CSharpRTMP.Core.Streaming.MP3Document.BuildFrames C# (CSharp) Метод

        protected override bool BuildFrames()
        {
            //1. Build the map with frame sizes
            InitFrameSizes();

            //2. Go to the beginning of the file
            if (!MediaFile.SeekBegin())
            {
                Logger.FATAL("Unable to seek in file");
                return false;
            }

            if (!ParseMetadata())
            {
                Logger.WARN("Invalid metadata");
                if (!FindFrameData())
                {
                    Logger.FATAL("Unable to position on frame data");
                    return false;
                }
            }

            var firstBytes = new byte[4];

            double totalDuration = 0;
            var frame = new MediaFrame
            {
                Type = MediaFrameType.Audio,
                IsKeyFrame = true,
                DeltaTime = 0,
                IsBinaryHeader = false
            };

            while (MediaFile.Position < MediaFile.Length)
            {
                //3. Read the first 4 bytes
                if (!MediaFile.ReadBuffer(firstBytes, 4))
                {
                    Logger.FATAL("Unable to read 4 byte");
                    return false;
                }

                if ((firstBytes[0] == 0xff) &&
                        ((firstBytes[1] >> 5) == 7))
                {
                    //4. Possible frame. Read the header
                    byte version = (byte)((firstBytes[1] >> 3) & 0x03);
                    byte layer = (byte)((firstBytes[1] >> 1) & 0x03);
                    byte bitRateIndex = (byte)(firstBytes[2] >> 4);
                    byte sampleRateIndex = (byte)((firstBytes[2] >> 2) & 0x03);
                    byte paddingBit = (byte)((firstBytes[2] >> 1) & 0x01);

                    //5. get the freame length
                    frame.Start = (uint)(MediaFile.Position - 4);
                    frame.Length = _frameSizes[version,layer,bitRateIndex,sampleRateIndex,paddingBit];
                    if (frame.Length == 0)
                    {
                        Logger.FATAL("Invalid frame length: {0}:{1}:{2}:{3}:{4}; Cusror: {5}",
                                version, layer, bitRateIndex, sampleRateIndex,
                                paddingBit, MediaFile.Position);
                        return false;
                    }

                    //6. Compute the frame duration and save the frame start
                    var samplesCount = layer == LAYER_1 ? 384 : 1152;
                    frame.AbsoluteTime = (uint) (totalDuration * 1000);
                    totalDuration += samplesCount /
                            (double)(_samplingRates[version, sampleRateIndex]);

                    //7. Seek to the next frame
                    if (!MediaFile.SeekTo((long)(frame.Start + frame.Length)))
                    {
                        Logger.WARN("Unable to seek to {0}", frame.Start + frame.Length);
                        break;
                    }

                    //8. All good. Save the frame
                    _frames.Add(frame);
                }
                else
                {
                    break;
                }
            }


            return true;
        }