[FFmpeg-cvslog] mov: Add an option to toggle dref opening

[Derek Buitenhuis]

ffmpeg | branch: release/2.6 | Derek Buitenhuis <derek.buitenhuis at gmail.com> | Fri Jan 15 17:03:49 2016 +0000| [1733981ec3ac8d3631be29c137797c043e1d87e5] | committer: Michael Niedermayer

mov: Add an option to toggle dref opening

This feature is mostly only used by NLE software, and is
both of dubious value being enabled by default, and a
possible security risk.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 712d962a6a29b1099cd872cfb07867175a93ac4c)

Conflicts:

	libavformat/isom.h
	libavformat/mov.c
	libavformat/version.h

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1733981ec3ac8d3631be29c137797c043e1d87e5
---

 libavformat/isom.h |    1 +
 libavformat/mov.c  |   22 +++++++++++++++++-----
 2 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/libavformat/isom.h b/libavformat/isom.h
index d233839..2f031145 100644
--- a/libavformat/isom.h
+++ b/libavformat/isom.h
@@ -197,6 +197,7 @@ typedef struct MOVContext {
     MOVFragmentIndex** fragment_index_data;
     unsigned fragment_index_count;
     int atom_depth;
+    int enable_drefs;
 } MOVContext;
 
 int ff_mp4_read_descr_len(AVIOContext *pb);
diff --git a/libavformat/mov.c b/libavformat/mov.c
index ba7b332..f9921b7 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -2701,13 +2701,23 @@ static int mov_read_trak(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 
     if (sc->dref_id-1 < sc->drefs_count && sc->drefs[sc->dref_id-1].path) {
         MOVDref *dref = &sc->drefs[sc->dref_id - 1];
-        if (mov_open_dref(&sc->pb, c->fc->filename, dref, &c->fc->interrupt_callback,
-            c->use_absolute_path, c->fc) < 0)
-            av_log(c->fc, AV_LOG_ERROR,
-                   "stream %d, error opening alias: path='%s', dir='%s', "
-                   "filename='%s', volume='%s', nlvl_from=%d, nlvl_to=%d\n",
+        if (c->enable_drefs) {
+            if (mov_open_dref(&sc->pb, c->fc->filename, dref, &c->fc->interrupt_callback,
+                              c->use_absolute_path, c->fc) < 0)
+                av_log(c->fc, AV_LOG_ERROR,
+                       "stream %d, error opening alias: path='%s', dir='%s', "
+                       "filename='%s', volume='%s', nlvl_from=%d, nlvl_to=%d\n",
+                       st->index, dref->path, dref->dir, dref->filename,
+                       dref->volume, dref->nlvl_from, dref->nlvl_to);
+        } else {
+            av_log(c->fc, AV_LOG_WARNING,
+                   "Skipped opening external track: "
+                   "stream %d, alias: path='%s', dir='%s', "
+                   "filename='%s', volume='%s', nlvl_from=%d, nlvl_to=%d."
+                   "Set enable_drefs to allow this.\n",
                    st->index, dref->path, dref->dir, dref->filename,
                    dref->volume, dref->nlvl_from, dref->nlvl_to);
+        }
     } else {
         sc->pb = c->fc->pb;
         sc->pb_is_copied = 1;
@@ -4389,6 +4399,8 @@ static const AVOption mov_options[] = {
         AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, .flags = FLAGS },
     { "export_xmp", "Export full XMP metadata", OFFSET(export_xmp),
         AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, .flags = FLAGS },
+    { "enable_drefs", "Enable external track support.", OFFSET(enable_drefs), AV_OPT_TYPE_INT,
+        {.i64 = 0}, 0, 1, FLAGS },
     { NULL },
 };