[FFmpeg-devel] [PATCH v13 1/4] libavutil/wchar_filename.h: Add whcartoutf8, wchartoansi and utf8toansi

[Nil Admirari]

These functions are going to be used in libavformat/avisynth.c
and fftools/cmdutils.c to remove MAX_PATH limit.
---
 libavutil/wchar_filename.h | 51 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/libavutil/wchar_filename.h b/libavutil/wchar_filename.h
index f36d9df..90f6a53 100644
--- a/libavutil/wchar_filename.h
+++ b/libavutil/wchar_filename.h
@@ -41,6 +41,57 @@ static inline int utf8towchar(const char *filename_utf8, wchar_t **filename_w)
     return 0;
 }
 
+av_warn_unused_result
+static inline int wchartocp(unsigned int code_page, const wchar_t *filename_w,
+                            char **filename)
+{
+    DWORD flags = code_page == CP_UTF8 ? MB_ERR_INVALID_CHARS : 0;
+    int num_chars = WideCharToMultiByte(code_page, flags, filename_w, -1,
+                                        NULL, 0, NULL, NULL);
+    if (num_chars <= 0) {
+        *filename = NULL;
+        return 0;
+    }
+    *filename = av_calloc(num_chars, sizeof(char));
+    if (!*filename) {
+        errno = ENOMEM;
+        return -1;
+    }
+    WideCharToMultiByte(code_page, flags, filename_w, -1,
+                        *filename, num_chars, NULL, NULL);
+    return 0;
+}
+
+av_warn_unused_result
+static inline int wchartoutf8(const wchar_t *filename_w, char **filename)
+{
+    return wchartocp(CP_UTF8, filename_w, filename);
+}
+
+av_warn_unused_result
+static inline int wchartoansi(const wchar_t *filename_w, char **filename)
+{
+    return wchartocp(CP_ACP, filename_w, filename);
+}
+
+av_warn_unused_result
+static inline int utf8toansi(const char *filename_utf8, char **filename)
+{
+    wchar_t *filename_w = NULL;
+    int ret = -1;
+    if (utf8towchar(filename_utf8, &filename_w))
+        return -1;
+
+    if (!filename_w) {
+        *filename = NULL;
+        return 0;
+    }
+
+    ret = wchartoansi(filename_w, filename);
+    av_free(filename_w);
+    return ret;
+}
+
 /**
  * Checks for extended path prefixes for which normalization needs to be skipped.
  * see .NET6: PathInternal.IsExtended()
-- 
2.34.1