summaryrefslogtreecommitdiffstats
path: root/dom
diff options
context:
space:
mode:
authortrav90 <travawine@palemoon.org>2018-12-08 16:28:34 -0600
committertrav90 <travawine@palemoon.org>2018-12-08 16:28:34 -0600
commiteb6fdca18bc8858bd5e85a0c2543985d01cf78e6 (patch)
tree6af444672716b49f4bbf3142cadc96381b5ce4e2 /dom
parent09cf173394adb294dd81362745b66f618968517b (diff)
downloadUXP-eb6fdca18bc8858bd5e85a0c2543985d01cf78e6.tar
UXP-eb6fdca18bc8858bd5e85a0c2543985d01cf78e6.tar.gz
UXP-eb6fdca18bc8858bd5e85a0c2543985d01cf78e6.tar.lz
UXP-eb6fdca18bc8858bd5e85a0c2543985d01cf78e6.tar.xz
UXP-eb6fdca18bc8858bd5e85a0c2543985d01cf78e6.zip
Remove the old MP3FrameParser
All former users of the old MP3 parsing code are gone, so we can now just remove the parser itself as well.
Diffstat (limited to 'dom')
-rw-r--r--dom/media/MP3FrameParser.cpp591
-rw-r--r--dom/media/MP3FrameParser.h219
-rw-r--r--dom/media/moz.build2
3 files changed, 0 insertions, 812 deletions
diff --git a/dom/media/MP3FrameParser.cpp b/dom/media/MP3FrameParser.cpp
deleted file mode 100644
index 242e3df00..000000000
--- a/dom/media/MP3FrameParser.cpp
+++ /dev/null
@@ -1,591 +0,0 @@
-/* -*- 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
diff --git a/dom/media/MP3FrameParser.h b/dom/media/MP3FrameParser.h
deleted file mode 100644
index d2ba791fd..000000000
--- a/dom/media/MP3FrameParser.h
+++ /dev/null
@@ -1,219 +0,0 @@
-/* -*- 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/. */
-
-#ifndef MP3FrameParser_h
-#define MP3FrameParser_h
-
-#include <stdint.h>
-
-#include "mozilla/Mutex.h"
-#include "nsString.h"
-#include "Intervals.h"
-
-namespace mozilla {
-
-// Simple parser to tell whether we've found an ID3 header and how long it is,
-// so that we can skip it.
-// XXX maybe actually parse this stuff?
-class ID3Parser
-{
-public:
- ID3Parser();
-
- void Reset();
- bool ParseChar(char ch);
- bool IsParsed() const;
- uint32_t GetHeaderLength() const;
-
-private:
- uint32_t mCurrentChar;
- uint8_t mVersion;
- uint8_t mFlags;
- uint32_t mHeaderLength;
-};
-
-struct MP3Frame {
- uint16_t mSync1 : 8; // Always all set
- uint16_t mProtected : 1; // Ignored
- uint16_t mLayer : 2;
- uint16_t mVersion : 2;
- uint16_t mSync2 : 3; // Always all set
- uint16_t mPrivate : 1; // Ignored
- uint16_t mPad : 1;
- uint16_t mSampleRate : 2; // Index into mpeg_srates above
- uint16_t mBitrate : 4; // Index into mpeg_bitrates above
-
- uint16_t CalculateLength();
-};
-
-// Buffering parser for MP3 frames.
-class MP3Parser
-{
-public:
- MP3Parser();
-
- // Forget all data the parser has seen so far.
- void Reset();
-
- // Parse the given byte. If we have found a frame header, return the length of
- // the frame.
- uint16_t ParseFrameLength(uint8_t ch);
-
- // Get the sample rate from the current header.
- uint32_t GetSampleRate();
-
- // Get the number of samples per frame.
- uint32_t GetSamplesPerFrame();
-
-private:
- uint32_t mCurrentChar;
- union {
- uint8_t mRaw[3];
- MP3Frame mFrame;
- } mData;
-};
-
-
-// A description of the MP3 format and its extensions is available at
-//
-// http://www.codeproject.com/Articles/8295/MPEG-Audio-Frame-Header
-//
-// The data in MP3 streams is split into small frames, with each frame
-// containing a fixed number of samples. The duration of a frame depends
-// on the frame's bit rate and sample rate. Both values can vary among
-// frames, so it is necessary to examine each individual frame of an MP3
-// stream to calculate the stream's overall duration.
-//
-// The MP3 frame parser extracts information from an MP3 data stream. It
-// accepts a range of frames of an MP3 stream as input, and parses all
-// frames for their duration. Callers can query the stream's overall
-// duration from the parser.
-//
-// Call the methods NotifyDataArrived or Parse to add new data. If you added
-// information for a certain stream position, you cannot go back to previous
-// positions. The parser will simply ignore the input. If you skip stream
-// positions, the duration of the related MP3 frames will be estimated from
-// the stream's average.
-//
-// The method GetDuration returns calculated duration of the stream, including
-// estimates for skipped ranges.
-//
-// All public methods are thread-safe.
-
-class MP3FrameParser
-{
-public:
- explicit MP3FrameParser(int64_t aLength=-1);
-
- bool IsMP3() {
- MutexAutoLock mon(mLock);
- return mIsMP3 != NOT_MP3;
- }
-
- void Parse(const uint8_t* aBuffer, uint32_t aLength, uint64_t aStreamOffset);
-
- // Returns the duration, in microseconds. If the entire stream has not
- // been parsed yet, this is an estimate based on the bitrate of the
- // frames parsed so far.
- int64_t GetDuration();
-
- // Returns the offset of the first MP3 frame in the stream, or -1 of
- // no MP3 frame has been detected yet.
- int64_t GetMP3Offset();
-
- // Returns true if we've seen the whole first frame of the MP3 stream, and
- // therefore can make an estimate on the stream duration.
- // Otherwise, returns false.
- bool ParsedHeaders();
-
- // Returns true if we know the exact duration of the MP3 stream;
- // false otherwise.
- bool HasExactDuration();
-
- // Returns true if the parser needs more data for duration estimation.
- bool NeedsData();
- // Assign the total lenght of this mp3 stream
- void SetLength(int64_t aLength) {
- MutexAutoLock mon(mLock);
- mLength = aLength;
- }
-private:
-
- // Parses aBuffer, starting at offset 0. Returns the number of bytes
- // parsed, relative to the start of the buffer. Note this may be
- // greater than aLength if the headers in the buffer indicate that
- // the frame or ID3 tag extends outside of aBuffer. Returns failure
- // if too many non-MP3 bytes are parsed.
- nsresult ParseBuffer(const uint8_t* aBuffer,
- uint32_t aLength,
- int64_t aStreamOffset,
- uint32_t* aOutBytesRead);
-
- // A low-contention lock for protecting the parser results
- Mutex mLock;
-
- // ID3 header parser. Keeps state between reads in case the header falls
- // in between.
- ID3Parser mID3Parser;
-
- // MP3 frame header parser.
- MP3Parser mMP3Parser;
-
- // If we read |MAX_SKIPPED_BYTES| from the stream without finding any MP3
- // frames, we give up and report |NOT_MP3|. Here we track the cumulative size
- // of any ID3 headers we've seen so big ID3 sections aren't counted towards
- // skipped bytes.
- uint32_t mTotalID3Size;
-
- // All fields below are protected by mLock
-
- // We keep stats on the size of all the frames we've seen, as well as how many
- // so that we can estimate the duration of the rest of the stream.
- uint64_t mTotalFrameSize;
- uint64_t mFrameCount;
-
- // Offset of the last data parsed. This is the end offset of the last data
- // block parsed, so it's the start offset we expect to get on the next
- // call to Parse().
- uint64_t mOffset;
-
- // Total length of the stream in bytes.
- int64_t mLength;
-
- // Offset of first MP3 frame in the bitstream. Has value -1 until the
- // first MP3 frame is found.
- int64_t mMP3Offset;
-
- // The exact number of frames in this stream, if we know it. -1 otherwise.
- int64_t mNumFrames;
-
- // Number of audio samples per second and per frame. Fixed through the whole
- // file. If we know these variables as well as the number of frames in the
- // file, we can get an exact duration for the stream.
- uint16_t mSamplesPerSecond;
- uint16_t mSamplesPerFrame;
-
- // If the MP3 has a variable bitrate, then there *should* be metadata about
- // the encoding in the first frame. We buffer the first frame here.
- nsCString mFirstFrame;
-
- // While we are reading the first frame, this is the stream offset of the
- // last byte of that frame. -1 at all other times.
- int64_t mFirstFrameEnd;
-
- enum eIsMP3 {
- MAYBE_MP3, // We're giving the stream the benefit of the doubt...
- DEFINITELY_MP3, // We've hit at least one ID3 tag or MP3 frame.
- NOT_MP3 // Not found any evidence of the stream being MP3.
- };
-
- eIsMP3 mIsMP3;
-
-};
-
-} // namespace mozilla
-
-#endif
diff --git a/dom/media/moz.build b/dom/media/moz.build
index b3db05af1..772f27b35 100644
--- a/dom/media/moz.build
+++ b/dom/media/moz.build
@@ -127,7 +127,6 @@ EXPORTS += [
'MediaTrackList.h',
'MP3Decoder.h',
'MP3Demuxer.h',
- 'MP3FrameParser.h',
'NextFrameSeekTask.h',
'nsIDocumentActivity.h',
'PrincipalChangeObserver.h',
@@ -236,7 +235,6 @@ UNIFIED_SOURCES += [
'MediaTrackList.cpp',
'MP3Decoder.cpp',
'MP3Demuxer.cpp',
- 'MP3FrameParser.cpp',
'NextFrameSeekTask.cpp',
'QueueObject.cpp',
'SeekJob.cpp',