demux: refactor tag handling

Make the code somewhat reuseable, instead of bound to a single demuxer
instance. The plan is to add support for per-chapter tags later.

demux/demux.c

@@ -542,6 +542,7 @@ static struct demuxer *open_given_type(struct MPOpts *opts,
         .filepos = -1,
         .opts = opts,
         .filename = talloc_strdup(demuxer, stream->url),
+        .metadata = talloc_zero(demuxer, struct mp_tags),
     };
     demuxer->params = params; // temporary during open()
     stream_seek(stream, stream->start_pos);
@@ -684,6 +685,42 @@ int demux_seek(demuxer_t *demuxer, float rel_seek_secs, int flags)
     return 1;
 }
 
+void mp_tags_set_str(struct mp_tags *tags, const char *key, const char *value)
+{
+    mp_tags_set_bstr(tags, bstr0(key), bstr0(value));
+}
+
+void mp_tags_set_bstr(struct mp_tags *tags, bstr key, bstr value)
+{
+    for (int n = 0; n < tags->num_keys; n++) {
+        if (bstrcasecmp0(key, tags->keys[n]) == 0) {
+            talloc_free(tags->values[n]);
+            tags->values[n] = talloc_strndup(tags, value.start, value.len);
+            return;
+        }
+    }
+
+    MP_RESIZE_ARRAY(tags, tags->keys,   tags->num_keys + 1);
+    MP_RESIZE_ARRAY(tags, tags->values, tags->num_keys + 1);
+    tags->keys[tags->num_keys]   = talloc_strndup(tags, key.start,   key.len);
+    tags->values[tags->num_keys] = talloc_strndup(tags, value.start, value.len);
+    tags->num_keys++;
+}
+
+char *mp_tags_get_str(struct mp_tags *tags, const char *key)
+{
+    return mp_tags_get_bstr(tags, bstr0(key));
+}
+
+char *mp_tags_get_bstr(struct mp_tags *tags, bstr key)
+{
+    for (int n = 0; n < tags->num_keys; n++) {
+        if (bstrcasecmp0(key, tags->keys[n]) == 0)
+            return tags->values[n];
+    }
+    return NULL;
+}
+
 int demux_info_add(demuxer_t *demuxer, const char *opt, const char *param)
 {
     return demux_info_add_bstr(demuxer, bstr0(opt), bstr0(param));
@@ -691,49 +728,34 @@ int demux_info_add(demuxer_t *demuxer, const char *opt, const char *param)
 
 int demux_info_add_bstr(demuxer_t *demuxer, struct bstr opt, struct bstr param)
 {
-    char **info = demuxer->info;
+    char *oldval = mp_tags_get_bstr(demuxer->metadata, opt);
-    int n = 0;
+    if (oldval) {
-
+        if (bstrcmp0(param, oldval) == 0)
-
-    for (n = 0; info && info[2 * n] != NULL; n++) {
-        if (!bstrcasecmp(opt, bstr0(info[2*n]))) {
-            if (!bstrcmp(param, bstr0(info[2*n + 1]))) {
-                mp_msg(MSGT_DEMUX, MSGL_V, "Demuxer info %.*s set to unchanged value %.*s\n",
-                       BSTR_P(opt), BSTR_P(param));
-                return 0;
-            }
-            mp_tmsg(MSGT_DEMUX, MSGL_INFO, "Demuxer info %.*s changed to %.*s\n",
-                    BSTR_P(opt), BSTR_P(param));
-            talloc_free(info[2*n + 1]);
-            info[2*n + 1] = talloc_strndup(demuxer->info, param.start, param.len);
             return 0;
-        }
+        mp_tmsg(MSGT_DEMUX, MSGL_INFO, "Demuxer info %.*s changed to %.*s\n",
+                BSTR_P(opt), BSTR_P(param));
     }
 
-    info = demuxer->info = talloc_realloc(demuxer, info, char *, 2 * (n + 2));
+    mp_tags_set_bstr(demuxer->metadata, opt, param);
-    info[2*n]     = talloc_strndup(demuxer->info, opt.start,   opt.len);
-    info[2*n + 1] = talloc_strndup(demuxer->info, param.start, param.len);
-    memset(&info[2 * (n + 1)], 0, 2 * sizeof(char *));
-
     return 1;
 }
 
 int demux_info_print(demuxer_t *demuxer)
 {
-    char **info = demuxer->info;
+    struct mp_tags *info = demuxer->metadata;
     int n;
 
     if (!info)
         return 0;
 
     mp_tmsg(MSGT_DEMUX, MSGL_INFO, "Clip info:\n");
-    for (n = 0; info[2 * n] != NULL; n++) {
+    for (n = 0; n < info->num_keys; n++) {
-        mp_msg(MSGT_DEMUX, MSGL_INFO, " %s: %s\n", info[2 * n],
+        mp_msg(MSGT_DEMUX, MSGL_INFO, " %s: %s\n", info->keys[n],
-               info[2 * n + 1]);
+               info->values[n]);
         mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_CLIP_INFO_NAME%d=%s\n", n,
-               info[2 * n]);
+               info->keys[n]);
         mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_CLIP_INFO_VALUE%d=%s\n", n,
-               info[2 * n + 1]);
+               info->values[n]);
     }
     mp_msg(MSGT_IDENTIFY, MSGL_INFO, "ID_CLIP_INFO_N=%d\n", n);
 
@@ -742,15 +764,7 @@ int demux_info_print(demuxer_t *demuxer)
 
 char *demux_info_get(demuxer_t *demuxer, const char *opt)
 {
-    int i;
+    return mp_tags_get_str(demuxer->metadata, opt);
-    char **info = demuxer->info;
-
-    for (i = 0; info && info[2 * i] != NULL; i++) {
-        if (!strcasecmp(opt, info[2 * i]))
-            return info[2 * i + 1];
-    }
-
-    return NULL;
 }
 
 void demux_info_update(struct demuxer *demuxer)

demux/demux.h

@@ -111,6 +111,12 @@ typedef struct demuxer_desc {
     int (*control)(struct demuxer *demuxer, int cmd, void *arg);
 } demuxer_desc_t;
 
+struct mp_tags {
+    char **keys;
+    char **values;
+    int num_keys;
+};
+
 typedef struct demux_chapter
 {
     int original_index;
@@ -185,8 +191,9 @@ typedef struct demuxer {
     // If the file is a playlist file
     struct playlist *playlist;
 
+    struct mp_tags *metadata;
+
     void *priv;   // demuxer-specific internal data
-    char **info;  // metadata
     struct MPOpts *opts;
     struct demuxer_params *params;
 } demuxer_t;
@@ -282,4 +289,9 @@ double demux_packet_list_duration(struct demux_packet **pkts, int num_pkts);
 struct demux_packet *demux_packet_list_fill(struct demux_packet **pkts,
                                             int num_pkts, int *current);
 
+void mp_tags_set_str(struct mp_tags *tags, const char *key, const char *value);
+void mp_tags_set_bstr(struct mp_tags *tags, bstr key, bstr value);
+char *mp_tags_get_str(struct mp_tags *tags, const char *key);
+char *mp_tags_get_bstr(struct mp_tags *tags, bstr key);
+
 #endif /* MPLAYER_DEMUXER_H */

mpvcore/command.c

@@ -636,39 +636,38 @@ static int mp_property_angle(m_option_t *prop, int action, void *arg,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
-/// Demuxer meta data
+static int tag_property(m_option_t *prop, int action, void *arg,
-static int mp_property_metadata(m_option_t *prop, int action, void *arg,
+                        struct mp_tags *tags)
-                                MPContext *mpctx)
 {
-    struct demuxer *demuxer = mpctx->master_demuxer;
-    if (!demuxer)
-        return M_PROPERTY_UNAVAILABLE;
-
     static const m_option_t key_type =
     {
-        "metadata", NULL, CONF_TYPE_STRING, 0, 0, 0, NULL
+        "tags", NULL, CONF_TYPE_STRING, 0, 0, 0, NULL
     };
 
     switch (action) {
     case M_PROPERTY_GET: {
         char **slist = NULL;
-        m_option_copy(prop, &slist, &demuxer->info);
+        int num = 0;
+        for (int n = 0; n < tags->num_keys; n++) {
+            MP_TARRAY_APPEND(NULL, slist, num, tags->keys[n]);
+            MP_TARRAY_APPEND(NULL, slist, num, tags->values[n]);
+        }
+        MP_TARRAY_APPEND(NULL, slist, num, NULL);
         *(char ***)arg = slist;
         return M_PROPERTY_OK;
     }
     case M_PROPERTY_PRINT: {
-        char **list = demuxer->info;
         char *res = NULL;
-        for (int n = 0; list && list[n]; n += 2) {
+        for (int n = 0; n < tags->num_keys; n++) {
             res = talloc_asprintf_append_buffer(res, "%s: %s\n",
-                                                list[n], list[n + 1]);
+                                                tags->keys[n], tags->values[n]);
         }
         *(char **)arg = res;
         return res ? M_PROPERTY_OK : M_PROPERTY_UNAVAILABLE;
     }
     case M_PROPERTY_KEY_ACTION: {
         struct m_property_action_arg *ka = arg;
-        char *meta = demux_info_get(demuxer, ka->key);
+        char *meta = mp_tags_get_str(tags, ka->key);
         if (!meta)
             return M_PROPERTY_UNKNOWN;
         switch (ka->action) {
@@ -684,6 +683,17 @@ static int mp_property_metadata(m_option_t *prop, int action, void *arg,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
+/// Demuxer meta data
+static int mp_property_metadata(m_option_t *prop, int action, void *arg,
+                                MPContext *mpctx)
+{
+    struct demuxer *demuxer = mpctx->master_demuxer;
+    if (!demuxer)
+        return M_PROPERTY_UNAVAILABLE;
+
+    return tag_property(prop, action, arg, demuxer->metadata);
+}
+
 static int mp_property_pause(m_option_t *prop, int action, void *arg,
                              void *ctx)
 {