demux: enrich edition titles with codec/resolution/bitrate info

Extract the codec descriptor out of mp_format_track_metadata into a
shared demux_append_codec_desc() helper, and use it from a new
demux_compose_edition_title() composer that both demux_timeline.c and
demux_lavf.c call when building editions. Codec block is only added
when the program has exactly one stream of that kind, and fields
already present in the prefix (e.g. WxH from yt-dlp's format label)
are skipped to avoid duplication.

demux/demux.c

@@ -1249,6 +1249,76 @@ const char *stream_type_name(enum stream_type type)
     }
 }
 
+static void append_field(void *ta_ctx, bstr *dst, const char *skip_dup,
+                         const char *value)
+{
+    if (skip_dup && skip_dup[0] && strstr(skip_dup, value))
+        return;
+    bstr_xappend_asprintf(ta_ctx, dst, " %s", value);
+}
+
+void demux_append_codec_desc(void *ta_ctx, bstr *dst, struct sh_stream *sh,
+                             const char *skip_dup)
+{
+    struct mp_codec_params *c = sh->codec;
+
+    bstr_xappend0(ta_ctx, dst, c->codec ? c->codec : "<unknown>");
+
+    if (c->codec_profile)
+        bstr_xappend_asprintf(ta_ctx, dst, " [%s]", c->codec_profile);
+    if (c->disp_w)
+        append_field(ta_ctx, dst, skip_dup,
+                     mp_tprintf(32, "%dx%d", c->disp_w, c->disp_h));
+    if (c->fps && !sh->image) {
+        char *fps = mp_format_double(ta_ctx, c->fps, 4, false, false, true);
+        append_field(ta_ctx, dst, skip_dup, mp_tprintf(32, "%s fps", fps));
+    }
+    if (c->channels.num)
+        bstr_xappend_asprintf(ta_ctx, dst, " %dch", c->channels.num);
+    if (c->samplerate)
+        bstr_xappend_asprintf(ta_ctx, dst, " %d Hz", c->samplerate);
+    int bitrate = 0;
+    if (c->bitrate > 0 && c->bitrate < INT_MAX - 500) {
+        bitrate = (c->bitrate + 500) / 1000;
+    } else if (sh->hls_bitrate > 0 && sh->hls_bitrate < INT_MAX - 500) {
+        bitrate = (sh->hls_bitrate + 500) / 1000;
+    }
+    if (bitrate)
+        append_field(ta_ctx, dst, skip_dup, mp_tprintf(32, "%d kbps", bitrate));
+}
+
+char *demux_compose_edition_title(void *ta_ctx, struct demuxer *demuxer,
+                                  int program_id, const char *prefix)
+{
+    struct sh_stream *vsh = NULL, *ash = NULL;
+    int video_count = 0, audio_count = 0;
+    int num = demux_get_num_stream(demuxer);
+    for (int i = 0; i < num; i++) {
+        struct sh_stream *s = demux_get_stream(demuxer, i);
+        if (s->program_id != program_id)
+            continue;
+        if (s->type == STREAM_VIDEO) { video_count++; vsh = s; }
+        else if (s->type == STREAM_AUDIO) { audio_count++; ash = s; }
+    }
+
+    bstr dst = {0};
+    if (prefix && prefix[0])
+        bstr_xappend0(ta_ctx, &dst, prefix);
+    if (video_count == 1) {
+        bstr_xappend0(ta_ctx, &dst, dst.len ? " (" : "(");
+        demux_append_codec_desc(ta_ctx, &dst, vsh, prefix);
+        bstr_xappend0(ta_ctx, &dst, ")");
+    }
+    if (audio_count == 1) {
+        bstr_xappend0(ta_ctx, &dst, dst.len ? " (" : "(");
+        demux_append_codec_desc(ta_ctx, &dst, ash, prefix);
+        bstr_xappend0(ta_ctx, &dst, ")");
+    }
+    if (!dst.len)
+        return NULL;
+    return bstrto0(ta_ctx, dst);
+}
+
 static struct sh_stream *demuxer_get_cc_track_locked(struct sh_stream *stream)
 {
     struct sh_stream *sh = stream->ds->cc;

demux/demux.h

@@ -370,4 +370,18 @@ bool demux_matroska_uid_cmp(struct matroska_segment_uid *a,
 
 const char *stream_type_name(enum stream_type type);
 
+// Append a codec descriptor for stream `sh` to output string `dst`
+// Fields that are unset are skipped. If `skip_dup` is non-NULL, fields whose
+// formatted value already appears in it are skipped too.
+void demux_append_codec_desc(void *ta_ctx, bstr *dst, struct sh_stream *sh,
+                             const char *skip_dup);
+
+// Compose a descriptive edition title. Walks the demuxer's streams matching
+// `program_id`, and when exactly one video / one audio stream is present,
+// appends a parenthesized codec descriptor for it. When multiple tracks of a
+// a type are present, no descriptor is appended. Returns NULL if
+// nothing useful would be produced; otherwise a talloc'd string.
+char *demux_compose_edition_title(void *ta_ctx, struct demuxer *demuxer,
+                                  int program_id, const char *prefix);
+
 #endif /* MPLAYER_DEMUXER_H */

demux/demux_lavf.c

@@ -995,57 +995,48 @@ static void build_editions(demuxer_t *demuxer)
         };
         mp_tags_copy_from_av_dictionary(ed.metadata, prog->metadata);
 
-        // AVProgram is unlikely to have a "title" tag, but just in case,
-        // don't override it.
-        char *title = mp_tags_get_str(ed.metadata, "title");
-        if (title)
-            goto done;
-
-        char *service_name = mp_tags_get_str(ed.metadata, "service_name");
-        if (service_name) {
-            mp_tags_set_str(ed.metadata, "title", service_name);
-            goto done;
-        }
-
-        // If program/variant has a single video (or audio) stream, use the
-        // "comment" metadata as the name.
-        char *rendition_name = NULL;
         int video_count = 0, audio_count = 0;
         int video_idx = -1, audio_idx = -1;
         for (unsigned j = 0; j < prog->nb_stream_indexes; j++) {
             unsigned idx = prog->stream_index[j];
             if (idx >= priv->num_streams || !priv->streams[idx]->sh)
                 continue;
-            if (priv->streams[idx]->sh->type == STREAM_VIDEO) {
+            struct sh_stream *sh = priv->streams[idx]->sh;
+            if (sh->type == STREAM_VIDEO) {
                 video_count++;
                 video_idx = idx;
-            } else if (priv->streams[idx]->sh->type == STREAM_AUDIO) {
+            } else if (sh->type == STREAM_AUDIO) {
                 audio_count++;
                 audio_idx = idx;
             }
         }
-        int name_idx = video_count == 1 ? video_idx : audio_count == 1 ? audio_idx : -1;
-        if (name_idx >= 0)
-            rendition_name = mp_tags_get_str(priv->streams[name_idx]->sh->tags, "comment");
 
-        if (rendition_name) {
-            mp_tags_set_str(ed.metadata, "title", rendition_name);
-            goto done;
+        const char *prefix = mp_tags_get_str(ed.metadata, "title");
+        if (!prefix)
+            prefix = mp_tags_get_str(ed.metadata, "service_name");
+        if (!prefix) {
+            int name_idx = video_count == 1 ? video_idx
+                         : audio_count == 1 ? audio_idx : -1;
+            if (name_idx >= 0)
+                prefix = mp_tags_get_str(priv->streams[name_idx]->sh->tags, "comment");
         }
-
-        char *vb = mp_tags_get_str(ed.metadata, "variant_bitrate");
-        char *end;
-        double rate = vb ? strtoll(vb, &end, 10) : 0;
-        if (rate > 0 && *end == '\0') {
-            rate /= 1000.0;
-            if (rate < 1000) {
-                mp_tags_set_str(ed.metadata, "title", mp_tprintf(42, "Bitrate: %.f kbps", rate));
-            } else {
-                mp_tags_set_str(ed.metadata, "title", mp_tprintf(42, "Bitrate: %.3f Mbps", rate / 1000.0));
+        if (!prefix) {
+            char *vb = mp_tags_get_str(ed.metadata, "variant_bitrate");
+            char *end;
+            double rate = vb ? strtoll(vb, &end, 10) : 0;
+            if (rate > 0 && *end == '\0') {
+                rate /= 1000.0;
+                prefix = rate < 1000
+                    ? mp_tprintf(42, "Bitrate: %.f kbps", rate)
+                    : mp_tprintf(42, "Bitrate: %.3f Mbps", rate / 1000.0);
             }
         }
 
-done:
+        char *title = demux_compose_edition_title(demuxer, demuxer,
+                                                  prog->id, prefix);
+        if (title)
+            mp_tags_set_str(ed.metadata, "title", title);
+
         MP_TARRAY_APPEND(demuxer, demuxer->editions, demuxer->num_editions, ed);
     }
 

demux/demux_timeline.c

@@ -667,22 +667,21 @@ static void build_editions(struct demuxer *demuxer)
             .metadata = talloc_zero(demuxer, struct mp_tags),
         };
 
-        // Use title from the first video stream in this program as edition
-        // title, falling back to any stream with a title.
-        const char *fallback_title = NULL;
+        const char *prefix = NULL;
+        bool prefix_is_video = false;
         for (int i = n; i < num_streams; i++) {
             struct sh_stream *s = demux_get_stream(demuxer, i);
             if (s->program_id != sh->program_id || !s->title)
                 continue;
-            if (s->type == STREAM_VIDEO) {
-                fallback_title = s->title;
-                break;
+            if (!prefix || (!prefix_is_video && s->type == STREAM_VIDEO)) {
+                prefix = s->title;
+                prefix_is_video = s->type == STREAM_VIDEO;
             }
-            if (!fallback_title)
-                fallback_title = s->title;
         }
-        if (fallback_title)
-            mp_tags_set_str(ed.metadata, "title", fallback_title);
+        char *title = demux_compose_edition_title(demuxer, demuxer,
+                                                  sh->program_id, prefix);
+        if (title)
+            mp_tags_set_str(ed.metadata, "title", title);
 
         MP_TARRAY_APPEND(demuxer, demuxer->editions, demuxer->num_editions, ed);
     }

player/misc.c

@@ -366,31 +366,15 @@ char *mp_format_track_metadata(void *ctx, struct track *t, bool add_lang)
     if (t->title)
         bstr_xappend_asprintf(ctx, &dst, "'%s' ", t->title);
 
-    const char *codec = s ? s->codec->codec : NULL;
-
     bstr_xappend0(ctx, &dst, "(");
 
     if (add_lang && t->lang)
         bstr_xappend_asprintf(ctx, &dst, "%s ", t->lang);
 
-    bstr_xappend0(ctx, &dst, codec ? codec : "<unknown>");
-
-    if (s && s->codec->codec_profile)
-        bstr_xappend_asprintf(ctx, &dst, " [%s]", s->codec->codec_profile);
-    if (s && s->codec->disp_w)
-        bstr_xappend_asprintf(ctx, &dst, " %dx%d", s->codec->disp_w, s->codec->disp_h);
-    if (s && s->codec->fps && !t->image) {
-        char *fps = mp_format_double(ctx, s->codec->fps, 4, false, false, true);
-        bstr_xappend_asprintf(ctx, &dst, " %s fps", fps);
-    }
-    if (s && s->codec->channels.num)
-        bstr_xappend_asprintf(ctx, &dst, " %dch", s->codec->channels.num);
-    if (s && s->codec->samplerate)
-        bstr_xappend_asprintf(ctx, &dst, " %d Hz", s->codec->samplerate);
-    if (s && s->codec->bitrate > 0 && s->codec->bitrate < INT_MAX - 500) {
-        bstr_xappend_asprintf(ctx, &dst, " %d kbps", (s->codec->bitrate + 500) / 1000);
-    } else if (s && s->hls_bitrate > 0 && s->hls_bitrate < INT_MAX - 500) {
-        bstr_xappend_asprintf(ctx, &dst, " %d kbps", (s->hls_bitrate + 500) / 1000);
+    if (s) {
+        demux_append_codec_desc(ctx, &dst, s, NULL);
+    } else {
+        bstr_xappend0(ctx, &dst, "<unknown>");
     }
     bstr_xappend0(ctx, &dst, ")");