コード例 #1
0
 private bool IsCorrectHeader(Packet headerPacket, byte headerType)
 {
     byte[] header = Read(headerPacket.FileOffset, VorbisHeaderInfo.PacketHeaderSize);
     if (header[VorbisHeaderInfo.HeaderTypeIndex] != headerType)
         return false;
     string magicSeq = Encoding.ASCII.GetString(header, VorbisHeaderInfo.MagicSeqIndex, VorbisHeaderInfo.MagicSeqSize);
     if (magicSeq != VorbisHeaderInfo.MagicSeq)
         return false;
     return true;
 }
コード例 #2
0
        private bool IsVorbisStream(Packet idHeader, Packet commentHeader, Packet setupHeader)
        {
            if (idHeader.Size < VorbisHeaderInfo.PacketHeaderSize)
                return false;
            if (commentHeader.Size < VorbisHeaderInfo.PacketHeaderSize)
                return false;
            if (setupHeader.Size < VorbisHeaderInfo.PacketHeaderSize)
                return false;

            return IsCorrectHeader(idHeader, VorbisHeaderInfo.IdHeaderType) &&
                   IsCorrectHeader(commentHeader, VorbisHeaderInfo.CommentHeaderType) &&
                   IsCorrectHeader(setupHeader, VorbisHeaderInfo.SetupHeaderType);
        }
コード例 #3
0
ファイル: PacketReader.cs プロジェクト: paszczi/MLabs.Ogg
        public IEnumerable<Packet> ReadPackets(IEnumerable<Page> pages)
        {
            if (pages == null) throw new ArgumentNullException("pages");

            long fileOffset = 0;
            int size = 0;
            int firstPage = 0;
            int pageIndex = 0;
            int numberOfSegments = 0;
            bool hasPacket = false;

            foreach (var page in pages)
            {
                //if the previous page had unfinished packet, this page must be marked as continuation
                if (hasPacket && page.PageType != PageType.Continuation)
                        throw new InvalidStreamException("Packet didn't finish on previous page, but next page is not marked as Continuation");
                
                foreach (var segment in page.Segments)
                {
                    //start new packet
                    if (!hasPacket)
                    {
                        fileOffset = segment.FileOffset;
                        firstPage = pageIndex;
                        hasPacket = true;
                    }
                    numberOfSegments++;
                    size += segment.Size;

                    //packet spans across several segments
                    if (segment.Size == ExtendedSegmentSize) continue;

                    Packet p = new Packet(fileOffset, size, firstPage, numberOfSegments);
                    yield return p;

                    //reset values
                    size = 0;
                    fileOffset = 0;
                    hasPacket = false;
                    numberOfSegments = 0;
                }
                pageIndex++;
            }
            yield break;
        }
コード例 #4
0
 private void ParseCommentHeader(VorbisStream vorbis, Packet packet)
 {
     FileStream.Seek(packet.FileOffset + VorbisHeaderInfo.VendorLengthIndex, SeekOrigin.Begin);
     uint vendorLength = BitConverter.ToUInt32(ReadNoSeek(4), 0);
     var vendorString = Encoding.UTF8.GetString(ReadNoSeek((int) vendorLength), 0, (int) vendorLength);
     
     uint userCommentListLength = BitConverter.ToUInt32(ReadNoSeek(4), 0);
     IList<string> userComments = new List<string>((int) userCommentListLength);
     for (uint i = 0; i < userCommentListLength; i++)
     {
         uint length = BitConverter.ToUInt32(ReadNoSeek(4), 0);
         string userComment = Encoding.UTF8.GetString(ReadNoSeek((int) length), 0, (int) length);
         userComments.Add(userComment);
     }
     bool framingFlag = BitConverter.ToBoolean(ReadNoSeek(1), 0);
     if (!framingFlag)
         throw new InvalidStreamException("Framing flag at the end of the comment header is not set");
     vorbis.Comments = new VorbisComments(vendorString, userComments);
 }
コード例 #5
0
        private void ParseIdHeder(VorbisStream vorbisStream, Packet idHeader)
        {
            byte[] identificationHeader = Read(idHeader.FileOffset, idHeader.Size);
            byte version = identificationHeader[VorbisHeaderInfo.VersionIndex];
            byte audioChannels = identificationHeader[VorbisHeaderInfo.AudioChannelsIndex];
            uint audioSampleRate = BitConverter.ToUInt32(identificationHeader, VorbisHeaderInfo.AudioSampleRateIndex);
            int maxBitrate = BitConverter.ToInt32(identificationHeader, VorbisHeaderInfo.MaximumBitrateIndex);
            int nominalBitrate = BitConverter.ToInt32(identificationHeader, VorbisHeaderInfo.NominalBitrateIndex);
            int minBitrate = BitConverter.ToInt32(identificationHeader, VorbisHeaderInfo.MinimumBitrateIndex);
            uint blockSize0 = (uint) Math.Pow(2, (identificationHeader[VorbisHeaderInfo.BlockSizeIndex] & VorbisHeaderInfo.BlockSize0Mask));
            uint blockSize1 = (uint) Math.Pow(2, identificationHeader[VorbisHeaderInfo.BlockSizeIndex] >> 4);
            byte framingFlag = identificationHeader[VorbisHeaderInfo.FramingFlagIndex];

            vorbisStream.Version = version;
            vorbisStream.AudioChannels = audioChannels;
            vorbisStream.SampleRate = audioSampleRate;
            vorbisStream.BlockSize0 = blockSize0;
            vorbisStream.BlockSize1 = blockSize1;
            vorbisStream.FramingFlag = framingFlag;
            vorbisStream.MaxBitrate = maxBitrate;
            vorbisStream.MinBitrate = minBitrate;
            vorbisStream.NominalBitrate = nominalBitrate;
        }