[Libav-user] Requesting help to port Audacity to recent FFmpeg

Michael Niedermayer michaelni at gmx.at
Wed May 14 19:27:38 CEST 2014


Hi

On Sun, May 11, 2014 at 09:16:29PM +0200, Benjamin Drung wrote:
> Hi,
> 
> Audacity, the digital audio editor used by millions, has import/export
> support for a wide range of audio formats using the FFmpeg libraries.
> Audacity compiles only against FFmpeg < 1.0 [1]. The FFmpeg libraries
> have changed from time to time and Audacity needs non-trivial work to
> support any supported FFmpeg version. Sadly, no Audacity developer has
> the time and skill to port Audacity to a recent FFmpeg API.
> 
> That's why I send this mail to this mailing list to request help. Is
> there anyone who has the time and skill to help porting Audacity to the
> latest FFmpeg API version?
> 
> [1] http://bugzilla.audacityteam.org/show_bug.cgi?id=606

ive updated audacity to build with ffmpeg HEAD
note, this works but is not finished, so please clone/fork it and help

https://github.com/michaelni/audacity

also it still uses some internal API parts from ffmpeg
so it needs this patch to ffmpeg:

diff --git a/libavformat/libavformat.v b/libavformat/libavformat.v
index 0b47668..0d5d3b0 100644
--- a/libavformat/libavformat.v
+++ b/libavformat/libavformat.v
@@ -21,6 +21,8 @@ LIBAVFORMAT_$MAJOR {
                 ffurl_size;
                 ffurl_write;
                 ffurl_protocol_next;
+                ffio_fdopen;
+                ffurl_register_protocol;
                 url_open;
                 url_close;
                 url_write;

and it needs to #include libavformat/url.h (which isnt installed be
default)

Planar audio input works, but can certainly be implemented more optimal
and faster in audacity, export works but not planar export.
ive commented some options out as they are handled differently now
and audacity certainly wants a proper GUI that lists for each codec
what options/parameters it supports and not just the old 5 ones hacked
back in. I dunno audacity well enough to quickly add such GUI and
didnt want to waste time to hack these 5 back in as they where

The useage of URLProtocol also should be removed, i assume this can
be simplified quite a bit

again, if you are reading this and care about audacity or ffmpeg,
please clone/fork my repo above and pick some issue up and improve
the code. if noone does ill probably continue to work on this as i
find time

Iam also CCing audacity-devel as they probably want to know about this

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct answer.
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