[FFmpeg-devel] [PATCH 02/10] lavfi: support unknown channel layouts.

[Stefano Sabatini]

On date Wednesday 2013-01-16 17:50:16 +0100, Nicolas George encoded:
> 
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
>  libavfilter/audio.c         |    2 +-
>  libavfilter/avcodec.c       |    3 --
>  libavfilter/avfiltergraph.c |   85 ++++++++++++++++++++++++++++++++++++++++---
>  libavfilter/formats.c       |   82 ++++++++++++++++++++++++++++++++++++-----
>  libavfilter/formats.h       |   31 ++++++++++++++++
>  5 files changed, 184 insertions(+), 19 deletions(-)
[...]
> @@ -663,7 +720,23 @@ static void swap_channel_layouts_on_filter(AVFilterContext *filter)
>              int out_channels      = av_get_channel_layout_nb_channels(out_chlayout);
>              int count_diff        = out_channels - in_channels;
>              int matched_channels, extra_channels;
> -            int score = 0;
> +            int score = 100000;
> +
> +            if (FF_LAYOUT2COUNT(in_chlayout) || FF_LAYOUT2COUNT(out_chlayout)) {
> +                /* Compute score in case the input or output layout encodes
> +                   a channel count; in this case the score is not altered by
> +                   the computation afterwards, as in_chlayout and
> +                   out_chlayout have both been set to 0 */
> +                if (FF_LAYOUT2COUNT(in_chlayout))
> +                    in_channels = FF_LAYOUT2COUNT(in_chlayout);
> +                if (FF_LAYOUT2COUNT(out_chlayout))
> +                    out_channels = FF_LAYOUT2COUNT(out_chlayout);
> +                score -= 10000 + FFABS(out_channels - in_channels) +
> +                         (in_channels > out_channels ? 10000 : 0);
> +                in_chlayout = out_chlayout = 0;
> +                /* Let the remaining computation run, even if the score
> +                   value is not altered */
> +            }

Much better, thanks.

[...]
> diff --git a/libavfilter/formats.h b/libavfilter/formats.h
> index c5a4e3d..dd52ec8 100644
> --- a/libavfilter/formats.h
> +++ b/libavfilter/formats.h
> @@ -69,15 +69,46 @@ struct AVFilterFormats {
>      struct AVFilterFormats ***refs; ///< references to this list
>  };
>  
> +/**
> + * A list of supported channel layouts.
> + *
> + * The list works the same as AVFilterFormats, except for the following
> + * differences:
> + * - A list with all_layouts = 1 means all channel layouts with a known
> + *   disposition; nb_channel_layouts must then be 0.
> + * - A list with all_counts = 1 means all channel counts, with a known or
> + *   unknown disposition ; nb_channel_layouts must then be 0 and all_layouts 1.

nit: "disposition ;" -> "disposition;"

[...]

No more comments from me, looks good assuming FATE is happy with it.
-- 
FFmpeg = Fiendish & Frightening Multipurpose Plastic Experimenting God