hwcontext_vulkan: let users enable device and instance extensions using options

Also documents all options supported by the hwdevice.
This lets users enable all extensions they need without writing their own
instance initialization code.

doc/ffmpeg.texi

@@ -1034,6 +1034,18 @@ If @var{device} is an integer, it selects the device by its index in a
 system-dependent list of devices.  If @var{device} is any other string, it
 selects the first device with a name containing that string as a substring.
 
+The following options are recognized:
+@table @option
+@item debug
+If set to 1, enables the validation layer, if installed.
+@item linear_images
+If set to 1, images allocated by the hwcontext will be linear and locally mappable.
+@item instance_extensions
+A plus separated list of additional instance extensions to enable.
+@item device_extensions
+A plus separated list of additional device extensions to enable.
+@end table
+
 Examples:
 @table @emph
 @item -init_hw_device vulkan:1
@@ -1041,6 +1053,9 @@ Choose the second device on the system.
 
 @item -init_hw_device vulkan:RADV
 Choose the first device with a name containing the string @emph{RADV}.
+
+@item -init_hw_device vulkan:0,instance_extensions=VK_KHR_wayland_surface+VK_KHR_xcb_surface
+Choose the first device and enable the Wayland and XCB instance extensions.
 @end table
 
 @end table

libavutil/hwcontext_vulkan.c

@@ -98,9 +98,13 @@ typedef struct AVVkFrameInternal {
         list = av_realloc_array(list, sizeof(*list), ++count);                 \
         if (!list) {                                                           \
             err = AVERROR(ENOMEM);                                             \
-            goto end;                                                          \
+            goto fail;                                                         \
+        }                                                                      \
+        list[count - 1] = av_strdup(val);                                      \
+        if (!list[count - 1]) {                                                \
+            err = AVERROR(ENOMEM);                                             \
+            goto fail;                                                         \
         }                                                                      \
-        list[count - 1] = val;                                                 \
     } while(0)
 
 static const struct {
@@ -261,7 +265,7 @@ static VkBool32 vk_dbg_callback(VkDebugUtilsMessageSeverityFlagBitsEXT severity,
     return 0;
 }
 
-static int check_extensions(AVHWDeviceContext *ctx, int dev,
+static int check_extensions(AVHWDeviceContext *ctx, int dev, AVDictionary *opts,
                             const char * const **dst, uint32_t *num, int debug)
 {
     const char *tstr;
@@ -273,6 +277,8 @@ static int check_extensions(AVHWDeviceContext *ctx, int dev,
     const char *mod;
     int optional_exts_num;
     uint32_t sup_ext_count;
+    char *user_exts_str = NULL;
+    AVDictionaryEntry *user_exts;
     VkExtensionProperties *sup_ext;
     const VulkanOptExtension *optional_exts;
 
@@ -280,6 +286,14 @@ static int check_extensions(AVHWDeviceContext *ctx, int dev,
         mod = "instance";
         optional_exts = optional_instance_exts;
         optional_exts_num = FF_ARRAY_ELEMS(optional_instance_exts);
+        user_exts = av_dict_get(opts, "instance_extensions", NULL, 0);
+        if (user_exts) {
+            user_exts_str = av_strdup(user_exts->value);
+            if (!user_exts_str) {
+                err = AVERROR(ENOMEM);
+                goto fail;
+            }
+        }
         vkEnumerateInstanceExtensionProperties(NULL, &sup_ext_count, NULL);
         sup_ext = av_malloc_array(sup_ext_count, sizeof(VkExtensionProperties));
         if (!sup_ext)
@@ -289,6 +303,14 @@ static int check_extensions(AVHWDeviceContext *ctx, int dev,
         mod = "device";
         optional_exts = optional_device_exts;
         optional_exts_num = FF_ARRAY_ELEMS(optional_device_exts);
+        user_exts = av_dict_get(opts, "device_extensions", NULL, 0);
+        if (user_exts) {
+            user_exts_str = av_strdup(user_exts->value);
+            if (!user_exts_str) {
+                err = AVERROR(ENOMEM);
+                goto fail;
+            }
+        }
         vkEnumerateDeviceExtensionProperties(hwctx->phys_dev, NULL,
                                              &sup_ext_count, NULL);
         sup_ext = av_malloc_array(sup_ext_count, sizeof(VkExtensionProperties));
@@ -336,19 +358,52 @@ static int check_extensions(AVHWDeviceContext *ctx, int dev,
             }
         }
         if (found) {
+            av_log(ctx, AV_LOG_VERBOSE, "Using %s extension \"%s\"\n", mod, tstr);
             ADD_VAL_TO_LIST(extension_names, extensions_found, tstr);
         } else {
             av_log(ctx, AV_LOG_ERROR, "Debug extension \"%s\" not found!\n",
                    tstr);
             err = AVERROR(EINVAL);
-            goto end;
+            goto fail;
+        }
+    }
+
+    if (user_exts_str) {
+        char *save, *token = av_strtok(user_exts_str, "+", &save);
+        while (token) {
+            found = 0;
+            for (int j = 0; j < sup_ext_count; j++) {
+                if (!strcmp(token, sup_ext[j].extensionName)) {
+                    found = 1;
+                    break;
+                }
+            }
+            if (found) {
+                av_log(ctx, AV_LOG_VERBOSE, "Using %s extension \"%s\"\n", mod, tstr);
+                ADD_VAL_TO_LIST(extension_names, extensions_found, token);
+            } else {
+                av_log(ctx, AV_LOG_ERROR, "%s extension \"%s\" not found!\n",
+                       mod, token);
+                err = AVERROR(EINVAL);
+                goto fail;
+            }
+            token = av_strtok(NULL, "+", &save);
         }
     }
 
     *dst = extension_names;
     *num = extensions_found;
 
-end:
+    av_free(user_exts_str);
+    av_free(sup_ext);
+    return 0;
+
+fail:
+    if (extension_names)
+        for (int i = 0; i < extensions_found; i++)
+            av_free((void *)extension_names[i]);
+    av_free(extension_names);
+    av_free(user_exts_str);
     av_free(sup_ext);
     return err;
 }
@@ -376,7 +431,7 @@ static int create_instance(AVHWDeviceContext *ctx, AVDictionary *opts)
     };
 
     /* Check for present/missing extensions */
-    err = check_extensions(ctx, 0, &inst_props.ppEnabledExtensionNames,
+    err = check_extensions(ctx, 0, opts, &inst_props.ppEnabledExtensionNames,
                            &inst_props.enabledExtensionCount, debug_mode);
     if (err < 0)
         return err;
@@ -391,6 +446,8 @@ static int create_instance(AVHWDeviceContext *ctx, AVDictionary *opts)
     ret = vkCreateInstance(&inst_props, hwctx->alloc, &hwctx->inst);
 
     /* Free used memory */
+    for (int i = 0; i < inst_props.enabledExtensionCount; i++)
+        av_free((void *)inst_props.ppEnabledExtensionNames[i]);
     av_free((void *)inst_props.ppEnabledExtensionNames);
 
     /* Check for errors */
@@ -777,13 +834,15 @@ static int vulkan_device_create_internal(AVHWDeviceContext *ctx,
     if ((err = search_queue_families(ctx, &dev_info)))
         goto end;
 
-    if ((err = check_extensions(ctx, 1, &dev_info.ppEnabledExtensionNames,
+    if ((err = check_extensions(ctx, 1, opts, &dev_info.ppEnabledExtensionNames,
                                 &dev_info.enabledExtensionCount, 0)))
         goto end;
 
     ret = vkCreateDevice(hwctx->phys_dev, &dev_info, hwctx->alloc,
                          &hwctx->act_dev);
 
+    for (int i = 0; i < dev_info.enabledExtensionCount; i++)
+        av_free((void *)dev_info.ppEnabledExtensionNames[i]);
     av_free((void *)dev_info.ppEnabledExtensionNames);
 
     if (ret != VK_SUCCESS) {