diff --git a/libvmaf/include/getopt.h b/libvmaf/include/getopt.h
new file mode 100644
index 000000000..57bb43d4a
--- /dev/null
+++ b/libvmaf/include/getopt.h
@@ -0,0 +1,36 @@
+#ifndef VMAF_GETOPT_H
+#define VMAF_GETOPT_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern char *optarg;
+extern int optind;
+extern int opterr;
+extern int optopt;
+
+int getopt(int argc, char *const *argv, const char *optstring);
+int getopt_long(int argc, char *const *argv, const char *shortopts,
+                const struct option *longopts, int32_t *longind);
+int getopt_long_only(int argc, char *const *argv, const char *shortopts,
+                     const struct option *longopts, int32_t *longind);
+
+struct option {
+    const char *name;
+    int has_arg;
+    int *flag;
+    int val;
+};
+
+#define no_argument 0
+#define required_argument 1
+#define optional_argument 2
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* VMAF_GETOPT_H */
diff --git a/libvmaf/src/compat/msvc/stdatomic.h b/libvmaf/src/compat/msvc/stdatomic.h
index 979ee2ba8..7540775fd 100644
--- a/libvmaf/src/compat/msvc/stdatomic.h
+++ b/libvmaf/src/compat/msvc/stdatomic.h
@@ -39,8 +39,6 @@
 
 #include <windows.h>
 
-#include "common/attributes.h"
-
 typedef volatile LONG  __declspec(align(32)) atomic_int;
 typedef volatile ULONG __declspec(align(32)) atomic_uint;
 
diff --git a/libvmaf/src/feature/ciede.c b/libvmaf/src/feature/ciede.c
index 7bbfa8f60..8e523b507 100644
--- a/libvmaf/src/feature/ciede.c
+++ b/libvmaf/src/feature/ciede.c
@@ -52,6 +52,11 @@ SOFTWARE.
 #include "mem.h"
 #include "opt.h"
 
+#ifndef M_PI
+/* There are a lot of M_PI definitions but none generic to be included */
+#define M_PI 3.14159265358979323846264338327
+#endif // M_PI
+
 typedef struct CiedeState {
     VmafPicture ref;
     VmafPicture dist;
diff --git a/libvmaf/src/feature/integer_adm.c b/libvmaf/src/feature/integer_adm.c
index 269dbb5e8..e4f849051 100644
--- a/libvmaf/src/feature/integer_adm.c
+++ b/libvmaf/src/feature/integer_adm.c
@@ -31,6 +31,26 @@
 #include <arm_neon.h>
 #endif
 
+#ifdef _MSC_VER
+#include <intrin.h>
+
+/* Provide small fallbacks for GCC builtins used upstream. These are only
+ * defined for MSVC to avoid interfering with other compilers. */
+static inline int __builtin_clz(unsigned x) {
+    if (x == 0) return 32;
+    unsigned long index;
+    _BitScanReverse(&index, x);
+    return 31 - (int)index;
+}
+
+static inline int __builtin_clzll(unsigned long long x) {
+    if (x == 0) return 64;
+    unsigned long index;
+    _BitScanReverse64(&index, x);
+    return 63 - (int)index;
+}
+#endif
+
 typedef struct AdmState {
     size_t integer_stride;
     AdmBuffer buf;
diff --git a/libvmaf/src/feature/integer_vif.c b/libvmaf/src/feature/integer_vif.c
index fd6a82317..1f1135795 100644
--- a/libvmaf/src/feature/integer_vif.c
+++ b/libvmaf/src/feature/integer_vif.c
@@ -630,23 +630,27 @@ static int init(VmafFeatureExtractor *fex, enum VmafPixelFormat pix_fmt,
     if (!data) return -ENOMEM;
     memset(data, 0, data_sz);
 
-    s->public.buf.data = data; data += pad_size;
-    s->public.buf.ref = data; data += frame_size + pad_size + pad_size;
-    s->public.buf.dis = data; data += frame_size + pad_size;
-    s->public.buf.mu1 = data; data += h * s->public.buf.stride_16;
-    s->public.buf.mu2 = data; data += h * s->public.buf.stride_16;
-    s->public.buf.mu1_32 = data; data += s->public.buf.stride_32;
-    s->public.buf.mu2_32 = data; data += s->public.buf.stride_32;
-    s->public.buf.ref_sq = data; data += s->public.buf.stride_32;
-    s->public.buf.dis_sq = data; data += s->public.buf.stride_32;
-    s->public.buf.ref_dis = data; data += s->public.buf.stride_32;
-    s->public.buf.tmp.mu1 = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.mu2 = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.ref = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.dis = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.ref_dis = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.ref_convol = data; data += s->public.buf.stride_tmp;
-    s->public.buf.tmp.dis_convol = data;
+    /* Keep original layout but perform offset arithmetic on a byte pointer.
+    * This avoids undefined behavior on some compilers when doing pointer
+    * arithmetic with non-char pointer types (MSVC is strict about this). */
+    s->public.buf.data = data;
+    unsigned char *d = (unsigned char *)data + pad_size;
+    s->public.buf.ref = (void *)d; d += frame_size + pad_size + pad_size;
+    s->public.buf.dis = (void *)d; d += frame_size + pad_size;
+    s->public.buf.mu1 = (void *)d; d += h * s->public.buf.stride_16;
+    s->public.buf.mu2 = (void *)d; d += h * s->public.buf.stride_16;
+    s->public.buf.mu1_32 = (void *)d; d += s->public.buf.stride_32;
+    s->public.buf.mu2_32 = (void *)d; d += s->public.buf.stride_32;
+    s->public.buf.ref_sq = (void *)d; d += s->public.buf.stride_32;
+    s->public.buf.dis_sq = (void *)d; d += s->public.buf.stride_32;
+    s->public.buf.ref_dis = (void *)d; d += s->public.buf.stride_32;
+    s->public.buf.tmp.mu1 = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.mu2 = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.ref = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.dis = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.ref_dis = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.ref_convol = (void *)d; d += s->public.buf.stride_tmp;
+    s->public.buf.tmp.dis_convol = (void *)d;
 
     s->feature_name_dict =
         vmaf_feature_name_dict_from_provided_features(fex->provided_features,
diff --git a/libvmaf/src/feature/mkdirp.c b/libvmaf/src/feature/mkdirp.c
index 16fe966b3..d4faa220a 100644
--- a/libvmaf/src/feature/mkdirp.c
+++ b/libvmaf/src/feature/mkdirp.c
@@ -6,7 +6,15 @@
 // MIT licensed
 //
 
-#include <unistd.h>
+#ifdef _MSC_VER
+# include <io.h>
+# include <direct.h> /* _mkdir, _wmkdir */
+# ifndef strdup
+#  define strdup _strdup
+# endif
+#else
+# include <unistd.h>
+#endif
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
@@ -64,12 +72,18 @@ mkdirp(const char *path, mode_t mode) {
   free(parent);
 
   // make this one if parent has been made
-  #ifdef _WIN32
-    // http://msdn.microsoft.com/en-us/library/2fkk4dzw.aspx
-    int rc = mkdir(pathname);
-  #else
-    int rc = mkdir(pathname, mode);
-  #endif
+#ifdef _MSC_VER
+  /* On MSVC use _mkdir which takes only a path.
+   * Microsoft docs: _mkdir and _wmkdir create a new directory and return 0
+   * on success or -1 on error, setting errno accordingly. See CRT docs:
+   * https://learn.microsoft.com/en-us/c-runtime-library/reference/mkdir-wmkdir
+   *
+   * The CRT documents that _mkdir/_wmkdir behave like mkdir but accept only
+   * a path (no mode) and set errno on failure (EEXIST, ENOENT, ...). */
+  int rc = _mkdir(pathname);
+#else
+  int rc = mkdir(pathname, mode);
+#endif
 
   free(pathname);
 
diff --git a/libvmaf/src/feature/mkdirp.h b/libvmaf/src/feature/mkdirp.h
index 02371fb57..e7776eba4 100644
--- a/libvmaf/src/feature/mkdirp.h
+++ b/libvmaf/src/feature/mkdirp.h
@@ -12,6 +12,11 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
+#ifdef _MSC_VER
+/* On MSVC provide a minimal mode_t typedef */
+typedef int mode_t;
+#endif
+
 /*
  * Recursively `mkdir(path, mode)`
  */
diff --git a/libvmaf/src/libvmaf.c b/libvmaf/src/libvmaf.c
index 18ccff0e6..4f2d42eca 100644
--- a/libvmaf/src/libvmaf.c
+++ b/libvmaf/src/libvmaf.c
@@ -894,7 +894,8 @@ int vmaf_score_pooled_model_collection(VmafContext *vmaf,
     const char *suffix_stddev = "_stddev";
     const size_t name_sz =
         strlen(model_collection->name) + strlen(suffix_lo) + 1;
-    char name[name_sz];
+    char *name = malloc(name_sz);
+    if (!name) return -ENOMEM;
     memset(name, 0, name_sz);
 
     snprintf(name, name_sz, "%s%s", model_collection->name, suffix_bagging);
@@ -917,6 +918,7 @@ int vmaf_score_pooled_model_collection(VmafContext *vmaf,
                                      &score->bootstrap.ci.p95.hi,
                                      index_low, index_high);
 
+    free(name);
     return err;
 }
 
diff --git a/libvmaf/src/log.c b/libvmaf/src/log.c
index f93c7379f..142e9c35d 100644
--- a/libvmaf/src/log.c
+++ b/libvmaf/src/log.c
@@ -19,7 +19,13 @@
 #include "libvmaf/libvmaf.h"
 
 #include <stdarg.h>
-#include <unistd.h>
+#ifdef _WIN32
+# include <io.h>
+# define isatty _isatty
+# define fileno _fileno
+#else
+# include <unistd.h>
+#endif
 
 static enum VmafLogLevel vmaf_log_level = VMAF_LOG_LEVEL_INFO;
 static int istty = 0;
diff --git a/libvmaf/src/predict.c b/libvmaf/src/predict.c
index 9926de15b..5a0379d73 100644
--- a/libvmaf/src/predict.c
+++ b/libvmaf/src/predict.c
@@ -358,7 +358,9 @@ static int vmaf_bootstrap_predict_score_at_index(
                                         VmafModelCollectionScore *score)
 {
     int err = 0;
-    double scores[model_collection->cnt];
+    /* Use heap allocation to avoid large stack arrays on MSVC */
+    double *scores = malloc(sizeof(double) * model_collection->cnt);
+    if (!scores) return -ENOMEM;
 
     for (unsigned i = 0; i < model_collection->cnt; i++) {
         // mean, stddev, etc. are calculated on untransformed/unclipped scores
@@ -370,7 +372,7 @@ static int vmaf_bootstrap_predict_score_at_index(
                                           feature_collector, index,
                                           &scores[i], false,
                                           false, flags);
-        if (err) return err;
+        if (err) { free(scores); return err; }
 
         // do not override the model's transform/clip behavior
         // write the scores to the feature collector
@@ -378,7 +380,7 @@ static int vmaf_bootstrap_predict_score_at_index(
         err = vmaf_predict_score_at_index(model_collection->model[i],
                                           feature_collector, index,
                                           &score, true, false, 0);
-        if (err) return err;
+        if (err) { free(scores); return err; }
     }
 
     score->type = VMAF_MODEL_COLLECTION_SCORE_BOOTSTRAP;
@@ -424,7 +426,8 @@ static int vmaf_bootstrap_predict_score_at_index(
     const char *suffix_stddev = "_stddev";
     const size_t name_sz =
         strlen(model_collection->name) + strlen(suffix_lo) + 1;
-    char name[name_sz];
+    char *name = malloc(name_sz);
+    if (!name) { free(scores); return -ENOMEM; }
     memset(name, 0, name_sz);
 
     snprintf(name, name_sz, "%s%s", model_collection->name, suffix_bagging);
@@ -443,6 +446,8 @@ static int vmaf_bootstrap_predict_score_at_index(
     err |= vmaf_feature_collector_append(feature_collector, name,
                                          score->bootstrap.ci.p95.hi,
                                          index);
+    free(name);
+    free(scores);
     return err;
 }
 
diff --git a/libvmaf/src/read_json_model.c b/libvmaf/src/read_json_model.c
index 08405d3b7..677f58ef0 100644
--- a/libvmaf/src/read_json_model.c
+++ b/libvmaf/src/read_json_model.c
@@ -493,15 +493,19 @@ static int model_collection_parse(json_stream *s, VmafModel **model,
     if (!c.name) return -ENOMEM;
 
     const size_t cfg_name_sz = strlen(name) + 5 + 1;
-    char cfg_name[cfg_name_sz];
+    char *cfg_name = malloc(cfg_name_sz);
+    if (!cfg_name) { free((char*)name); return -ENOMEM; }
 
     const size_t generated_key_sz = 4 + 1;
-    char generated_key[generated_key_sz];
+    char *generated_key = malloc(generated_key_sz);
+    if (!generated_key) { free(cfg_name); free((char*)name); return -ENOMEM; }
 
     unsigned i = 0;
     while (json_peek(s) != JSON_OBJECT_END && !json_get_error(s)) {
-        if (json_next(s) != JSON_STRING)
-            return -EINVAL;
+        if (json_next(s) != JSON_STRING) {
+            err = -EINVAL;
+            goto cleanup;
+        }
 
         const char *key = json_get_string(s, NULL);
         snprintf(generated_key, generated_key_sz, "%d", i);
@@ -509,24 +513,26 @@ static int model_collection_parse(json_stream *s, VmafModel **model,
         if (!strcmp(key, generated_key)) {
             VmafModel *m;
             err = vmaf_read_json_model(&m, &c, s);
-            if (err) return err;
+            if (err) { free(generated_key); free(cfg_name); free((char*)name); return err; }
 
             if (i == 0) {
                 *model = m;
                 c.name = cfg_name;
             } else {
                 err = vmaf_model_collection_append(model_collection, m);
-                if (err) return err;
+                if (err) { free(generated_key); free(cfg_name); free((char*)name); return err; }
             }
 
             sprintf((char*)c.name, "%s_%04d", name, ++i);
-            continue;
         }
 
         json_skip(s);
     }
 
+    cleanup:
     free((char*)name);
+    free(generated_key);
+    free(cfg_name);
     if (!(*model_collection)) return -EINVAL;
     return err;
 }
diff --git a/libvmaf/tools/compat/getopt/getopt.c b/libvmaf/tools/compat/getopt/getopt.c
new file mode 100644
index 000000000..d2ea18308
--- /dev/null
+++ b/libvmaf/tools/compat/getopt/getopt.c
@@ -0,0 +1,52 @@
+/* Minimal getopt compatibility implementation for platforms without getopt.h */
+
+#include "getopt.h"
+#include <stdlib.h>
+#include <string.h>
+
+char *optarg = NULL;
+int optind = 1;
+int opterr = 1;
+int optopt = '?';
+
+int getopt(int argc, char *const *argv, const char *optstring) {
+    static int sp = 1;
+    if (optind >= argc) return -1;
+    char *arg = argv[optind];
+    if (arg[0] != '-' || arg[1] == '\0') return -1;
+    if (strcmp(arg, "--") == 0) { optind++; return -1; }
+    char c = arg[sp];
+    const char *oli = strchr(optstring, c);
+    if (!oli) {
+        optopt = c;
+        if (arg[++sp] == '\0') { optind++; sp = 1; }
+        return '?';
+    }
+    if (oli[1] == ':') {
+        if (arg[sp+1] != '\0') {
+            optarg = &arg[sp+1];
+            optind++;
+        } else if (optind+1 < argc) {
+            optarg = argv[++optind];
+            optind++;
+        } else {
+            optopt = c;
+            if (optstring[0] == ':') return ':'; else return '?';
+        }
+        sp = 1;
+    } else {
+        if (arg[++sp] == '\0') { optind++; sp = 1; }
+    }
+    return c;
+}
+
+int getopt_long(int argc, char *const *argv, const char *shortopts,
+                const struct option *longopts, int32_t *longind) {
+    (void)longopts; (void)longind;
+    return getopt(argc, argv, shortopts);
+}
+
+int getopt_long_only(int argc, char *const *argv, const char *shortopts,
+                     const struct option *longopts, int32_t *longind) {
+    return getopt_long(argc, argv, shortopts, longopts, longind);
+}
diff --git a/libvmaf/tools/meson.build b/libvmaf/tools/meson.build
index 0016d9c23..b98300cce 100644
--- a/libvmaf/tools/meson.build
+++ b/libvmaf/tools/meson.build
@@ -3,14 +3,19 @@ if cc.has_function('strsep')
   compat_cflags += '-DHAVE_STRSEP'
 endif
 
+compat_getopt = []
+if cc.get_id() == 'msvc'
+  compat_getopt = ['compat/getopt/getopt.c']
+endif
+
 vmaf = executable(
-    'vmaf',
-    ['vmaf.c', 'cli_parse.c', 'y4m_input.c', 'vidinput.c', 'yuv_input.c'],
-    include_directories : [libvmaf_inc, vmaf_include],
-    dependencies: [stdatomic_dependency, cuda_dependency],
-    c_args : [vmaf_cflags_common, compat_cflags],
-    link_with : get_option('default_library') == 'both' ? libvmaf.get_static_lib() : libvmaf,
-    install : true,
+  'vmaf',
+  compat_getopt + ['vmaf.c', 'cli_parse.c', 'y4m_input.c', 'vidinput.c', 'yuv_input.c'],
+  include_directories : [libvmaf_inc, vmaf_include],
+  dependencies: [stdatomic_dependency, cuda_dependency],
+  c_args : [vmaf_cflags_common, compat_cflags],
+  link_with : get_option('default_library') == 'both' ? libvmaf.get_static_lib() : libvmaf,
+  install : true,
 )
 
 subdir('test')
diff --git a/libvmaf/tools/vmaf.c b/libvmaf/tools/vmaf.c
index 316a04892..e467cc4d3 100644
--- a/libvmaf/tools/vmaf.c
+++ b/libvmaf/tools/vmaf.c
@@ -1,7 +1,17 @@
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#if defined(_WIN32) || defined(_WIN64)
+#include <io.h>
+#ifndef isatty
+#define isatty _isatty
+#endif
+#ifndef fileno
+#define fileno _fileno
+#endif
+#else
 #include <unistd.h>
+#endif
 
 #include "cli_parse.h"
 #include "spinner.h"
@@ -271,11 +281,24 @@ int main(int argc, char *argv[])
     VmafModelCollection **model_collection;
     const size_t model_collection_sz =
         sizeof(*model_collection) * c.model_cnt;
-    model_collection = malloc(model_sz);
+    model_collection = malloc(model_collection_sz);
+    if (!model_collection) {
+        fprintf(stderr, "memory allocation error\n");
+        return -1;
+    }
     memset(model_collection, 0, model_collection_sz);
 
-    const char *model_collection_label[c.model_cnt];
+    const char **model_collection_label = NULL;
     unsigned model_collection_cnt = 0;
+    if (c.model_cnt) {
+        model_collection_label = malloc(sizeof(*model_collection_label) * c.model_cnt);
+        if (!model_collection_label) {
+            fprintf(stderr, "memory allocation error\n");
+            free(model_collection);
+            free(model);
+            return -1;
+        }
+    }
 
     for (unsigned i = 0; i < c.model_cnt; i++) {
         if (c.model_config[i].version) {
@@ -501,6 +524,8 @@ int main(int argc, char *argv[])
     for (unsigned i = 0; i < model_collection_cnt; i++)
         vmaf_model_collection_destroy(model_collection[i]);
     free(model_collection);
+    if (model_collection_label)
+        free((void*)model_collection_label);
 
     video_input_close(&vid_ref);
     video_input_close(&vid_dist);