[FFmpeg-devel] [PATCH v9 2/6] libavformat/avisynth.c: Remove MAX_PATH limit

[Martin Storsjö]

On Fri, 15 Apr 2022, Nil Admirari wrote:

> ---
> libavformat/avisynth.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/libavformat/avisynth.c b/libavformat/avisynth.c
> index 8ba2bdea..f7bea8c3 100644
> --- a/libavformat/avisynth.c
> +++ b/libavformat/avisynth.c
> @@ -34,6 +34,7 @@
> /* Platform-specific directives. */
> #ifdef _WIN32
>   #include "compat/w32dlfcn.h"
> +  #include "libavutil/wchar_filename.h"
>   #undef EXTERN_C
>   #define AVISYNTH_LIB "avisynth"
> #else
> @@ -810,8 +811,7 @@ static int avisynth_open_file(AVFormatContext *s)
>     AVS_Value arg, val;
>     int ret;
> #ifdef _WIN32
> -    char filename_ansi[MAX_PATH * 4];
> -    wchar_t filename_wc[MAX_PATH * 4];
> +    char *filename_ansi = NULL;
> #endif
>
>     if (ret = avisynth_context_create(s))
> @@ -819,10 +819,12 @@ static int avisynth_open_file(AVFormatContext *s)
>
> #ifdef _WIN32
>     /* Convert UTF-8 to ANSI code page */
> -    MultiByteToWideChar(CP_UTF8, 0, s->url, -1, filename_wc, MAX_PATH * 4);
> -    WideCharToMultiByte(CP_THREAD_ACP, 0, filename_wc, -1, filename_ansi,
> -                        MAX_PATH * 4, NULL, NULL);
> +    if (utf8toansi(s->url, &filename_ansi)) {
> +        ret = AVERROR_UNKNOWN;
> +        goto fail;
> +    }
>     arg = avs_new_value_string(filename_ansi);
> +    av_free(filename_ansi);
> #else
>     arg = avs_new_value_string(s->url);
> #endif

This looks ok to me, but as mentioned in the other patch, I think CP_ACP 
actually would be more correct than the current CP_THREAD_ACP 
(https://github.com/ocaml/ocaml/issues/7854), so it could be worthwhile to 
change that at the same time (either just as part of this refactoring, or 
as a totally separate patch for clarity).

// Martin