demux: fix rar support for files containing DTS audio tracks

With a recent cleanup, rar support was stuffed into demux_playlist.c
(because "opening" rar files pretty much just lists archive contents and
adds them to a playlist using a special rar:// protocol, which will
actually access the rar file contents).

Since demux_playlist.c is probed _after_ demux_lavf.c (and should/must
be), libavformat was given the chance to detect DTS streams embedded
within the rar file. This is not really what we want, and a regression
what happened before rar listing was moved to demux_playlist.c.

Fix it by moving the rar listing into its own pseudo-demuxer, and let ir
probe before demux_lavf.c.

(Yes, this feature still has users.)

demux/demux.c

@@ -54,6 +54,7 @@ extern const demuxer_desc_t demuxer_desc_libass;
 extern const demuxer_desc_t demuxer_desc_subreader;
 extern const demuxer_desc_t demuxer_desc_playlist;
 extern const demuxer_desc_t demuxer_desc_disc;
+extern const demuxer_desc_t demuxer_desc_rar;
 
 /* Please do not add any new demuxers here. If you want to implement a new
  * demuxer, add it to libavformat, except for wrappers around external
@@ -72,6 +73,7 @@ const demuxer_desc_t *const demuxer_list[] = {
     &demuxer_desc_libass,
 #endif
     &demuxer_desc_matroska,
+    &demuxer_desc_rar,
     &demuxer_desc_lavf,
     &demuxer_desc_mf,
     &demuxer_desc_playlist,

demux/demux_playlist.c

@@ -23,7 +23,6 @@
 #include "common/playlist.h"
 #include "options/path.h"
 #include "stream/stream.h"
-#include "stream/rar.h"
 #include "demux.h"
 
 #define PROBE_SIZE (8 * 1024)
@@ -189,30 +188,6 @@ static int parse_pls(struct pl_parser *p)
     return 0;
 }
 
-static int parse_rar(struct pl_parser *p)
-{
-    if (RarProbe(p->s))
-        return -1;
-    if (p->probing)
-        return 0;
-
-    int count;
-    rar_file_t **files;
-    if (RarParse(p->s, &count, &files))
-        return -1;
-
-    p->pl->disable_safety = true; // make it load rar://
-    char *prefix = mp_url_escape(p, p->real_stream->url, "~|");
-    for (int n = 0; n < count; n++) {
-        // stream_rar.c does the real work
-        playlist_add_file(p->pl,
-                talloc_asprintf(p, "rar://%s|%s", prefix, files[n]->name));
-        RarFileDelete(files[n]);
-    }
-    talloc_free(files);
-    return 0;
-}
-
 static int parse_txt(struct pl_parser *p)
 {
     if (!p->force)
@@ -245,7 +220,6 @@ static const struct pl_format formats[] = {
     {"mov", parse_mov_rtsptext},
     {"pls", parse_pls,
      MIME_TYPES("audio/x-scpls")},
-    {"rar", parse_rar},
     {"txt", parse_txt},
 };
 

demux/demux_rar.c

@@ -0,0 +1,62 @@
+/*
+ * This file is part of mpv.
+ *
+ * mpv is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * mpv is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with mpv.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "common/common.h"
+#include "common/playlist.h"
+#include "stream/stream.h"
+#include "stream/rar.h"
+#include "demux.h"
+
+static int open_file(struct demuxer *demuxer, enum demux_check check)
+{
+    if (RarProbe(demuxer->stream))
+        return -1;
+
+    int count;
+    rar_file_t **files;
+    if (RarParse(demuxer->stream, &count, &files))
+        return -1;
+
+    void *tmp = talloc_new(NULL);
+    talloc_steal(tmp, files);
+
+    struct playlist *pl = talloc_zero(demuxer, struct playlist);
+    demuxer->playlist = pl;
+
+    // make it load rar://
+    pl->disable_safety = true;
+
+    char *prefix = mp_url_escape(tmp, demuxer->stream->url, "~|");
+    for (int n = 0; n < count; n++) {
+        // stream_rar.c does the real work
+        playlist_add_file(pl,
+                talloc_asprintf(tmp, "rar://%s|%s", prefix, files[n]->name));
+        RarFileDelete(files[n]);
+    }
+
+    demuxer->filetype = "rar";
+    demuxer->fully_read = true;
+
+    talloc_free(tmp);
+    return 0;
+}
+
+const struct demuxer_desc demuxer_desc_rar = {
+    .name = "rar",
+    .desc = "Rar archive file",
+    .open = open_file,
+};

old-makefile

@@ -169,6 +169,7 @@ SOURCES = audio/audio.c \
           demux/demux_mkv.c \
           demux/demux_mkv_timeline.c \
           demux/demux_playlist.c \
+          demux/demux_rar.c \
           demux/demux_raw.c \
           demux/demux_subreader.c \
           demux/ebml.c \

wscript_build.py

@@ -170,6 +170,7 @@ def build(ctx):
         ( "demux/demux_mkv_timeline.c" ),
         ( "demux/demux_playlist.c" ),
         ( "demux/demux_raw.c" ),
+        ( "demux/demux_rar.c" ),
         ( "demux/demux_subreader.c" ),
         ( "demux/demux_tv.c",                    "tv" ),
         ( "demux/ebml.c" ),