[Ffmpeg-devel] [PATCH] Cygwin vhook, always static avformat

[Diego Biurrun]

On Mon, Aug 07, 2006 at 04:37:10PM +0200, V?ctor Paesa wrote:
> 
> > But it has the downsize of creating huge vhooks.  This is not
> > acceptable.  I'm confident that this is just a matter of finding the
> > right linker incantation ...
> 
> Using (a) there would be huge vhooks only for static builds.
> The linker docs mentions undefined sysmbols as one limitation of Win32
> loader, I have not been able to find the proper linker spell ...
> 
> I tried other ways to circumvent this.
> 
> e) Extract symbol list from .EXE to create a .def, that will be used to
> create an import library
> (see section "Building and Using DLLs" in Cygwin's User Guide)
> 
> [...] 
> 
> Let's run it:
> $ ../ffmpeg -i ~/SmallConcert.avi -vhook './null.dll' output.avi
> FFmpeg version SVN-rUNKNOWN, Copyright (c) 2000-2004 Fabrice Bellard
>   configuration:  --enable-static --disable-shared
>   libavutil version: 49.0.0
>   libavcodec version: 51.11.0
>   libavformat version: 50.5.0
>   built on Aug  7 2006 12:55:21, gcc: 3.4.4 (cygming special)
> (gdc 0.12, using dmd 0.125)
> Input #0, avi, from '/home/wzrlpy/SmallConcert.avi':
>   Duration: 00:00:20.2, start: 0.000000, bitrate: 30349 kb/s
>   Stream #0.0: Video: dvvideo, yuv420p, 720x576, 25.00 fps(r)
>   Stream #0.1: Audio: pcm_s16le, 48000 Hz, stereo, 1536 kb/s
> Permission denied
> Failed to add video hook function: ./null.dll
> 
> No idea why I got that "Permission denied", ffmpeg_g.exe shows appropiate
> permissions:
> 
> $ ls -l ffmpeg_g*
> -rw-r--r-- 1 wzrlpy Users   536888 Aug  7 15:38 ffmpeg_g.a
> -rw-r--r-- 1 wzrlpy Users    11888 Aug  7 15:38 ffmpeg_g.def
> -rwxr-xr-x 1 wzrlpy Users 10016527 Aug  7 15:28 ffmpeg_g.exe
> 
> So way (e) does not work.

Hmmm, I'm sure you just haven't found the reason for the problem here.
I believe you should try to investigate further.

Diego