From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 56878434A8 for ; Mon, 13 Jun 2022 20:50:57 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 028EE68B5B0; Mon, 13 Jun 2022 23:50:55 +0300 (EEST) Received: from mail8.parnet.fi (mail8.parnet.fi [77.234.108.134]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id 84C3F68B1DD for ; Mon, 13 Jun 2022 23:50:48 +0300 (EEST) Received: from mail9.parnet.fi (mail9.parnet.fi [77.234.108.21]) by mail8.parnet.fi with ESMTP id 25DKolu3008393-25DKolu4008393 for ; Mon, 13 Jun 2022 23:50:47 +0300 Received: from foo.martin.st (host-97-187.parnet.fi [77.234.97.187]) by mail9.parnet.fi (Postfix) with ESMTPS id 7F187A142E for ; Mon, 13 Jun 2022 23:50:47 +0300 (EEST) Date: Mon, 13 Jun 2022 23:50:46 +0300 (EEST) From: =?ISO-8859-15?Q?Martin_Storsj=F6?= To: FFmpeg development discussions and patches In-Reply-To: <20220613162626.11541-1-nil-admirari@mailo.com> Message-ID: References: <20220613162626.11541-1-nil-admirari@mailo.com> MIME-Version: 1.0 X-FE-Policy-ID: 3:14:2:SYSTEM Subject: Re: [FFmpeg-devel] [PATCH v14 1/5] libavutil: Add wchartoutf8(), wchartoansi(), utf8toansi() and getenv_utf8() X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: On Mon, 13 Jun 2022, Nil Admirari wrote: > wchartoutf8() converts strings returned by WinAPI into UTF-8, > which is FFmpeg's preffered encoding. > > Some external dependencies, such as AviSynth, are still > not Unicode-enabled. utf8toansi() converts UTF-8 strings > into ANSI in two steps: UTF-8 -> wchar_t -> ANSI. > wchartoansi() is responsible for the second step of the conversion. > Conversion in just one step is not supported by WinAPI. > > Since these character converting functions allocate the buffer > of necessary size, they also facilitate the removal of MAX_PATH limit > in places where fixed-size ANSI/WCHAR strings were used > as filename buffers. > > getenv_utf8() wraps _wgetenv() converting its input from > and its output to UTF-8. Compared to plain getenv(), > getenv_utf8() requires a cleanup. > > Because of that, in places that only test the existence of > an environment variable or compare its value with a string > consisting entirely of ASCII characters, the use of plain getenv() > is still preferred. (libavutil/log.c check_color_terminal() > is an example of such a place.) > > Plain getenv() is also preffered in UNIX-only code, > such as bktr.c, fbdev_common.c, oss.c in libavdevice > or af_ladspa.c in libavfilter. > --- > libavutil/getenv_utf8.h | 63 ++++++++++++++++++++++++++++++++++++++ > libavutil/wchar_filename.h | 51 ++++++++++++++++++++++++++++++ > 2 files changed, 114 insertions(+) > create mode 100644 libavutil/getenv_utf8.h > > diff --git a/libavutil/getenv_utf8.h b/libavutil/getenv_utf8.h > new file mode 100644 > index 0000000000..2c48a36355 > --- /dev/null > +++ b/libavutil/getenv_utf8.h > @@ -0,0 +1,63 @@ > +/* > + * 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 AVUTIL_GETENV_UTF8_H > +#define AVUTIL_GETENV_UTF8_H > + > +#include > + > +#include "mem.h" > + > +#ifdef _WIN32 > + > +#include "libavutil/wchar_filename.h" > + > +static inline char *getenv_utf8(const char *varname) > +{ > + wchar_t *varname_w, *var_w; > + char *var; > + > + if (utf8towchar(varname, &varname_w)) > + return NULL; > + if (!varname_w) > + return NULL; > + > + var_w = _wgetenv(varname_w); > + av_free(varname_w); > + > + if (!var_w) > + return NULL; > + if (wchartoutf8(var_w, &var)) > + return NULL; > + > + return var; > + > + // No CP_ACP fallback compared to other *_utf8() functions: > + // non UTF-8 strings must not be returned. > +} Note, there are Windows configurations that entirely lack getenv() (and presumably _wgetenv() too), namely the Windows Store App / Windows Phone App API subsets for Windows 8.x. I think those functions were allowed again in Windows 10 though... In configure, we have this: check_func_headers stdlib.h getenv enabled getenv || echo "#define getenv(x) NULL" >> $TMPH I guess we'd might have to add getenv to e.g. the SYSTEM_FUNCS list, so we'd get a HAVE_GETENV in config.h - then we could make getenv_utf8 a no-op if HAVE_GETENV is 0. (I'm not in a situation where I can test and investigate properly right now, I can maybe look closer into it later.) // Martin _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".