD-1B/resolve/main/pytorch_lora_weights.safetensors
  * https://huggingface.co/kylielee505/mylcmlorassd/resolve/main/pytorch_lora_weights.safetensors
 
-These files can be used out-of-the-box, unlike the models described in the next section.
+## Vega
+
+Segmind's Vega model is available online here:
+
+ * https://huggingface.co/segmind/Segmind-Vega/resolve/main/segmind-vega.safetensors
+ 
+VegaRT is an example for an LCM-LoRA:
+
+ * https://huggingface.co/segmind/Segmind-VegaRT/resolve/main/pytorch_lora_weights.safetensors
+
+Both files can be used out-of-the-box, unlike the models described in next sections.
 
 
 ## SD1.x, SD2.x with tiny U-Nets

docs/esrgan.md

@@ -1,6 +1,6 @@
 ## Using ESRGAN to upscale results
 
-You can use ESRGAN to upscale the generated images. At the moment, only the [RealESRGAN_x4plus_anime_6B.pth](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.2.4/RealESRGAN_x4plus_anime_6B.pth) model is supported. Support for more models of this architecture will be added soon.
+You can use ESRGAN—such as the model [RealESRGAN_x4plus_anime_6B.pth](https://github.com/xinntao/Real-ESRGAN/releases/download/v0.2.2.4/RealESRGAN_x4plus_anime_6B.pth)—to upscale the generated images and improve their overall resolution and clarity.
 
 - Specify the model path using the `--upscale-model PATH` parameter. example:
 

examples/server/main.cpp

@@ -86,21 +86,6 @@ std::vector<uint8_t> base64_decode(const std::string& encoded_string) {
     return ret;
 }
 
-std::string iso_timestamp_now() {
-    using namespace std::chrono;
-    auto now      = system_clock::now();
-    std::time_t t = system_clock::to_time_t(now);
-    std::tm tm{};
-#ifdef _MSC_VER
-    gmtime_s(&tm, &t);
-#else
-    gmtime_r(&t, &tm);
-#endif
-    std::ostringstream oss;
-    oss << std::put_time(&tm, "%Y-%m-%dT%H:%M:%SZ");
-    return oss.str();
-}
-
 struct SDSvrParams {
     std::string listen_ip = "127.0.0.1";
     int listen_port       = 1234;
@@ -404,7 +389,7 @@ int main(int argc, const char** argv) {
             }
 
             json out;
-            out["created"]       = iso_timestamp_now();
+            out["created"]       = static_cast<long long>(std::time(nullptr));
             out["data"]          = json::array();
             out["output_format"] = output_format;
 
@@ -692,7 +677,7 @@ int main(int argc, const char** argv) {
             }
 
             json out;
-            out["created"]       = iso_timestamp_now();
+            out["created"]       = static_cast<long long>(std::time(nullptr));
             out["data"]          = json::array();
             out["output_format"] = output_format;
 
@@ -732,6 +717,327 @@ int main(int argc, const char** argv) {
         }
     });
 
+    // sdapi endpoints (AUTOMATIC1111 / Forge)
+
+    auto sdapi_any2img = [&](const httplib::Request& req, httplib::Response& res, bool img2img) {
+        try {
+            if (req.body.empty()) {
+                res.status = 400;
+                res.set_content(R"({"error":"empty body"})", "application/json");
+                return;
+            }
+
+            json j = json::parse(req.body);
+
+            std::string prompt          = j.value("prompt", "");
+            std::string negative_prompt = j.value("negative_prompt", "");
+            int width                   = j.value("width", 512);
+            int height                  = j.value("height", 512);
+            int steps                   = j.value("steps", -1);
+            float cfg_scale             = j.value("cfg_scale", 7.f);
+            int64_t seed                = j.value("seed", -1);
+            int batch_size              = j.value("batch_size", 1);
+            int clip_skip               = j.value("clip_skip", -1);
+            std::string sampler_name    = j.value("sampler_name", "");
+            std::string scheduler_name  = j.value("scheduler", "");
+
+            auto bad = [&](const std::string& msg) {
+                res.status = 400;
+                res.set_content("{\"error\":\"" + msg + "\"}", "application/json");
+                return;
+            };
+
+            if (width <= 0 || height <= 0) {
+                return bad("width and height must be positive");
+            }
+
+            if (steps < 1 || steps > 150) {
+                return bad("steps must be in range [1, 150]");
+            }
+
+            if (batch_size < 1 || batch_size > 8) {
+                return bad("batch_size must be in range [1, 8]");
+            }
+
+            if (cfg_scale < 0.f) {
+                return bad("cfg_scale must be positive");
+            }
+
+            if (prompt.empty()) {
+                return bad("prompt required");
+            }
+
+            auto get_sample_method = [](std::string name) -> enum sample_method_t {
+                enum sample_method_t result = str_to_sample_method(name.c_str());
+                if (result != SAMPLE_METHOD_COUNT) return result;
+                // some applications use a hardcoded sampler list
+                std::transform(name.begin(), name.end(), name.begin(),
+                               [](unsigned char c) { return std::tolower(c); });
+                static const std::unordered_map<std::string_view, sample_method_t> hardcoded{
+                    {"euler a", EULER_A_SAMPLE_METHOD},
+                    {"k_euler_a", EULER_A_SAMPLE_METHOD},
+                    {"euler", EULER_SAMPLE_METHOD},
+                    {"k_euler", EULER_SAMPLE_METHOD},
+                    {"heun", HEUN_SAMPLE_METHOD},
+                    {"k_heun", HEUN_SAMPLE_METHOD},
+                    {"dpm2", DPM2_SAMPLE_METHOD},
+                    {"k_dpm_2", DPM2_SAMPLE_METHOD},
+                    {"lcm", LCM_SAMPLE_METHOD},
+                    {"ddim", DDIM_TRAILING_SAMPLE_METHOD},
+                    {"dpm++ 2m", DPMPP2M_SAMPLE_METHOD},
+                    {"k_dpmpp_2m", DPMPP2M_SAMPLE_METHOD}};
+                auto it            = hardcoded.find(name);
+                if (it != hardcoded.end()) return it->second;
+                return SAMPLE_METHOD_COUNT;
+            };
+
+            enum sample_method_t sample_method = get_sample_method(sampler_name);
+
+            enum scheduler_t scheduler = str_to_scheduler(scheduler_name.c_str());
+
+            // avoid excessive resource usage
+
+            SDGenerationParams gen_params         = default_gen_params;
+            gen_params.prompt                     = prompt;
+            gen_params.negative_prompt            = negative_prompt;
+            gen_params.width                      = width;
+            gen_params.height                     = height;
+            gen_params.seed                       = seed;
+            gen_params.sample_params.sample_steps = steps;
+            gen_params.batch_count                = batch_size;
+
+            if (clip_skip > 0) {
+                gen_params.clip_skip = clip_skip;
+            }
+
+            if (sample_method != SAMPLE_METHOD_COUNT) {
+                gen_params.sample_params.sample_method = sample_method;
+            }
+
+            if (scheduler != SCHEDULER_COUNT) {
+                gen_params.sample_params.scheduler = scheduler;
+            }
+
+            LOG_DEBUG("%s\n", gen_params.to_string().c_str());
+
+            sd_image_t init_image    = {(uint32_t)gen_params.width, (uint32_t)gen_params.height, 3, nullptr};
+            sd_image_t control_image = {(uint32_t)gen_params.width, (uint32_t)gen_params.height, 3, nullptr};
+            sd_image_t mask_image    = {(uint32_t)gen_params.width, (uint32_t)gen_params.height, 1, nullptr};
+            std::vector<uint8_t> mask_data;
+            std::vector<sd_image_t> pmid_images;
+            std::vector<sd_image_t> ref_images;
+
+            if (img2img) {
+                auto decode_image = [](sd_image_t& image, std::string encoded) -> bool {
+                    // remove data URI prefix if present ("data:image/png;base64,")
+                    auto comma_pos = encoded.find(',');
+                    if (comma_pos != std::string::npos) {
+                        encoded = encoded.substr(comma_pos + 1);
+                    }
+                    std::vector<uint8_t> img_data = base64_decode(encoded);
+                    if (!img_data.empty()) {
+                        int img_w         = image.width;
+                        int img_h         = image.height;
+                        uint8_t* raw_data = load_image_from_memory(
+                            (const char*)img_data.data(), (int)img_data.size(),
+                            img_w, img_h,
+                            image.width, image.height, image.channel);
+                        if (raw_data) {
+                            image = {(uint32_t)img_w, (uint32_t)img_h, image.channel, raw_data};
+                            return true;
+                        }
+                    }
+                    return false;
+                };
+
+                if (j.contains("init_images") && j["init_images"].is_array() && !j["init_images"].empty()) {
+                    std::string encoded = j["init_images"][0].get<std::string>();
+                    decode_image(init_image, encoded);
+                }
+
+                if (j.contains("mask") && j["mask"].is_string()) {
+                    std::string encoded = j["mask"].get<std::string>();
+                    decode_image(mask_image, encoded);
+                    bool inpainting_mask_invert = j.value("inpainting_mask_invert", 0) != 0;
+                    if (inpainting_mask_invert && mask_image.data != nullptr) {
+                        for (uint32_t i = 0; i < mask_image.width * mask_image.height; i++) {
+                            mask_image.data[i] = 255 - mask_image.data[i];
+                        }
+                    }
+                } else {
+                    mask_data          = std::vector<uint8_t>(width * height, 255);
+                    mask_image.width   = width;
+                    mask_image.height  = height;
+                    mask_image.channel = 1;
+                    mask_image.data    = mask_data.data();
+                }
+
+                if (j.contains("extra_images") && j["extra_images"].is_array()) {
+                    for (auto extra_image : j["extra_images"]) {
+                        std::string encoded  = extra_image.get<std::string>();
+                        sd_image_t tmp_image = {(uint32_t)gen_params.width, (uint32_t)gen_params.height, 3, nullptr};
+                        if (decode_image(tmp_image, encoded)) {
+                            ref_images.push_back(tmp_image);
+                        }
+                    }
+                }
+
+                float denoising_strength = j.value("denoising_strength", -1.f);
+                if (denoising_strength >= 0.f) {
+                    denoising_strength  = std::min(denoising_strength, 1.0f);
+                    gen_params.strength = denoising_strength;
+                }
+            }
+
+            sd_img_gen_params_t img_gen_params = {
+                gen_params.lora_vec.data(),
+                static_cast<uint32_t>(gen_params.lora_vec.size()),
+                gen_params.prompt.c_str(),
+                gen_params.negative_prompt.c_str(),
+                gen_params.clip_skip,
+                init_image,
+                ref_images.data(),
+                (int)ref_images.size(),
+                gen_params.auto_resize_ref_image,
+                gen_params.increase_ref_index,
+                mask_image,
+                gen_params.width,
+                gen_params.height,
+                gen_params.sample_params,
+                gen_params.strength,
+                gen_params.seed,
+                gen_params.batch_count,
+                control_image,
+                gen_params.control_strength,
+                {
+                    pmid_images.data(),
+                    (int)pmid_images.size(),
+                    gen_params.pm_id_embed_path.c_str(),
+                    gen_params.pm_style_strength,
+                },  // pm_params
+                ctx_params.vae_tiling_params,
+                gen_params.cache_params,
+            };
+
+            sd_image_t* results = nullptr;
+            int num_results     = 0;
+
+            {
+                std::lock_guard<std::mutex> lock(sd_ctx_mutex);
+                results     = generate_image(sd_ctx, &img_gen_params);
+                num_results = gen_params.batch_count;
+            }
+
+            json out;
+            out["images"]     = json::array();
+            out["parameters"] = j;  // TODO should return changed defaults
+            out["info"]       = "";
+
+            for (int i = 0; i < num_results; i++) {
+                if (results[i].data == nullptr) {
+                    continue;
+                }
+
+                auto image_bytes = write_image_to_vector(ImageFormat::PNG,
+                                                         results[i].data,
+                                                         results[i].width,
+                                                         results[i].height,
+                                                         results[i].channel);
+
+                if (image_bytes.empty()) {
+                    LOG_ERROR("write image to mem failed");
+                    continue;
+                }
+
+                std::string b64 = base64_encode(image_bytes);
+                out["images"].push_back(b64);
+            }
+
+            res.set_content(out.dump(), "application/json");
+            res.status = 200;
+
+            if (init_image.data) {
+                stbi_image_free(init_image.data);
+            }
+            if (mask_image.data && mask_data.empty()) {
+                stbi_image_free(mask_image.data);
+            }
+            for (auto ref_image : ref_images) {
+                stbi_image_free(ref_image.data);
+            }
+
+        } catch (const std::exception& e) {
+            res.status = 500;
+            json err;
+            err["error"]   = "server_error";
+            err["message"] = e.what();
+            res.set_content(err.dump(), "application/json");
+        }
+    };
+
+    svr.Post("/sdapi/v1/txt2img", [&](const httplib::Request& req, httplib::Response& res) {
+        sdapi_any2img(req, res, false);
+    });
+
+    svr.Post("/sdapi/v1/img2img", [&](const httplib::Request& req, httplib::Response& res) {
+        sdapi_any2img(req, res, true);
+    });
+
+    svr.Get("/sdapi/v1/samplers", [&](const httplib::Request&, httplib::Response& res) {
+        std::vector<std::string> sampler_names;
+        sampler_names.push_back("default");
+        for (int i = 0; i < SAMPLE_METHOD_COUNT; i++) {
+            sampler_names.push_back(sd_sample_method_name((sample_method_t)i));
+        }
+        json r = json::array();
+        for (auto name : sampler_names) {
+            json entry;
+            entry["name"]    = name;
+            entry["aliases"] = json::array({name});
+            entry["options"] = json::object();
+            r.push_back(entry);
+        }
+        res.set_content(r.dump(), "application/json");
+    });
+
+    svr.Get("/sdapi/v1/schedulers", [&](const httplib::Request&, httplib::Response& res) {
+        std::vector<std::string> scheduler_names;
+        scheduler_names.push_back("default");
+        for (int i = 0; i < SCHEDULER_COUNT; i++) {
+            scheduler_names.push_back(sd_scheduler_name((scheduler_t)i));
+        }
+        json r = json::array();
+        for (auto name : scheduler_names) {
+            json entry;
+            entry["name"]  = name;
+            entry["label"] = name;
+            r.push_back(entry);
+        }
+        res.set_content(r.dump(), "application/json");
+    });
+
+    svr.Get("/sdapi/v1/sd-models", [&](const httplib::Request&, httplib::Response& res) {
+        fs::path model_path = ctx_params.model_path;
+        json entry;
+        entry["title"]      = model_path.stem();
+        entry["model_name"] = model_path.stem();
+        entry["filename"]   = model_path.filename();
+        entry["hash"]       = "8888888888";
+        entry["sha256"]     = "8888888888888888888888888888888888888888888888888888888888888888";
+        entry["config"]     = nullptr;
+        json r              = json::array();
+        r.push_back(entry);
+        res.set_content(r.dump(), "application/json");
+    });
+
+    svr.Get("/sdapi/v1/options", [&](const httplib::Request&, httplib::Response& res) {
+        fs::path model_path = ctx_params.model_path;
+        json r;
+        r["samples_format"]      = "png";
+        r["sd_model_checkpoint"] = model_path.stem();
+        res.set_content(r.dump(), "application/json");
+    });
+
     LOG_INFO("listening on: %s:%d\n", svr_params.listen_ip.c_str(), svr_params.listen_port);
     svr.listen(svr_params.listen_ip, svr_params.listen_port);
 

model.cpp

@@ -1040,6 +1040,7 @@ SDVersion ModelLoader::get_sd_version() {
     int64_t patch_embedding_channels = 0;
     bool has_img_emb                 = false;
     bool has_middle_block_1          = false;
+    bool has_output_block_311        = false;
     bool has_output_block_71         = false;
 
     for (auto& [name, tensor_storage] : tensor_storage_map) {
@@ -1100,6 +1101,9 @@ SDVersion ModelLoader::get_sd_version() {
             tensor_storage.name.find("unet.mid_block.resnets.1.") != std::string::npos) {
             has_middle_block_1 = true;
         }
+        if (tensor_storage.name.find("model.diffusion_model.output_blocks.3.1.transformer_blocks.1") != std::string::npos) {
+            has_output_block_311 = true;
+        }
         if (tensor_storage.name.find("model.diffusion_model.output_blocks.7.1") != std::string::npos) {
             has_output_block_71 = true;
         }
@@ -1138,6 +1142,9 @@ SDVersion ModelLoader::get_sd_version() {
             return VERSION_SDXL_PIX2PIX;
         }
         if (!has_middle_block_1) {
+            if (!has_output_block_311) {
+                return VERSION_SDXL_VEGA;
+            }
             return VERSION_SDXL_SSD1B;
         }
         return VERSION_SDXL;

model.h

@@ -32,6 +32,7 @@ enum SDVersion {
     VERSION_SDXL,
     VERSION_SDXL_INPAINT,
     VERSION_SDXL_PIX2PIX,
+    VERSION_SDXL_VEGA,
     VERSION_SDXL_SSD1B,
     VERSION_SVD,
     VERSION_SD3,
@@ -66,7 +67,7 @@ static inline bool sd_version_is_sd2(SDVersion version) {
 }
 
 static inline bool sd_version_is_sdxl(SDVersion version) {
-    if (version == VERSION_SDXL || version == VERSION_SDXL_INPAINT || version == VERSION_SDXL_PIX2PIX || version == VERSION_SDXL_SSD1B) {
+    if (version == VERSION_SDXL || version == VERSION_SDXL_INPAINT || version == VERSION_SDXL_PIX2PIX || version == VERSION_SDXL_SSD1B || version == VERSION_SDXL_VEGA) {
         return true;
     }
     return false;

stable-diffusion.cpp

@@ -35,6 +35,7 @@ const char* model_version_to_str[] = {
     "SDXL",
     "SDXL Inpaint",
     "SDXL Instruct-Pix2Pix",
+    "SDXL (Vega)",
     "SDXL (SSD1B)",
     "SVD",
     "SD3.x",
@@ -623,7 +624,7 @@ public:
                         LOG_INFO("Using Conv2d direct in the vae model");
                         first_stage_model->set_conv2d_direct_enabled(true);
                     }
-                    if (version == VERSION_SDXL &&
+                    if (sd_version_is_sdxl(version) &&
                         (strlen(SAFE_STR(sd_ctx_params->vae_path)) == 0 || sd_ctx_params->force_sdxl_vae_conv_scale)) {
                         float vae_conv_2d_scale = 1.f / 32.f;
                         LOG_WARN(

unet.hpp

@@ -201,6 +201,9 @@ public:
             num_head_channels     = 64;
             num_heads             = -1;
             use_linear_projection = true;
+            if (version == VERSION_SDXL_VEGA) {
+                transformer_depth = {1, 1, 2};
+            }
         } else if (version == VERSION_SVD) {
             in_channels           = 8;
             out_channels          = 4;
@@ -319,7 +322,7 @@ public:
         }
         if (!tiny_unet) {
             blocks["middle_block.0"] = std::shared_ptr<GGMLBlock>(get_resblock(ch, time_embed_dim, ch));
-            if (version != VERSION_SDXL_SSD1B) {
+            if (version != VERSION_SDXL_SSD1B && version != VERSION_SDXL_VEGA) {
                 blocks["middle_block.1"] = std::shared_ptr<GGMLBlock>(get_attention_layer(ch,
                                                                                           n_head,
                                                                                           d_head,
@@ -520,7 +523,7 @@ public:
         // middle_block
         if (!tiny_unet) {
             h = resblock_forward("middle_block.0", ctx, h, emb, num_video_frames);  // [N, 4*model_channels, h/8, w/8]
-            if (version != VERSION_SDXL_SSD1B) {
+            if (version != VERSION_SDXL_SSD1B && version != VERSION_SDXL_VEGA) {
                 h = attention_layer_forward("middle_block.1", ctx, h, context, num_video_frames);  // [N, 4*model_channels, h/8, w/8]
                 h = resblock_forward("middle_block.2", ctx, h, emb, num_video_frames);             // [N, 4*model_channels, h/8, w/8]
             }