Add m-esr52 at 52.6.0

1 files changed, 591 insertions, 0 deletions

diff --git a/dom/media/MP3FrameParser.cpp b/dom/media/MP3FrameParser.cpp
new file mode 100644
index 000000000..242e3df00
--- /dev/null
+++ b/dom/media/MP3FrameParser.cpp
@@ -0,0 +1,591 @@
+/* -*- 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 <algorithm>
+
+#include "nsMemory.h"
+#include "MP3FrameParser.h"
+#include "VideoUtils.h"
+
+
+#define FROM_BIG_ENDIAN(X) ((uint32_t)((uint8_t)(X)[0] << 24 | (uint8_t)(X)[1] << 16 | \
+                                       (uint8_t)(X)[2] << 8 | (uint8_t)(X)[3]))
+
+
+namespace mozilla {
+
+/*
+ * Following code taken from http://www.hydrogenaudio.org/forums/index.php?showtopic=85125
+ * with permission from the author, Nick Wallette <sirnickity@gmail.com>.
+ */
+
+/* BEGIN shameless copy and paste */
+
+// Bitrates - use [version][layer][bitrate]
+const uint16_t mpeg_bitrates[4][4][16] = {
+  { // Version 2.5
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Reserved
+    { 0,   8,  16,  24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0 }, // Layer 3
+    { 0,   8,  16,  24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0 }, // Layer 2
+    { 0,  32,  48,  56,  64,  80,  96, 112, 128, 144, 160, 176, 192, 224, 256, 0 }  // Layer 1
+  },
+  { // Reserved
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Invalid
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Invalid
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Invalid
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }  // Invalid
+  },
+  { // Version 2
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Reserved
+    { 0,   8,  16,  24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0 }, // Layer 3
+    { 0,   8,  16,  24,  32,  40,  48,  56,  64,  80,  96, 112, 128, 144, 160, 0 }, // Layer 2
+    { 0,  32,  48,  56,  64,  80,  96, 112, 128, 144, 160, 176, 192, 224, 256, 0 }  // Layer 1
+  },
+  { // Version 1
+    { 0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0,   0, 0 }, // Reserved
+    { 0,  32,  40,  48,  56,  64,  80,  96, 112, 128, 160, 192, 224, 256, 320, 0 }, // Layer 3
+    { 0,  32,  48,  56,  64,  80,  96, 112, 128, 160, 192, 224, 256, 320, 384, 0 }, // Layer 2
+    { 0,  32,  64,  96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448, 0 }, // Layer 1
+  }
+};
+
+// Sample rates - use [version][srate]
+const uint16_t mpeg_srates[4][4] = {
+    { 11025, 12000,  8000, 0 }, // MPEG 2.5
+    {     0,     0,     0, 0 }, // Reserved
+    { 22050, 24000, 16000, 0 }, // MPEG 2
+    { 44100, 48000, 32000, 0 }  // MPEG 1
+};
+
+// Samples per frame - use [version][layer]
+const uint16_t mpeg_frame_samples[4][4] = {
+//    Rsvd     3     2     1  < Layer  v Version
+    {    0,  576, 1152,  384 }, //       2.5
+    {    0,    0,    0,    0 }, //       Reserved
+    {    0,  576, 1152,  384 }, //       2
+    {    0, 1152, 1152,  384 }  //       1
+};
+
+// Slot size (MPEG unit of measurement) - use [layer]
+const uint8_t mpeg_slot_size[4] = { 0, 1, 1, 4 }; // Rsvd, 3, 2, 1
+
+uint16_t
+MP3Frame::CalculateLength()
+{
+  // Lookup real values of these fields
+  uint32_t  bitrate   = mpeg_bitrates[mVersion][mLayer][mBitrate] * 1000;
+  uint32_t  samprate  = mpeg_srates[mVersion][mSampleRate];
+  uint16_t  samples   = mpeg_frame_samples[mVersion][mLayer];
+  uint8_t   slot_size = mpeg_slot_size[mLayer];
+
+  // In-between calculations
+  float     bps       = (float)samples / 8.0;
+  float     fsize     = ( (bps * (float)bitrate) / (float)samprate )
+    + ( (mPad) ? slot_size : 0 );
+
+  // Frame sizes are truncated integers
+  return (uint16_t)fsize;
+}
+
+/* END shameless copy and paste */
+
+
+/** MP3Parser methods **/
+
+MP3Parser::MP3Parser()
+  : mCurrentChar(0)
+{ }
+
+void
+MP3Parser::Reset()
+{
+  mCurrentChar = 0;
+}
+
+uint16_t
+MP3Parser::ParseFrameLength(uint8_t ch)
+{
+  mData.mRaw[mCurrentChar] = ch;
+
+  MP3Frame &frame = mData.mFrame;
+
+  // Validate MP3 header as we read. We can't mistake the start of an MP3 frame
+  // for the middle of another frame due to the sync byte at the beginning
+  // of the frame.
+
+  // The only valid position for an all-high byte is the sync byte at the
+  // beginning of the frame.
+  if (ch == 0xff) {
+    mCurrentChar = 0;
+  }
+
+  // Make sure the current byte is valid in context. If not, reset the parser.
+  if (mCurrentChar == 2) {
+    if (frame.mBitrate == 0x0f) {
+      goto fail;
+    }
+  } else if (mCurrentChar == 1) {
+    if (frame.mSync2 != 0x07
+        || frame.mVersion == 0x01
+        || frame.mLayer == 0x00) {
+      goto fail;
+    }
+  }
+
+  // The only valid character at the beginning of the header is 0xff. Fail if
+  // it's different.
+  if (mCurrentChar == 0 && frame.mSync1 != 0xff) {
+    // Couldn't find the sync byte. Fail.
+    return 0;
+  }
+
+  mCurrentChar++;
+  MOZ_ASSERT(mCurrentChar <= sizeof(MP3Frame));
+
+  // Don't have a full header yet.
+  if (mCurrentChar < sizeof(MP3Frame)) {
+    return 0;
+  }
+
+  // Woo, valid header. Return the length.
+  mCurrentChar = 0;
+  return frame.CalculateLength();
+
+fail:
+  Reset();
+  return 0;
+}
+
+uint32_t
+MP3Parser::GetSampleRate()
+{
+  MP3Frame &frame = mData.mFrame;
+  return mpeg_srates[frame.mVersion][frame.mSampleRate];
+}
+
+uint32_t
+MP3Parser::GetSamplesPerFrame()
+{
+  MP3Frame &frame = mData.mFrame;
+  return mpeg_frame_samples[frame.mVersion][frame.mLayer];
+}
+
+
+/** ID3Parser methods **/
+
+const char sID3Head[3] = { 'I', 'D', '3' };
+const uint32_t ID3_HEADER_LENGTH = 10;
+const uint32_t ID3_FOOTER_LENGTH = 10;
+const uint8_t ID3_FOOTER_PRESENT = 0x10;
+
+ID3Parser::ID3Parser()
+  : mCurrentChar(0)
+  , mVersion(0)
+  , mFlags(0)
+  , mHeaderLength(0)
+{ }
+
+void
+ID3Parser::Reset()
+{
+  mCurrentChar = mVersion = mFlags = mHeaderLength = 0;
+}
+
+bool
+ID3Parser::ParseChar(char ch)
+{
+  switch (mCurrentChar) {
+    // The first three bytes of an ID3v2 header must match the string "ID3".
+    case 0: case 1: case 2:
+      if (ch != sID3Head[mCurrentChar]) {
+        goto fail;
+      }
+      break;
+    // The fourth and fifth bytes give the version, between 2 and 4.
+    case 3:
+      if (ch < '\2' || ch > '\4') {
+        goto fail;
+      }
+      mVersion = uint8_t(ch);
+      break;
+    case 4:
+      if (ch != '\0') {
+        goto fail;
+      }
+      break;
+    // The sixth byte gives the flags; valid flags depend on the version.
+    case 5:
+      if ((ch & (0xff >> mVersion)) != '\0') {
+        goto fail;
+      }
+      mFlags = uint8_t(ch);
+      break;
+    // Bytes seven through ten give the sum of the byte length of the extended
+    // header, the padding and the frames after unsynchronisation.
+    // These bytes form a 28-bit integer, with the high bit of each byte unset.
+    case 6: case 7: case 8: case 9:
+      if (ch & 0x80) {
+        goto fail;
+      }
+      mHeaderLength <<= 7;
+      mHeaderLength |= ch;
+      if (mCurrentChar == 9) {
+        mHeaderLength += ID3_HEADER_LENGTH;
+        mHeaderLength += (mFlags & ID3_FOOTER_PRESENT) ? ID3_FOOTER_LENGTH : 0;
+      }
+      break;
+    default:
+      MOZ_CRASH("Header already fully parsed!");
+  }
+
+  mCurrentChar++;
+
+  return IsParsed();
+
+fail:
+  if (mCurrentChar) {
+    Reset();
+    return ParseChar(ch);
+  }
+  Reset();
+  return false;
+}
+
+bool
+ID3Parser::IsParsed() const
+{
+  return mCurrentChar >= ID3_HEADER_LENGTH;
+}
+
+uint32_t
+ID3Parser::GetHeaderLength() const
+{
+  MOZ_ASSERT(IsParsed(),
+             "Queried length of ID3 header before parsing finished.");
+  return mHeaderLength;
+}
+
+
+/** VBR header helper stuff **/
+
+// Helper function to find a VBR header in an MP3 frame.
+// Based on information from
+// http://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header
+
+const uint32_t VBRI_TAG = FROM_BIG_ENDIAN("VBRI");
+const uint32_t VBRI_OFFSET = 32 - sizeof(MP3Frame);
+const uint32_t VBRI_FRAME_COUNT_OFFSET = VBRI_OFFSET + 14;
+const uint32_t VBRI_MIN_FRAME_SIZE = VBRI_OFFSET + 26;
+
+const uint32_t XING_TAG = FROM_BIG_ENDIAN("Xing");
+enum XingFlags {
+  XING_HAS_NUM_FRAMES = 0x01,
+  XING_HAS_NUM_BYTES = 0x02,
+  XING_HAS_TOC = 0x04,
+  XING_HAS_VBR_SCALE = 0x08
+};
+
+static int64_t
+ParseXing(const char *aBuffer)
+{
+  uint32_t flags = FROM_BIG_ENDIAN(aBuffer + 4);
+
+  if (!(flags & XING_HAS_NUM_FRAMES)) {
+    NS_WARNING("VBR file without frame count. Duration estimation likely to "
+               "be totally wrong.");
+    return -1;
+  }
+
+  int64_t numFrames = -1;
+  if (flags & XING_HAS_NUM_FRAMES) {
+    numFrames = FROM_BIG_ENDIAN(aBuffer + 8);
+  }
+
+  return numFrames;
+}
+
+static int64_t
+FindNumVBRFrames(const nsCString& aFrame)
+{
+  const char *buffer = aFrame.get();
+  const char *bufferEnd = aFrame.get() + aFrame.Length();
+
+  // VBRI header is nice and well-defined; let's try to find that first.
+  if (aFrame.Length() > VBRI_MIN_FRAME_SIZE &&
+      FROM_BIG_ENDIAN(buffer + VBRI_OFFSET) == VBRI_TAG) {
+    return FROM_BIG_ENDIAN(buffer + VBRI_FRAME_COUNT_OFFSET);
+  }
+
+  // We have to search for the Xing header as its position can change.
+  for (; buffer + sizeof(XING_TAG) < bufferEnd; buffer++) {
+    if (FROM_BIG_ENDIAN(buffer) == XING_TAG) {
+      return ParseXing(buffer);
+    }
+  }
+
+  return -1;
+}
+
+
+/** MP3FrameParser methods **/
+
+// Some MP3's have large ID3v2 tags, up to 150KB, so we allow lots of
+// skipped bytes to be read, just in case, before we give up and assume
+// we're not parsing an MP3 stream.
+static const uint32_t MAX_SKIPPED_BYTES = 4096;
+
+enum {
+  MP3_HEADER_LENGTH   = 4,
+};
+
+MP3FrameParser::MP3FrameParser(int64_t aLength)
+: mLock("MP3FrameParser.mLock"),
+  mTotalID3Size(0),
+  mTotalFrameSize(0),
+  mFrameCount(0),
+  mOffset(0),
+  mLength(aLength),
+  mMP3Offset(-1),
+  mSamplesPerSecond(0),
+  mFirstFrameEnd(-1),
+  mIsMP3(MAYBE_MP3)
+{ }
+
+nsresult MP3FrameParser::ParseBuffer(const uint8_t* aBuffer,
+                                     uint32_t aLength,
+                                     int64_t aStreamOffset,
+                                     uint32_t* aOutBytesRead)
+{
+  // Iterate forwards over the buffer, looking for ID3 tag, or MP3
+  // Frame headers.
+  const uint8_t *buffer = aBuffer;
+  const uint8_t *bufferEnd = aBuffer + aLength;
+
+  // If we haven't found any MP3 frame data yet, there might be ID3 headers
+  // we can skip over.
+  if (mMP3Offset < 0) {
+    for (const uint8_t *ch = buffer; ch < bufferEnd; ch++) {
+      if (mID3Parser.ParseChar(*ch)) {
+        // Found an ID3 header. We don't care about the body of the header, so
+        // just skip past.
+        buffer = ch + mID3Parser.GetHeaderLength() - (ID3_HEADER_LENGTH - 1);
+
+        if (buffer <= ch) {
+          return NS_ERROR_FAILURE;
+        }
+
+        ch = buffer;
+
+        mTotalID3Size += mID3Parser.GetHeaderLength();
+
+        // Yes, this is an MP3!
+        mIsMP3 = DEFINITELY_MP3;
+
+        mID3Parser.Reset();
+      }
+    }
+  }
+
+  // The first MP3 frame in a variable bitrate stream can contain metadata
+  // for duration estimation and seeking, so we buffer that first frame here.
+  if (aStreamOffset < mFirstFrameEnd) {
+    uint64_t copyLen = std::min((int64_t)aLength, mFirstFrameEnd - aStreamOffset);
+    mFirstFrame.Append((const char *)buffer, copyLen);
+    buffer += copyLen;
+  }
+
+  while (buffer < bufferEnd) {
+    uint16_t frameLen = mMP3Parser.ParseFrameLength(*buffer);
+
+    if (frameLen) {
+      // We've found an MP3 frame!
+      // This is the first frame (and the only one we'll bother parsing), so:
+      // * Mark this stream as MP3;
+      // * Store the offset at which the MP3 data started; and
+      // * Start buffering the frame, as it might contain handy metadata.
+
+      // We're now sure this is an MP3 stream.
+      mIsMP3 = DEFINITELY_MP3;
+
+      // We need to know these to convert the number of frames in the stream
+      // to the length of the stream in seconds.
+      mSamplesPerSecond = mMP3Parser.GetSampleRate();
+      mSamplesPerFrame = mMP3Parser.GetSamplesPerFrame();
+
+      // If the stream has a constant bitrate, we should only need the length
+      // of the first frame and the length (in bytes) of the stream to
+      // estimate the length (in seconds).
+      mTotalFrameSize += frameLen;
+      mFrameCount++;
+
+      // If |mMP3Offset| isn't set then this is the first MP3 frame we have
+      // seen in the stream, which is useful for duration estimation.
+      if (mMP3Offset > -1) {
+        uint16_t skip = frameLen - sizeof(MP3Frame);
+        buffer += skip ? skip : 1;
+        continue;
+      }
+
+      // Remember the offset of the MP3 stream.
+      // We're at the last byte of an MP3Frame, so MP3 data started
+      // sizeof(MP3Frame) - 1 bytes ago.
+      mMP3Offset = aStreamOffset
+        + (buffer - aBuffer)
+        - (sizeof(MP3Frame) - 1);
+
+      buffer++;
+
+      // If the stream has a variable bitrate, the first frame has metadata
+      // we need for duration estimation and seeking. Start buffering it so we
+      // can parse it later.
+      mFirstFrameEnd = mMP3Offset + frameLen;
+      uint64_t currOffset = buffer - aBuffer + aStreamOffset;
+      uint64_t copyLen = std::min(mFirstFrameEnd - currOffset,
+                                  (uint64_t)(bufferEnd - buffer));
+      mFirstFrame.Append((const char *)buffer, copyLen);
+
+      buffer += copyLen;
+
+    } else {
+      // Nothing to see here. Move along.
+      buffer++;
+    }
+  }
+
+  *aOutBytesRead = buffer - aBuffer;
+
+  if (mFirstFrameEnd > -1 && mFirstFrameEnd <= aStreamOffset + buffer - aBuffer) {
+    // We have our whole first frame. Try to find a VBR header.
+    mNumFrames = FindNumVBRFrames(mFirstFrame);
+    mFirstFrameEnd = -1;
+  }
+
+  return NS_OK;
+}
+
+void MP3FrameParser::Parse(const uint8_t* aBuffer, uint32_t aLength, uint64_t aOffset)
+{
+  MutexAutoLock mon(mLock);
+
+  if (HasExactDuration()) {
+    // We know the duration; nothing to do here.
+    return;
+  }
+
+  const uint8_t* buffer = aBuffer;
+  int32_t length = aLength;
+  uint64_t offset = aOffset;
+
+  // Got some data we have seen already. Skip forward to what we need.
+  if (aOffset < mOffset) {
+    buffer += mOffset - aOffset;
+    length -= mOffset - aOffset;
+    offset = mOffset;
+
+    if (length <= 0) {
+      return;
+    }
+  }
+
+  // If there is a discontinuity in the input stream, reset the state of the
+  // parsers so we don't get any partial headers.
+  if (mOffset < aOffset) {
+    if (!mID3Parser.IsParsed()) {
+      // Only reset this if it hasn't finished yet.
+      mID3Parser.Reset();
+    }
+
+    if (mFirstFrameEnd > -1) {
+      NS_WARNING("Discontinuity in input while buffering first frame.");
+      mFirstFrameEnd = -1;
+    }
+
+    mMP3Parser.Reset();
+  }
+
+  uint32_t bytesRead = 0;
+  if (NS_FAILED(ParseBuffer(buffer,
+                            length,
+                            offset,
+                            &bytesRead))) {
+    return;
+  }
+
+  MOZ_ASSERT(length <= (int)bytesRead, "All bytes should have been consumed");
+
+  // Update next data offset
+  mOffset = offset + bytesRead;
+
+  // If we've parsed lots of data and we still have nothing, just give up.
+  // We don't count ID3 headers towards the skipped bytes count, as MP3 files
+  // can have massive ID3 sections.
+  if (!mID3Parser.IsParsed() && mMP3Offset < 0 &&
+      mOffset - mTotalID3Size > MAX_SKIPPED_BYTES) {
+    mIsMP3 = NOT_MP3;
+  }
+}
+
+int64_t MP3FrameParser::GetDuration()
+{
+  MutexAutoLock mon(mLock);
+
+  if (!ParsedHeaders() || !mSamplesPerSecond) {
+    // Not a single frame decoded yet.
+    return -1;
+  }
+
+  MOZ_ASSERT(mFrameCount > 0 && mTotalFrameSize > 0,
+             "Frame parser should have seen at least one MP3 frame of positive length.");
+
+  if (!mFrameCount || !mTotalFrameSize) {
+    // This should never happen.
+    return -1;
+  }
+
+  double frames;
+  if (mNumFrames < 0) {
+    // Estimate the number of frames in the stream based on the average frame
+    // size and the length of the MP3 file.
+    double frameSize = (double)mTotalFrameSize / mFrameCount;
+    frames = (double)(mLength - mMP3Offset) / frameSize;
+  } else {
+    // We know the exact number of frames from the VBR header.
+    frames = mNumFrames;
+  }
+
+  // The duration of each frame is constant over a given stream.
+  double usPerFrame = USECS_PER_S * mSamplesPerFrame / mSamplesPerSecond;
+
+  return frames * usPerFrame;
+}
+
+int64_t MP3FrameParser::GetMP3Offset()
+{
+  MutexAutoLock mon(mLock);
+  return mMP3Offset;
+}
+
+bool MP3FrameParser::ParsedHeaders()
+{
+  // We have seen both the beginning and the end of the first MP3 frame in the
+  // stream.
+  return mMP3Offset > -1 && mFirstFrameEnd < 0;
+}
+
+bool MP3FrameParser::HasExactDuration()
+{
+  return ParsedHeaders() && mNumFrames > -1;
+}
+
+bool MP3FrameParser::NeedsData()
+{
+  // If we don't know the duration exactly then either:
+  //  - we're still waiting for a VBR header; or
+  //  - we look at all frames to constantly update our duration estimate.
+  return IsMP3() && !HasExactDuration();
+}
+
+} // namespace mozilla