Beispiel #1
0
        /// <summary>
        /// 获取标签帧长度
        /// </summary>
        /// <returns></returns>
        private void GetTAGFrameLength()
        {
            //必须为"ID3"否则认为标签不存在
            byte[] mp3Header = MP3Buffer.GetRange(0, 3).ToArray();

            //MP3Stream.Read(mp3Header, 0, mp3Header.Length);

            if (Encoding.ASCII.GetString(mp3Header) != "ID3")
            {
                throw new NotImplementedException("暂只能识别ID3的MP3音频");
            }
            //版本号 ID3V2.3 就记录 3
            byte ver = MP3Buffer[3];
            //副版本号此版本记录为
            byte Revision = MP3Buffer[4];
            //存放标志的字节,这个版本只定义了三位
            byte flag = MP3Buffer[5];

            //标签大小,包括标签头的 10 个字节和所有的标签帧的大小
            byte[] size = MP3Buffer.GetRange(6, 4).ToArray();
            //MP3Stream.Read(size, 0, size.Length);

            MP3Buffer.RemoveRange(0, 10);

            TAGFrameLength = (size[0] & 0x7F) * 0x200000 + (size[1] & 0x7F) * 0x400 + (size[2] & 0x7F) * 0x80
                             + (size[3] & 0x7F);
        }
Beispiel #2
0
        /// <summary>
        /// 获取标签帧
        /// </summary>
        /// <returns></returns>
        public byte[] GetTAGFrame()
        {
            GetTAGFrameLength();

            byte[] frameBuffer = MP3Buffer.GetRange(0, TAGFrameLength).ToArray();
            MP3Buffer.RemoveRange(0, TAGFrameLength);
            //MP3Stream.Read(frameBuffer, 0, frameBuffer.Length);
            return(frameBuffer);
        }
Beispiel #3
0
        /// <summary>
        /// 获取数据帧长度
        /// </summary>
        /// <returns></returns>
        private int GetAuidoFrameLength(out double playTime)
        {
            playTime = 0;

            byte[] headerBuffer = MP3Buffer.GetRange(0, 4).ToArray();
            //MP3Stream.Read(headerBuffer, 0, headerBuffer.Length);
            ////读取位置回到ff fb
            //MP3Stream.Position = MP3Stream.Position - 4;

            if (headerBuffer[0] != 0xFF)
            {
                Console.WriteLine("没有读取到FF头");

                return(0);
            }

            MP3AudioFrameHeader header = new MP3AudioFrameHeader(headerBuffer);

            int length = 0;
            //每帧采样数
            int frameCount = FrameCountDictionary[header.Version][header.Layer];
            //比特率
            int kbps = KBPSDictionary[header.Version][header.Layer][header.BitrateIndex];
            //采样率
            double khz = KHZDictionary[header.Version][header.SamplingFrequency];

            switch (header.Layer)
            {
            //11 -> Layer 1, L1
            case "11":
                break;

            //10 -> Layer 2, L2
            //01 -> Layer 3, L3
            case "10":
            case "01":
                length   = (int)Math.Floor(((frameCount / 8 * kbps) / khz)) + (header.Padding == "0" ? 0 : 1);
                playTime = frameCount / khz;
                break;

            default:
                break;
            }

            return(length);
        }
Beispiel #4
0
        public byte[] GetAudioFrame(out double playTime)
        {
            playTime = 0;
            if (MP3Buffer.Count == 0)
            {
                return(new byte[0]);
            }
            int audioFrameLength = GetAuidoFrameLength(out playTime);

            if (audioFrameLength == 0)
            {
                return(new byte[0]);
            }
            byte[] audioBuffer = MP3Buffer.GetRange(0, audioFrameLength).ToArray();

            //MP3Stream.Read(audioBuffer, 0, audioFrameLength);
            MP3Buffer.RemoveRange(0, audioFrameLength);
            return(audioBuffer);
        }