demux: get rid of free_demuxer[_and_stream]()

Them being separate is just dumb. Replace them with a single
demux_free() function, and free its stream by default. Not freeing the
stream is only needed in 1 special case (demux_disc.c), use a special
flag to not free the stream in this case.

common/playlist.c

@@ -297,7 +297,7 @@ struct playlist *playlist_parse_file(const char *file, struct mp_cancel *cancel,
                          "pass it to the player\ndirectly. Don't use --playlist.\n");
         }
     }
-    free_demuxer_and_stream(d);
+    demux_free(d);
 
     if (ret) {
         mp_verbose(log, "Playlist successfully parsed\n");

demux/demux.c

@@ -130,6 +130,8 @@ struct demux_internal {
     struct demuxer *d_thread;   // accessed by demuxer impl. (producer)
     struct demuxer *d_user;     // accessed by player (consumer)
 
+    bool owns_stream;
+
     // The lock protects the packet queues (struct demux_stream),
     // and the fields below.
     pthread_mutex_t lock;
@@ -943,7 +945,7 @@ int demux_get_num_stream(struct demuxer *demuxer)
     return r;
 }
 
-void free_demuxer(demuxer_t *demuxer)
+void demux_free(struct demuxer *demuxer)
 {
     if (!demuxer)
         return;
@@ -958,6 +960,9 @@ void free_demuxer(demuxer_t *demuxer)
     demux_flush(demuxer);
     assert(in->total_bytes == 0);
 
+    if (in->owns_stream)
+        free_stream(demuxer->stream);
+
     for (int n = 0; n < in->num_streams; n++)
         talloc_free(in->streams[n]);
     pthread_mutex_destroy(&in->lock);
@@ -965,15 +970,6 @@ void free_demuxer(demuxer_t *demuxer)
     talloc_free(demuxer);
 }
 
-void free_demuxer_and_stream(struct demuxer *demuxer)
-{
-    if (!demuxer)
-        return;
-    struct stream *s = demuxer->stream;
-    free_demuxer(demuxer);
-    free_stream(s);
-}
-
 // Start the demuxer thread, which reads ahead packets on its own.
 void demux_start_thread(struct demuxer *demuxer)
 {
@@ -2307,7 +2303,7 @@ static struct demuxer *open_given_type(struct mpv_global *global,
         return demuxer;
     }
 
-    free_demuxer(demuxer);
+    demux_free(demuxer);
     return NULL;
 }
 
@@ -2316,6 +2312,9 @@ static const int d_request[] = {DEMUX_CHECK_REQUEST, -1};
 static const int d_force[]   = {DEMUX_CHECK_FORCE, -1};
 
 // params can be NULL
+// If params->does_not_own_stream==false, this does _not_ free the stream if
+// opening fails. But if it succeeds, a later demux_free() call will free the
+// stream.
 struct demuxer *demux_open(struct stream *stream, struct demuxer_params *params,
                            struct mpv_global *global)
 {
@@ -2355,6 +2354,8 @@ struct demuxer *demux_open(struct stream *stream, struct demuxer_params *params,
                 if (demuxer) {
                     talloc_steal(demuxer, log);
                     log = NULL;
+                    demuxer->in->owns_stream =
+                        params ? !params->does_not_own_stream : false;
                     goto done;
                 }
             }
@@ -2368,16 +2369,16 @@ done:
 
 // Convenience function: open the stream, enable the cache (according to params
 // and global opts.), open the demuxer.
-// (use free_demuxer_and_stream() to free the underlying stream too)
 // Also for some reason may close the opened stream if it's not needed.
 struct demuxer *demux_open_url(const char *url,
-                                struct demuxer_params *params,
-                                struct mp_cancel *cancel,
-                                struct mpv_global *global)
+                               struct demuxer_params *params,
+                               struct mp_cancel *cancel,
+                               struct mpv_global *global)
 {
     struct demuxer_params dummy = {0};
     if (!params)
         params = &dummy;
+    assert(!params->does_not_own_stream); // API user error
     struct stream *s = stream_create(url, STREAM_READ | params->stream_flags,
                                      cancel, global);
     if (!s)

demux/demux.h

@@ -177,6 +177,7 @@ struct demuxer_params {
     bool initial_readahead;
     bstr init_fragment;
     bool skip_lavf_probing;
+    bool does_not_own_stream; // if false, stream is free'd on demux_free()
     // -- demux_open_url() only
     int stream_flags;
     bool disable_cache;
@@ -249,8 +250,7 @@ typedef struct {
     int aid, vid, sid; //audio, video and subtitle id
 } demux_program_t;
 
-void free_demuxer(struct demuxer *demuxer);
-void free_demuxer_and_stream(struct demuxer *demuxer);
+void demux_free(struct demuxer *demuxer);
 
 void demux_add_packet(struct sh_stream *stream, demux_packet_t *dp);
 void demuxer_feed_caption(struct sh_stream *stream, demux_packet_t *dp);

demux/demux_disc.c

@@ -285,7 +285,10 @@ static int d_open(demuxer_t *demuxer, enum demux_check check)
     if (check != DEMUX_CHECK_FORCE)
         return -1;
 
-    struct demuxer_params params = {.force_format = "+lavf"};
+    struct demuxer_params params = {
+        .force_format = "+lavf",
+        .does_not_own_stream = true,
+    };
 
     struct stream *cur = demuxer->stream;
     const char *sname = "";
@@ -350,7 +353,7 @@ static int d_open(demuxer_t *demuxer, enum demux_check check)
 static void d_close(demuxer_t *demuxer)
 {
     struct priv *p = demuxer->priv;
-    free_demuxer(p->slave);
+    demux_free(p->slave);
 }
 
 static int d_control(demuxer_t *demuxer, int cmd, void *arg)

demux/demux_mkv_timeline.c

@@ -217,7 +217,7 @@ static bool check_file_seg(struct tl_ctx *ctx, char *filename, int segment)
             }
 
             if (stream_wants_cache(d->stream, ctx->opts->stream_cache)) {
-                free_demuxer_and_stream(d);
+                demux_free(d);
                 params.disable_cache = false;
                 params.matroska_wanted_uids = ctx->uids; // potentially reallocated, same data
                 d = demux_open_url(filename, &params, cancel, ctx->global);
@@ -230,7 +230,7 @@ static bool check_file_seg(struct tl_ctx *ctx, char *filename, int segment)
         }
     }
 
-    free_demuxer_and_stream(d);
+    demux_free(d);
     return was_valid;
 }
 

demux/demux_timeline.c

@@ -147,7 +147,7 @@ static void close_lazy_segments(struct demuxer *demuxer)
     for (int n = 0; n < p->num_segments; n++) {
         struct segment *seg = p->segments[n];
         if (seg != p->current && seg->d && seg->lazy) {
-            free_demuxer_and_stream(seg->d);
+            demux_free(seg->d);
             seg->d = NULL;
         }
     }
@@ -431,7 +431,7 @@ static void d_close(struct demuxer *demuxer)
     p->current = NULL;
     close_lazy_segments(demuxer);
     timeline_destroy(p->tl);
-    free_demuxer(master);
+    demux_free(master);
 }
 
 static int d_control(struct demuxer *demuxer, int cmd, void *arg)

demux/timeline.c

@@ -34,9 +34,9 @@ void timeline_destroy(struct timeline *tl)
     for (int n = 0; n < tl->num_sources; n++) {
         struct demuxer *d = tl->sources[n];
         if (d != tl->demuxer && d != tl->track_layout)
-            free_demuxer_and_stream(d);
+            demux_free(d);
     }
     if (tl->track_layout && tl->track_layout != tl->demuxer)
-        free_demuxer_and_stream(tl->track_layout);
+        demux_free(tl->track_layout);
     talloc_free(tl);
 }

player/loadfile.c

@@ -136,7 +136,7 @@ static void cancel_and_free_demuxer(struct MPContext *mpctx,
     if (cancel)
         mp_cancel_trigger(cancel);
 
-    free_demuxer_and_stream(*demuxer);
+    demux_free(*demuxer);
     *demuxer = NULL;
 
     talloc_free(cancel);