[FFmpeg-devel] [PATCH] avdevice/pulse_audio_dec: identify channel layout

[Carl Eugen Hoyos]

Am So., 26. Jan. 2020 um 16:23 Uhr schrieb Federico Simoncelli
<federico.simoncelli at gmail.com>:
>
> This patch adds the attempt to identify the pulseaudio channel map and
> when possible set the relevant channel_layout parameter of the codec.
>
> The result is an improvement over the current behavior of guessing the
> layout based on the number of channels (for more information see
> guess_layout_max).
> ---
>  libavdevice/pulse_audio_dec.c | 37 +++++++++++++++++++++++++++++++----
>  1 file changed, 33 insertions(+), 4 deletions(-)
>
> diff --git a/libavdevice/pulse_audio_dec.c b/libavdevice/pulse_audio_dec.c
> index 50a3c971ae..2f76cfd474 100644
> --- a/libavdevice/pulse_audio_dec.c
> +++ b/libavdevice/pulse_audio_dec.c
> @@ -135,6 +135,34 @@ static av_cold int pulse_close(AVFormatContext *s)
>      return 0;
>  }
>
> +static int pulse_map_to_layout(pa_channel_map *cmap)
> +{
> +    const char *map_name = pa_channel_map_to_name(cmap);
> +
> +    if (strcmp(map_name, "mono") == 0)
> +        return AV_CH_LAYOUT_MONO;
> +
> +    if (strcmp(map_name, "stereo") == 0)
> +        return AV_CH_LAYOUT_STEREO;

> +    if (strcmp(map_name, "surround-40") == 0)
> +        return AV_CH_LAYOUT_4POINT0;
> +
> +    if (strcmp(map_name, "surround-41") == 0)
> +        return AV_CH_LAYOUT_4POINT1;
> +
> +    if (strcmp(map_name, "surround-50") == 0)
> +        return AV_CH_LAYOUT_5POINT0;
> +
> +    if (strcmp(map_name, "surround-51") == 0)
> +        return AV_CH_LAYOUT_5POINT1;
> +
> +    if (strcmp(map_name, "surround-71") == 0)
> +        return AV_CH_LAYOUT_7POINT1;

Can you confirm that with the existing code, user could set the channel_layout
for everything >= 3 channels? Does this still work after your patch?

Carl Eugen