DOS ain't dead

GOT IT !!!

I successfully built ffmpeg v5.1.4 for DOS
using djgpp cross compiler v12.2.0 running on Slackware Linux 64bit current.

http://glennmcc.org/ffmpeg514.zip

No success so-far with the v6.x branch.

---
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http://glennmcc.org/

> GOT IT !!!
>
> I successfully built ffmpeg v5.1.4 for DOS
> using djgpp cross compiler v12.2.0 running on Slackware Linux 64bit
> current.
>
> http://glennmcc.org/ffmpeg514.zip
>
> No success so-far with the v6.x branch.
Thank you! Your effort is much appreciated. It's great to have these recent compiles for DOS. We're pretty current when it comes to codec support / conversion now. And, with the fabulous SBEmu, DOS is now a real multimedia entertainment system and has "modern" PCI sound as well.

Finally, 30 years too late! But, it is fabulous. Good things come to those who wait - and tinker!

By the way, what does FFMpeg 6.0 bring to the table that's "necessary" for DOS? What's the compilation difficulty?

> > GOT IT !!!
> >
> > I successfully built ffmpeg v5.1.4 for DOS
> > using djgpp cross compiler v12.2.0 running on Slackware Linux 64bit
> > current.
> >
> > http://glennmcc.org/ffmpeg514.zip
> >
> > No success so-far with the v6.x branch.
> Thank you! Your effort is much appreciated. It's great to have these recent
> compiles for DOS. We're pretty current when it comes to codec support /
> conversion now. And, with the fabulous SBEmu, DOS is now a real multimedia
> entertainment system and has "modern" PCI sound as well.

You are very welcome... happy to make it available to everyone !

>
> Finally, 30 years too late! But, it is fabulous. Good things come to those
> who wait - and tinker!
>
> By the way, what does FFMpeg 6.0 bring to the table that's "necessary" for
> DOS? What's the compilation difficulty?

Don't know for sure yet what's going on with v6.x
Will get back to it sometime later to get more 'into it'.

Oh.... I must give everyone a head's up...
this new build of FFMPEG.EXE does not encode into WEBM
'cus I can't seem to find libvpx to go with the DJGPP cross compiler.

I keep getting a bunch of errors when I try to build it from source. :(

Q: does anyone happen to have a pre-compiled libvpx that you'd be willing to share ?

---
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http://glennmcc.org/

>
> Don't know for sure yet what's going on with v6.x
> Will get back to it sometime later to get more 'into it'.
>

Found the problem.
Tried building v6.1.1 for Linux but without pthreads.
_________________________________________________________

root@glennmcc-i7:~/build/ffmpeg-6.1.1# ./configure --disable-pthreads

root@glennmcc-i7:~/build/ffmpeg-6.1.1# time make

Even tho I disabled pthreads.... it still got these errors and it did not build ffmpeg, ffprobe, ffplay for Linux.

In file included from libavcodec/vulkan.c:19:
./libavutil/vulkan.c: In function 'ff_vk_exec_pool_free':
./libavutil/vulkan.c:267:9: error: implicit declaration of function 'pthread_mutex_destroy'; did you mean 'ff_mutex_destroy'? [-Werror=implicit-function-declaration]
267 | pthread_mutex_destroy(&e->lock);
| ^~~~~~~~~~~~~~~~~~~~~
| ff_mutex_destroy
./libavutil/vulkan.c: In function 'ff_vk_exec_pool_init':
./libavutil/vulkan.c:410:15: error: implicit declaration of function 'pthread_mutex_init' [-Werror=implicit-function-declaration]
410 | err = pthread_mutex_init(&e->lock, NULL);
| ^~~~~~~~~~~~~~~~~~
./libavutil/vulkan.c: In function 'ff_vk_exec_wait':
./libavutil/vulkan.c:507:5: error: implicit declaration of function 'pthread_mutex_lock' [-Werror=implicit-function-declaration]
507 | pthread_mutex_lock(&e->lock);
| ^~~~~~~~~~~~~~~~~~
./libavutil/vulkan.c:510:5: error: implicit declaration of function 'pthread_mutex_unlock'; did you mean 'ff_mutex_unlock'? [-Werror=implicit-function-declaration]
510 | pthread_mutex_unlock(&e->lock);
| ^~~~~~~~~~~~~~~~~~~~
| ff_mutex_unlock
cc1: some warnings being treated as errors
make: *** [ffbuild/common.mak:81: libavcodec/vulkan.o] Error 1
___________________________________________________________________

Conculsion:

Even for Linux the 6.x branch REQUIRES the current implementation of pthreads.

____________

And since the only thing I can find for DJGPP
is a 7yr old port of the 23.5yr old version of the prthreads source code.....
that's it.... we're noe 'frozen' at ffmpeg/ffprobe v5.1.4

[until someone ports the _current_ pthreads source code for use on DJGPP] ;)

__________________

As we see, v5.1.4 does _not_ require pthreads.

root@glennmcc-i7:~/build/ffmpeg-5.1.4# ./configure --disable-pthreads

root@glennmcc-i7:~/build/ffmpeg-5.1.4# time make

real 15m19.259s
user 14m23.767s
sys 0m46.352s

root@glennmcc-i7:~/build/ffmpeg-5.1.4# ls -l ffmpeg
-rwxr-xr-x 1 root root 21394296 Mar 11 22:11 ffmpeg*

root@glennmcc-i7:~/build/ffmpeg-5.1.4# ls -l ffprobe
-rwxr-xr-x 1 root root 21304664 Mar 11 22:11 ffprobe*

---
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http://glennmcc.org/

> >
> > Don't know for sure yet what's going on with v6.x
> > Will get back to it sometime later to get more 'into it'.
> >
>
> Found the problem.
> Tried building v6.1.1 for Linux but without pthreads.
> _________________________________________________________
>
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# ./configure --disable-pthreads
>
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# time make
>
> Even tho I disabled pthreads.... it still got these errors and it did not
> build ffmpeg, ffprobe, ffplay for Linux.
>
> In file included from libavcodec/vulkan.c:19:
> ./libavutil/vulkan.c: In function 'ff_vk_exec_pool_free':
> ./libavutil/vulkan.c:267:9: error: implicit declaration of function
> 'pthread_mutex_destroy'; did you mean 'ff_mutex_destroy'?
> [-Werror=implicit-function-declaration]
> 267 | pthread_mutex_destroy(&e->lock);
> | ^~~~~~~~~~~~~~~~~~~~~
> | ff_mutex_destroy
> ./libavutil/vulkan.c: In function 'ff_vk_exec_pool_init':
> ./libavutil/vulkan.c:410:15: error: implicit declaration of function
> 'pthread_mutex_init' [-Werror=implicit-function-declaration]
> 410 | err = pthread_mutex_init(&e->lock, NULL);
> | ^~~~~~~~~~~~~~~~~~
> ./libavutil/vulkan.c: In function 'ff_vk_exec_wait':
> ./libavutil/vulkan.c:507:5: error: implicit declaration of function
> 'pthread_mutex_lock' [-Werror=implicit-function-declaration]
> 507 | pthread_mutex_lock(&e->lock);
> | ^~~~~~~~~~~~~~~~~~
> ./libavutil/vulkan.c:510:5: error: implicit declaration of function
> 'pthread_mutex_unlock'; did you mean 'ff_mutex_unlock'?
> [-Werror=implicit-function-declaration]
> 510 | pthread_mutex_unlock(&e->lock);
> | ^~~~~~~~~~~~~~~~~~~~
> | ff_mutex_unlock
> cc1: some warnings being treated as errors
> make: *** [ffbuild/common.mak:81: libavcodec/vulkan.o] Error 1
> ___________________________________________________________________
>
> Conculsion:
>
> Even for Linux the 6.x branch REQUIRES the current implementation of
> pthreads.
>
> ____________
>
> And since the only thing I can find for DJGPP
> is a 7yr old port of the 23.5yr old version of the prthreads source
> code.....
> that's it.... we're noe 'frozen' at ffmpeg/ffprobe v5.1.4
>
> [until someone ports the _current_ pthreads source code for use on DJGPP]
> ;)
>
> __________________
>
> As we see, v5.1.4 does _not_ require pthreads.
>
>
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# ./configure --enable-pthreads
>
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# time make
>
> real 16m9.759s
> user 15m1.857s
> sys 0m47.397s
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# ls -l ffmpeg
> -rwxr-xr-x 1 root root 23139936 Mar 11 21:53 ffmpeg*
>
> root@glennmcc-i7:~/build/ffmpeg-6.1.1# ls -l ffprobe
> -rwxr-xr-x 1 root root 23013856 Mar 11 21:54 ffprobe*

you may report this to ffmpeg ML since it looks like a bug that pthreads can't be disabled in compilation time.

>
> you may report this to ffmpeg ML since it looks like a bug that pthreads
> can't be disabled in compilation time.

It's not a bug, it's a feature. ;)

Be that as it may.... bug report has now been filed.

https://trac.ffmpeg.org/ticket/10900#ticket

---
--
http://glennmcc.org/

> Oh.... I must give everyone a head's up...
> this new build of FFMPEG.EXE does not encode into WEBM
> 'cus I can't seem to find libvpx to go with the DJGPP cross compiler.
>
> I keep getting a bunch of errors when I try to build it from source. :(
>
> Q: does anyone happen to have a pre-compiled libvpx that you'd be willing
> to share ?
I also looked, and can't find libvpx source which claims to be able to compile with DJGPP. The closest I found was old source from FFMPEG 2.2.016 on SourceForge: https://sourceforge.net/projects/ffmpeg-x264-dos/files/

But the compilation instructions don't mention DOS or DJGPP specifically. And, it's very old code.

EDIT by rr: Soundforge -> SourceForge

> >
> > you may report this to ffmpeg ML since it looks like a bug that pthreads
> > can't be disabled in compilation time.
>
> It's not a bug, it's a feature. ;)
>
> Be that as it may.... bug report has now been filed.
>
> https://trac.ffmpeg.org/ticket/10900#ticket

Thank you roytam !

https://trac.ffmpeg.org/ticket/10900?action=diff&version=1

As a result of that bug report, and the comment by Gyan,
this new build script with the addition of --disable-vulkan
successfully built both FFPROBE.EXE for DOS

Now to get FFMPEG.EXE as-well.


---build-ffmpeg.sh ----

#!/bin/bash

# Set the DJGPP_PREFIX variable to the root directory of the DJGPP cross-compiler toolchain
export DJGPP_PREFIX="/archives-a/build/djgpp"
export PATH="$DJGPP_PREFIX/bin:$PATH"
export LIB="$DJGPP_PREFIX/lib/"
export GCC_EXEC_PREFIX="$DJGPP_PREFIX/lib/gcc/"
export INCLUDE="$DJGPP_PREFIX/include/"

# Define the target architecture by appending "/bin/i586-pc-msdosdjgpp" to the DJGPP_PREFIX
TARGET_ARCH="${DJGPP_PREFIX}/i586-pc-msdosdjgpp/bin/"

# Add the DJGPP_PREFIX/bin directory to the beginning of the PATH environment variable
export PATH="${DJGPP_PREFIX}/bin:$PATH"

# Define the version of FFmpeg to download
FFMPEG_VERSION="$1"

# Define the URL of the FFmpeg archive to download
FFMPEG_ARCHIVE="https://ffmpeg.org/releases/ffmpeg-${FFMPEG_VERSION}.tar.gz"

# Define the directory name where FFmpeg source will be extracted
FFMPEG_SOURCE_DIR="ffmpeg-${FFMPEG_VERSION}"

# Download the FFmpeg archive
wget -c "$FFMPEG_ARCHIVE"

# Remove any existing directory with the same name as FFMPEG_SOURCE_DIR
rm -rf "$FFMPEG_SOURCE_DIR"

# Extract the FFmpeg source from the downloaded archive
tar -xf "ffmpeg-${FFMPEG_VERSION}.tar.gz"

# Change the current directory to the FFmpeg source directory
cd $FFMPEG_SOURCE_DIR

# Run the configure script with specific options to prepare FFmpeg for cross-compilation
./configure \
--enable-cross-compile \
--cc="${TARGET_ARCH}gcc" \
--cxx="${TARGET_ARCH}g++" \
--ar="${TARGET_ARCH}ar" \
--as="${TARGET_ARCH}as" \
--ranlib="${TARGET_ARCH}ranlib" \
--sysroot="${DJGPP_PREFIX}" \
--disable-debug \
--arch=i486 \
--cpu=i486 \
--target-os=ms-dos \
--disable-doc \
--enable-gpl \
--disable-pthreads \
--disable-vulkan \
--disable-txtpages \
--extra-cflags="-w"

# Compile FFmpeg with multiple jobs, using the number of available processors
make -j$(nproc) 2>1errors.txt

________________________________________________________

ffprobe version 6.1.1 Copyright (c) 2007-2023 the FFmpeg developers
built with gcc 12.2.0 (GCC)
configuration: --enable-cross-compile --cc=/archives-a/build/djgpp/i586-pc-msdosdjgpp/bin/gcc --cxx=/archives-a/build/djgpp/i586-pc-msdosdjgpp/bin/g++ --ar=/archives-a/build/djgpp/i586-pc-msdosdjgpp/bin/ar --as=/archives-a/build/djgpp/i586-pc-msdosdjgpp/bin/as --ranlib=/archives-a/build/djgpp/i586-pc-msdosdjgpp/bin/ranlib --sysroot=/archives-a/build/djgpp --disable-debug --arch=i486 --cpu=i486 --target-os=ms-dos --disable-doc --enable-gpl --disable-pthreads --disable-vulkan --disable-txtpages --extra-cflags=-w
libavutil 58. 29.100 / 58. 29.100
libavcodec 60. 31.102 / 60. 31.102
libavformat 60. 16.100 / 60. 16.100
libavdevice 60. 3.100 / 60. 3.100
libavfilter 9. 12.100 / 9. 12.100
libswscale 7. 5.100 / 7. 5.100
libswresample 4. 12.100 / 4. 12.100
libpostproc 57. 3.100 / 57. 3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'big_bang.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: isommp42
creation_time : 2011-05-14T08:58:00.000000Z
Duration: 00:00:46.00, start: 0.000000, bitrate: 482 kb/s
Stream #0:0[0x1](und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(progressive), 624x352, 380 kb/s, 23.98 fps, 23.98 tbr, 1k tbn (default)
Metadata:
creation_time : 1970-01-01T00:00:00.000000Z
handler_name : VideoHandler
vendor_id : [0][0][0][0]
Stream #0:1[0x2](und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 95 kb/s (default)
Metadata:
creation_time : 2011-05-14T08:58:00.000000Z
handler_name : (C) 2007 Google Inc. v08.13.2007.
vendor_id : [0][0][0][0]
___________________________________________________________________________

---
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http://glennmcc.org/

> > It's not a bug, it's a feature. ;)
> >
> > Be that as it may.... bug report has now been filed.
> >
> > https://trac.ffmpeg.org/ticket/10900#ticket
>
> Thank you roytam !
>
> https://trac.ffmpeg.org/ticket/10900?action=diff&version=1
>
> As a result of that bug report, and the comment by Gyan,
> this new build script with the addition of --disable-vulkan
> successfully built both FFPROBE.EXE for DOS
>
> Now to get FFMPEG.EXE as-well.

18M each, but put both to a zip archive and your under at 17MB. I wonder how much code both tools have in common...

---
Forum admin

> > > It's not a bug, it's a feature. ;)
> > >
> > > Be that as it may.... bug report has now been filed.
> > >
> > > https://trac.ffmpeg.org/ticket/10900#ticket
> >
> > Thank you roytam !
> >
> > https://trac.ffmpeg.org/ticket/10900?action=diff&version=1
> >
> > As a result of that bug report, and the comment by Gyan,
> > this new build script with the addition of --disable-vulkan
> > successfully built both FFPROBE.EXE for DOS
> >
> > Now to get FFMPEG.EXE as-well.
>
> 18M each, but put both to a zip archive and your under at 17MB. I wonder
> how much code both tools have in common...

Well, had a look at the code of the 6.x branch and they have made
a whole TON of things dependent upon threads. :(

So, till someone is able to port a newer version of pthread
for use in DJGPP... we are still 'frozen' at v5.1.4

Unfortunately, that also goes for libvpx

Had a look at that old libvpx source code and even way back then
it too was dependent upon pthread :(

Therefore, even the build of v5.1.4 is still without WEBM encoding.

---
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http://glennmcc.org/

> But the compilation instructions don't mention DOS or DJGPP specifically.
> And, it's very old code.

This is my old FFMPEG DOS project, of course all this stuff are for DOS and contains a prebuilt *.a files. There's a batch file to build it all. I used DJGPP under WinXP cmd to build it. Sorry no time now for messing with newer version, I guess that old vpx would not be compatible with current ffmpeg and would need to be rebuild too...

---
DOS gives me freedom to unlimited HW access.

>... I guess that old vpx would not be compatible with current ffmpeg
> and would need to be rebuild too...

You are quite correct in those assumptions.

That libvpx did not work with the newer ffmpeg source code.

And all of my attempts to rebuild that libvpx source code yielded nothing
but tons of errors (same as with all attempts to rebuild pthreads). :(

The same goes for the new v1.14 line of libvpx source code...
nothing but errors when attempting to build it using the Linux DJGPP cross compiler v12.2.0

But even without pthreads & libvpx, at-least I was able to build that 'crippled' ffmpeg v5.1.4

---
--
http://glennmcc.org/

> but tons of errors (same as with all attempts to rebuild pthreads). :(

You were trying Juan's 2017 fixed port of FSU Pthreads (/v2tk/fpth314b.zip), right??

There was also a 2007 build (686+? ugh, using CMOVxx, IIRC) of GNU Pth (/v2gnu/pth207b.zip) that you could try.

Actually, I'm seeing (/v2tk/ffmg512b.zip) from Dec. 2022. It vaguely rings a bell, probably a quick port by Juan. Here's a link to Juan's announcement ("ANNOUNCE: DJGPP port of FFmpeg 5.1.2 uploaded.").

(To be honest, I never needed or really directly used Mplayer nor FFmpeg or such. I'm hardly a multimedia fiend.)

> > but tons of errors (same as with all attempts to rebuild pthreads). :(
>
> You were trying Juan's 2017 fixed port of FSU Pthreads
> (/v2tk/fpth314b.zip), right??
>
> There was also a 2007 build (686+? ugh, using CMOVxx, IIRC) of GNU Pth
> (/v2gnu/pth207b.zip) that you could try.
>
> Actually, I'm seeing (/v2tk/ffmg512b.zip) from Dec. 2022. It vaguely rings
> a bell, probably a quick port by Juan. Here's a link to Juan's
> announcement
> ("ANNOUNCE: DJGPP port of FFmpeg 5.1.2 uploaded.").
>

Thank you for the info and the links.

Had a look at his build script in the source package.

Looks like he may have run into the same 'road block' ... no libvpx
therefore his ffmpeg.exe also does not have the capability to encode into WEBM

> (To be honest, I never needed or really directly used Mplayer nor FFmpeg or
> such. I'm hardly a multimedia fiend.)

I too do not actually use ffmpeg nor mplayer in DOS anymore.
(used to quite few years ago, but now only in Linux)

This entire ffmpeg process (and my unsuccessful attempts at mplayer back in 2021/2022),
were both just to prove that it could still be done.

Even if someone finds or is able to port libvpx... I think I'm done with it now.

---
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http://glennmcc.org/

> The same goes for the new v1.14 line of libvpx source code...
> nothing but errors when attempting to build it using the Linux DJGPP cross
> compiler v12.2.0

OK, a bit more specifically, what cause the errors and in what phase?
As you are using linux crosscompiler I guess you have better chances than me in WinXP as you have handy all the GNU tools support for cmake/configure scripts etc. I used MinGW under windows for configure an then manually hacked makefiles for DJGPP - a pain in the a$$... I guess you succeed at least create the Makefile? Are there some configure options for libvpx that you can safely disable? Is libvpx dependent on pthreads? Can it be disabled?
If it fails later in djgpp compiling phase you may have problems with outdated libC/DJDEV - what vesion do you use? The official version is very outdated and there is something in development phase on CVS but seems to never become official. I did some builds but yeah it't pretty old now
https://sourceforge.net/projects/ffmpeg-x264-dos/files/djdev-2.05-cvs-11-01-2018.zip/download
Another source of issues may be if libvpx use some optimized inline/assembler modules that use SSE, I had to disable something like this in the past...

---
DOS gives me freedom to unlimited HW access.

> > The same goes for the new v1.14 line of libvpx source code...
> > nothing but errors when attempting to build it using the Linux DJGPP
> cross
> > compiler v12.2.0
>
> OK, a bit more specifically, what cause the errors and in what phase?
> As you are using linux crosscompiler I guess you have better chances than
> me in WinXP as you have handy all the GNU tools support for cmake/configure
> scripts etc. I used MinGW under windows for configure an then manually
> hacked makefiles for DJGPP - a pain in the a$$... I guess you succeed at
> least create the Makefile? Are there some configure options for libvpx that
> you can safely disable? Is libvpx dependent on pthreads? Can it be
> disabled?

All of the errors are due to this very old pthreads
(it's a 7yr old port of almost 24yrd source code)
https://groups.google.com/g/comp.os.msdos.djgpp/c/RNeA2ZUAhmI
https://arcb.csc.ncsu.edu/~mueller/pthreads/

libvpx seems to require pthreads and I've found no way to disable that requirement.

https://github.com/webmproject/libvpx

---
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http://glennmcc.org/

So we need new pthreads but it would be probably more complicated than just crosscompiling. I guess it heavily relies on OS threading functions that DOS naturally don't have and it would need some new code to emulate this. I can't say more to this as I never did a multithreading programming under win/linux so never used pthreads library...

---
DOS gives me freedom to unlimited HW access.