[FFmpeg-devel] [PATCH 1/3] fftools: Stop using av_fopen_utf8

[Soft Works]

> -----Original Message-----
> From: ffmpeg-devel <ffmpeg-devel-bounces at ffmpeg.org> On Behalf Of Martin
> Storsjö
> Sent: Friday, May 20, 2022 11:13 PM
> To: ffmpeg-devel at ffmpeg.org
> Subject: [FFmpeg-devel] [PATCH 1/3] fftools: Stop using av_fopen_utf8
> 
> Provide a header based inline reimplementation of it.
> 
> Using av_fopen_utf8 doesn't work outside of the libraries when built
> with MSVC as shared libraries (in the default configuration, where
> each DLL gets a separate statically linked CRT).
> ---
>  fftools/ffmpeg_opt.c |  3 +-
>  fftools/fopen_utf8.h | 71 ++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 73 insertions(+), 1 deletion(-)
>  create mode 100644 fftools/fopen_utf8.h
> 
> diff --git a/fftools/ffmpeg_opt.c b/fftools/ffmpeg_opt.c
> index 47e8b9b7bd..a5cd989d35 100644
> --- a/fftools/ffmpeg_opt.c
> +++ b/fftools/ffmpeg_opt.c
> @@ -28,6 +28,7 @@
>  #endif
> 
>  #include "ffmpeg.h"
> +#include "fopen_utf8.h"
>  #include "cmdutils.h"
>  #include "opt_common.h"
> 
> @@ -1882,7 +1883,7 @@ static OutputStream *new_video_stream(OptionsContext
> *o, AVFormatContext *oc, in
>                      video_enc->stats_in = logbuffer;
>                  }
>                  if (video_enc->flags & AV_CODEC_FLAG_PASS1) {
> -                    f = av_fopen_utf8(logfilename, "wb");
> +                    f = fopen_utf8(logfilename, "wb");
>                      if (!f) {
>                          av_log(NULL, AV_LOG_FATAL,
>                                 "Cannot write log file '%s' for pass-1
> encoding: %s\n",
> diff --git a/fftools/fopen_utf8.h b/fftools/fopen_utf8.h
> new file mode 100644
> index 0000000000..db57fcaec4
> --- /dev/null
> +++ b/fftools/fopen_utf8.h
> @@ -0,0 +1,71 @@
> +/*
> + * This file is part of FFmpeg.
> + *
> + * FFmpeg is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * FFmpeg is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with FFmpeg; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-
> 1301 USA
> + */
> +
> +#ifndef FFTOOLS_FOPEN_UTF8_H
> +#define FFTOOLS_FOPEN_UTF8_H
> +
> +#include <stdio.h>
> +
> +/* The fopen_utf8 function here is essentially equivalent to
> av_fopen_utf8,
> + * except that it doesn't set O_CLOEXEC, and that it isn't exported
> + * from a different library. (On Windows, each DLL might use a different
> + * CRT, and FILE* handles can't be shared across them.) */
> +
> +#ifdef _WIN32
> +#include "libavutil/wchar_filename.h"
> +
> +static inline FILE *fopen_utf8(const char *path_utf8, const char *mode)
> +{
> +    wchar_t *path_w, *mode_w;
> +    FILE *f;
> +
> +    /* convert UTF-8 to wide chars */
> +    if (utf8towchar(path_utf8, &path_w)) /* This sets errno on error. */
> +        return NULL;
> +    if (!path_w)
> +        goto fallback;
> +
> +    if (utf8towchar(mode, &mode_w))
> +        return NULL;
> +    if (!mode_w) {
> +        /* If failing to interpret the mode string as utf8, it is an
> invalid
> +         * parameter. */
> +        av_freep(&path_w);
> +        errno = EINVAL;
> +        return NULL;
> +    }
> +
> +    f = _wfopen(path_w, mode_w);
> +    av_freep(&path_w);
> +    av_freep(&mode_w);
> +
> +    return f;
> +fallback:
> +    /* path may be in CP_ACP */
> +    return fopen(path_utf8, mode);
> +}
> +
> +#else
> +
> +static inline FILE *fopen_utf8(const char *path, const char *mode)
> +{
> +    return fopen(path, mode);
> +}
> +#endif
> +
> +#endif /* FFTOOLS_FOPEN_UTF8_H */
> --

LGTM. (all three)

Tested with VS project build (full static linkage, though).

Thank you,
sw