コード例 #1
0
        private unsafe List <FlacFrameInformation> ScanThisShit(FlacMetadataStreamInfo streamInfo)
        {
            Stream stream = _stream;

            //if (!(stream is BufferedStream))
            //    stream = new BufferedStream(stream);

            byte[] buffer = new byte[BufferSize];
            stream.Position = 4; //fLaC

            //skip the metadata
            FlacMetadata.SkipMetadata(stream);

            List <FlacFrameInformation> frames    = new List <FlacFrameInformation>();
            FlacFrameInformation        frameInfo = new FlacFrameInformation();

            frameInfo.IsFirstFrame = true;

            FlacFrameHeader baseHeader = null;

            while (true)
            {
                int read = stream.Read(buffer, 0, buffer.Length);
                if (read <= FlacConstant.FrameHeaderSize)
                    break;

                fixed(byte *bufferPtr = buffer)
                {
                    byte *ptr = bufferPtr;

                    //for (int i = 0; i < read - FlacConstant.FrameHeaderSize; i++)
                    while ((bufferPtr + read - FlacConstant.FrameHeaderSize) > ptr)
                    {
                        if (*ptr++ == 0xFF && (*ptr & 0xF8) == 0xF8) //check sync
                        {
                            byte *ptrSafe = ptr;
                            ptr--;
                            FlacFrameHeader tmp;
                            if (IsFrame(ref ptr, streamInfo, out tmp))
                            {
                                FlacFrameHeader header = tmp;
                                if (frameInfo.IsFirstFrame)
                                {
                                    baseHeader             = header;
                                    frameInfo.IsFirstFrame = false;
                                }

                                if (baseHeader != null && baseHeader.IsFormatEqualTo(header))
                                {
                                    frameInfo.StreamOffset = stream.Position - read + ((ptrSafe - 1) - bufferPtr);
                                    frameInfo.Header       = header;
                                    frames.Add(frameInfo);

                                    frameInfo.SampleOffset += header.BlockSize;
                                }
                                else
                                {
                                    ptr = ptrSafe;
                                }
                            }
                            else
                            {
                                ptr = ptrSafe;
                            }
                        }
                    }
                }

                stream.Position -= FlacConstant.FrameHeaderSize;
            }

            return(frames);
        }