Enumerate v4l2 devices

device/device_list.c

@@ -0,0 +1,68 @@
+#include "device/device_list.h"
+
+#include <stddef.h>
+#include <stdlib.h>
+
+bool device_info_has_format(device_info_t *info, bool capture, unsigned format)
+{
+  if (!info) {
+    return false;
+  }
+
+  device_info_formats_t *formats = capture ? &info->capture_formats : &info->output_formats;
+
+  for (int i = 0; i < formats->n; i++) {
+    if (formats->formats[i] == format) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+device_info_t *device_list_find_m2m_format(device_list_t *list, unsigned output, unsigned capture)
+{
+  if (!list)
+    return NULL;
+
+  for (int i = 0; i < list->ndevices; i++) {
+    device_info_t *info = &list->devices[i];
+
+    if (info->m2m && device_info_has_format(info, false, output) && device_info_has_format(info, true, capture)) {
+      return info;
+    }
+  }
+
+  return NULL;
+}
+
+device_info_t *device_list_find_m2m_formats(device_list_t *list, unsigned output, unsigned capture_formats[], unsigned *found_format)
+{
+  for (int i = 0; capture_formats[i]; i++) {
+    device_info_t *info = device_list_find_m2m_format(list, output, capture_formats[i]);
+    if (info) {
+      if (found_format) {
+        *found_format = capture_formats[i];
+      }
+      return info;
+    }
+  }
+
+  return NULL;
+}
+
+void device_list_free(device_list_t *list)
+{
+  if (!list)
+    return;
+
+  for (int i = 0; i < list->ndevices; i++) {
+    device_info_t *info = &list->devices[i];
+    free(info->name);
+    free(info->path);
+    free(info->output_formats.formats);
+    free(info->capture_formats.formats);
+  }
+
+  free(list);
+}