Add Common Encryption support to BMFF, including subsample decryption.

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"
 
 namespace media {
 namespace mp4 {
 
 bool FileType::Parse(BoxReader* reader) {
   RCHECK(reader->ReadFourCC(&major_brand) && reader->Read4(&minor_version));
   size_t num_brands = (reader->size() - reader->pos()) / sizeof(FourCC);
   return reader->SkipBytes(sizeof(FourCC) * num_brands);  // compatible_brands
 }
 
 ProtectionSystemSpecificHeader::ProtectionSystemSpecificHeader() {}
 ProtectionSystemSpecificHeader::~ProtectionSystemSpecificHeader() {}
 FourCC ProtectionSystemSpecificHeader::BoxType() const { return FOURCC_PSSH; }
 
 bool ProtectionSystemSpecificHeader::Parse(BoxReader* reader) {
   uint32 size;
-  return reader->SkipBytes(4) &&
+  return reader->ReadFullBoxHeader() &&
          reader->ReadVec(&system_id, 16) &&
          reader->Read4(&size) &&
          reader->ReadVec(&data, size);
 }
 
 SampleAuxiliaryInformationOffset::SampleAuxiliaryInformationOffset() {}
 SampleAuxiliaryInformationOffset::~SampleAuxiliaryInformationOffset() {}
 FourCC SampleAuxiliaryInformationOffset::BoxType() const { return FOURCC_SAIO; }
 
 bool SampleAuxiliaryInformationOffset::Parse(BoxReader* reader) {
@@ skipping 40 matching lines @@
 
 bool OriginalFormat::Parse(BoxReader* reader) {
   return reader->ReadFourCC(&format);
 }
 
 SchemeType::SchemeType() : type(FOURCC_NULL), version(0) {}
 SchemeType::~SchemeType() {}
 FourCC SchemeType::BoxType() const { return FOURCC_SCHM; }
 
 bool SchemeType::Parse(BoxReader* reader) {
-  RCHECK(reader->SkipBytes(4) &&
+  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) {
   uint8 flag;
-  RCHECK(reader->SkipBytes(2) &&
+  RCHECK(reader->ReadFullBoxHeader() &&
+         reader->SkipBytes(2) &&
          reader->Read1(&flag) &&
          reader->Read1(&default_iv_size) &&
          reader->ReadVec(&default_kid, 16));
   is_encrypted = (flag != 0);
   if (is_encrypted) {
     RCHECK(default_iv_size == 8 || default_iv_size == 16);
   } else {
     RCHECK(default_iv_size == 0);
   }
   return true;
 }
 
 SchemeInfo::SchemeInfo() {}
 SchemeInfo::~SchemeInfo() {}
 FourCC SchemeInfo::BoxType() const { return FOURCC_SCHI; }
 
 bool SchemeInfo::Parse(BoxReader* reader) {
   return reader->ScanChildren() && reader->ReadChild(&track_encryption);
 }
 
 ProtectionSchemeInfo::ProtectionSchemeInfo() {}
 ProtectionSchemeInfo::~ProtectionSchemeInfo() {}
 FourCC ProtectionSchemeInfo::BoxType() const { return FOURCC_SINF; }
 
 bool ProtectionSchemeInfo::Parse(BoxReader* reader) {
-  return reader->ScanChildren() &&
+  RCHECK(reader->ScanChildren() &&
+         reader->ReadChild(&format) &&
          reader->ReadChild(&type) &&
-         reader->ReadChild(&info);
+         reader->ReadChild(&info));
+  return true;
 }
 
 MovieHeader::MovieHeader()
     : creation_time(0),
       modification_time(0),
       timescale(0),
       duration(0),
       rate(-1),
       volume(-1),
       next_track_id(0) {}
@@ skipping 223 matching lines @@
 
 bool VideoSampleEntry::Parse(BoxReader* reader) {
   format = reader->type();
   RCHECK(reader->SkipBytes(6) &&
          reader->Read2(&data_reference_index) &&
          reader->SkipBytes(16) &&
          reader->Read2(&width) &&
          reader->Read2(&height) &&
          reader->SkipBytes(50));
 
-  RCHECK(reader->ScanChildren());
-  RCHECK(reader->MaybeReadChild(&pixel_aspect));
-  if (format == FOURCC_ENCV) {
+  RCHECK(reader->ScanChildren() &&
+         reader->MaybeReadChild(&pixel_aspect));
+
+  if (format == FOURCC_ENCV)
     RCHECK(reader->ReadChild(&sinf));
+  if (format == FOURCC_AVC1 ||
+      (format == FOURCC_ENCV && sinf.format.format == FOURCC_AVC1)) {
+    RCHECK(reader->ReadChild(&avcc));
   }
-
-  // TODO(strobe): finalize format signaling for encrypted media
-  // (http://crbug.com/132351)
-  //
-  //  if (format == FOURCC_AVC1 ||
-  //      (format == FOURCC_ENCV &&
-  //       sinf.format.format == FOURCC_AVC1)) {
-    RCHECK(reader->ReadChild(&avcc));
-  //  }
   return true;
 }
 
 ElementaryStreamDescriptor::ElementaryStreamDescriptor() {}
 
 ElementaryStreamDescriptor::~ElementaryStreamDescriptor() {}
 
 FourCC ElementaryStreamDescriptor::BoxType() const {
   return FOURCC_ESDS;
 }
 
 bool ElementaryStreamDescriptor::Parse(BoxReader* reader) {
   std::vector<uint8> data;
   ESDescriptor es_desc;
 
   RCHECK(reader->ReadFullBoxHeader());
   RCHECK(reader->ReadVec(&data, reader->size() - reader->pos()));

[ddorwin, 2012/07/17 01:14:21]

To verify, pos() is an index? index() might be a better name since pos() _could_
be a pointer.

   RCHECK(es_desc.Parse(data));
 
   object_type = es_desc.object_type();
 
   RCHECK(aac.Parse(es_desc.decoder_specific_info()));
 
   return true;
 }
 
 AudioSampleEntry::AudioSampleEntry()
@@ skipping 17 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) {
+  if (format == FOURCC_ENCA)
     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 57 matching lines @@
          reader->MaybeReadChild(&edit));
   return true;
 }
 
 MovieExtendsHeader::MovieExtendsHeader() : fragment_duration(0) {}
 MovieExtendsHeader::~MovieExtendsHeader() {}
 FourCC MovieExtendsHeader::BoxType() const { return FOURCC_MEHD; }
 
 bool MovieExtendsHeader::Parse(BoxReader* reader) {
   RCHECK(reader->ReadFullBoxHeader());
   if (reader->version() == 1) {

[ddorwin, 2012/07/17 01:14:21]

Comment. V1 was... All other versions ...

[strobe_, 2012/07/19 02:43:35]

Like most of this file, this is essentially a line-for-line translation of the
box definitions in ISO 14496-12. The name "version" is misleading, since this
pattern was always in the spec AFAICT (in multiple places) and is not tied to
any spec version.

     RCHECK(reader->Read8(&fragment_duration));
   } else {
     RCHECK(reader->Read4Into8(&fragment_duration));
   }
   return true;
 }
 
 TrackExtends::TrackExtends()
     : track_id(0),
       default_sample_description_index(0),
@@ skipping 185 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