Ignore unrecognized protection schemes in ISO BMFF files.

media/mp4/box_definitions.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/mp4/box_definitions.h"
 
 #include "base/logging.h"
 #include "media/mp4/es_descriptor.h"
 #include "media/mp4/rcheck.h"
 
@@ skipping 73 matching lines @@
 }
 
 SchemeType::SchemeType() : type(FOURCC_NULL), version(0) {}
 SchemeType::~SchemeType() {}
 FourCC SchemeType::BoxType() const { return FOURCC_SCHM; }
 
 bool SchemeType::Parse(BoxReader* reader) {
   RCHECK(reader->ReadFullBoxHeader() &&
          reader->ReadFourCC(&type) &&
          reader->Read4(&version));
-  RCHECK(type == FOURCC_CENC);
   return true;
 }
 
 TrackEncryption::TrackEncryption()
   : is_encrypted(false), default_iv_size(0) {
 }
 TrackEncryption::~TrackEncryption() {}
 FourCC TrackEncryption::BoxType() const { return FOURCC_TENC; }
 
 bool TrackEncryption::Parse(BoxReader* reader) {
@@ skipping 20 matching lines @@
   return reader->ScanChildren() && reader->ReadChild(&track_encryption);
 }
 
 ProtectionSchemeInfo::ProtectionSchemeInfo() {}
 ProtectionSchemeInfo::~ProtectionSchemeInfo() {}
 FourCC ProtectionSchemeInfo::BoxType() const { return FOURCC_SINF; }
 
 bool ProtectionSchemeInfo::Parse(BoxReader* reader) {
   RCHECK(reader->ScanChildren() &&
          reader->ReadChild(&format) &&
-         reader->ReadChild(&type) &&
-         reader->ReadChild(&info));
+         reader->ReadChild(&type));
+  if (type.type == FOURCC_CENC)
+    RCHECK(reader->ReadChild(&info));
+  // Other protection schemes are silently ignored. Since the protection scheme
+  // type can't be determined until this box is opened, we return 'true' for
+  // non-CENC protection scheme types. It is the parent box's responsibility to
+  // ensure that this scheme type is a supported one.
   return true;
 }
 
 MovieHeader::MovieHeader()
     : creation_time(0),
       modification_time(0),
       timescale(0),
       duration(0),
       rate(-1),
       volume(-1),
@@ skipping 227 matching lines @@
   RCHECK(reader->SkipBytes(6) &&
          reader->Read2(&data_reference_index) &&
          reader->SkipBytes(16) &&
          reader->Read2(&width) &&
          reader->Read2(&height) &&
          reader->SkipBytes(50));
 
   RCHECK(reader->ScanChildren() &&
          reader->MaybeReadChild(&pixel_aspect));
 
-  if (format == FOURCC_ENCV)
-    RCHECK(reader->ReadChild(&sinf));
+  if (format == FOURCC_ENCV) {
+    // Continue scanning until a recognized protection scheme is found, or until
+    // we run out of protection schemes.
+    while (sinf.type.type != FOURCC_CENC)
+      RCHECK(reader->ReadChild(&sinf));

[ddorwin, 2012/07/28 00:41:21]

This causes a DLOG(ERROR) even though it will happen every time when we run out
of PSes. I think this should be:
  if (!ReadChild())
    return false;

+  }
+
   if (format == FOURCC_AVC1 ||
       (format == FOURCC_ENCV && sinf.format.format == FOURCC_AVC1)) {
     RCHECK(reader->ReadChild(&avcc));
   }
   return true;
 }
 
 ElementaryStreamDescriptor::ElementaryStreamDescriptor()
     : object_type(kForbidden) {}
 
@@ skipping 39 matching lines @@
          reader->Read2(&data_reference_index) &&
          reader->SkipBytes(8) &&
          reader->Read2(&channelcount) &&
          reader->Read2(&samplesize) &&
          reader->SkipBytes(4) &&
          reader->Read4(&samplerate));
   // Convert from 16.16 fixed point to integer
   samplerate >>= 16;
 
   RCHECK(reader->ScanChildren());
-  if (format == FOURCC_ENCA)
-    RCHECK(reader->ReadChild(&sinf));
+  if (format == FOURCC_ENCA) {
+    // Continue scanning until a recognized protection scheme is found, or until
+    // we run out of protection schemes.
+    while (sinf.type.type != FOURCC_CENC)
+      RCHECK(reader->ReadChild(&sinf));
+  }
+
   RCHECK(reader->ReadChild(&esds));
   return true;
 }
 
 MediaHeader::MediaHeader()
     : creation_time(0),
       modification_time(0),
       timescale(0),
       duration(0) {}
 MediaHeader::~MediaHeader() {}
@@ skipping 267 matching lines @@
 bool MovieFragment::Parse(BoxReader* reader) {
   RCHECK(reader->ScanChildren() &&
          reader->ReadChild(&header) &&
          reader->ReadChildren(&tracks) &&
          reader->MaybeReadChildren(&pssh));
   return true;
 }
 
 }  // namespace mp4
 }  // namespace media