audio: add --audio-spdif as new method for enabling passthrough

This provides a new method for enabling spdif passthrough. The old
method via --ad (--ad=spdif:ac3 etc.) is deprecated. The deprecated
method will probably stop working at some point.

This also supports PCM fallback. One caveat is that it will lose at
least 1 audio packet in doing so. (I don't care enough to prevent this.)

(This is named after the old S/PDIF connector, because it uses the same
underlying technology as far as the higher level protoco is concerned.
Also, the user should be renamed that passthrough is backwards.)

2 files changed, 29 insertions, 0 deletions

diff --git a/common/codecs.c b/common/codecs.c
index f89ef0c318..35d270989d 100644
--- a/common/codecs.c
+++ b/common/codecs.c
@@ -130,6 +130,28 @@ struct mp_decoder_list *mp_select_decoders(struct mp_decoder_list *all,
     return list;
 }
 
+// selection is a ","-separated list of decoders, all in the given family.
+struct mp_decoder_list *mp_select_decoder_list(struct mp_decoder_list *all,
+                                               const char *codec,
+                                               const char *family,
+                                               const char *selection)
+{
+    struct mp_decoder_list *list = talloc_zero(NULL, struct mp_decoder_list);
+    bstr sel = bstr0(selection);
+    while (sel.len) {
+        bstr decoder;
+        bstr_split_tok(sel, ",", &decoder, &sel);
+        add_new(list, find_decoder(all, bstr0(family), decoder), codec);
+    }
+    return list;
+}
+
+void mp_append_decoders(struct mp_decoder_list *list, struct mp_decoder_list *a)
+{
+    for (int n = 0; n < a->num_entries; n++)
+        add_new(list, &a->entries[n], NULL);
+}
+
 void mp_print_decoders(struct mp_log *log, int msgl, const char *header,
                        struct mp_decoder_list *list)
 {
diff --git a/common/codecs.h b/common/codecs.h
index 105aab5a82..a262ed6582 100644
--- a/common/codecs.h
+++ b/common/codecs.h
@@ -37,6 +37,13 @@ struct mp_decoder_list *mp_select_decoders(struct mp_decoder_list *all,
                                            const char *codec,
                                            const char *selection);
 
+struct mp_decoder_list *mp_select_decoder_list(struct mp_decoder_list *all,
+                                               const char *codec,
+                                               const char *family,
+                                               const char *selection);
+
+void mp_append_decoders(struct mp_decoder_list *list, struct mp_decoder_list *a);
+
 struct mp_log;
 void mp_print_decoders(struct mp_log *log, int msgl, const char *header,
                        struct mp_decoder_list *list);