Add m-esr52 at 52.6.0

1 files changed, 1839 insertions, 0 deletions

diff --git a/dom/media/ogg/OggCodecState.cpp b/dom/media/ogg/OggCodecState.cpp
new file mode 100644
index 000000000..6830639e8
--- /dev/null
+++ b/dom/media/ogg/OggCodecState.cpp
@@ -0,0 +1,1839 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim:set ts=2 sw=2 sts=2 et cindent: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <string.h>
+
+#include "mozilla/EndianUtils.h"
+#include <stdint.h>
+
+#include "nsDebug.h"
+#include "OggCodecState.h"
+#include "OpusParser.h"
+#include "VideoUtils.h"
+#include <algorithm>
+
+#include <opus/opus.h>
+#include "opus/opus_multistream.h"
+
+// On Android JellyBean, the hardware.h header redefines version_major and
+// version_minor, which breaks our build.  See:
+// https://bugzilla.mozilla.org/show_bug.cgi?id=912702#c6
+#ifdef MOZ_WIDGET_GONK
+#ifdef version_major
+#undef version_major
+#endif
+#ifdef version_minor
+#undef version_minor
+#endif
+#endif
+
+namespace mozilla {
+
+extern LazyLogModule gMediaDecoderLog;
+#define LOG(type, msg) MOZ_LOG(gMediaDecoderLog, type, msg)
+
+/** Decoder base class for Ogg-encapsulated streams. */
+OggCodecState*
+OggCodecState::Create(ogg_page* aPage)
+{
+  NS_ASSERTION(ogg_page_bos(aPage), "Only call on BOS page!");
+  nsAutoPtr<OggCodecState> codecState;
+  if (aPage->body_len > 6 && memcmp(aPage->body+1, "theora", 6) == 0) {
+    codecState = new TheoraState(aPage);
+  } else if (aPage->body_len > 6 && memcmp(aPage->body+1, "vorbis", 6) == 0) {
+    codecState = new VorbisState(aPage);
+  } else if (aPage->body_len > 8 && memcmp(aPage->body, "OpusHead", 8) == 0) {
+    codecState = new OpusState(aPage);
+  } else if (aPage->body_len > 8 && memcmp(aPage->body, "fishead\0", 8) == 0) {
+    codecState = new SkeletonState(aPage);
+  } else if (aPage->body_len > 5 && memcmp(aPage->body, "\177FLAC", 5) == 0) {
+    codecState = new FlacState(aPage);
+  } else {
+    codecState = new OggCodecState(aPage, false);
+  }
+  return codecState->OggCodecState::InternalInit() ? codecState.forget() : nullptr;
+}
+
+OggCodecState::OggCodecState(ogg_page* aBosPage, bool aActive)
+  : mPacketCount(0)
+  , mSerial(ogg_page_serialno(aBosPage))
+  , mActive(aActive)
+  , mDoneReadingHeaders(!aActive)
+{
+  MOZ_COUNT_CTOR(OggCodecState);
+  memset(&mState, 0, sizeof(ogg_stream_state));
+}
+
+OggCodecState::~OggCodecState()
+{
+  MOZ_COUNT_DTOR(OggCodecState);
+  Reset();
+#ifdef DEBUG
+  int ret =
+#endif
+  ogg_stream_clear(&mState);
+  NS_ASSERTION(ret == 0, "ogg_stream_clear failed");
+}
+
+nsresult
+OggCodecState::Reset()
+{
+  if (ogg_stream_reset(&mState) != 0) {
+    return NS_ERROR_FAILURE;
+  }
+  mPackets.Erase();
+  ClearUnstamped();
+  return NS_OK;
+}
+
+void
+OggCodecState::ClearUnstamped()
+{
+  for (uint32_t i = 0; i < mUnstamped.Length(); ++i) {
+    OggCodecState::ReleasePacket(mUnstamped[i]);
+  }
+  mUnstamped.Clear();
+}
+
+bool
+OggCodecState::InternalInit()
+{
+  int ret = ogg_stream_init(&mState, mSerial);
+  return ret == 0;
+}
+
+bool
+OggCodecState::IsValidVorbisTagName(nsCString& aName)
+{
+  // Tag names must consist of ASCII 0x20 through 0x7D,
+  // excluding 0x3D '=' which is the separator.
+  uint32_t length = aName.Length();
+  const char* data = aName.Data();
+  for (uint32_t i = 0; i < length; i++) {
+    if (data[i] < 0x20 || data[i] > 0x7D || data[i] == '=') {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool
+OggCodecState::AddVorbisComment(MetadataTags* aTags,
+                                const char* aComment,
+                                uint32_t aLength)
+{
+  const char* div = (const char*)memchr(aComment, '=', aLength);
+  if (!div) {
+    LOG(LogLevel::Debug, ("Skipping comment: no separator"));
+    return false;
+  }
+  nsCString key = nsCString(aComment, div-aComment);
+  if (!IsValidVorbisTagName(key)) {
+    LOG(LogLevel::Debug, ("Skipping comment: invalid tag name"));
+    return false;
+  }
+  uint32_t valueLength = aLength - (div-aComment);
+  nsCString value = nsCString(div + 1, valueLength);
+  if (!IsUTF8(value)) {
+    LOG(LogLevel::Debug, ("Skipping comment: invalid UTF-8 in value"));
+    return false;
+  }
+  aTags->Put(key, value);
+  return true;
+}
+
+void
+VorbisState::RecordVorbisPacketSamples(ogg_packet* aPacket, long aSamples)
+{
+#ifdef VALIDATE_VORBIS_SAMPLE_CALCULATION
+  mVorbisPacketSamples[aPacket] = aSamples;
+#endif
+}
+
+void
+VorbisState::ValidateVorbisPacketSamples(ogg_packet* aPacket, long aSamples)
+{
+#ifdef VALIDATE_VORBIS_SAMPLE_CALCULATION
+  NS_ASSERTION(mVorbisPacketSamples[aPacket] == aSamples,
+    "Decoded samples for Vorbis packet don't match expected!");
+  mVorbisPacketSamples.erase(aPacket);
+#endif
+}
+
+void
+VorbisState::AssertHasRecordedPacketSamples(ogg_packet* aPacket)
+{
+#ifdef VALIDATE_VORBIS_SAMPLE_CALCULATION
+  NS_ASSERTION(mVorbisPacketSamples.count(aPacket) == 1,
+    "Must have recorded packet samples");
+#endif
+}
+
+static ogg_packet*
+Clone(ogg_packet* aPacket)
+{
+  ogg_packet* p = new ogg_packet();
+  memcpy(p, aPacket, sizeof(ogg_packet));
+  p->packet = new unsigned char[p->bytes];
+  memcpy(p->packet, aPacket->packet, p->bytes);
+  return p;
+}
+
+void
+OggCodecState::ReleasePacket(ogg_packet* aPacket)
+{
+  if (aPacket)
+    delete [] aPacket->packet;
+  delete aPacket;
+}
+
+void
+OggPacketQueue::Append(ogg_packet* aPacket)
+{
+  nsDeque::Push(aPacket);
+}
+
+bool
+OggCodecState::IsPacketReady()
+{
+  return !mPackets.IsEmpty();
+}
+
+ogg_packet*
+OggCodecState::PacketOut()
+{
+  if (mPackets.IsEmpty()) {
+    return nullptr;
+  }
+  return mPackets.PopFront();
+}
+
+ogg_packet*
+OggCodecState::PacketPeek()
+{
+  if (mPackets.IsEmpty()) {
+    return nullptr;
+  }
+  return mPackets.PeekFront();
+}
+
+void
+OggCodecState::PushFront(OggPacketQueue &&aOther)
+{
+  while (!aOther.IsEmpty()) {
+    mPackets.PushFront(aOther.Pop());
+  }
+}
+
+already_AddRefed<MediaRawData>
+OggCodecState::PacketOutAsMediaRawData()
+{
+  ogg_packet* packet = PacketOut();
+  if (!packet) {
+    return nullptr;
+  }
+
+  NS_ASSERTION(!IsHeader(packet), "PacketOutAsMediaRawData can only be called on non-header packets");
+  RefPtr<MediaRawData> sample = new MediaRawData(packet->packet, packet->bytes);
+  if (packet->bytes && !sample->Data()) {
+    // OOM.
+    ReleasePacket(packet);
+    return nullptr;
+  }
+
+  int64_t end_tstamp = Time(packet->granulepos);
+  NS_ASSERTION(end_tstamp >= 0, "timestamp invalid");
+
+  int64_t duration = PacketDuration(packet);
+  NS_ASSERTION(duration >= 0, "duration invalid");
+
+  sample->mTimecode = packet->granulepos;
+  sample->mTime = end_tstamp - duration;
+  sample->mDuration = duration;
+  sample->mKeyframe = IsKeyframe(packet);
+  sample->mEOS = packet->e_o_s;
+
+  ReleasePacket(packet);
+
+  return sample.forget();
+}
+
+nsresult
+OggCodecState::PageIn(ogg_page* aPage)
+{
+  if (!mActive) {
+    return NS_OK;
+  }
+  NS_ASSERTION(static_cast<uint32_t>(ogg_page_serialno(aPage)) == mSerial,
+               "Page must be for this stream!");
+  if (ogg_stream_pagein(&mState, aPage) == -1) {
+    return NS_ERROR_FAILURE;
+  }
+  int r;
+  do {
+    ogg_packet packet;
+    r = ogg_stream_packetout(&mState, &packet);
+    if (r == 1) {
+      mPackets.Append(Clone(&packet));
+    }
+  } while (r != 0);
+  if (ogg_stream_check(&mState)) {
+    NS_WARNING("Unrecoverable error in ogg_stream_packetout");
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+nsresult
+OggCodecState::PacketOutUntilGranulepos(bool& aFoundGranulepos)
+{
+  int r;
+  aFoundGranulepos = false;
+  // Extract packets from the sync state until either no more packets
+  // come out, or we get a data packet with non -1 granulepos.
+  do {
+    ogg_packet packet;
+    r = ogg_stream_packetout(&mState, &packet);
+    if (r == 1) {
+      ogg_packet* clone = Clone(&packet);
+      if (IsHeader(&packet)) {
+        // Header packets go straight into the packet queue.
+        mPackets.Append(clone);
+      } else {
+        // We buffer data packets until we encounter a granulepos. We'll
+        // then use the granulepos to figure out the granulepos of the
+        // preceeding packets.
+        mUnstamped.AppendElement(clone);
+        aFoundGranulepos = packet.granulepos > 0;
+      }
+    }
+  } while (r != 0 && !aFoundGranulepos);
+  if (ogg_stream_check(&mState)) {
+    NS_WARNING("Unrecoverable error in ogg_stream_packetout");
+    return NS_ERROR_FAILURE;
+  }
+  return NS_OK;
+}
+
+TheoraState::TheoraState(ogg_page* aBosPage)
+  : OggCodecState(aBosPage, true)
+  , mSetup(0)
+  , mCtx(0)
+  , mPixelAspectRatio(0)
+{
+  MOZ_COUNT_CTOR(TheoraState);
+  th_info_init(&mInfo);
+  th_comment_init(&mComment);
+}
+
+TheoraState::~TheoraState()
+{
+  MOZ_COUNT_DTOR(TheoraState);
+  th_setup_free(mSetup);
+  th_decode_free(mCtx);
+  th_comment_clear(&mComment);
+  th_info_clear(&mInfo);
+}
+
+bool
+TheoraState::Init()
+{
+  if (!mActive) {
+    return false;
+  }
+
+  int64_t n = mInfo.aspect_numerator;
+  int64_t d = mInfo.aspect_denominator;
+
+  mPixelAspectRatio = (n == 0 || d == 0)
+    ? 1.0f : static_cast<float>(n) / static_cast<float>(d);
+
+  // Ensure the frame and picture regions aren't larger than our prescribed
+  // maximum, or zero sized.
+  nsIntSize frame(mInfo.frame_width, mInfo.frame_height);
+  nsIntRect picture(mInfo.pic_x, mInfo.pic_y, mInfo.pic_width, mInfo.pic_height);
+  if (!IsValidVideoRegion(frame, picture, frame)) {
+    return mActive = false;
+  }
+
+  mCtx = th_decode_alloc(&mInfo, mSetup);
+  if (!mCtx) {
+    return mActive = false;
+  }
+
+  return true;
+}
+
+bool
+TheoraState::DecodeHeader(ogg_packet* aPacket)
+{
+  nsAutoRef<ogg_packet> autoRelease(aPacket);
+  mPacketCount++;
+  int ret = th_decode_headerin(&mInfo,
+                               &mComment,
+                               &mSetup,
+                               aPacket);
+
+  // We must determine when we've read the last header packet.
+  // th_decode_headerin() does not tell us when it's read the last header, so
+  // we must keep track of the headers externally.
+  //
+  // There are 3 header packets, the Identification, Comment, and Setup
+  // headers, which must be in that order. If they're out of order, the file
+  // is invalid. If we've successfully read a header, and it's the setup
+  // header, then we're done reading headers. The first byte of each packet
+  // determines it's type as follows:
+  //    0x80 -> Identification header
+  //    0x81 -> Comment header
+  //    0x82 -> Setup header
+  // See http://www.theora.org/doc/Theora.pdf Chapter 6, "Bitstream Headers",
+  // for more details of the Ogg/Theora containment scheme.
+  bool isSetupHeader = aPacket->bytes > 0 && aPacket->packet[0] == 0x82;
+  if (ret < 0 || mPacketCount > 3) {
+    // We've received an error, or the first three packets weren't valid
+    // header packets. Assume bad input.
+    // Our caller will deactivate the bitstream.
+    return false;
+  } else if (ret > 0 && isSetupHeader && mPacketCount == 3) {
+    // Successfully read the three header packets.
+    mDoneReadingHeaders = true;
+  }
+  return true;
+}
+
+int64_t
+TheoraState::Time(int64_t granulepos)
+{
+  if (!mActive) {
+    return -1;
+  }
+  return TheoraState::Time(&mInfo, granulepos);
+}
+
+bool
+TheoraState::IsHeader(ogg_packet* aPacket)
+{
+  return th_packet_isheader(aPacket);
+}
+
+# define TH_VERSION_CHECK(_info,_maj,_min,_sub) \
+ (((_info)->version_major>(_maj)||(_info)->version_major==(_maj))&& \
+ (((_info)->version_minor>(_min)||(_info)->version_minor==(_min))&& \
+ (_info)->version_subminor>=(_sub)))
+
+int64_t
+TheoraState::Time(th_info* aInfo, int64_t aGranulepos)
+{
+  if (aGranulepos < 0 || aInfo->fps_numerator == 0) {
+    return -1;
+  }
+  // Implementation of th_granule_frame inlined here to operate
+  // on the th_info structure instead of the theora_state.
+  int shift = aInfo->keyframe_granule_shift;
+  ogg_int64_t iframe = aGranulepos >> shift;
+  ogg_int64_t pframe = aGranulepos - (iframe << shift);
+  int64_t frameno = iframe + pframe - TH_VERSION_CHECK(aInfo, 3, 2, 1);
+  CheckedInt64 t =
+    ((CheckedInt64(frameno) + 1) * USECS_PER_S) * aInfo->fps_denominator;
+  if (!t.isValid()) {
+    return -1;
+  }
+  t /= aInfo->fps_numerator;
+  return t.isValid() ? t.value() : -1;
+}
+
+int64_t TheoraState::StartTime(int64_t granulepos)
+{
+  if (granulepos < 0 || !mActive || mInfo.fps_numerator == 0) {
+    return -1;
+  }
+  CheckedInt64 t =
+    (CheckedInt64(th_granule_frame(mCtx, granulepos)) * USECS_PER_S)
+    * mInfo.fps_denominator;
+  if (!t.isValid()) {
+    return -1;
+  }
+  return t.value() / mInfo.fps_numerator;
+}
+
+int64_t
+TheoraState::PacketDuration(ogg_packet* aPacket)
+{
+  if (!mActive || mInfo.fps_numerator == 0) {
+    return -1;
+  }
+  CheckedInt64 t =
+    SaferMultDiv(mInfo.fps_denominator, USECS_PER_S, mInfo.fps_numerator);
+  return t.isValid() ? t.value() : -1;
+}
+
+int64_t
+TheoraState::MaxKeyframeOffset()
+{
+  // Determine the maximum time in microseconds by which a key frame could
+  // offset for the theora bitstream. Theora granulepos encode time as:
+  // ((key_frame_number << granule_shift) + frame_offset).
+  // Therefore the maximum possible time by which any frame could be offset
+  // from a keyframe is the duration of (1 << granule_shift) - 1) frames.
+  int64_t frameDuration;
+
+  // Max number of frames keyframe could possibly be offset.
+  int64_t keyframeDiff = (1 << mInfo.keyframe_granule_shift) - 1;
+
+  // Length of frame in usecs.
+  frameDuration = (mInfo.fps_denominator * USECS_PER_S) / mInfo.fps_numerator;
+
+  // Total time in usecs keyframe can be offset from any given frame.
+  return frameDuration * keyframeDiff;
+}
+
+bool
+TheoraState::IsKeyframe(ogg_packet* pkt)
+{
+  // first bit of packet is 1 for header, 0 for data
+  // second bit of packet is 1 for inter frame, 0 for intra frame
+  return (pkt->bytes >= 1 && (pkt->packet[0] & 0x40) == 0x00);
+}
+
+nsresult
+TheoraState::PageIn(ogg_page* aPage)
+{
+  if (!mActive)
+    return NS_OK;
+  NS_ASSERTION(static_cast<uint32_t>(ogg_page_serialno(aPage)) == mSerial,
+               "Page must be for this stream!");
+  if (ogg_stream_pagein(&mState, aPage) == -1)
+    return NS_ERROR_FAILURE;
+  bool foundGp;
+  nsresult res = PacketOutUntilGranulepos(foundGp);
+  if (NS_FAILED(res))
+    return res;
+  if (foundGp && mDoneReadingHeaders) {
+    // We've found a packet with a granulepos, and we've loaded our metadata
+    // and initialized our decoder. Determine granulepos of buffered packets.
+    ReconstructTheoraGranulepos();
+    for (uint32_t i = 0; i < mUnstamped.Length(); ++i) {
+      ogg_packet* packet = mUnstamped[i];
+#ifdef DEBUG
+      NS_ASSERTION(!IsHeader(packet), "Don't try to recover header packet gp");
+      NS_ASSERTION(packet->granulepos != -1, "Packet must have gp by now");
+#endif
+      mPackets.Append(packet);
+    }
+    mUnstamped.Clear();
+  }
+  return NS_OK;
+}
+
+// Returns 1 if the Theora info struct is decoding a media of Theora
+// version (maj,min,sub) or later, otherwise returns 0.
+int
+TheoraVersion(th_info* info,
+              unsigned char maj,
+              unsigned char min,
+              unsigned char sub)
+{
+  ogg_uint32_t ver = (maj << 16) + (min << 8) + sub;
+  ogg_uint32_t th_ver = (info->version_major << 16) +
+                        (info->version_minor << 8) +
+                        info->version_subminor;
+  return (th_ver >= ver) ? 1 : 0;
+}
+
+void
+TheoraState::ReconstructTheoraGranulepos()
+{
+  if (mUnstamped.Length() == 0) {
+    return;
+  }
+  ogg_int64_t lastGranulepos = mUnstamped[mUnstamped.Length() - 1]->granulepos;
+  NS_ASSERTION(lastGranulepos != -1, "Must know last granulepos");
+
+  // Reconstruct the granulepos (and thus timestamps) of the decoded
+  // frames. Granulepos are stored as ((keyframe<<shift)+offset). We
+  // know the granulepos of the last frame in the list, so we can infer
+  // the granulepos of the intermediate frames using their frame numbers.
+  ogg_int64_t shift = mInfo.keyframe_granule_shift;
+  ogg_int64_t version_3_2_1 = TheoraVersion(&mInfo,3,2,1);
+  ogg_int64_t lastFrame = th_granule_frame(mCtx,
+                                           lastGranulepos) + version_3_2_1;
+  ogg_int64_t firstFrame = lastFrame - mUnstamped.Length() + 1;
+
+  // Until we encounter a keyframe, we'll assume that the "keyframe"
+  // segment of the granulepos is the first frame, or if that causes
+  // the "offset" segment to overflow, we assume the required
+  // keyframe is maximumally offset. Until we encounter a keyframe
+  // the granulepos will probably be wrong, but we can't decode the
+  // frame anyway (since we don't have its keyframe) so it doesn't really
+  // matter.
+  ogg_int64_t keyframe = lastGranulepos >> shift;
+
+  // The lastFrame, firstFrame, keyframe variables, as well as the frame
+  // variable in the loop below, store the frame number for Theora
+  // version >= 3.2.1 streams, and store the frame index for Theora
+  // version < 3.2.1 streams.
+  for (uint32_t i = 0; i < mUnstamped.Length() - 1; ++i) {
+    ogg_int64_t frame = firstFrame + i;
+    ogg_int64_t granulepos;
+    ogg_packet* packet = mUnstamped[i];
+    bool isKeyframe = th_packet_iskeyframe(packet) == 1;
+
+    if (isKeyframe) {
+      granulepos = frame << shift;
+      keyframe = frame;
+    } else if (frame >= keyframe &&
+                frame - keyframe < ((ogg_int64_t)1 << shift))
+    {
+      // (frame - keyframe) won't overflow the "offset" segment of the
+      // granulepos, so it's safe to calculate the granulepos.
+      granulepos = (keyframe << shift) + (frame - keyframe);
+    } else {
+      // (frame - keyframeno) will overflow the "offset" segment of the
+      // granulepos, so we take "keyframe" to be the max possible offset
+      // frame instead.
+      ogg_int64_t k = std::max(frame - (((ogg_int64_t)1 << shift) - 1), version_3_2_1);
+      granulepos = (k << shift) + (frame - k);
+    }
+    // Theora 3.2.1+ granulepos store frame number [1..N], so granulepos
+    // should be > 0.
+    // Theora 3.2.0 granulepos store the frame index [0..(N-1)], so
+    // granulepos should be >= 0.
+    NS_ASSERTION(granulepos >= version_3_2_1,
+                  "Invalid granulepos for Theora version");
+
+    // Check that the frame's granule number is one more than the
+    // previous frame's.
+    NS_ASSERTION(i == 0 ||
+                 th_granule_frame(mCtx, granulepos) ==
+                 th_granule_frame(mCtx, mUnstamped[i-1]->granulepos) + 1,
+                 "Granulepos calculation is incorrect!");
+
+    packet->granulepos = granulepos;
+  }
+
+  // Check that the second to last frame's granule number is one less than
+  // the last frame's (the known granule number). If not our granulepos
+  // recovery missed a beat.
+  NS_ASSERTION(mUnstamped.Length() < 2 ||
+    th_granule_frame(mCtx, mUnstamped[mUnstamped.Length()-2]->granulepos) + 1 ==
+    th_granule_frame(mCtx, lastGranulepos),
+    "Granulepos recovery should catch up with packet->granulepos!");
+}
+
+nsresult
+VorbisState::Reset()
+{
+  nsresult res = NS_OK;
+  if (mActive && vorbis_synthesis_restart(&mDsp) != 0) {
+    res = NS_ERROR_FAILURE;
+  }
+  if (NS_FAILED(OggCodecState::Reset())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  mGranulepos = 0;
+  mPrevVorbisBlockSize = 0;
+
+  return res;
+}
+
+VorbisState::VorbisState(ogg_page* aBosPage)
+  : OggCodecState(aBosPage, true)
+  , mPrevVorbisBlockSize(0)
+  , mGranulepos(0)
+{
+  MOZ_COUNT_CTOR(VorbisState);
+  vorbis_info_init(&mInfo);
+  vorbis_comment_init(&mComment);
+  memset(&mDsp, 0, sizeof(vorbis_dsp_state));
+  memset(&mBlock, 0, sizeof(vorbis_block));
+}
+
+VorbisState::~VorbisState()
+{
+  MOZ_COUNT_DTOR(VorbisState);
+  Reset();
+  vorbis_block_clear(&mBlock);
+  vorbis_dsp_clear(&mDsp);
+  vorbis_info_clear(&mInfo);
+  vorbis_comment_clear(&mComment);
+}
+
+bool
+VorbisState::DecodeHeader(ogg_packet* aPacket)
+{
+  nsAutoRef<ogg_packet> autoRelease(aPacket);
+  mPacketCount++;
+  int ret = vorbis_synthesis_headerin(&mInfo,
+                                      &mComment,
+                                      aPacket);
+  // We must determine when we've read the last header packet.
+  // vorbis_synthesis_headerin() does not tell us when it's read the last
+  // header, so we must keep track of the headers externally.
+  //
+  // There are 3 header packets, the Identification, Comment, and Setup
+  // headers, which must be in that order. If they're out of order, the file
+  // is invalid. If we've successfully read a header, and it's the setup
+  // header, then we're done reading headers. The first byte of each packet
+  // determines it's type as follows:
+  //    0x1 -> Identification header
+  //    0x3 -> Comment header
+  //    0x5 -> Setup header
+  // For more details of the Vorbis/Ogg containment scheme, see the Vorbis I
+  // Specification, Chapter 4, Codec Setup and Packet Decode:
+  // http://www.xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-580004
+
+  bool isSetupHeader = aPacket->bytes > 0 && aPacket->packet[0] == 0x5;
+
+  if (ret < 0 || mPacketCount > 3) {
+    // We've received an error, or the first three packets weren't valid
+    // header packets. Assume bad input. Our caller will deactivate the
+    // bitstream.
+    return false;
+  } else if (ret == 0 && isSetupHeader && mPacketCount == 3) {
+    // Successfully read the three header packets.
+    // The bitstream remains active.
+    mDoneReadingHeaders = true;
+  }
+  return true;
+}
+
+bool
+VorbisState::Init()
+{
+  if (!mActive) {
+    return false;
+  }
+
+  int ret = vorbis_synthesis_init(&mDsp, &mInfo);
+  if (ret != 0) {
+    NS_WARNING("vorbis_synthesis_init() failed initializing vorbis bitstream");
+    return mActive = false;
+  }
+  ret = vorbis_block_init(&mDsp, &mBlock);
+  if (ret != 0) {
+    NS_WARNING("vorbis_block_init() failed initializing vorbis bitstream");
+    if (mActive) {
+      vorbis_dsp_clear(&mDsp);
+    }
+    return mActive = false;
+  }
+  return true;
+}
+
+int64_t
+VorbisState::Time(int64_t granulepos)
+{
+  if (!mActive) {
+    return -1;
+  }
+
+  return VorbisState::Time(&mInfo, granulepos);
+}
+
+int64_t
+VorbisState::Time(vorbis_info* aInfo, int64_t aGranulepos)
+{
+  if (aGranulepos == -1 || aInfo->rate == 0) {
+    return -1;
+  }
+  CheckedInt64 t = SaferMultDiv(aGranulepos, USECS_PER_S, aInfo->rate);
+  return t.isValid() ? t.value() : 0;
+}
+
+int64_t
+VorbisState::PacketDuration(ogg_packet* aPacket)
+{
+  if (!mActive) {
+    return -1;
+  }
+  if (aPacket->granulepos == -1) {
+    return -1;
+  }
+  // @FIXME store these in a more stable place
+  if (mVorbisPacketSamples.count(aPacket) == 0) {
+    // We haven't seen this packet, don't know its size?
+    return -1;
+  }
+
+  long samples = mVorbisPacketSamples[aPacket];
+  return Time(samples);
+}
+
+bool
+VorbisState::IsHeader(ogg_packet* aPacket)
+{
+  // The first byte in each Vorbis header packet is either 0x01, 0x03, or 0x05,
+  // i.e. the first bit is odd. Audio data packets have their first bit as 0x0.
+  // Any packet with its first bit set cannot be a data packet, it's a
+  // (possibly invalid) header packet.
+  // See: http://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-610004.2.1
+  return aPacket->bytes > 0 ? (aPacket->packet[0] & 0x1) : false;
+}
+
+MetadataTags*
+VorbisState::GetTags()
+{
+  MetadataTags* tags;
+  NS_ASSERTION(mComment.user_comments, "no vorbis comment strings!");
+  NS_ASSERTION(mComment.comment_lengths, "no vorbis comment lengths!");
+  tags = new MetadataTags;
+  for (int i = 0; i < mComment.comments; i++) {
+    AddVorbisComment(tags, mComment.user_comments[i],
+                     mComment.comment_lengths[i]);
+  }
+  return tags;
+}
+
+nsresult
+VorbisState::PageIn(ogg_page* aPage)
+{
+  if (!mActive) {
+    return NS_OK;
+  }
+  NS_ASSERTION(static_cast<uint32_t>(ogg_page_serialno(aPage)) == mSerial,
+               "Page must be for this stream!");
+  if (ogg_stream_pagein(&mState, aPage) == -1)
+    return NS_ERROR_FAILURE;
+  bool foundGp;
+  nsresult res = PacketOutUntilGranulepos(foundGp);
+  if (NS_FAILED(res)) {
+    return res;
+  }
+  if (foundGp && mDoneReadingHeaders) {
+    // We've found a packet with a granulepos, and we've loaded our metadata
+    // and initialized our decoder. Determine granulepos of buffered packets.
+    ReconstructVorbisGranulepos();
+    for (uint32_t i = 0; i < mUnstamped.Length(); ++i) {
+      ogg_packet* packet = mUnstamped[i];
+      AssertHasRecordedPacketSamples(packet);
+      NS_ASSERTION(!IsHeader(packet), "Don't try to recover header packet gp");
+      NS_ASSERTION(packet->granulepos != -1, "Packet must have gp by now");
+      mPackets.Append(packet);
+    }
+    mUnstamped.Clear();
+  }
+  return NS_OK;
+}
+
+nsresult
+VorbisState::ReconstructVorbisGranulepos()
+{
+  // The number of samples in a Vorbis packet is:
+  // window_blocksize(previous_packet)/4+window_blocksize(current_packet)/4
+  // See: http://xiph.org/vorbis/doc/Vorbis_I_spec.html#x1-230001.3.2
+  // So we maintain mPrevVorbisBlockSize, the block size of the last packet
+  // encountered. We also maintain mGranulepos, which is the granulepos of
+  // the last encountered packet. This enables us to give granulepos to
+  // packets when the last packet in mUnstamped doesn't have a granulepos
+  // (for example if the stream was truncated).
+  //
+  // We validate our prediction of the number of samples decoded when
+  // VALIDATE_VORBIS_SAMPLE_CALCULATION is defined by recording the predicted
+  // number of samples, and verifing we extract that many when decoding
+  // each packet.
+
+  NS_ASSERTION(mUnstamped.Length() > 0, "Length must be > 0");
+  ogg_packet* last = mUnstamped.LastElement();
+  NS_ASSERTION(last->e_o_s || last->granulepos >= 0,
+    "Must know last granulepos!");
+  if (mUnstamped.Length() == 1) {
+    ogg_packet* packet = mUnstamped[0];
+    long blockSize = vorbis_packet_blocksize(&mInfo, packet);
+    if (blockSize < 0) {
+      // On failure vorbis_packet_blocksize returns < 0. If we've got
+      // a bad packet, we just assume that decode will have to skip this
+      // packet, i.e. assume 0 samples are decodable from this packet.
+      blockSize = 0;
+      mPrevVorbisBlockSize = 0;
+    }
+    long samples = mPrevVorbisBlockSize / 4 + blockSize / 4;
+    mPrevVorbisBlockSize = blockSize;
+    if (packet->granulepos == -1) {
+      packet->granulepos = mGranulepos + samples;
+    }
+
+    // Account for a partial last frame
+    if (packet->e_o_s && packet->granulepos >= mGranulepos) {
+       samples = packet->granulepos - mGranulepos;
+    }
+
+    mGranulepos = packet->granulepos;
+    RecordVorbisPacketSamples(packet, samples);
+    return NS_OK;
+  }
+
+  bool unknownGranulepos = last->granulepos == -1;
+  int totalSamples = 0;
+  for (int32_t i = mUnstamped.Length() - 1; i > 0; i--) {
+    ogg_packet* packet = mUnstamped[i];
+    ogg_packet* prev = mUnstamped[i-1];
+    ogg_int64_t granulepos = packet->granulepos;
+    NS_ASSERTION(granulepos != -1, "Must know granulepos!");
+    long prevBlockSize = vorbis_packet_blocksize(&mInfo, prev);
+    long blockSize = vorbis_packet_blocksize(&mInfo, packet);
+
+    if (blockSize < 0 || prevBlockSize < 0) {
+      // On failure vorbis_packet_blocksize returns < 0. If we've got
+      // a bad packet, we just assume that decode will have to skip this
+      // packet, i.e. assume 0 samples are decodable from this packet.
+      blockSize = 0;
+      prevBlockSize = 0;
+    }
+
+    long samples = prevBlockSize / 4 + blockSize / 4;
+    totalSamples += samples;
+    prev->granulepos = granulepos - samples;
+    RecordVorbisPacketSamples(packet, samples);
+  }
+
+  if (unknownGranulepos) {
+    for (uint32_t i = 0; i < mUnstamped.Length(); i++) {
+      ogg_packet* packet = mUnstamped[i];
+      packet->granulepos += mGranulepos + totalSamples + 1;
+    }
+  }
+
+  ogg_packet* first = mUnstamped[0];
+  long blockSize = vorbis_packet_blocksize(&mInfo, first);
+  if (blockSize < 0) {
+    mPrevVorbisBlockSize = 0;
+    blockSize = 0;
+  }
+
+  long samples = (mPrevVorbisBlockSize == 0) ? 0 :
+                  mPrevVorbisBlockSize / 4 + blockSize / 4;
+  int64_t start = first->granulepos - samples;
+  RecordVorbisPacketSamples(first, samples);
+
+  if (last->e_o_s && start < mGranulepos) {
+    // We've calculated that there are more samples in this page than its
+    // granulepos claims, and it's the last page in the stream. This is legal,
+    // and we will need to prune the trailing samples when we come to decode it.
+    // We must correct the timestamps so that they follow the last Vorbis page's
+    // samples.
+    int64_t pruned = mGranulepos - start;
+    for (uint32_t i = 0; i < mUnstamped.Length() - 1; i++) {
+      mUnstamped[i]->granulepos += pruned;
+    }
+#ifdef VALIDATE_VORBIS_SAMPLE_CALCULATION
+    mVorbisPacketSamples[last] -= pruned;
+#endif
+  }
+
+  mPrevVorbisBlockSize = vorbis_packet_blocksize(&mInfo, last);
+  mPrevVorbisBlockSize = std::max(static_cast<long>(0), mPrevVorbisBlockSize);
+  mGranulepos = last->granulepos;
+
+  return NS_OK;
+}
+
+OpusState::OpusState(ogg_page* aBosPage)
+  : OggCodecState(aBosPage, true)
+  , mParser(nullptr)
+  , mDecoder(nullptr)
+  , mSkip(0)
+  , mPrevPacketGranulepos(0)
+  , mPrevPageGranulepos(0)
+{
+  MOZ_COUNT_CTOR(OpusState);
+}
+
+OpusState::~OpusState()
+{
+  MOZ_COUNT_DTOR(OpusState);
+  Reset();
+
+  if (mDecoder) {
+    opus_multistream_decoder_destroy(mDecoder);
+    mDecoder = nullptr;
+  }
+}
+
+nsresult
+OpusState::Reset()
+{
+  return Reset(false);
+}
+
+nsresult
+OpusState::Reset(bool aStart)
+{
+  nsresult res = NS_OK;
+
+  if (mActive && mDecoder) {
+    // Reset the decoder.
+    opus_multistream_decoder_ctl(mDecoder, OPUS_RESET_STATE);
+    // Let the seek logic handle pre-roll if we're not seeking to the start.
+    mSkip = aStart ? mParser->mPreSkip : 0;
+    // This lets us distinguish the first page being the last page vs. just
+    // not having processed the previous page when we encounter the last page.
+    mPrevPageGranulepos = aStart ? 0 : -1;
+    mPrevPacketGranulepos = aStart ? 0 : -1;
+  }
+
+  // Clear queued data.
+  if (NS_FAILED(OggCodecState::Reset())) {
+    return NS_ERROR_FAILURE;
+  }
+
+  LOG(LogLevel::Debug, ("Opus decoder reset, to skip %d", mSkip));
+
+  return res;
+}
+
+bool
+OpusState::Init(void)
+{
+  if (!mActive) {
+    return false;
+  }
+
+  int error;
+
+  NS_ASSERTION(mDecoder == nullptr, "leaking OpusDecoder");
+
+  mDecoder = opus_multistream_decoder_create(mParser->mRate,
+                                             mParser->mChannels,
+                                             mParser->mStreams,
+                                             mParser->mCoupledStreams,
+                                             mParser->mMappingTable,
+                                             &error);
+
+  mSkip = mParser->mPreSkip;
+
+  LOG(LogLevel::Debug, ("Opus decoder init, to skip %d", mSkip));
+
+  return error == OPUS_OK;
+}
+
+bool
+OpusState::DecodeHeader(ogg_packet* aPacket)
+{
+  nsAutoRef<ogg_packet> autoRelease(aPacket);
+  switch(mPacketCount++) {
+    // Parse the id header.
+    case 0:
+      mParser = new OpusParser;
+      if (!mParser->DecodeHeader(aPacket->packet, aPacket->bytes)) {
+        return false;
+      }
+      mRate = mParser->mRate;
+      mChannels = mParser->mChannels;
+      mPreSkip = mParser->mPreSkip;
+#ifdef MOZ_SAMPLE_TYPE_FLOAT32
+      mGain = mParser->mGain;
+#else
+      mGain_Q16 = mParser->mGain_Q16;
+#endif
+      break;
+
+    // Parse the metadata header.
+    case 1:
+      if (!mParser->DecodeTags(aPacket->packet, aPacket->bytes)) {
+        return false;
+      }
+      break;
+
+    // We made it to the first data packet (which includes reconstructing
+    // timestamps for it in PageIn). Success!
+    default:
+      mDoneReadingHeaders = true;
+      // Put it back on the queue so we can decode it.
+      mPackets.PushFront(autoRelease.disown());
+      break;
+  }
+  return true;
+}
+
+/* Construct and return a tags hashmap from our internal array */
+MetadataTags*
+OpusState::GetTags()
+{
+  MetadataTags* tags;
+
+  tags = new MetadataTags;
+  for (uint32_t i = 0; i < mParser->mTags.Length(); i++) {
+    AddVorbisComment(tags, mParser->mTags[i].Data(), mParser->mTags[i].Length());
+  }
+
+  return tags;
+}
+
+/* Return the timestamp (in microseconds) equivalent to a granulepos. */
+int64_t
+OpusState::Time(int64_t aGranulepos)
+{
+  if (!mActive) {
+    return -1;
+  }
+
+  return Time(mParser->mPreSkip, aGranulepos);
+}
+
+int64_t
+OpusState::Time(int aPreSkip, int64_t aGranulepos)
+{
+  if (aGranulepos < 0) {
+    return -1;
+  }
+
+  // Ogg Opus always runs at a granule rate of 48 kHz.
+  CheckedInt64 t = SaferMultDiv(aGranulepos - aPreSkip, USECS_PER_S, 48000);
+  return t.isValid() ? t.value() : -1;
+}
+
+bool
+OpusState::IsHeader(ogg_packet* aPacket)
+{
+  return aPacket->bytes >= 16 &&
+         (!memcmp(aPacket->packet, "OpusHead", 8) ||
+          !memcmp(aPacket->packet, "OpusTags", 8));
+}
+
+nsresult
+OpusState::PageIn(ogg_page* aPage)
+{
+  if (!mActive) {
+    return NS_OK;
+  }
+  NS_ASSERTION(static_cast<uint32_t>(ogg_page_serialno(aPage)) == mSerial,
+               "Page must be for this stream!");
+  if (ogg_stream_pagein(&mState, aPage) == -1)
+    return NS_ERROR_FAILURE;
+
+  bool haveGranulepos;
+  nsresult rv = PacketOutUntilGranulepos(haveGranulepos);
+  if (NS_FAILED(rv) || !haveGranulepos || mPacketCount < 2) {
+    return rv;
+  }
+  if (!ReconstructOpusGranulepos()) {
+    return NS_ERROR_FAILURE;
+  }
+  for (uint32_t i = 0; i < mUnstamped.Length(); i++) {
+    ogg_packet* packet = mUnstamped[i];
+    NS_ASSERTION(!IsHeader(packet), "Don't try to play a header packet");
+    NS_ASSERTION(packet->granulepos != -1, "Packet should have a granulepos");
+    mPackets.Append(packet);
+  }
+  mUnstamped.Clear();
+  return NS_OK;
+}
+
+// Helper method to return the change in granule position due to an Opus packet
+// (as distinct from the number of samples in the packet, which depends on the
+// decoder rate). It should work with a multistream Opus file, and continue to
+// work should we ever allow the decoder to decode at a rate other than 48 kHz.
+// It even works before we've created the actual Opus decoder.
+static int
+GetOpusDeltaGP(ogg_packet* packet)
+{
+  int nframes;
+  nframes = opus_packet_get_nb_frames(packet->packet, packet->bytes);
+  if (nframes > 0) {
+    return nframes*opus_packet_get_samples_per_frame(packet->packet, 48000);
+  }
+  NS_WARNING("Invalid Opus packet.");
+  return nframes;
+}
+
+int64_t
+OpusState::PacketDuration(ogg_packet* aPacket)
+{
+  CheckedInt64 t = SaferMultDiv(GetOpusDeltaGP(aPacket), USECS_PER_S, 48000);
+  return t.isValid() ? t.value() : -1;
+}
+
+bool
+OpusState::ReconstructOpusGranulepos(void)
+{
+  NS_ASSERTION(mUnstamped.Length() > 0, "Must have unstamped packets");
+  ogg_packet* last = mUnstamped.LastElement();
+  NS_ASSERTION(last->e_o_s || last->granulepos > 0,
+      "Must know last granulepos!");
+  int64_t gp;
+  // If this is the last page, and we've seen at least one previous page (or
+  // this is the first page)...
+  if (last->e_o_s) {
+    if (mPrevPageGranulepos != -1) {
+      // If this file only has one page and the final granule position is
+      // smaller than the pre-skip amount, we MUST reject the stream.
+      if (!mDoneReadingHeaders && last->granulepos < mPreSkip)
+        return false;
+      int64_t last_gp = last->granulepos;
+      gp = mPrevPageGranulepos;
+      // Loop through the packets forwards, adding the current packet's
+      // duration to the previous granulepos to get the value for the
+      // current packet.
+      for (uint32_t i = 0; i < mUnstamped.Length() - 1; ++i) {
+        ogg_packet* packet = mUnstamped[i];
+        int offset = GetOpusDeltaGP(packet);
+        // Check for error (negative offset) and overflow.
+        if (offset >= 0 && gp <= INT64_MAX - offset) {
+          gp += offset;
+          if (gp >= last_gp) {
+            NS_WARNING("Opus end trimming removed more than a full packet.");
+            // We were asked to remove a full packet's worth of data or more.
+            // Encoders SHOULD NOT produce streams like this, but we'll handle
+            // it for them anyway.
+            gp = last_gp;
+            for (uint32_t j = i+1; j < mUnstamped.Length(); ++j) {
+              OggCodecState::ReleasePacket(mUnstamped[j]);
+            }
+            mUnstamped.RemoveElementsAt(i+1, mUnstamped.Length() - (i+1));
+            last = packet;
+            last->e_o_s = 1;
+          }
+        }
+        packet->granulepos = gp;
+      }
+      mPrevPageGranulepos = last_gp;
+      return true;
+    } else {
+      NS_WARNING("No previous granule position to use for Opus end trimming.");
+      // If we don't have a previous granule position, fall through.
+      // We simply won't trim any samples from the end.
+      // TODO: Are we guaranteed to have seen a previous page if there is one?
+    }
+  }
+
+  gp = last->granulepos;
+  // Loop through the packets backwards, subtracting the next
+  // packet's duration from its granulepos to get the value
+  // for the current packet.
+  for (uint32_t i = mUnstamped.Length() - 1; i > 0; i--) {
+    int offset = GetOpusDeltaGP(mUnstamped[i]);
+    // Check for error (negative offset) and overflow.
+    if (offset >= 0) {
+      if (offset <= gp) {
+        gp -= offset;
+      } else {
+        // If the granule position of the first data page is smaller than the
+        // number of decodable audio samples on that page, then we MUST reject
+        // the stream.
+        if (!mDoneReadingHeaders)
+          return false;
+        // It's too late to reject the stream.
+        // If we get here, this almost certainly means the file has screwed-up
+        // timestamps somewhere after the first page.
+        NS_WARNING("Clamping negative Opus granulepos to zero.");
+        gp = 0;
+      }
+    }
+    mUnstamped[i - 1]->granulepos = gp;
+  }
+
+  // Check to make sure the first granule position is at least as large as the
+  // total number of samples decodable from the first page with completed
+  // packets. This requires looking at the duration of the first packet, too.
+  // We MUST reject such streams.
+  if (!mDoneReadingHeaders && GetOpusDeltaGP(mUnstamped[0]) > gp) {
+    return false;
+  }
+  mPrevPageGranulepos = last->granulepos;
+  return true;
+}
+
+already_AddRefed<MediaRawData>
+OpusState::PacketOutAsMediaRawData()
+{
+  ogg_packet* packet = PacketPeek();
+  uint32_t frames = 0;
+  const int64_t endFrame = packet->granulepos;
+
+  if (!packet) {
+    return nullptr;
+  }
+  if (packet->e_o_s) {
+    frames = GetOpusDeltaGP(packet);
+  }
+
+  RefPtr<MediaRawData> data = OggCodecState::PacketOutAsMediaRawData();
+  if (!data) {
+    return nullptr;
+  }
+
+  if (data->mEOS && mPrevPacketGranulepos != -1) {
+    // If this is the last packet, perform end trimming.
+    int64_t startFrame = mPrevPacketGranulepos;
+    frames -= std::max<int64_t>(
+      0, std::min(endFrame - startFrame, static_cast<int64_t>(frames)));
+    data->mDiscardPadding = frames;
+  }
+
+  // Save this packet's granule position in case we need to perform end
+  // trimming on the next packet.
+  mPrevPacketGranulepos = endFrame;
+
+  return data.forget();
+}
+
+FlacState::FlacState(ogg_page* aBosPage)
+  : OggCodecState(aBosPage, true)
+{
+}
+
+bool
+FlacState::DecodeHeader(ogg_packet* aPacket)
+{
+  nsAutoRef<ogg_packet> autoRelease(aPacket);
+
+  if (!mParser.DecodeHeaderBlock(aPacket->packet, aPacket->bytes)) {
+    return false;
+  }
+  if (mParser.HasFullMetadata()) {
+    mDoneReadingHeaders = true;
+  }
+  return true;
+}
+
+int64_t
+FlacState::Time(int64_t granulepos)
+{
+  if (!mParser.mInfo.IsValid()) {
+    return -1;
+  }
+  CheckedInt64 t =
+      SaferMultDiv(granulepos, USECS_PER_S, mParser.mInfo.mRate);
+  if (!t.isValid()) {
+    return -1;
+  }
+  return t.value();
+}
+
+int64_t
+FlacState::PacketDuration(ogg_packet* aPacket)
+{
+  return mParser.BlockDuration(aPacket->packet, aPacket->bytes);
+}
+
+bool
+FlacState::IsHeader(ogg_packet* aPacket)
+{
+  return mParser.IsHeaderBlock(aPacket->packet, aPacket->bytes);
+}
+
+nsresult
+FlacState::PageIn(ogg_page* aPage)
+{
+  if (!mActive) {
+    return NS_OK;
+  }
+  NS_ASSERTION(static_cast<uint32_t>(ogg_page_serialno(aPage)) == mSerial,
+               "Page must be for this stream!");
+  if (ogg_stream_pagein(&mState, aPage) == -1)
+    return NS_ERROR_FAILURE;
+  bool foundGp;
+  nsresult res = PacketOutUntilGranulepos(foundGp);
+  if (NS_FAILED(res)) {
+    return res;
+  }
+  if (foundGp && mDoneReadingHeaders) {
+    // We've found a packet with a granulepos, and we've loaded our metadata
+    // and initialized our decoder. Determine granulepos of buffered packets.
+    ReconstructFlacGranulepos();
+    for (uint32_t i = 0; i < mUnstamped.Length(); ++i) {
+      ogg_packet* packet = mUnstamped[i];
+      NS_ASSERTION(!IsHeader(packet), "Don't try to recover header packet gp");
+      NS_ASSERTION(packet->granulepos != -1, "Packet must have gp by now");
+      mPackets.Append(packet);
+    }
+    mUnstamped.Clear();
+  }
+  return NS_OK;
+}
+
+// Return a hash table with tag metadata.
+MetadataTags*
+FlacState::GetTags()
+{
+  return mParser.GetTags();
+}
+
+const AudioInfo&
+FlacState::Info()
+{
+  return mParser.mInfo;
+}
+
+bool
+FlacState::ReconstructFlacGranulepos(void)
+{
+  NS_ASSERTION(mUnstamped.Length() > 0, "Must have unstamped packets");
+  ogg_packet* last = mUnstamped.LastElement();
+  NS_ASSERTION(last->e_o_s || last->granulepos > 0,
+      "Must know last granulepos!");
+  int64_t gp;
+
+  gp = last->granulepos;
+  // Loop through the packets backwards, subtracting the next
+  // packet's duration from its granulepos to get the value
+  // for the current packet.
+  for (uint32_t i = mUnstamped.Length() - 1; i > 0; i--) {
+    int offset =
+        mParser.BlockDuration(mUnstamped[i]->packet, mUnstamped[i]->bytes);
+    // Check for error (negative offset) and overflow.
+    if (offset >= 0) {
+      if (offset <= gp) {
+        gp -= offset;
+      } else {
+        // If the granule position of the first data page is smaller than the
+        // number of decodable audio samples on that page, then we MUST reject
+        // the stream.
+        if (!mDoneReadingHeaders) {
+          return false;
+        }
+        // It's too late to reject the stream.
+        // If we get here, this almost certainly means the file has screwed-up
+        // timestamps somewhere after the first page.
+        NS_WARNING("Clamping negative granulepos to zero.");
+        gp = 0;
+      }
+    }
+    mUnstamped[i - 1]->granulepos = gp;
+  }
+
+  return true;
+}
+
+SkeletonState::SkeletonState(ogg_page* aBosPage)
+  : OggCodecState(aBosPage, true)
+  , mVersion(0)
+  , mPresentationTime(0)
+  , mLength(0)
+{
+  MOZ_COUNT_CTOR(SkeletonState);
+}
+
+SkeletonState::~SkeletonState()
+{
+  MOZ_COUNT_DTOR(SkeletonState);
+}
+
+// Support for Ogg Skeleton 4.0, as per specification at:
+// http://wiki.xiph.org/Ogg_Skeleton_4
+
+// Minimum length in bytes of a Skeleton header packet.
+static const long SKELETON_MIN_HEADER_LEN = 28;
+static const long SKELETON_4_0_MIN_HEADER_LEN = 80;
+
+// Minimum length in bytes of a Skeleton 4.0 index packet.
+static const long SKELETON_4_0_MIN_INDEX_LEN = 42;
+
+// Minimum length in bytes of a Skeleton 3.0/4.0 Fisbone packet.
+static const long SKELETON_MIN_FISBONE_LEN = 52;
+
+// Minimum possible size of a compressed index keypoint.
+static const size_t MIN_KEY_POINT_SIZE = 2;
+
+// Byte offset of the major and minor version numbers in the
+// Ogg Skeleton 4.0 header packet.
+static const size_t SKELETON_VERSION_MAJOR_OFFSET = 8;
+static const size_t SKELETON_VERSION_MINOR_OFFSET = 10;
+
+// Byte-offsets of the presentation time numerator and denominator
+static const size_t SKELETON_PRESENTATION_TIME_NUMERATOR_OFFSET = 12;
+static const size_t SKELETON_PRESENTATION_TIME_DENOMINATOR_OFFSET = 20;
+
+// Byte-offsets of the length of file field in the Skeleton 4.0 header packet.
+static const size_t SKELETON_FILE_LENGTH_OFFSET = 64;
+
+// Byte-offsets of the fields in the Skeleton index packet.
+static const size_t INDEX_SERIALNO_OFFSET = 6;
+static const size_t INDEX_NUM_KEYPOINTS_OFFSET = 10;
+static const size_t INDEX_TIME_DENOM_OFFSET = 18;
+static const size_t INDEX_FIRST_NUMER_OFFSET = 26;
+static const size_t INDEX_LAST_NUMER_OFFSET = 34;
+static const size_t INDEX_KEYPOINT_OFFSET = 42;
+
+// Byte-offsets of the fields in the Skeleton Fisbone packet.
+static const size_t FISBONE_MSG_FIELDS_OFFSET = 8;
+static const size_t FISBONE_SERIALNO_OFFSET = 12;
+
+static bool
+IsSkeletonBOS(ogg_packet* aPacket)
+{
+  static_assert(SKELETON_MIN_HEADER_LEN >= 8,
+                "Minimum length of skeleton BOS header incorrect");
+  return aPacket->bytes >= SKELETON_MIN_HEADER_LEN &&
+         memcmp(reinterpret_cast<char*>(aPacket->packet), "fishead", 8) == 0;
+}
+
+static bool
+IsSkeletonIndex(ogg_packet* aPacket)
+{
+  static_assert(SKELETON_4_0_MIN_INDEX_LEN >= 5,
+                "Minimum length of skeleton index header incorrect");
+  return aPacket->bytes >= SKELETON_4_0_MIN_INDEX_LEN &&
+         memcmp(reinterpret_cast<char*>(aPacket->packet), "index", 5) == 0;
+}
+
+static bool
+IsSkeletonFisbone(ogg_packet* aPacket)
+{
+  static_assert(SKELETON_MIN_FISBONE_LEN >= 8,
+                "Minimum length of skeleton fisbone header incorrect");
+  return aPacket->bytes >= SKELETON_MIN_FISBONE_LEN &&
+         memcmp(reinterpret_cast<char*>(aPacket->packet), "fisbone", 8) == 0;
+}
+
+// Reads a variable length encoded integer at p. Will not read
+// past aLimit. Returns pointer to character after end of integer.
+static const unsigned char*
+ReadVariableLengthInt(const unsigned char* p,
+                      const unsigned char* aLimit,
+                      int64_t& n)
+{
+  int shift = 0;
+  int64_t byte = 0;
+  n = 0;
+  while (p < aLimit &&
+         (byte & 0x80) != 0x80 &&
+         shift < 57)
+  {
+    byte = static_cast<int64_t>(*p);
+    n |= ((byte & 0x7f) << shift);
+    shift += 7;
+    p++;
+  }
+  return p;
+}
+
+bool
+SkeletonState::DecodeIndex(ogg_packet* aPacket)
+{
+  NS_ASSERTION(aPacket->bytes >= SKELETON_4_0_MIN_INDEX_LEN,
+               "Index must be at least minimum size");
+  if (!mActive) {
+    return false;
+  }
+
+  uint32_t serialno = LittleEndian::readUint32(aPacket->packet + INDEX_SERIALNO_OFFSET);
+  int64_t numKeyPoints = LittleEndian::readInt64(aPacket->packet + INDEX_NUM_KEYPOINTS_OFFSET);
+
+  int64_t endTime = 0, startTime = 0;
+  const unsigned char* p = aPacket->packet;
+
+  int64_t timeDenom = LittleEndian::readInt64(aPacket->packet + INDEX_TIME_DENOM_OFFSET);
+  if (timeDenom == 0) {
+    LOG(LogLevel::Debug, ("Ogg Skeleton Index packet for stream %u has 0 "
+                       "timestamp denominator.", serialno));
+    return (mActive = false);
+  }
+
+  // Extract the start time.
+  int64_t timeRawInt = LittleEndian::readInt64(p + INDEX_FIRST_NUMER_OFFSET);
+  CheckedInt64 t = SaferMultDiv(timeRawInt, USECS_PER_S, timeDenom);
+  if (!t.isValid()) {
+    return (mActive = false);
+  } else {
+    startTime = t.value();
+  }
+
+  // Extract the end time.
+  timeRawInt = LittleEndian::readInt64(p + INDEX_LAST_NUMER_OFFSET);
+  t = SaferMultDiv(timeRawInt, USECS_PER_S, timeDenom);
+  if (!t.isValid()) {
+    return (mActive = false);
+  } else {
+    endTime = t.value();
+  }
+
+  // Check the numKeyPoints value read, ensure we're not going to run out of
+  // memory while trying to decode the index packet.
+  CheckedInt64 minPacketSize =
+    (CheckedInt64(numKeyPoints) * MIN_KEY_POINT_SIZE) + INDEX_KEYPOINT_OFFSET;
+  if (!minPacketSize.isValid())
+  {
+    return (mActive = false);
+  }
+
+  int64_t sizeofIndex = aPacket->bytes - INDEX_KEYPOINT_OFFSET;
+  int64_t maxNumKeyPoints = sizeofIndex / MIN_KEY_POINT_SIZE;
+  if (aPacket->bytes < minPacketSize.value() ||
+      numKeyPoints > maxNumKeyPoints ||
+      numKeyPoints < 0) {
+    // Packet size is less than the theoretical minimum size, or the packet is
+    // claiming to store more keypoints than it's capable of storing. This means
+    // that the numKeyPoints field is too large or small for the packet to
+    // possibly contain as many packets as it claims to, so the numKeyPoints
+    // field is possibly malicious. Don't try decoding this index, we may run
+    // out of memory.
+    LOG(LogLevel::Debug, ("Possibly malicious number of key points reported "
+                       "(%lld) in index packet for stream %u.",
+                       numKeyPoints,
+                       serialno));
+    return (mActive = false);
+  }
+
+  nsAutoPtr<nsKeyFrameIndex> keyPoints(new nsKeyFrameIndex(startTime, endTime));
+
+  p = aPacket->packet + INDEX_KEYPOINT_OFFSET;
+  const unsigned char* limit = aPacket->packet + aPacket->bytes;
+  int64_t numKeyPointsRead = 0;
+  CheckedInt64 offset = 0;
+  CheckedInt64 time = 0;
+  while (p < limit && numKeyPointsRead < numKeyPoints) {
+    int64_t delta = 0;
+    p = ReadVariableLengthInt(p, limit, delta);
+    offset += delta;
+    if (p == limit ||
+        !offset.isValid() ||
+        offset.value() > mLength ||
+        offset.value() < 0) {
+      return (mActive = false);
+    }
+    p = ReadVariableLengthInt(p, limit, delta);
+    time += delta;
+    if (!time.isValid() ||
+        time.value() > endTime ||
+        time.value() < startTime) {
+      return (mActive = false);
+    }
+    CheckedInt64 timeUsecs = SaferMultDiv(time.value(), USECS_PER_S, timeDenom);
+    if (!timeUsecs.isValid()) {
+      return (mActive = false);
+    }
+    keyPoints->Add(offset.value(), timeUsecs.value());
+    numKeyPointsRead++;
+  }
+
+  int32_t keyPointsRead = keyPoints->Length();
+  if (keyPointsRead > 0) {
+    mIndex.Put(serialno, keyPoints.forget());
+  }
+
+  LOG(LogLevel::Debug, ("Loaded %d keypoints for Skeleton on stream %u",
+                     keyPointsRead, serialno));
+  return true;
+}
+
+nsresult
+SkeletonState::IndexedSeekTargetForTrack(uint32_t aSerialno,
+                                         int64_t aTarget,
+                                         nsKeyPoint& aResult)
+{
+  nsKeyFrameIndex* index = nullptr;
+  mIndex.Get(aSerialno, &index);
+
+  if (!index || index->Length() == 0 ||
+      aTarget < index->mStartTime || aTarget > index->mEndTime) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Binary search to find the last key point with time less than target.
+  int start = 0;
+  int end = index->Length() - 1;
+  while (end > start) {
+    int mid = start + ((end - start + 1) >> 1);
+    if (index->Get(mid).mTime == aTarget) {
+       start = mid;
+       break;
+    } else if (index->Get(mid).mTime < aTarget) {
+      start = mid;
+    } else {
+      end = mid - 1;
+    }
+  }
+
+  aResult = index->Get(start);
+  NS_ASSERTION(aResult.mTime <= aTarget, "Result should have time <= target");
+  return NS_OK;
+}
+
+nsresult
+SkeletonState::IndexedSeekTarget(int64_t aTarget,
+                                 nsTArray<uint32_t>& aTracks,
+                                 nsSeekTarget& aResult)
+{
+  if (!mActive || mVersion < SKELETON_VERSION(4,0)) {
+    return NS_ERROR_FAILURE;
+  }
+  // Loop over all requested tracks' indexes, and get the keypoint for that
+  // seek target. Record the keypoint with the lowest offset, this will be
+  // our seek result. User must seek to the one with lowest offset to ensure we
+  // pass "keyframes" on all tracks when we decode forwards to the seek target.
+  nsSeekTarget r;
+  for (uint32_t i=0; i<aTracks.Length(); i++) {
+    nsKeyPoint k;
+    if (NS_SUCCEEDED(IndexedSeekTargetForTrack(aTracks[i], aTarget, k)) &&
+        k.mOffset < r.mKeyPoint.mOffset) {
+      r.mKeyPoint = k;
+      r.mSerial = aTracks[i];
+    }
+  }
+  if (r.IsNull()) {
+    return NS_ERROR_FAILURE;
+  }
+  LOG(LogLevel::Debug, ("Indexed seek target for time %lld is offset %lld",
+                     aTarget, r.mKeyPoint.mOffset));
+  aResult = r;
+  return NS_OK;
+}
+
+nsresult
+SkeletonState::GetDuration(const nsTArray<uint32_t>& aTracks,
+                           int64_t& aDuration)
+{
+  if (!mActive ||
+      mVersion < SKELETON_VERSION(4,0) ||
+      !HasIndex() ||
+      aTracks.Length() == 0) {
+    return NS_ERROR_FAILURE;
+  }
+  int64_t endTime = INT64_MIN;
+  int64_t startTime = INT64_MAX;
+  for (uint32_t i=0; i<aTracks.Length(); i++) {
+    nsKeyFrameIndex* index = nullptr;
+    mIndex.Get(aTracks[i], &index);
+    if (!index) {
+      // Can't get the timestamps for one of the required tracks, fail.
+      return NS_ERROR_FAILURE;
+    }
+    if (index->mEndTime > endTime) {
+      endTime = index->mEndTime;
+    }
+    if (index->mStartTime < startTime) {
+      startTime = index->mStartTime;
+    }
+  }
+  NS_ASSERTION(endTime > startTime, "Duration must be positive");
+  CheckedInt64 duration = CheckedInt64(endTime) - startTime;
+  aDuration = duration.isValid() ? duration.value() : 0;
+  return duration.isValid() ? NS_OK : NS_ERROR_FAILURE;
+}
+
+bool
+SkeletonState::DecodeFisbone(ogg_packet* aPacket)
+{
+  if (aPacket->bytes < static_cast<long>(FISBONE_MSG_FIELDS_OFFSET + 4)) {
+    return false;
+  }
+  uint32_t offsetMsgField =
+    LittleEndian::readUint32(aPacket->packet + FISBONE_MSG_FIELDS_OFFSET);
+
+  if (aPacket->bytes < static_cast<long>(FISBONE_SERIALNO_OFFSET + 4)) {
+      return false;
+  }
+  uint32_t serialno =
+    LittleEndian::readUint32(aPacket->packet + FISBONE_SERIALNO_OFFSET);
+
+  CheckedUint32 checked_fields_pos =
+    CheckedUint32(FISBONE_MSG_FIELDS_OFFSET) + offsetMsgField;
+  if (!checked_fields_pos.isValid() ||
+      aPacket->bytes < static_cast<int64_t>(checked_fields_pos.value())) {
+    return false;
+  }
+  int64_t msgLength = aPacket->bytes - checked_fields_pos.value();
+  char* msgProbe = (char*)aPacket->packet + checked_fields_pos.value();
+  char* msgHead = msgProbe;
+  nsAutoPtr<MessageField> field(new MessageField());
+
+  const static FieldPatternType kFieldTypeMaps[] = {
+      {"Content-Type:", eContentType},
+      {"Role:", eRole},
+      {"Name:", eName},
+      {"Language:", eLanguage},
+      {"Title:", eTitle},
+      {"Display-hint:", eDisplayHint},
+      {"Altitude:", eAltitude},
+      {"TrackOrder:", eTrackOrder},
+      {"Track dependencies:", eTrackDependencies}
+  };
+
+  bool isContentTypeParsed = false;
+  while (msgLength > 1) {
+    if (*msgProbe == '\r' && *(msgProbe+1) == '\n') {
+      nsAutoCString strMsg(msgHead, msgProbe-msgHead);
+      for (size_t i = 0; i < ArrayLength(kFieldTypeMaps); i++) {
+        if (strMsg.Find(kFieldTypeMaps[i].mPatternToRecognize) != -1) {
+          // The content of message header fields follows [RFC2822], and the
+          // mandatory message field must be encoded in US-ASCII, others
+          // must be be encoded in UTF-8. "Content-Type" must come first
+          // for all of message header fields.
+          // See http://svn.annodex.net/standards/draft-pfeiffer-oggskeleton-current.txt.
+          if (i != 0 && !isContentTypeParsed) {
+            return false;
+          }
+
+          if ((i == 0 && IsASCII(strMsg)) || (i != 0 && IsUTF8(strMsg))) {
+            EMsgHeaderType eHeaderType = kFieldTypeMaps[i].mMsgHeaderType;
+            if (!field->mValuesStore.Contains(eHeaderType)) {
+              uint32_t nameLen = strlen(kFieldTypeMaps[i].mPatternToRecognize);
+              field->mValuesStore.Put(eHeaderType, new nsCString(msgHead+nameLen,
+                                                                 msgProbe-msgHead-nameLen));
+            }
+            isContentTypeParsed = i==0 ? true : isContentTypeParsed;
+          }
+          break;
+        }
+      }
+      msgProbe += 2;
+      msgLength -= 2;
+      msgHead = msgProbe;
+      continue;
+    }
+    msgLength--;
+    msgProbe++;
+  }
+
+  if (!mMsgFieldStore.Contains(serialno)) {
+    mMsgFieldStore.Put(serialno, field.forget());
+  } else {
+    return false;
+  }
+
+  return true;
+}
+
+bool
+SkeletonState::DecodeHeader(ogg_packet* aPacket)
+{
+  nsAutoRef<ogg_packet> autoRelease(aPacket);
+  if (IsSkeletonBOS(aPacket)) {
+    uint16_t verMajor =
+      LittleEndian::readUint16(aPacket->packet + SKELETON_VERSION_MAJOR_OFFSET);
+    uint16_t verMinor =
+      LittleEndian::readUint16(aPacket->packet + SKELETON_VERSION_MINOR_OFFSET);
+
+    // Read the presentation time. We read this before the version check as the
+    // presentation time exists in all versions.
+    int64_t n =
+      LittleEndian::readInt64(aPacket->packet + SKELETON_PRESENTATION_TIME_NUMERATOR_OFFSET);
+    int64_t d =
+      LittleEndian::readInt64(aPacket->packet + SKELETON_PRESENTATION_TIME_DENOMINATOR_OFFSET);
+    mPresentationTime =
+      d == 0 ? 0 : (static_cast<float>(n) / static_cast<float>(d)) * USECS_PER_S;
+
+    mVersion = SKELETON_VERSION(verMajor, verMinor);
+    // We can only care to parse Skeleton version 4.0+.
+    if (mVersion < SKELETON_VERSION(4,0) ||
+        mVersion >= SKELETON_VERSION(5,0) ||
+        aPacket->bytes < SKELETON_4_0_MIN_HEADER_LEN) {
+      return false;
+    }
+
+    // Extract the segment length.
+    mLength =
+      LittleEndian::readInt64(aPacket->packet + SKELETON_FILE_LENGTH_OFFSET);
+
+    LOG(LogLevel::Debug, ("Skeleton segment length: %lld", mLength));
+
+    // Initialize the serialno-to-index map.
+    return true;
+  } else if (IsSkeletonIndex(aPacket) && mVersion >= SKELETON_VERSION(4,0)) {
+    return DecodeIndex(aPacket);
+  } else if (IsSkeletonFisbone(aPacket)) {
+    return DecodeFisbone(aPacket);
+  } else if (aPacket->e_o_s) {
+    mDoneReadingHeaders = true;
+    return true;
+  }
+  return true;
+}
+
+} // namespace mozilla
+