[vlc-commits] demux: mp4: fix reading stsd v2 extensions

[Francois Cartegnie]

vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Thu Jul 21 17:20:02 2016 +0200| [287979713ff2d0c41d38274885c652639cf3971b] | committer: Francois Cartegnie

demux: mp4: fix reading stsd v2 extensions

miscomputed offset breaking audio extensions
like channels mapping.

regression refs #12002 sample

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=287979713ff2d0c41d38274885c652639cf3971b
---

 modules/demux/mp4/libmp4.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/modules/demux/mp4/libmp4.c b/modules/demux/mp4/libmp4.c
index ed71bc3..2341f89 100644
--- a/modules/demux/mp4/libmp4.c
+++ b/modules/demux/mp4/libmp4.c
@@ -2165,10 +2165,11 @@ static int MP4_ReadBox_sample_soun( stream_t *p_stream, MP4_Box_t *p_box )
                  p_box->data.p_sample_soun->i_constbytesperaudiopacket,
                  p_box->data.p_sample_soun->i_constLPCMframesperaudiopacket );
 #endif
-        /* @72 bytes */
-        i_extoffset = VLC_CLIP( i_extoffset, i_read, p_box->i_size );
-        p_peek += i_extoffset;
-        i_read -= i_extoffset;
+        /* @72 bytes + */
+        if( i_extoffset > i_actually_read )
+            i_extoffset = i_actually_read;
+        p_peek = &p_buff[i_extoffset];
+        i_read = i_actually_read - i_extoffset;
     }
     else
     {