[EME] Add support for sbgp and sgpd boxes in the traf box

4 files changed, 252 insertions, 0 deletions

diff --git a/media/libstagefright/binding/Index.cpp b/media/libstagefright/binding/Index.cpp
index 9d6ab5028..a3a3f9847 100644
--- a/media/libstagefright/binding/Index.cpp
+++ b/media/libstagefright/binding/Index.cpp
@@ -143,6 +143,11 @@ already_AddRefed<MediaRawData> SampleIterator::GetNext()
     writer->mCrypto.mValid = true;
     writer->mCrypto.mIVSize = ivSize;
 
+    CencSampleEncryptionInfoEntry* sampleInfo = GetSampleEncryptionEntry();
+    if (sampleInfo) {
+      writer->mCrypto.mKeyId.AppendElements(sampleInfo->mKeyId);
+    }
+
     if (!reader.ReadArray(writer->mCrypto.mIV, ivSize)) {
       return nullptr;
     }
@@ -170,6 +175,47 @@ already_AddRefed<MediaRawData> SampleIterator::GetNext()
   return sample.forget();
 }
 
+CencSampleEncryptionInfoEntry* SampleIterator::GetSampleEncryptionEntry()
+{
+  nsTArray<Moof>& moofs = mIndex->mMoofParser->Moofs();
+  Moof* currentMoof = &moofs[mCurrentMoof];
+  SampleToGroupEntry* sampleToGroupEntry = nullptr;
+
+  uint32_t seen = 0;
+
+  for (SampleToGroupEntry& entry : currentMoof->mSampleToGroupEntries) {
+    if (seen + entry.mSampleCount > mCurrentSample) {
+      sampleToGroupEntry = &entry;
+      break;
+    }
+    seen += entry.mSampleCount;
+  }
+
+  // ISO-14496-12 Section 8.9.2.3 and 8.9.4 : group description index
+  // (1) ranges from 1 to the number of sample group entries in the track
+  // level SampleGroupDescription Box, or (2) takes the value 0 to
+  // indicate that this sample is a member of no group, in this case, the
+  // sample is associated with the default values specified in
+  // TrackEncryption Box, or (3) starts at 0x10001, i.e. the index value
+  // 1, with the value 1 in the top 16 bits, to reference fragment-local
+  // SampleGroupDescription Box.
+
+  if (!sampleToGroupEntry || sampleToGroupEntry->mGroupDescriptionIndex == 0) {
+    return nullptr;
+  }
+
+  uint32_t group_index = sampleToGroupEntry->mGroupDescriptionIndex;
+
+  if (group_index > SampleToGroupEntry::kFragmentGroupDescriptionIndexBase) {
+    group_index -= SampleToGroupEntry::kFragmentGroupDescriptionIndexBase;
+  }
+
+  // The group_index is one indexed
+  return group_index > currentMoof->mSampleEncryptionInfoEntries.Length()
+         ? nullptr
+         : &currentMoof->mSampleEncryptionInfoEntries.ElementAt(group_index - 1);
+}
+
 Sample* SampleIterator::Get()
 {
   if (!mIndex->mMoofParser) {
diff --git a/media/libstagefright/binding/MoofParser.cpp b/media/libstagefright/binding/MoofParser.cpp
index 491967a12..970bc2325 100644
--- a/media/libstagefright/binding/MoofParser.cpp
+++ b/media/libstagefright/binding/MoofParser.cpp
@@ -27,6 +27,8 @@ namespace mp4_demuxer
 using namespace stagefright;
 using namespace mozilla;
 
+const uint32_t kKeyIdSize = 16;
+
 bool
 MoofParser::RebuildFragmentedIndex(const MediaByteRangeSet& aByteRanges)
 {
@@ -501,6 +503,18 @@ Moof::ParseTraf(Box& aBox, Trex& aTrex, Mvhd& aMvhd, Mdhd& aMdhd, Edts& aEdts, S
     } else if (!aTrex.mTrackId || tfhd.mTrackId == aTrex.mTrackId) {
       if (box.IsType("tfdt")) {
         tfdt = Tfdt(box);
+      } else if (box.IsType("sgpd")) {
+        Sgpd sgpd(box);
+        if (sgpd.IsValid() && sgpd.mGroupingType == "seig") {
+          mSampleEncryptionInfoEntries.Clear();
+          mSampleEncryptionInfoEntries.AppendElements(sgpd.mEntries);
+        }
+      } else if (box.IsType("sbgp")) {
+        Sbgp sbgp(box);
+        if (sbgp.IsValid() && sbgp.mGroupingType == "seig") {
+          mSampleToGroupEntries.Clear();
+          mSampleToGroupEntries.AppendElements(sbgp.mEntries);
+        }
       } else if (box.IsType("saiz")) {
         mSaizs.AppendElement(Saiz(box, aSinf.mDefaultEncryptionType));
       } else if (box.IsType("saio")) {
@@ -1050,5 +1064,143 @@ Saio::Saio(Box& aBox, AtomType aDefaultType)
   mValid = true;
 }
 
+Sbgp::Sbgp(Box& aBox)
+{
+  BoxReader reader(aBox);
+
+  if (!reader->CanReadType<uint32_t>()) {
+    LOG(Sbgp, "Incomplete Box (missing flags)");
+    return;
+  }
+
+  uint32_t flags = reader->ReadU32();
+  const uint8_t version = flags >> 24;
+  flags = flags & 0xffffff;
+
+  // Make sure we have enough bytes to read as far as the count.
+  uint32_t need = (version == 1 ? sizeof(uint32_t) : 0) + sizeof(uint32_t) * 2;
+  if (reader->Remaining() < need) {
+    LOG(Sbgp, "Incomplete Box (have:%lld, need:%lld)",
+        (uint64_t)reader->Remaining(), (uint64_t)need);
+    return;
+  }
+
+  mGroupingType = reader->ReadU32();
+
+  if (version == 1) {
+    mGroupingTypeParam = reader->Read32();
+  }
+
+  uint32_t count = reader->ReadU32();
+
+  // Make sure we can read all the entries.
+  need = sizeof(uint32_t) * 2 * count;
+  if (reader->Remaining() < need) {
+    LOG(Sbgp, "Incomplete Box (have:%lld, need:%lld). Failed to read entries",
+        (uint64_t)reader->Remaining(), (uint64_t)need);
+    return;
+  }
+
+  for (uint32_t i = 0; i < count; i++) {
+    uint32_t sampleCount = reader->ReadU32();
+    uint32_t groupDescriptionIndex = reader->ReadU32();
+
+    SampleToGroupEntry entry(sampleCount, groupDescriptionIndex);
+    mEntries.AppendElement(entry);
+  }
+
+  mValid = true;
+}
+
+Sgpd::Sgpd(Box& aBox)
+{
+  BoxReader reader(aBox);
+
+  if (!reader->CanReadType<uint32_t>()) {
+    LOG(Sgpd, "Incomplete Box (missing flags)");
+    return;
+  }
+
+  uint32_t flags = reader->ReadU32();
+  const uint8_t version = flags >> 24;
+  flags = flags & 0xffffff;
+
+  uint32_t need = ((flags & 1) ? sizeof(uint32_t) : 0) + sizeof(uint32_t) * 2;
+  if (reader->Remaining() < need) {
+    LOG(Sgpd, "Incomplete Box (have:%lld need:%lld)",
+        (uint64_t)reader->Remaining(), (uint64_t)need);
+    return;
+  }
+
+  mGroupingType = reader->ReadU32();
+
+  const uint32_t entrySize = sizeof(uint32_t) + kKeyIdSize;
+  uint32_t defaultLength = 0;
+
+  if (version == 1) {
+    defaultLength = reader->ReadU32();
+    if (defaultLength < entrySize && defaultLength != 0) {
+      return;
+    }
+  }
+
+  uint32_t count = reader->ReadU32();
+
+  // Make sure we have sufficient remaining bytes to read the entries.
+  need =
+    count * (sizeof(uint32_t) * (version == 1 && defaultLength == 0 ? 2 : 1) +
+             kKeyIdSize * sizeof(uint8_t));
+  if (reader->Remaining() < need) {
+    LOG(Sgpd, "Incomplete Box (have:%lld need:%lld). Failed to read entries",
+        (uint64_t)reader->Remaining(), (uint64_t)need);
+    return;
+  }
+  for (uint32_t i = 0; i < count; ++i) {
+    if (version == 1 && defaultLength == 0) {
+      uint32_t descriptionLength = reader->ReadU32();
+      if (descriptionLength < entrySize) {
+        return;
+      }
+    }
+
+    CencSampleEncryptionInfoEntry entry;
+    bool valid = entry.Init(reader);
+    if (!valid) {
+      return;
+    }
+    mEntries.AppendElement(entry);
+  }
+
+  mValid = true;
+}
+
+bool CencSampleEncryptionInfoEntry::Init(BoxReader& aReader)
+{
+  // Skip a reserved byte.
+  aReader->ReadU8();
+
+  uint8_t possiblePatternInfo = aReader->ReadU8();
+  uint8_t flag = aReader->ReadU8();
+
+  mIVSize = aReader->ReadU8();
+
+  // Read the key id.
+  for (uint32_t i = 0; i < kKeyIdSize; ++i) {
+    mKeyId.AppendElement(aReader->ReadU8());
+  }
+
+  mIsEncrypted = flag != 0;
+
+  if (mIsEncrypted) {
+    if (mIVSize != 8 && mIVSize != 16) {
+      return false;
+    }
+  } else if (mIVSize != 0) {
+    return false;
+  }
+
+  return true;
+}
+
 #undef LOG
 }
diff --git a/media/libstagefright/binding/include/mp4_demuxer/Index.h b/media/libstagefright/binding/include/mp4_demuxer/Index.h
index d566c9459..ca254f73d 100644
--- a/media/libstagefright/binding/include/mp4_demuxer/Index.h
+++ b/media/libstagefright/binding/include/mp4_demuxer/Index.h
@@ -32,6 +32,9 @@ public:
   Microseconds GetNextKeyframeTime();
 private:
   Sample* Get();
+
+  CencSampleEncryptionInfoEntry* GetSampleEncryptionEntry();
+
   void Next();
   RefPtr<Index> mIndex;
   friend class Index;
diff --git a/media/libstagefright/binding/include/mp4_demuxer/MoofParser.h b/media/libstagefright/binding/include/mp4_demuxer/MoofParser.h
index 814f806fc..47bd27287 100644
--- a/media/libstagefright/binding/include/mp4_demuxer/MoofParser.h
+++ b/media/libstagefright/binding/include/mp4_demuxer/MoofParser.h
@@ -17,6 +17,7 @@ typedef int64_t Microseconds;
 
 class Box;
 class BoxContext;
+class BoxReader;
 class Moof;
 
 class Mvhd : public Atom
@@ -160,6 +161,53 @@ public:
   FallibleTArray<uint64_t> mOffsets;
 };
 
+struct SampleToGroupEntry
+{
+public:
+  static const uint32_t kTrackGroupDescriptionIndexBase = 0;
+  static const uint32_t kFragmentGroupDescriptionIndexBase = 0x10000;
+
+  SampleToGroupEntry(uint32_t aSampleCount, uint32_t aGroupDescriptionIndex)
+    : mSampleCount(aSampleCount)
+    , mGroupDescriptionIndex(aGroupDescriptionIndex)
+    {
+    }
+
+  uint32_t mSampleCount;
+  uint32_t mGroupDescriptionIndex;
+};
+
+class Sbgp final : public Atom // SampleToGroup box.
+{
+public:
+  explicit Sbgp(Box& aBox);
+
+  AtomType mGroupingType;
+  uint32_t mGroupingTypeParam;
+  nsTArray<SampleToGroupEntry> mEntries;
+};
+
+struct CencSampleEncryptionInfoEntry final
+{
+public:
+  CencSampleEncryptionInfoEntry() { }
+
+  bool Init(BoxReader& aReader);
+
+  bool mIsEncrypted = false;
+  uint8_t mIVSize = 0;
+  nsTArray<uint8_t> mKeyId;
+};
+
+class Sgpd final : public Atom // SampleGroupDescription box.
+{
+public:
+  explicit Sgpd(Box& aBox);
+
+  AtomType mGroupingType;
+  nsTArray<CencSampleEncryptionInfoEntry> mEntries;
+};
+
 class AuxInfo {
 public:
   AuxInfo(int64_t aMoofOffset, Saiz& aSaiz, Saio& aSaio);
@@ -182,6 +230,9 @@ public:
   Interval<Microseconds> mTimeRange;
   FallibleTArray<Sample> mIndex;
 
+  nsTArray<CencSampleEncryptionInfoEntry> mSampleEncryptionInfoEntries;
+  nsTArray<SampleToGroupEntry> mSampleToGroupEntries;
+
   nsTArray<Saiz> mSaizs;
   nsTArray<Saio> mSaios;