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-rw-r--r--dom/media/ogg/OpusParser.cpp217
1 files changed, 217 insertions, 0 deletions
diff --git a/dom/media/ogg/OpusParser.cpp b/dom/media/ogg/OpusParser.cpp
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+/* -*- 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 "mozilla/EndianUtils.h"
+
+#include "OpusParser.h"
+#include "VideoUtils.h"
+
+#include "opus/opus.h"
+extern "C" {
+#include "opus/opus_multistream.h"
+}
+
+#include <cmath>
+
+namespace mozilla {
+
+extern LazyLogModule gMediaDecoderLog;
+#define OPUS_LOG(type, msg) MOZ_LOG(gMediaDecoderLog, type, msg)
+
+OpusParser::OpusParser()
+ : mRate(0),
+ mNominalRate(0),
+ mChannels(0),
+ mPreSkip(0),
+#ifdef MOZ_SAMPLE_TYPE_FLOAT32
+ mGain(1.0f),
+#else
+ mGain_Q16(65536),
+#endif
+ mChannelMapping(0),
+ mStreams(0),
+ mCoupledStreams(0),
+ mPrevPacketGranulepos(0) {
+}
+
+bool OpusParser::DecodeHeader(unsigned char* aData, size_t aLength) {
+ if (aLength < 19 || memcmp(aData, "OpusHead", 8)) {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: unrecognized header"));
+ return false;
+ }
+
+ mRate = 48000; // The Opus decoder runs at 48 kHz regardless.
+
+ int version = aData[8];
+ // Accept file format versions 0.x.
+ if ((version & 0xf0) != 0) {
+ OPUS_LOG(LogLevel::Debug,
+ ("Rejecting unknown Opus file version %d", version));
+ return false;
+ }
+
+ mChannels = aData[9];
+ if (mChannels < 1) {
+ OPUS_LOG(LogLevel::Debug,
+ ("Invalid Opus file: Number of channels %d", mChannels));
+ return false;
+ }
+
+ mPreSkip = LittleEndian::readUint16(aData + 10);
+ mNominalRate = LittleEndian::readUint32(aData + 12);
+ double gain_dB = LittleEndian::readInt16(aData + 16) / 256.0;
+#ifdef MOZ_SAMPLE_TYPE_FLOAT32
+ mGain = static_cast<float>(pow(10, 0.05 * gain_dB));
+#else
+ mGain_Q16 = static_cast<int32_t>(std::min(
+ 65536 * pow(10, 0.05 * gain_dB) + 0.5, static_cast<double>(INT32_MAX)));
+#endif
+ mChannelMapping = aData[18];
+
+ if (mChannelMapping == 0) {
+ // Mapping family 0 only allows two channels
+ if (mChannels > 2) {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: too many channels (%d) for"
+ " mapping family 0.",
+ mChannels));
+ return false;
+ }
+ mStreams = 1;
+ mCoupledStreams = mChannels - 1;
+ mMappingTable[0] = 0;
+ mMappingTable[1] = 1;
+ } else if (mChannelMapping == 1 || mChannelMapping == 2 ||
+ mChannelMapping == 255) {
+ // Currently only up to 8 channels are defined for mapping family 1
+ if (mChannelMapping == 1 && mChannels > 8) {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: too many channels (%d) for"
+ " mapping family 1.",
+ mChannels));
+ return false;
+ }
+ if (mChannelMapping == 2) {
+ if (!IsValidMapping2ChannelsCount(mChannels)) {
+ return false;
+ }
+ }
+ if (aLength > static_cast<unsigned>(20 + mChannels)) {
+ mStreams = aData[19];
+ mCoupledStreams = aData[20];
+ int i;
+ for (i = 0; i < mChannels; i++) {
+ mMappingTable[i] = aData[21 + i];
+ }
+ } else {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: channel mapping %d,"
+ " but no channel mapping table",
+ mChannelMapping));
+ return false;
+ }
+ } else {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: unsupported channel mapping "
+ "family %d",
+ mChannelMapping));
+ return false;
+ }
+ if (mStreams < 1) {
+ OPUS_LOG(LogLevel::Debug, ("Invalid Opus file: no streams"));
+ return false;
+ }
+ if (mCoupledStreams > mStreams) {
+ OPUS_LOG(LogLevel::Debug,
+ ("Invalid Opus file: more coupled streams (%d) than "
+ "total streams (%d)",
+ mCoupledStreams, mStreams));
+ return false;
+ }
+
+#ifdef DEBUG
+ OPUS_LOG(LogLevel::Debug, ("Opus stream header:"));
+ OPUS_LOG(LogLevel::Debug, (" channels: %d", mChannels));
+ OPUS_LOG(LogLevel::Debug, (" preskip: %d", mPreSkip));
+ OPUS_LOG(LogLevel::Debug, (" original: %d Hz", mNominalRate));
+ OPUS_LOG(LogLevel::Debug, (" gain: %.2f dB", gain_dB));
+ OPUS_LOG(LogLevel::Debug, ("Channel Mapping:"));
+ OPUS_LOG(LogLevel::Debug, (" family: %d", mChannelMapping));
+ OPUS_LOG(LogLevel::Debug, (" streams: %d", mStreams));
+#endif
+ return true;
+}
+
+bool OpusParser::DecodeTags(unsigned char* aData, size_t aLength) {
+ if (aLength < 16 || memcmp(aData, "OpusTags", 8)) return false;
+
+ // Copy out the raw comment lines, but only do basic validation
+ // checks against the string packing: too little data, too many
+ // comments, or comments that are too long. Rejecting these cases
+ // helps reduce the propagation of broken files.
+ // We do not ensure they are valid UTF-8 here, nor do we validate
+ // the required ASCII_TAG=value format of the user comments.
+ const unsigned char* buf = aData + 8;
+ uint32_t bytes = aLength - 8;
+ uint32_t len;
+ // Read the vendor string.
+ len = LittleEndian::readUint32(buf);
+ buf += 4;
+ bytes -= 4;
+ if (len > bytes) return false;
+ mVendorString = nsCString(reinterpret_cast<const char*>(buf), len);
+ buf += len;
+ bytes -= len;
+ // Read the user comments.
+ if (bytes < 4) return false;
+ uint32_t ncomments = LittleEndian::readUint32(buf);
+ buf += 4;
+ bytes -= 4;
+ // If there are so many comments even their length fields
+ // won't fit in the packet, stop reading now.
+ if (ncomments > (bytes >> 2)) return false;
+ for (uint32_t i = 0; i < ncomments; i++) {
+ if (bytes < 4) return false;
+ len = LittleEndian::readUint32(buf);
+ buf += 4;
+ bytes -= 4;
+ if (len > bytes) return false;
+ mTags.AppendElement(nsCString(reinterpret_cast<const char*>(buf), len));
+ buf += len;
+ bytes -= len;
+ }
+
+#ifdef DEBUG
+ OPUS_LOG(LogLevel::Debug, ("Opus metadata header:"));
+ OPUS_LOG(LogLevel::Debug, (" vendor: %s", mVendorString.get()));
+ for (uint32_t i = 0; i < mTags.Length(); i++) {
+ OPUS_LOG(LogLevel::Debug, (" %s", mTags[i].get()));
+ }
+#endif
+ return true;
+}
+
+/* static */
+bool OpusParser::IsValidMapping2ChannelsCount(uint8_t aChannels) {
+ // https://tools.ietf.org/html/draft-ietf-codec-ambisonics-08#page-4
+ // For both channel mapping family 2 and family 3, the allowed numbers
+ // of channels: (1 + n)^2 + 2j for n = 0, 1, ..., 14 and j = 0 or 1,
+ // where n denotes the (highest) ambisonic order and j denotes whether
+ // or not there is a separate non-diegetic stereo stream Explicitly the
+ // allowed number of channels are 1, 3, 4, 6, 9, 11, 16, 18, 25, 27, 36,
+ // 38, 49, 51, 64, 66, 81, 83, 100, 102, 121, 123, 144, 146, 169, 171,
+ // 196, 198, 225, and 227.
+
+ // We use the property that int(sqrt(n)) == int(sqrt(n+2)) for n != 3
+ // which is handled by the test n^2 + 2 != channel
+ if (aChannels < 1 || aChannels > 227) {
+ return false;
+ }
+ double val = sqrt(aChannels);
+ int32_t valInt = int32_t(val);
+ return val == valInt || valInt * valInt + 2 == aChannels;
+}
+
+#undef OPUS_LOG
+
+} // namespace mozilla
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