[FFmpeg-devel] [PATCH] avfilter: add native headphone spatialization filter

[wm4]

On Thu, 8 Jun 2017 13:24:39 +0200
Paul B Mahol <onemda at gmail.com> wrote:

> On 6/8/17, wm4 <nfxjfg at googlemail.com> wrote:
> > On Thu, 8 Jun 2017 11:36:02 +0200
> > Paul B Mahol <onemda at gmail.com> wrote:
> >  
> >> On 6/8/17, wm4 <nfxjfg at googlemail.com> wrote:  
> >> > On Thu,  8 Jun 2017 08:13:48 +0200
> >> > Paul B Mahol <onemda at gmail.com> wrote:
> >> >  
> >> >> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> >> >> ---  
> >> >
> >> > Feeding the coefficients as additional audio inputs, and using amovie
> >> > to load them, seems like an extremely awkward choice. It would make
> >> > sense to me if there actually were a set of input coefficients per
> >> > actual audio input, but that's not the case. Instead, the efficients
> >> > are a much smaller stream than the main audio input.
> >> >
> >> > Why not load the coefficients directly?  
> >>
> >> I'm not going to add yet another movie filter.
> >> The amovie is there just because I used same filtergraph with mpv to
> >> be able to seek.  
> >
> > A user would need to connect all the inputs even with ffmpeg CLI. Not
> > sure why you're talking about "another movie filter" - why not just
> > load the coefficients directly, using a custom format if necessary?
> > From what I understand, you need to do something special to produce
> > those coefficient wav files anyway.  
> 
> SOFA is custom format, subset of HDF, alternative is wav, wav
> can hold 16/24/32 int/float samples.
> 
> SOFA just holds bunch of HRTF coefficients of various loudspeakers positions.
> 
> I'm not going to NIH libmysofa or invent yet another new format just to hold all
> IRs when only subset of them are ever used.
> 
> So take it or leave it. I'm pretty happy with this filter,
> its even faster when seeking than sofalizer.

I'd probably leave it. Using wav audio is a ridiculous way of storing
coefficients, when you could just dump them as arrays into a trivial
custom file format.