diff --git a/demux/demux.c b/demux/demux.c
index 6c4f9542f8..3aade0f200 100644
--- a/demux/demux.c
+++ b/demux/demux.c
@@ -1878,6 +1878,7 @@ static struct demux_packet *dequeue_packet(struct demux_stream *ds)
     // This implies this function is actually called from "the" user thread.
     if (pkt->pos >= ds->in->d_user->filepos)
         ds->in->d_user->filepos = pkt->pos;
+    ds->in->d_user->filesize = ds->in->stream_size;
 
     pkt->pts = MP_ADD_PTS(pkt->pts, ds->in->ts_offset);
     pkt->dts = MP_ADD_PTS(pkt->dts, ds->in->ts_offset);
@@ -3114,31 +3115,10 @@ static void update_cache(struct demux_internal *in)
     pthread_mutex_unlock(&in->lock);
 }
 
-// must be called locked
-static int cached_stream_control(struct demux_internal *in, int cmd, void *arg)
-{
-    switch (cmd) {
-    case STREAM_CTRL_GET_SIZE:
-        if (in->stream_size < 0)
-            return STREAM_UNSUPPORTED;
-        *(int64_t *)arg = in->stream_size;
-        return STREAM_OK;
-    }
-    return STREAM_ERROR;
-}
-
 // must be called locked
 static int cached_demux_control(struct demux_internal *in, int cmd, void *arg)
 {
     switch (cmd) {
-    case DEMUXER_CTRL_STREAM_CTRL: {
-        struct demux_ctrl_stream_ctrl *c = arg;
-        int r = cached_stream_control(in, c->ctrl, c->arg);
-        if (r == STREAM_ERROR)
-            break;
-        c->res = r;
-        return CONTROL_OK;
-    }
     case DEMUXER_CTRL_GET_BITRATE_STATS: {
         double *rates = arg;
         for (int n = 0; n < STREAM_TYPE_COUNT; n++)
@@ -3217,14 +3197,6 @@ static void thread_demux_control(void *p)
 
     pthread_mutex_unlock(&in->lock);
 
-    if (cmd == DEMUXER_CTRL_STREAM_CTRL) {
-        struct demux_ctrl_stream_ctrl *c = arg;
-        if (in->threading)
-            MP_VERBOSE(demuxer, "blocking for STREAM_CTRL %d\n", c->ctrl);
-        c->res = stream_control(demuxer->stream, c->ctrl, c->arg);
-        if (c->res != STREAM_UNSUPPORTED)
-            r = CONTROL_OK;
-    }
     if (r != CONTROL_OK) {
         if (in->threading)
             MP_VERBOSE(demuxer, "blocking for DEMUXER_CTRL %d\n", cmd);
@@ -3272,13 +3244,6 @@ int demux_control(demuxer_t *demuxer, int cmd, void *arg)
     return r;
 }
 
-int demux_stream_control(demuxer_t *demuxer, int ctrl, void *arg)
-{
-    struct demux_ctrl_stream_ctrl c = {ctrl, arg, STREAM_UNSUPPORTED};
-    demux_control(demuxer, DEMUXER_CTRL_STREAM_CTRL, &c);
-    return c.res;
-}
-
 bool demux_cancel_test(struct demuxer *demuxer)
 {
     return mp_cancel_test(demuxer->cancel);
diff --git a/demux/demux.h b/demux/demux.h
index b8d5cb5ee0..1bb8e2f7c8 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -32,8 +32,6 @@
 
 enum demux_ctrl {
     DEMUXER_CTRL_SWITCHED_TRACKS = 1,
-    DEMUXER_CTRL_IDENTIFY_PROGRAM,
-    DEMUXER_CTRL_STREAM_CTRL,
     DEMUXER_CTRL_GET_READER_STATE,
     DEMUXER_CTRL_GET_BITRATE_STATS, // double[STREAM_TYPE_COUNT]
     DEMUXER_CTRL_REPLACE_STREAM,
@@ -192,6 +190,7 @@ typedef struct demuxer {
     const demuxer_desc_t *desc; ///< Demuxer description structure
     const char *filetype; // format name when not identified by demuxer (libavformat)
     int64_t filepos;  // input stream current pos.
+    int64_t filesize;
     char *filename;  // same as stream->url
     bool seekable;
     bool partially_seekable; // true if _maybe_ seekable; implies seekable=true
@@ -243,7 +242,6 @@ typedef struct demuxer {
 
     // Since the demuxer can run in its own thread, and the stream is not
     // thread-safe, only the demuxer is allowed to access the stream directly.
-    // You can freely use demux_stream_control() to send STREAM_CTRLs.
     // Also note that the stream can get replaced if fully_read is set.
     struct stream *stream;
 } demuxer_t;
@@ -308,8 +306,6 @@ int demuxer_add_chapter(demuxer_t *demuxer, char *name,
 void demux_set_stream_tags(struct demuxer *demuxer, struct sh_stream *sh,
                            struct mp_tags *tags);
 
-int demux_stream_control(demuxer_t *demuxer, int ctrl, void *arg);
-
 void demux_metadata_changed(demuxer_t *demuxer);
 void demux_update(demuxer_t *demuxer);
 
diff --git a/player/command.c b/player/command.c
index dacdbed3f8..3621fae90c 100644
--- a/player/command.c
+++ b/player/command.c
@@ -557,9 +557,7 @@ static int mp_property_file_size(void *ctx, struct m_property *prop,
     if (!mpctx->demuxer)
         return M_PROPERTY_UNAVAILABLE;
 
-    int64_t size;
-    if (demux_stream_control(mpctx->demuxer, STREAM_CTRL_GET_SIZE, &size) < 1)
-        return M_PROPERTY_UNAVAILABLE;
+    int64_t size = mpctx->demuxer->filesize;
 
     if (action == M_PROPERTY_PRINT) {
         *(char **)arg = format_file_size(size);
diff --git a/player/playloop.c b/player/playloop.c
index 85cc9f7faf..0326e32779 100644
--- a/player/playloop.c
+++ b/player/playloop.c
@@ -519,11 +519,9 @@ double get_current_pos_ratio(struct MPContext *mpctx, bool use_range)
     if (len > 0)
         ans = MPCLAMP((pos - start) / len, 0, 1);
     if (ans < 0 || demuxer->ts_resets_possible) {
-        int64_t size;
-        if (demux_stream_control(demuxer, STREAM_CTRL_GET_SIZE, &size) > 0) {
-            if (size > 0 && demuxer->filepos >= 0)
-                ans = MPCLAMP(demuxer->filepos / (double)size, 0, 1);
-        }
+        int64_t size = demuxer->filesize;
+        if (size > 0 && demuxer->filepos >= 0)
+            ans = MPCLAMP(demuxer->filepos / (double)size, 0, 1);
     }
     if (use_range) {
         if (mpctx->opts->play_frames > 0)