audio: add some setters for mp_audio, and require filters to use them

mp_audio has some redundant fields. Setters like mp_audio_set_format()
initialize these properly.

Also move the mp_audio struct to a the file audio.c.

We can remove a mysterious line of code from af.c:

    in.format |= af_bits2fmt(in.bps * 8);

I'm not sure if this was ever actually needed, or if it was some kind of
"make it work" quick-fix that works against the way things were supposed
to work. All filters etc. now set the format correctly, so if there ever
was a need for this code, it's definitely gone.

1 files changed, 3 insertions, 4 deletions

diff --git a/audio/filter/af_channels.c b/audio/filter/af_channels.c
index ac396a51cd..f6369936d6 100644
--- a/audio/filter/af_channels.c
+++ b/audio/filter/af_channels.c
@@ -164,8 +164,7 @@ static int control(struct af_instance* af, int cmd, void* arg)
     }
 
     af->data->rate   = ((struct mp_audio*)arg)->rate;
-    af->data->format = ((struct mp_audio*)arg)->format;
-    af->data->bps    = ((struct mp_audio*)arg)->bps;
+    mp_audio_set_format(af->data, ((struct mp_audio*)arg)->format);
     af->mul          = (double)af->data->nch / ((struct mp_audio*)arg)->nch;
     return check_routes(s,((struct mp_audio*)arg)->nch,af->data->nch);
   case AF_CONTROL_COMMAND_LINE:{
@@ -208,7 +207,7 @@ static int control(struct af_instance* af, int cmd, void* arg)
       return AF_ERROR;
     }
 
-    af->data->nch=((int*)arg)[0];
+    mp_audio_set_num_channels(af->data, ((int*)arg)[0]);
     if(!s->router)
       mp_msg(MSGT_AFILTER, MSGL_V, "[channels] Changing number of channels"
 	     " to %i\n",af->data->nch);
@@ -248,7 +247,7 @@ static struct mp_audio* play(struct af_instance* af, struct mp_audio* data)
   // Set output data
   c->audio = l->audio;
   c->len   = c->len / c->nch * l->nch;
-  c->nch   = l->nch;
+  mp_audio_set_num_channels(c, l->nch);
 
   return c;
 }