commands: add show_tracks_osd command to display audio and subtitle tracks on OSD

The command lists the audio and subtitle tracks in the current file on the
OSD. It also marks the currently active streams.
Video streams are not shown, as files with more than one video stream are
exceedingly rare.

DOCS/OUTDATED-tech/slave.txt

@@ -496,6 +496,9 @@ volume <value> [abs]
 show_chapters_osd
     Show the list of chapters in the currently played file on the OSD.
 
+show_tracks_osd
+    Show the list audio and subtitle tracks in the currently played file on the OSD.
+
 Available properties:
 
 name               type      min     max     get set step comment

command.c

@@ -2844,6 +2844,85 @@ static void show_chapters_on_osd(MPContext *mpctx)
     talloc_free(res);
 }
 
+static void show_tracks_on_osd(MPContext *mpctx)
+{
+    struct MPOpts *opts = &mpctx->opts;
+    char *res = NULL;
+    const char *IND = "";
+    int n;
+    int cnt = 0;
+    struct sh_audio *cur_a;
+    struct sh_sub *cur_s;
+    demux_stream_t *d_sub;
+    demuxer_t *demuxer = mpctx->demuxer;
+
+    if (!demuxer)
+        return;
+
+    cur_a = mpctx->sh_audio;
+    d_sub = mpctx->d_sub;
+    cur_s = d_sub && opts->sub_id >= 0 ? d_sub->sh : NULL;
+
+    for (n = 0; n < MAX_V_STREAMS; n++) {
+        struct sh_video *v = demuxer->v_streams[n];
+        if (v) {
+            cnt++;
+        }
+    }
+    if (cnt > 1)
+        res = talloc_asprintf_append(res, "(Warning: more than one video stream.)\n");
+
+#define STD_TRACK_HDR(st, id)                                   \
+    res = talloc_asprintf_append(res, "%s(%d) ", IND, st->id);  \
+    if (st->title) {                                            \
+        res = talloc_asprintf_append(res, "'%s' ", st->title);  \
+    }                                                           \
+    if (st->lang) {                                             \
+        res = talloc_asprintf_append(res, "(%s) ", st->lang);   \
+    }
+
+    for (n = 0; n < MAX_A_STREAMS; n++) {
+        struct sh_audio *a = demuxer->a_streams[n];
+        if (a) {
+            cnt++;
+            if (a == cur_a)
+                res = talloc_asprintf_append(res, "> ");
+            STD_TRACK_HDR(a, aid)
+            if (a == cur_a)
+                res = talloc_asprintf_append(res, "<");
+            res = talloc_asprintf_append(res, "\n");
+        }
+    }
+
+    res = talloc_asprintf_append(res, "\n");
+
+    for (n = 0; n < MAX_S_STREAMS; n++) {
+        struct sh_sub *s = demuxer->s_streams[n];
+        if (s) {
+            cnt++;
+            if (s == cur_s)
+                res = talloc_asprintf_append(res, "> ");
+            STD_TRACK_HDR(s, sid)
+            char *type = "?";
+            switch (s->type) {
+            case 't': type = "SRT"; break;
+            case 'v': type = "VOB"; break;
+            case 'a': type = NULL; break; //"ASS/SSA";
+            }
+            if (type)
+                res = talloc_asprintf_append(res, " [%s]", type);
+            if (s == cur_s)
+                res = talloc_asprintf_append(res, "<");
+            res = talloc_asprintf_append(res, "\n");
+        }
+    }
+
+#undef STD_TRACK_HDR
+
+    set_osd_msg(OSD_MSG_TEXT, 1, opts->osd_duration, "%s", res);
+    talloc_free(res);
+}
+
 void run_command(MPContext *mpctx, mp_cmd_t *cmd)
 {
     struct MPOpts *opts = &mpctx->opts;
@@ -3663,6 +3742,9 @@ void run_command(MPContext *mpctx, mp_cmd_t *cmd)
     case MP_CMD_SHOW_CHAPTERS:
         show_chapters_on_osd(mpctx);
         break;
+    case MP_CMD_SHOW_TRACKS:
+        show_tracks_on_osd(mpctx);
+        break;
 
     default:
         mp_msg(MSGT_CPLAYER, MSGL_V,

input/input.c

@@ -223,6 +223,7 @@ static const mp_cmd_t mp_cmds[] = {
   { MP_CMD_AF_CMDLINE, "af_cmdline", { ARG_STRING, ARG_STRING } },
 
   { MP_CMD_SHOW_CHAPTERS, "show_chapters_osd", },
+  { MP_CMD_SHOW_TRACKS, "show_tracks_osd", },
 
   {0}
 };

input/input.h

@@ -155,6 +155,7 @@ enum mp_command_type {
     MP_CMD_AF_CMDLINE,
 
     MP_CMD_SHOW_CHAPTERS,
+    MP_CMD_SHOW_TRACKS,
 };
 
 // The arg types