[vlc-devel] [vlc-commits] trivial_mixer: try to fix dual-mono (fixes #12673)

[Thomas Guillem]

It's much better with your last commit but I still hear a small glitch.
Do you want my sample ?

On Mon, Nov 3, 2014, at 14:53, Thomas Guillem wrote:
> This breaks conversion: 'f32l'->'f32l' 44100 Hz->44100 Hz Mono->Stereo.
> 
> Reproduced with a AAC mono sample on android or on desktop with pulse
> forced to output stereo.
> 
> On Sun, Nov 2, 2014, at 11:10, Rémi Denis-Courmont wrote:
> > vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Nov  2
> > 12:08:56 2014 +0200| [d6388f26bb6efef29397ba91b02befc427b3423e] |
> > committer: Rémi Denis-Courmont
> > 
> > trivial_mixer: try to fix dual-mono (fixes #12673)
> > 
> > Original channels is under-specified in my opinion. If you know where
> > the design documentation is, please tell me.
> > 
> > > http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=d6388f26bb6efef29397ba91b02befc427b3423e
> > ---
> > 
> >  modules/audio_filter/channel_mixer/trivial.c |   81
> >  ++++++++++++++++----------
> >  1 file changed, 50 insertions(+), 31 deletions(-)
> > 
> > diff --git a/modules/audio_filter/channel_mixer/trivial.c
> > b/modules/audio_filter/channel_mixer/trivial.c
> > index a8c20dd..d05155a 100644
> > --- a/modules/audio_filter/channel_mixer/trivial.c
> > +++ b/modules/audio_filter/channel_mixer/trivial.c
> > @@ -185,45 +185,64 @@ static block_t *ReverseStereo( filter_t *p_filter,
> > block_t *p_buf )
> >  static int Create( vlc_object_t *p_this )
> >  {
> >      filter_t *p_filter = (filter_t *)p_this;
> > -    block_t *(*func)(filter_t *, block_t *) = NULL;
> > +    const audio_format_t *infmt = &p_filter->fmt_in.audio;
> > +    const audio_format_t *outfmt = &p_filter->fmt_out.audio;
> >  
> > -    if( p_filter->fmt_in.audio.i_format !=
> > p_filter->fmt_out.audio.i_format
> > -     || p_filter->fmt_in.audio.i_rate != p_filter->fmt_out.audio.i_rate
> > -     || p_filter->fmt_in.audio.i_format != VLC_CODEC_FL32 )
> > +    if( infmt->i_format != outfmt->i_format
> > +     || infmt->i_rate != outfmt->i_rate
> > +     || infmt->i_format != VLC_CODEC_FL32 )
> >          return VLC_EGENERIC;
> > -    if( p_filter->fmt_in.audio.i_physical_channels
> > -           == p_filter->fmt_out.audio.i_physical_channels
> > -     && p_filter->fmt_in.audio.i_original_channels
> > -           == p_filter->fmt_out.audio.i_original_channels )
> > +    if( infmt->i_physical_channels == outfmt->i_physical_channels
> > +     && infmt->i_original_channels == outfmt->i_original_channels )
> >          return VLC_EGENERIC;
> >  
> > -    const bool b_reverse_stereo =
> > p_filter->fmt_out.audio.i_original_channels & AOUT_CHAN_REVERSESTEREO;
> > -    bool b_dualmono2stereo = (p_filter->fmt_in.audio.i_original_channels
> > & AOUT_CHAN_DUALMONO );
> > -    b_dualmono2stereo &= (p_filter->fmt_out.audio.i_physical_channels &
> > ( AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT ));
> > -    b_dualmono2stereo &= ((p_filter->fmt_out.audio.i_physical_channels &
> > AOUT_CHAN_PHYSMASK) != (p_filter->fmt_in.audio.i_physical_channels &
> > AOUT_CHAN_PHYSMASK));
> > -
> > -    if( likely( !b_reverse_stereo && ! b_dualmono2stereo ) )
> > +    if( outfmt->i_physical_channels == AOUT_CHANS_STEREO )
> >      {
> > -        if( aout_FormatNbChannels( &p_filter->fmt_out.audio )
> > -            > aout_FormatNbChannels( &p_filter->fmt_in.audio ) )
> > -            func = Upmix;
> > -        else
> > -            func = Downmix;
> > +        bool swap = (outfmt->i_original_channels &
> > AOUT_CHAN_REVERSESTEREO)
> > +                  != (infmt->i_original_channels &
> > AOUT_CHAN_REVERSESTEREO);
> > +
> > +        if( (outfmt->i_original_channels & AOUT_CHAN_PHYSMASK)
> > +                                                            ==
> > AOUT_CHAN_LEFT )
> > +        {
> > +            p_filter->pf_audio_filter = swap ? CopyRight : CopyLeft;
> > +            return VLC_SUCCESS;
> > +        }
> > +
> > +        if( (outfmt->i_original_channels & AOUT_CHAN_PHYSMASK)
> > +                                                           ==
> > AOUT_CHAN_RIGHT )
> > +        {
> > +            p_filter->pf_audio_filter = swap ? CopyLeft : CopyRight;
> > +            return VLC_SUCCESS;
> > +        }
> > +
> > +        if( swap )
> > +        {
> > +            p_filter->pf_audio_filter = ReverseStereo;
> > +            return VLC_SUCCESS;
> > +        }
> >      }
> > -    /* Special case from dual mono to stereo */
> > -    else if( b_dualmono2stereo )
> > +
> > +    if ( aout_FormatNbChannels( outfmt ) == 1 )
> >      {
> > -        bool right = !(p_filter->fmt_out.audio.i_original_channels &
> > AOUT_CHAN_LEFT);
> > -        if( p_filter->fmt_out.audio.i_physical_channels ==
> > AOUT_CHAN_CENTER )
> > -            /* Mono mode */
> > -            func = right ? ExtractRight : ExtractLeft;
> > -        else
> > -            /* Fake-stereo mode */
> > -            func = right ? CopyRight : CopyLeft;
> > +        bool mono = !!(infmt->i_original_channels & AOUT_CHAN_DUALMONO);
> > +
> > +        if( mono && (infmt->i_original_channels & AOUT_CHAN_LEFT) )
> > +        {
> > +            p_filter->pf_audio_filter = ExtractLeft;
> > +            return VLC_SUCCESS;
> > +        }
> > +
> > +        if( mono && (infmt->i_original_channels & AOUT_CHAN_RIGHT) )
> > +        {
> > +            p_filter->pf_audio_filter = ExtractRight;
> > +            return VLC_SUCCESS;
> > +        }
> >      }
> > -    else /* b_reverse_stereo */
> > -        func = ReverseStereo;
> >  
> > -    p_filter->pf_audio_filter = func;
> > +    if( aout_FormatNbChannels( outfmt ) > aout_FormatNbChannels( infmt )
> > )
> > +        p_filter->pf_audio_filter = Upmix;
> > +    else
> > +        p_filter->pf_audio_filter = Downmix;
> > +
> >      return VLC_SUCCESS;
> >  }
> > 
> > _______________________________________________
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> > vlc-commits at videolan.org
> > https://mailman.videolan.org/listinfo/vlc-commits
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