Here is the same thing only readable...
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Media.Rtp
{
public class JpegFrame : RtpFrame
{
#region Statics
static byte[] CreateStartOfInformation()
{
return new byte[] { 0xff, 0xd8 };
}
static byte[] CreateJFIFHeader(uint type, uint width, uint height, ArraySegment<byte> tables, uint dri)
{
List<byte> result = new List<byte>();
result.AddRange(CreateStartOfInformation());
result.Add(0xff);
result.Add(0xe0);
result.Add(0x00);
result.Add(0x10);
result.Add((byte)'J');
result.Add((byte)'F');
result.Add((byte)'I');
result.Add((byte)'F');
result.Add(0x00);
result.Add(0x01);
result.Add(0x01);
result.Add(0x00);
result.Add(0x00);
result.Add(0x01);
result.Add(0x00);
result.Add(0x01);
result.Add(0x00);
result.Add(0x00);
if (dri > 0)
{
result.AddRange(CreateDataRestartIntervalMarker(dri));
}
result.AddRange(CreateQuantizationTablesMarker(tables));
result.Add(0xff);
result.Add(0xc0);
result.Add(0x00);
result.Add(0x11);
result.Add(0x08);
result.Add((byte)(height >> 8));
result.Add((byte)height);
result.Add((byte)(width >> 8));
result.Add((byte)width);
result.Add(0x03);
result.Add(0x01);
result.Add((byte)(type > 0 ? 0x22 : 0x21));
result.Add(0x00);
result.Add(0x02);
result.Add(0x11);
result.Add(0x01);
result.Add(0x03);
result.Add(0x11);
result.Add(0x01);
result.AddRange(CreateHuffmanTableMarker(lum_dc_codelens, lum_dc_symbols, 0, 0));
result.AddRange(CreateHuffmanTableMarker(lum_ac_codelens, lum_ac_symbols, 0, 1));
result.AddRange(CreateHuffmanTableMarker(chm_dc_codelens, chm_dc_symbols, 1, 0));
result.AddRange(CreateHuffmanTableMarker(chm_ac_codelens, chm_ac_symbols, 1, 1));
result.Add(0xff);
result.Add(0xda);
result.Add(0x00);
result.Add(0x0c);
result.Add(0x03);
result.Add(0x01);
result.Add(0x00);
result.Add(0x02);
result.Add(0x11);
result.Add(0x03);
result.Add(0x11);
result.Add(0x00);
result.Add(0x3f);
result.Add(0x00);
return result.ToArray();
}
static byte[] defaultQuantizers = new byte[]
{
16, 11, 12, 14, 12, 10, 16, 14,
13, 14, 18, 17, 16, 19, 24, 40,
26, 24, 22, 22, 24, 49, 35, 37,
29, 40, 58, 51, 61, 60, 57, 51,
56, 55, 64, 72, 92, 78, 64, 68,
87, 69, 55, 56, 80, 109, 81, 87,
95, 98, 103, 104, 103, 62, 77, 113,
121, 112, 100, 120, 92, 101, 103, 99,
17, 18, 18, 24, 21, 24, 47, 26,
26, 47, 99, 66, 56, 66, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99,
99, 99, 99, 99, 99, 99, 99, 99
};
static byte[] CreateQuantizationTables(uint Q)
{
int factor = (int)Q;
int q;
if (Q < 1) factor = 1;
else if (Q > 99) factor = 99;
if (Q < 50)
{
q = 5000 / factor;
}
else
{
q = 200 - factor * 2;
}
byte[] resultTables = new byte[128];
for (int i = 0; i < 128; ++i)
{
int newVal = (defaultQuantizers[i] * q + 50) / 100;
if (newVal < 1) newVal = 1;
else if (newVal > 255) newVal = 255;
resultTables[i] = (byte)newVal;
}
return resultTables;
}
static byte[] CreateQuantizationTablesMarker(ArraySegment<byte> tables)
{
List<byte> result = new List<byte>();
int tableSize = tables.Count / 2;
result.Add(0xff);
result.Add(0xdb);
result.Add(0x00);
result.Add((byte)(tableSize + 3));
result.Add(0x00);
for (int i = 0, e = tableSize; i < e; ++i)
{
result.Add(tables.Array[tables.Offset + i]);
}
result.Add(0xff);
result.Add(0xdb);
result.Add(0x00);
result.Add((byte)(tableSize + 3));
result.Add(0x01);
for (int i = tableSize, e = tables.Count; i < e; ++i)
{
result.Add(tables.Array[tables.Offset + i]);
}
return result.ToArray();
}
static byte[] lum_dc_codelens = {
0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
};
static byte[] lum_dc_symbols = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
static byte[] lum_ac_codelens = {
0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d,
};
static byte[] lum_ac_symbols = {
0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12,
0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07,
0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08,
0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0,
0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16,
0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28,
0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98,
0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6,
0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5,
0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4,
0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2,
0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea,
0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa,
};
static byte[] chm_dc_codelens = {
0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
};
static byte[] chm_dc_symbols = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
};
static byte[] chm_ac_codelens = {
0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77,
};
static byte[] chm_ac_symbols = {
0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21,
0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71,
0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91,
0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0,
0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34,
0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26,
0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38,
0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48,
0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58,
0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68,
0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96,
0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5,
0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4,
0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3,
0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2,
0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda,
0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9,
0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8,
0xf9, 0xfa,
};
static byte[] CreateHuffmanTableMarker(byte[] codeLens, byte[] symbols, int tableNo, int tableClass)
{
List<byte> result = new List<byte>();
result.Add(0xff);
result.Add(0xc4);
result.Add(0x00);
result.Add((byte)(3 + codeLens.Length + symbols.Length));
result.Add((byte)((tableClass << 4) | tableNo));
result.AddRange(codeLens);
result.AddRange(symbols);
return result.ToArray();
}
static byte[] CreateDataRestartIntervalMarker(uint dri)
{
return new byte[] { 0xff, 0xdd, 0x00, 0x04, (byte)(dri >> 8), (byte)(dri) };
}
#endregion
internal System.IO.MemoryStream Buffer = new System.IO.MemoryStream();
internal System.Drawing.Image Image;
public JpegFrame() : base(26) { }
public JpegFrame(RtpFrame f) : base(f) { if (PayloadType != 26) throw new ArgumentException("Expected the payload type 26, Found type: " + f.PayloadType); }
internal void ProcessPackets()
{
ArraySegment<byte> tables = default(ArraySegment<byte>);
uint FragmentOffset, TypeSpecific, Type, Quality, Width, Height, DataRestartInterval = 0;
for (int i = 0, e = this.Packets.Count, last = e - 1; i < e; ++i)
{
int offset = 0;
RtpPacket packet = this.Packets[i];
TypeSpecific = (uint)(packet.Payload[offset++]);
FragmentOffset = (uint)(packet.Payload[offset++] << 16 | packet.Payload[offset++] << 8 | packet.Payload[offset++]);
if (i == 0 && FragmentOffset != 0) continue;
Type = (uint)(packet.Payload[offset++]);
Quality = (uint)packet.Payload[offset++];
Width = (uint)(packet.Payload[offset++] * 8);
Height = (uint)(packet.Payload[offset++] * 8);
if (FragmentOffset == 0)
{
if (packet.Payload[offset] == 0xff && packet.Payload[offset + 1] == 0xd8)
{
goto WritePacket;
}
if (Type > 63)
{
DataRestartInterval = (uint)(packet.Payload[offset++] << 8 | packet.Payload[offset++]);
}
if (Quality > 127)
{
uint MBZ = (uint)(packet.Payload[offset++]);
uint Precision = (uint)(packet.Payload[offset++]);
uint Length = (uint)(packet.Payload[offset++] << 8 | packet.Payload[offset++]);
if(Length > 0)
{
tables = new ArraySegment<byte>(packet.Payload, offset, (int)Length);
offset += (int)Length;
}
else
{
tables = new ArraySegment<byte>(CreateQuantizationTables(Quality));
}
}
byte[] header = CreateJFIFHeader(Type, Width, Height, tables, DataRestartInterval);
Buffer.Write(header, 0, header.Length);
}
WritePacket:
Buffer.Write(packet.Payload, offset, packet.Payload.Length - offset);
if (i == last && packet.Payload[packet.Payload.Length - 2] != 0xff && packet.Payload[packet.Payload.Length - 1] != 0xd9)
{
Buffer.WriteByte(0xff);
Buffer.WriteByte(0xd9);
}
}
Buffer.Seek(0, System.IO.SeekOrigin.Begin);
}
public System.Drawing.Image ToImage()
{
try
{
if (Image != null) return Image;
ProcessPackets();
return Image = System.Drawing.Image.FromStream(Buffer, false, true);
}
catch { throw; }
finally
{
Buffer.Dispose();
Buffer = null;
}
}
}
}
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