[FFmpeg-devel] [PATCH] avformat: avisynth demuxer rewrite

[d s]

On Sat, Oct 20, 2012 at 12:53 PM, Ramiro Polla <ramiro.polla at gmail.com> wrote:
> Hi,
>
> On 09/22/2012 05:27 PM, d s wrote:
>>
>> Dear ffmpeg-devel,
>>
>> The current Avisynth demuxer is misnamed; rather, it would be more
>> appropriately described as a VfW demuxer. This email contains a
>> rewrite of the demuxer that uses the Avisynth library directly, with
>> the following benefits:
>>
>> 1) useful error messages instead of video clips with error text
>> 2) no dependency on VfW, and hence no requirement for the related
>> SDKs/libraries
>> 3) able to support AvxSynth (https://github.com/avxsynth/avxsynth/wiki) on
>> Linux
>>
>> I have tested the demuxer on both Windows and Linux and verified that
>> I was able to ffprobe YV12, YUY2, and RGB32 scripts as well as encode
>> them to rawvideo.
>>
>> Review and comments would be appreciated.
>
>
> Will there be any change in the way avisynth is used in ffmpeg's command
> line? This change could use some documentation.
>
There are no command line changes, and the patch adds no command line arguments.

>> --- configure.orig      2012-06-07 17:01:19.000000000 -0400
>> +++ configure   2012-09-10 02:07:56.300063208 -0400
>> @@ -3204,7 +3204,9 @@
>>  check_mathfunc truncf
>>
>>  # these are off by default, so fail if requested and not available
>> -enabled avisynth   && require2 vfw32 "windows.h vfw.h" AVIFileInit
>> -lavifil32
>> +enabled avisynth   && { { check_lib2 "windows.h" LoadLibrary &&
>> check_header "avisynth_c.h"; } ||
>> +                        { check_lib2 "dlfcn.h" dlopen -ldl &&
>> check_header "avxsynth_c.h"; } ||
>> +                        die "ERROR: avisynth and/or LoadLibrary/dlopen
>> not found"; }
>
>
> Why is avxsynth_c.h not installed with avxsynth? Where can users find
> instructions on how to properly install the library so it is detected/used
> by ffmpeg? This should be documented somewhere. Same thing goes to finding
> avisynth_c.h.
>
> Using avxsynth_c.h provided with avxsynth I get some errors such as:
> error: unknown type name ‘avs_create_script_environment_func’
>
> I can try again once I can actually test.
>
The patch requires changes to avxsynth_c.h that have not been pushed
to the public repository. We were waiting for review on this patch
before making the changes available.