[MPlayer-dev-eng] [EPAMP] an effect plugin API for media players: anyone interested?

[Ivan Kalvachev]

On 6/2/08, Stefano D'Angelo <zanga.mail at gmail.com> wrote:
> Hello,
>
> First of all, I'm sorry for the worst cross-posting ever.
>
> My name's Stefano D'Angelo and I'm the author of NASPRO
> (http://naspro.atheme.org), a project whose main aim is to build up a
> system to make all sound processing APIs interoperable.
>
> Since my project was recently accepted to become part of the Atheme
> community (http://www.atheme.org) and began working close to the
> audacious (http://audacious-media-player.org) developers, I could see
> there actually were serious reasons behind the lack of standardization
> for sound processing in the arena of media players.
>
> Now, I wrote a first draft of a new sound processing API called EPAMP
> especially targetted at media players; you can find it here:
> http://naspro.atheme.org/content/epamp-draft-1
>
> With this mail, I'm trying to get some feedback (possibly in the Talk
> page on the NASPRO wiki) about it and possibly to involve anyone who
> is interested in its development.
>
> Anyway, notice that the user interface part of the API is still
> missing and that my project (NASPRO) will support this new API, giving
> applications using it the possibility to access non-EPAMP plugins
> without touching a single line of code (currently supported APIs are
> audacious' and LADSPA, while DSSI, LV2, GStreamer and possibly VST are
> more or less planned for the near future).
>
> In case you're not interested and want to start a flame, please just ignore
> me.
>
> This message is being sent to the communities/developers behind the
> following projects:
>  - Amarok
>  - Aqualung
>  - Audio Overload
>  - BMPx
>  - Banshee
>  - cmus
>  - Decibel Audio Player
>  - Exaile
>  - FALF Player
>  - Freevo
>  - GStreamer
>  - Helix Player
>  - Herrie
>  - JaJuk
>  - JuK (KDE multimedia)
>  - Linux Audio Developers
>  - KPlayer
>  - Kaffeine
>  - lamip
>  - The LAMP
>  - MPlayer
>  - Miro
>  - mpg123
>  - mpg321
>  - Muine
>  - MPD
>  - music on console
>  - Noatun
>  - ogg123 (vorbis-tools)
>  - Ogle
>  - Quod Libet
>  - Rhythmbox
>  - Sipie
>  - SnackAmp
>  - Sonata
>  - Songbird
>  - UADE
>  - SMPlayer
>  - VLC
>  - wxMusik
>  - XMMS2
>  - Xfmedia
>  - Xine
>  - Zinf
>
> If you know someone else who could be interested, feel free to forward this.
>
> Best regards,
>
> Stefano D'Angelo
> zanga.mail at gmail.com

MPlayer have audio filter that is able to load LADSPA plugins, so I
guess somebody should test your improvements.

We currently don't have maintainer for our audio sound system,
so it may some time for experts to contact you.

I just took a look of the draft you have given URL.
I have only 2 remarks.

1. You define the known audio formats as bit-flags. I see no sense of
doing that when they can't be combined. I don't expect that all
possible audio formats would be limited to 32. ;)

2. I couldn't spot where you handle the delay. From what I've heard
audio filters need to work with past and future samples, so some
filter add additional delay. Using few such filters could accumulate
significant delay that could be noticed in application that need to
keep sync between audio and video.


I mean no offense, but our own audio system seems more mature than
your draft And I think that our audio system have a lot of space for
improvement.
(well, i guess it's normal for a draft;).

Wish you luck.