[SCM] libav/experimental: mxf: Override faulty PreviousPartition entries

[siretart at users.alioth.debian.org]

The following commit has been merged in the experimental branch:
commit 842ea36c747eb6537c4236114346cb7a3e9a8df1
Author: Luca Barbato <lu_zero at gentoo.org>
Date:   Thu Mar 13 16:12:05 2014 +0100

    mxf: Override faulty PreviousPartition entries
    
    Some files set the PreviousPartition field to point to its own offset.
    
    If we are parsing forward the Previous partition is immediately known
    and its value could be used, otherwise we can safely point to the
    header.
    
    Reported-By: Jean Baptiste Kempf <jb at videolan.org>

diff --git a/libavformat/mxfdec.c b/libavformat/mxfdec.c
index 734c50a..39ab462 100644
--- a/libavformat/mxfdec.c
+++ b/libavformat/mxfdec.c
@@ -478,6 +478,26 @@ static int mxf_read_partition_pack(void *arg, AVIOContext *pb, int tag, int size
     avio_read(pb, op, sizeof(UID));
     nb_essence_containers = avio_rb32(pb);
 
+    if (partition->this_partition &&
+        partition->previous_partition == partition->this_partition) {
+        av_log(mxf->fc, AV_LOG_ERROR,
+               "PreviousPartition equal to ThisPartition %"PRIx64"\n",
+               partition->previous_partition);
+        /* override with the actual previous partition offset */
+        if (!mxf->parsing_backward && mxf->last_forward_partition > 1) {
+            MXFPartition *prev =
+                mxf->partitions + mxf->last_forward_partition - 2;
+            partition->previous_partition = prev->this_partition;
+        }
+        /* if no previous body partition are found point to the header
+         * partition */
+        if (partition->previous_partition == partition->this_partition);
+            partition->previous_partition = 0;
+        av_log(mxf->fc, AV_LOG_ERROR,
+               "Overriding PreviousPartition with %"PRIx64"\n",
+               partition->previous_partition);
+    }
+
     /* some files don'thave FooterPartition set in every partition */
     if (footer_partition) {
         if (mxf->footer_partition && mxf->footer_partition != footer_partition) {

-- 
Libav/FFmpeg packaging