This is a port of FFmpeg 5.1.2 to MSDOS/DJGPP.

  FFmpeg is the leading multimedia framework, able to decode, encode,
  transcode, mux, demux, stream, filter and play pretty much anything
  that humans and machines have created. It supports the most obscure
  ancient formats up to the cutting edge. No matter if they were
  designed by some standards committee, the community or a corporation.

  FFmpeg Libraries for developers
    libavutil is a library containing functions for simplifying programming,
    including random number generators, data structures, mathematics routines,
    core multimedia utilities, and much more.
    libavcodec is a library containing decoders and encoders for audio/video
    codecs.
    libavformat is a library containing demuxers and muxers for multimedia
    container formats.
    libavdevice is a library containing input and output devices for grabbing
    from and rendering to many common multimedia input/output software frameworks,
    including Video4Linux, Video4Linux2, VfW, and ALSA.
    libavfilter is a library containing media filters.
    libswscale is a library performing highly optimized image scaling and color
    space/pixel format conversion operations.
    libswresample is a library performing highly optimized audio resampling,
    rematrixing and sample format conversion operations.




1.:     DJGPP specific changes.
        =======================

      - This port will be configured and be build in the "0build" directory.
      - The port has been configured and compiled on WinXP SP3 and Win98SE.
        There is absolute no guarantee that this may be possible with any
        other plain DOS-like OS.  Especially not on MS-DOS 6.22 with or
        without LFN support.  Due to the use of long file names it will not
        be possible to configure and compile without LFN support.
      - This version of the port has been compiled using gcc1210, gpp1210
        and bnu2351b.  No previous compiler version has worked.

        As usual, all djgpp specific files (config.bat, diffs, readme files,
        etc.) are located in the djgpp subdir.

        For further information about FFmpeg please read the info docs and NEWS file.


2.:     Installing the binary package.
        ==============================

2.1.:   Copy the binary distribution into the top DJGPP installation directory
        and unzip it running *ONE* of the following commands:
          unzip32 ffmg512b.zip      or
          djtarx ffmg512b.zip       or
          pkunzip -d ffmg512b.zip


3.:     Building the binaries from sources.
        ===================================

3.1.:   Create a temporary directory and copy the source package into the
        directory.  If you download the source distribution from one of the
        DJGPP sites, just unzip it preserving the directory structure
        running *ONE* of the following commands:
          unzip32 ffmg512s.zip      or
          djtarx ffmg512s.zip       or
          pkunzip -d ffmg512s.zip

3.2.:   To build the binaries you will need the following binary packages:
          djdev205.zip (or a later but NOT a prior version)
          bsh4253b.zip (or a later but NOT a prior version)
          gccNNNb.zip, gppNNNb.zip, bnuNNNb.zip, makNNNb.zip, filNNNb.zip,
          shlNNNb.zip, txtNNNb.zip, txiNNNb.zip, grepNNNb.zip, sedNNNb.zip,
          mktmpNNb.zip perlNNNb.zip and difNNNb.zip.

        NNN represents the latest version number of the binary packages.  All
        this packages can be found in the "v2gnu" directory of any
        ftp.delorie.com mirror.
        You will need bsh4253b.zip or later and *NOT* a prior version or the
        build will fail.  The same applies to djdev205.zip.

        To build and use this port the latest DJGPP ports of the following
        libraries are required:
          http://ftp.delorie.com/pub/djgpp/current/v2apps/bz2-108a.zip
          http://ftp.delorie.com/pub/djgpp/current/v2apps/lzlb112a.zip
          http://ftp.delorie.com/pub/djgpp/current/v2apps/xz-525a.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/zlb1212b.zip

          http://ftp.delorie.com/pub/djgpp/current/v2tk/xml2914b.zip

          http://ftp.delorie.com/pub/djgpp/current/v2tk/ltha111b.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/lme3100b.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/logg135b.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/lops131b.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/lvbs137b.zip
          http://ftp.delorie.com/pub/djgpp/current/v2tk/x264-1b.zip
        and must be installed.  All those libraries may introduce even more
        dependencies that will have to be resolved by installing the missing
        libraries.

3.3.:   The package will be configured and will be build in a separate build
        directory under the top srcdir (aka FFmpeg-5.1.2) called "0build".
        To build the binaries cd into "djgpp" directory ans start djmake.sh.

        djmake.sh, among other things, will start the configure script passing
        to it a couple of arguments.  Read the shell script to check for the
        enabled and disabled options.

        Having urandom support enabled means that a entropy source must be
        available at runtime either as driver or as random data file.
        One such driver, NOISE.SYS, can be obtained from 
          "http://www.rahul.net/dkaufman/index.html"
        as:
          http://www.rahul.net/dkaufman/noise063a2.zip
        If the URLs are no longer available, the the followings can be used:
          http://web.archive.org/web/20051124224824/http://www.rahul.net/dkaufman/
        and:
          http://web.archive.org/web/20051124224824/http://www.rahul.net/dkaufman/noise063a2.zip

        Please read the instructions carefully.  This driver works on DOS and
        may be on some versions of Windows but it does not work for all versions
        of Windows.  For XP it does not work and I have found no replacement.
        If no noise source can be found then the library will create pseudo
        random data.

3.4.:   The port will be compiled by the shell script.  The screen output of
        the build process will be redirected to a file.  The build process
        takes on Win98SE in a virtual machine approximately 30 min.

3.5.:   The port will be tested by the shell script.  The screen output of the
        test process will be redirected to a file.  The test process takes on
        Win98SE in a virtual machine approximately 30 min.

3.6.:   To install the binary, info docs and man pages run the following command
        from the directory where you have configured the sources:
          make install

        This will install the products into your DJGPP installation tree given
        by the default prefix "/dev/env/DJDIR".  If you prefer to install them
        into some other directory you will have to set prefix to the appropriate
        value:
          make install prefix=z:/some/other/place



        Send FFmpeg specific bug reports to
        <https://ffmpeg.org/bugreports.html>.
        Send suggestions and bug reports concerning the DJGPP port
        to comp.os.msdos.djgpp or <djgpp@delorie.com>.


Enjoy.

          Guerrero, Juan Manuel <juan.guerrero@gmx.de>
