af_lavrresample: deprecate this filter

The future direction might be not having such a user-visible filter at
all, similar to how vf_scale went away (or actually, redirects to
libavfilter's vf_scale).

DOCS/interface-changes.rst

@@ -33,6 +33,8 @@ Interface changes
       its defaults), and various hw deinterlacing filters (like vf_vavpp), for
       which you will have to stop using --deinterlace=yes, and instead use the
       vf toggle commands and the filter enable/disable flag to customize it.
+    - deprecate --af=lavrresample. Use the ``--audio-resample-...`` options to
+      customize resampling, or the libavfilter ``--af=aresample`` filter.
  --- mpv 0.28.0 ---
     - rename --hwdec=mediacodec option to mediacodec-copy, to reflect
       conventions followed by other hardware video decoding APIs

DOCS/man/af.rst

@@ -29,6 +29,12 @@ Available filters are:
     This filter is automatically enabled if the audio output does not support
     the audio configuration of the file being played.
 
+    .. warning::
+
+        Deprecated. Either use the ``--audio-resample-...`` options to customize
+        resampling, or the libavfilter ``--af=aresample`` filter, which has its
+        own options.
+
     It supports only the following sample formats: u8, s16, s32, float.
 
     ``filter-size=<length>``

audio/filter/af.c

@@ -341,8 +341,9 @@ static int filter_reinit_with_conversion(struct af_stream *s, struct af_instance
         }
         if (!mp_audio_config_equals(af->prev->data, &in)) {
             // Retry with conversion filter added.
+            char *opts[] = {"deprecation-warning", "no", NULL};
             struct af_instance *new =
-                af_prepend(s, af, "lavrresample", NULL);
+                af_prepend(s, af, "lavrresample", opts);
             if (!new)
                 return AF_ERROR;
             new->auto_inserted = true;
@@ -408,7 +409,8 @@ static int af_do_reinit(struct af_stream *s, bool second_pass)
     s->first->fmt_in = s->first->fmt_out = s->input;
 
     if (mp_audio_config_valid(&convert_early)) {
-        struct af_instance *new = af_prepend(s, s->first, "lavrresample", NULL);
+        char *opts[] = {"deprecation-warning", "no", NULL};
+        struct af_instance *new = af_prepend(s, s->first, "lavrresample", opts);
         if (!new)
             return AF_ERROR;
         new->auto_inserted = true;

audio/filter/af_lavrresample.c

@@ -45,6 +45,7 @@ struct af_resample {
     struct mp_resample_opts opts;
     int global_normalize;
     struct mp_aconverter *converter;
+    int deprecation_warning;
 };
 
 static int control(struct af_instance *af, int cmd, void *arg)
@@ -149,6 +150,11 @@ static int af_open(struct af_instance *af)
 
     s->converter = mp_aconverter_create(af->global, af->log, &s->opts);
 
+    if (s->deprecation_warning) {
+        MP_WARN(af, "This filter is deprecated! Use the --audio-resample- options"
+                " to customize resampling, or the --af=aresample filter.\n");
+    }
+
     return AF_OK;
 }
 
@@ -183,6 +189,7 @@ const struct af_info af_info_lavrresample = {
         .opts = MP_RESAMPLE_OPTS_DEF,
         .playback_speed = 1.0,
         .allow_detach = 1,
+        .deprecation_warning = 1,
     },
     .options = (const struct m_option[]) {
         OPT_INTRANGE("filter-size", opts.filter_size, 0, 0, 32),
@@ -193,6 +200,7 @@ const struct af_info af_info_lavrresample = {
         OPT_CHOICE("normalize", opts.normalize, 0,
                    ({"no", 0}, {"yes", 1}, {"auto", -1})),
         OPT_KEYVALUELIST("o", opts.avopts, 0),
+        OPT_FLAG("deprecation-warning", deprecation_warning, 0),
         {0}
     },
     .set_defaults = set_defaults,

player/audio.c

@@ -110,10 +110,14 @@ static void recreate_speed_filters(struct MPContext *mpctx)
         return;
 
     int method = get_speed_method(mpctx);
-    char *filter = method == AF_CONTROL_SET_PLAYBACK_SPEED
-                 ? "scaletempo" : "lavrresample";
+    char *filter = "lavrresample";
+    char *args[] = {"deprecation-warning", "no", NULL};
+    if (method == AF_CONTROL_SET_PLAYBACK_SPEED) {
+        filter = "scaletempo";
+        args[0] = NULL;
+    }
 
-    if (!af_add(afs, filter, "playback-speed", NULL))
+    if (!af_add(afs, filter, "playback-speed", args))
         goto fail;
 
     if (!update_speed_filters(mpctx))