[vlc-devel] [PATCH] demux/mp4: fix PTS computation

[Frédéric Yhuel]

p_sample_offset_pts must be NULL if MP4_TRUN_SAMPLE_TIME_OFFSET is not
present. Then MP4_TrackGetPTSDelta would return -1 (instead of 0
previously), and PTS of video frames would be set to VLC_TS_INVALID,
which is the right thing to do in that case.
---
 modules/demux/mp4/mp4.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/modules/demux/mp4/mp4.c b/modules/demux/mp4/mp4.c
index c83be06..211a952 100644
--- a/modules/demux/mp4/mp4.c
+++ b/modules/demux/mp4/mp4.c
@@ -3247,7 +3247,8 @@ static int FreeAndResetChunk( mp4_chunk_t *ck )
     free( ck->p_sample_count_dts );
     free( ck->p_sample_delta_dts );
     free( ck->p_sample_count_pts );
-    free( ck->p_sample_offset_pts );
+    if( ck->p_sample_offset_pts )
+        free( ck->p_sample_offset_pts );
     free( ck->p_sample_size );
     for( uint32_t i = 0; i < ck->i_sample_count; i++ )
         free( ck->p_sample_data[i] );
@@ -3459,11 +3460,16 @@ static int MP4_frg_GetChunk( demux_t *p_demux, MP4_Box_t *p_chunk, unsigned *i_t
         return VLC_ENOMEM;
 
     ret->p_sample_count_pts = calloc( ret->i_sample_count, sizeof( uint32_t ) );
-    ret->p_sample_offset_pts = calloc( ret->i_sample_count, sizeof( int32_t ) );
-
-    if( !ret->p_sample_count_pts || !ret->p_sample_offset_pts )
+    if( !ret->p_sample_count_pts )
         return VLC_ENOMEM;
 
+    if( p_trun_data->i_flags & MP4_TRUN_SAMPLE_TIME_OFFSET )
+    {
+        ret->p_sample_offset_pts = calloc( ret->i_sample_count, sizeof( int32_t ) );
+        if( !ret->p_sample_offset_pts )
+            return VLC_ENOMEM;
+    }
+
     ret->p_sample_size = calloc( ret->i_sample_count, sizeof( uint32_t ) );
     if( !ret->p_sample_size )
         return VLC_ENOMEM;
@@ -3489,13 +3495,11 @@ static int MP4_frg_GetChunk( demux_t *p_demux, MP4_Box_t *p_chunk, unsigned *i_t
 
         ret->p_sample_count_dts[i] = ret->p_sample_count_pts[i] = 1;
 
-        if( p_trun_data->i_flags & MP4_TRUN_SAMPLE_TIME_OFFSET )
+        if( ret->p_sample_offset_pts )
         {
             ret->p_sample_offset_pts[i] =
                         p_trun_data->p_samples[i].i_composition_time_offset;
         }
-        else
-            ret->p_sample_offset_pts[i] = 0;
 
         if( p_trun_data->i_flags & MP4_TRUN_SAMPLE_SIZE )
             len = ret->p_sample_size[i] = p_trun_data->p_samples[i].i_size;
-- 
1.7.9.5