feat: add SmoothStep Scheduler (#813)

.gitignore

@@ -1,10 +1,10 @@
 build*/
+cmake-build-*/
 test/
 .vscode/
+.idea/
 .cache/
 *.swp
-.vscode/
-.idea/
 *.bat
 *.bin
 *.exe

CMakeLists.txt

@@ -149,3 +149,7 @@ if (SD_BUILD_EXAMPLES)
     add_subdirectory(examples)
 endif()
 
+set(SD_PUBLIC_HEADERS stable-diffusion.h)
+set_target_properties(${SD_LIB} PROPERTIES PUBLIC_HEADER "${SD_PUBLIC_HEADERS}")
+
+install(TARGETS ${SD_LIB} LIBRARY PUBLIC_HEADER)

denoiser.hpp

@@ -251,6 +251,35 @@ struct KarrasSchedule : SigmaSchedule {
     }
 };
 
+// Close to Beta Schedule, but increadably simple in code.
+struct SmoothStepSchedule : SigmaSchedule {
+    static constexpr float smoothstep(float x) {
+        return x * x * (3.0f - 2.0f * x);
+    }
+
+    std::vector<float> get_sigmas(uint32_t n, float /*sigma_min*/, float /*sigma_max*/, t_to_sigma_t t_to_sigma) override {
+        std::vector<float> result;
+        result.reserve(n + 1);
+
+        const int t_max = TIMESTEPS - 1;
+        if (n == 0) {
+            return result;
+        } else if (n == 1) {
+            result.push_back(t_to_sigma((float)t_max));
+            result.push_back(0.f);
+            return result;
+        }
+
+        for (uint32_t i = 0; i < n; i++) {
+            float u = 1.f - float(i) / float(n);
+            result.push_back(t_to_sigma(std::round(smoothstep(u) * t_max)));
+        }
+
+        result.push_back(0.f);
+        return result;
+    }
+};
+
 struct Denoiser {
     std::shared_ptr<SigmaSchedule> scheduler                                                 = std::make_shared<DiscreteSchedule>();
     virtual float sigma_min()                                                                = 0;

examples/cli/main.cpp

@@ -238,7 +238,7 @@ void print_usage(int argc, const char* argv[]) {
     printf("  --skip-layers LAYERS               Layers to skip for SLG steps: (default: [7,8,9])\n");
     printf("  --skip-layer-start START           SLG enabling point: (default: 0.01)\n");
     printf("  --skip-layer-end END               SLG disabling point: (default: 0.2)\n");
-    printf("  --scheduler {discrete, karras, exponential, ays, gits} Denoiser sigma scheduler (default: discrete)\n");
+    printf("  --scheduler {discrete, karras, exponential, ays, gits, smoothstep} Denoiser sigma scheduler (default: discrete)\n");
     printf("  --sampling-method {euler, euler_a, heun, dpm2, dpm++2s_a, dpm++2m, dpm++2mv2, ipndm, ipndm_v, lcm, ddim_trailing, tcd}\n");
     printf("                                     sampling method (default: \"euler_a\")\n");
     printf("  --steps  STEPS                     number of sample steps (default: 20)\n");
@@ -251,7 +251,7 @@ void print_usage(int argc, const char* argv[]) {
     printf("  --high-noise-skip-layers LAYERS    (high noise) Layers to skip for SLG steps: (default: [7,8,9])\n");
     printf("  --high-noise-skip-layer-start      (high noise) SLG enabling point: (default: 0.01)\n");
     printf("  --high-noise-skip-layer-end END    (high noise) SLG disabling point: (default: 0.2)\n");
-    printf("  --high-noise-scheduler {discrete, karras, exponential, ays, gits} Denoiser sigma scheduler (default: discrete)\n");
+    printf("  --high-noise-scheduler {discrete, karras, exponential, ays, gits, smoothstep} Denoiser sigma scheduler (default: discrete)\n");
     printf("  --high-noise-sampling-method {euler, euler_a, heun, dpm2, dpm++2s_a, dpm++2m, dpm++2mv2, ipndm, ipndm_v, lcm, ddim_trailing, tcd}\n");
     printf("                                     (high noise) sampling method (default: \"euler_a\")\n");
     printf("  --high-noise-steps  STEPS          (high noise) number of sample steps (default: -1 = auto)\n");

ggml_extend.hpp

@@ -56,6 +56,25 @@
 #define __STATIC_INLINE__ static inline
 #endif
 
+__STATIC_INLINE__ void ggml_log_callback_default(ggml_log_level level, const char* text, void*) {
+    switch (level) {
+        case GGML_LOG_LEVEL_DEBUG:
+            LOG_DEBUG(text);
+            break;
+        case GGML_LOG_LEVEL_INFO:
+            LOG_INFO(text);
+            break;
+        case GGML_LOG_LEVEL_WARN:
+            LOG_WARN(text);
+            break;
+        case GGML_LOG_LEVEL_ERROR:
+            LOG_ERROR(text);
+            break;
+        default:
+            LOG_DEBUG(text);
+    }
+}
+
 static_assert(GGML_MAX_NAME >= 128, "GGML_MAX_NAME must be at least 128");
 
 // n-mode trensor-matrix product
@@ -124,13 +143,6 @@ __STATIC_INLINE__ struct ggml_tensor* ggml_kronecker(ggml_context* ctx, struct g
                     b);
 }
 
-__STATIC_INLINE__ void ggml_log_callback_default(ggml_log_level level, const char* text, void* user_data) {
-    (void)level;
-    (void)user_data;
-    fputs(text, stderr);
-    fflush(stderr);
-}
-
 __STATIC_INLINE__ void ggml_tensor_set_f32_randn(struct ggml_tensor* tensor, std::shared_ptr<RNG> rng) {
     uint32_t n                        = (uint32_t)ggml_nelements(tensor);
     std::vector<float> random_numbers = rng->randn(n);

stable-diffusion.cpp

@@ -145,7 +145,6 @@ public:
 #endif
 #ifdef SD_USE_METAL
         LOG_DEBUG("Using Metal backend");
-        ggml_log_set(ggml_log_callback_default, nullptr);
         backend = ggml_backend_metal_init();
 #endif
 #ifdef SD_USE_VULKAN
@@ -192,6 +191,8 @@ public:
             rng = std::make_shared<PhiloxRNG>();
         }
 
+        ggml_log_set(ggml_log_callback_default, nullptr);
+
         init_backend();
 
         ModelLoader model_loader;
@@ -344,9 +345,6 @@ public:
                 LOG_INFO("Using flash attention in the diffusion model");
             }
             if (sd_version_is_sd3(version)) {
-                if (sd_ctx_params->diffusion_flash_attn) {
-                    LOG_WARN("flash attention in this diffusion model is currently unsupported!");
-                }
                 cond_stage_model = std::make_shared<SD3CLIPEmbedder>(clip_backend,
                                                                      offload_params_to_cpu,
                                                                      model_loader.tensor_storages_types);
@@ -362,6 +360,15 @@ public:
                     }
                 }
                 if (is_chroma) {
+                    if (sd_ctx_params->diffusion_flash_attn && sd_ctx_params->chroma_use_dit_mask) {
+                        LOG_WARN(
+                            "!!!It looks like you are using Chroma with flash attention. "
+                            "This is currently unsupported. "
+                            "If you find that the generated images are broken, "
+                            "try either disabling flash attention or specifying "
+                            "--chroma-disable-dit-mask as a workaround.");
+                    }
+
                     cond_stage_model = std::make_shared<T5CLIPEmbedder>(clip_backend,
                                                                         offload_params_to_cpu,
                                                                         model_loader.tensor_storages_types,
@@ -744,6 +751,10 @@ public:
                 denoiser->scheduler          = std::make_shared<GITSSchedule>();
                 denoiser->scheduler->version = version;
                 break;
+            case SMOOTHSTEP:
+                LOG_INFO("Running with SmoothStep scheduler");
+                denoiser->scheduler = std::make_shared<SmoothStepSchedule>();
+                break;
             case DEFAULT:
                 // Don't touch anything.
                 break;
@@ -1527,6 +1538,7 @@ const char* schedule_to_str[] = {
     "exponential",
     "ays",
     "gits",
+    "smoothstep",
 };
 
 const char* sd_schedule_name(enum scheduler_t scheduler) {
@@ -1546,7 +1558,7 @@ enum scheduler_t str_to_schedule(const char* str) {
 }
 
 void sd_ctx_params_init(sd_ctx_params_t* sd_ctx_params) {
-    memset((void*)sd_ctx_params, 0, sizeof(sd_ctx_params_t));
+    *sd_ctx_params                         = {};
     sd_ctx_params->vae_decode_only         = true;
     sd_ctx_params->vae_tiling              = false;
     sd_ctx_params->free_params_immediately = true;
@@ -1630,6 +1642,7 @@ char* sd_ctx_params_to_str(const sd_ctx_params_t* sd_ctx_params) {
 }
 
 void sd_sample_params_init(sd_sample_params_t* sample_params) {
+    *sample_params                             = {};
     sample_params->guidance.txt_cfg            = 7.0f;
     sample_params->guidance.img_cfg            = INFINITY;
     sample_params->guidance.distilled_guidance = 3.5f;
@@ -1676,9 +1689,9 @@ char* sd_sample_params_to_str(const sd_sample_params_t* sample_params) {
 }
 
 void sd_img_gen_params_init(sd_img_gen_params_t* sd_img_gen_params) {
-    memset((void*)sd_img_gen_params, 0, sizeof(sd_img_gen_params_t));
-    sd_img_gen_params->clip_skip = -1;
+    *sd_img_gen_params = {};
     sd_sample_params_init(&sd_img_gen_params->sample_params);
+    sd_img_gen_params->clip_skip        = -1;
     sd_img_gen_params->ref_images_count = 0;
     sd_img_gen_params->width            = 512;
     sd_img_gen_params->height           = 512;
@@ -1735,7 +1748,7 @@ char* sd_img_gen_params_to_str(const sd_img_gen_params_t* sd_img_gen_params) {
 }
 
 void sd_vid_gen_params_init(sd_vid_gen_params_t* sd_vid_gen_params) {
-    memset((void*)sd_vid_gen_params, 0, sizeof(sd_vid_gen_params_t));
+    *sd_vid_gen_params = {};
     sd_sample_params_init(&sd_vid_gen_params->sample_params);
     sd_sample_params_init(&sd_vid_gen_params->high_noise_sample_params);
     sd_vid_gen_params->high_noise_sample_params.sample_steps = -1;
@@ -1759,6 +1772,7 @@ sd_ctx_t* new_sd_ctx(const sd_ctx_params_t* sd_ctx_params) {
 
     sd_ctx->sd = new StableDiffusionGGML();
     if (sd_ctx->sd == NULL) {
+        free(sd_ctx);
         return NULL;
     }
 

stable-diffusion.h

@@ -57,6 +57,7 @@ enum scheduler_t {
     EXPONENTIAL,
     AYS,
     GITS,
+    SMOOTHSTEP,
     SCHEDULE_COUNT
 };
 

upscaler.cpp

@@ -19,13 +19,13 @@ struct UpscalerGGML {
 
     bool load_from_file(const std::string& esrgan_path,
                         bool offload_params_to_cpu) {
+        ggml_log_set(ggml_log_callback_default, nullptr);
 #ifdef SD_USE_CUDA
         LOG_DEBUG("Using CUDA backend");
         backend = ggml_backend_cuda_init(0);
 #endif
 #ifdef SD_USE_METAL
         LOG_DEBUG("Using Metal backend");
-        ggml_log_set(ggml_log_callback_default, nullptr);
         backend = ggml_backend_metal_init();
 #endif
 #ifdef SD_USE_VULKAN

util.cpp

@@ -414,7 +414,10 @@ void log_printf(sd_log_level_t level, const char* file, int line, const char* fo
     if (written >= 0 && written < LOG_BUFFER_SIZE) {
         vsnprintf(log_buffer + written, LOG_BUFFER_SIZE - written, format, args);
     }
-    strncat(log_buffer, "\n", LOG_BUFFER_SIZE - strlen(log_buffer));
+    size_t len = strlen(log_buffer);
+    if (log_buffer[len - 1] != '\n') {
+        strncat(log_buffer, "\n", LOG_BUFFER_SIZE - len);
+    }
 
     if (sd_log_cb) {
         sd_log_cb(level, log_buffer, sd_log_cb_data);