[vlc-commits] demux: mp4: handle broken ismv trun data offset

[Francois Cartegnie]

vlc | branch: master | Francois Cartegnie <fcvlcdev at free.fr> | Mon Nov  2 02:57:29 2015 +0100| [4a894c76b05c950e1692199af55b6984130198da] | committer: Francois Cartegnie

demux: mp4: handle broken ismv trun data offset

Some smooth streaming implicit trun data offset are
pointing to (seems) tfhd 1st byte, instead of moof,
resulting of first samples pointing inside moof.

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=4a894c76b05c950e1692199af55b6984130198da
---

 modules/demux/mp4/mp4.c |   26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/modules/demux/mp4/mp4.c b/modules/demux/mp4/mp4.c
index 0161464..77d4854 100644
--- a/modules/demux/mp4/mp4.c
+++ b/modules/demux/mp4/mp4.c
@@ -4312,9 +4312,21 @@ static bool AddFragment( demux_t *p_demux, MP4_Box_t *p_moox )
 
             /* Get data offset */
             if ( p_trundata->i_flags & MP4_TRUN_DATA_OFFSET )
-                i_trun_data_offset += __MAX( p_trundata->i_data_offset, 0 );
+            {
+                /* Fix for broken Trun data offset relative to tfhd instead of moof, as seen in smooth */
+                if( (BOXDATA(p_tfhd)->i_flags & MP4_TFHD_BASE_DATA_OFFSET) == 0 &&
+                    i_traf == 0 &&
+                    i_traf_base_data_offset + p_trundata->i_data_offset < p_new->p_moox->i_pos + p_new->p_moox->i_size + 8 )
+                {
+                    i_trun_data_offset += p_new->p_moox->i_size + 8;
+                }
+                else
+                    i_trun_data_offset += __MAX( p_trundata->i_data_offset, 0 );
+            }
             else
+            {
                 i_trun_data_offset += i_trun_size;
+            }
 
             i_trun_size = 0;
 
@@ -4837,7 +4849,7 @@ error:
     return VLC_SUCCESS;
 }
 
-static mp4_track_t * LeafGetTrackByTrunPos( demux_t *p_demux, const uint64_t i_pos, const uint64_t i_moofpos )
+static mp4_track_t * LeafGetTrackByTrunPos( demux_t *p_demux, const uint64_t i_pos, const uint64_t i_moofpos, const uint64_t i_moofsize )
 {
     demux_sys_t *p_sys = p_demux->p_sys;
 
@@ -4858,7 +4870,13 @@ static mp4_track_t * LeafGetTrackByTrunPos( demux_t *p_demux, const uint64_t i_p
           //  i_offset += i_moofpos;
 
         if (p_trun_data->i_flags & MP4_TRUN_DATA_OFFSET)
-            i_offset += p_trun_data->i_data_offset;
+        {
+            /* Fix for broken Trun data offset relative to tfhd instead of moof, as seen in smooth */
+            if(i_offset + p_trun_data->i_data_offset < i_moofpos + i_moofsize + 8)
+                i_offset = i_moofpos + i_moofsize + 8;
+            else
+                i_offset += p_trun_data->i_data_offset;
+        }
         else
             return p_track;
 
@@ -5028,7 +5046,7 @@ static int LeafParseMDATwithMOOF( demux_t *p_demux, MP4_Box_t *p_moof )
         return VLC_EGENERIC;
     if ( p_sys->b_smooth )
         i_pos -= p_moof->i_pos;
-    mp4_track_t *p_track = LeafGetTrackByTrunPos( p_demux, i_pos, p_moof->i_pos );
+    mp4_track_t *p_track = LeafGetTrackByTrunPos( p_demux, i_pos, p_moof->i_pos, p_moof->i_size );
     if( p_track )
     {
         uint32_t i_trun_sample_default_duration = 0;