C# 如何在.net中创建动画gif

有人知道如何使用c#创建动画gif吗？ 理想情况下，我会有一些控制的颜色减少使用

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使用imagemagick（作为外部启动的流程）是最佳选择吗？

如果不知道重要的质量参数，很难判断调用imagemagick是否是最佳选择。其他一些选择是：

• 关于codeplex的文章

它们的优点是，您不依赖于第三个部分库，而第三个部分库可能在所有执行代码的系统上都可用，也可能不可用

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此at MS支持说明了如何使用自定义颜色表保存gif（这需要完全信任）。动画gif只是每个图像的一组gif，标题中有一些附加信息。因此，将这两篇文章结合起来应该可以满足您的需要

有一个内置的.NET类，它将对GIF文件进行编码。

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要使用Windows窗体应用程序中的示例，请添加对这些程序集的引用：

C:\Program Files\Reference Assembly\Microsoft\Framework.NETFramework\v4.0\PresentationCore.dll C:\Program Files\Reference Assembly\Microsoft\Framework.NETFramework\v4.0\System.Xaml.dll C:\Program Files\Reference Assembly\Microsoft\Framework.NETFramework\v4.0\WindowsBase.dll

然后

• Int32Rect位于System.Windows命名空间中

• BitmapSizeOptions位于System.Windows.Media.Imaging命名空间中

• BitmapFrame位于System.Windows.Media.Imaging命名空间中

另外，不要忘记关闭文件流（类似于以下内容）：

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你也可以考虑使用IMAGEMAGIK库。

上列出的库有两个.net包装器

下面是一个关于如何使用的示例：

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此Gif动画创建器代码可以设置每帧的延迟：

使用.Net标准Gif编码并添加动画标题

编辑：使代码类似于典型的文件编写器

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Threading.Tasks;

/// <summary>
/// Creates a GIF using .Net GIF encoding and additional animation headers.
/// </summary>
public class GifWriter : IDisposable
{
    #region Fields
    const long SourceGlobalColorInfoPosition = 10,
        SourceImageBlockPosition = 789;

    readonly BinaryWriter _writer;
    bool _firstFrame = true;
    readonly object _syncLock = new object();
    #endregion

    /// <summary>
    /// Creates a new instance of GifWriter.
    /// </summary>
    /// <param name="OutStream">The <see cref="Stream"/> to output the Gif to.</param>
    /// <param name="DefaultFrameDelay">Default Delay between consecutive frames... FrameRate = 1000 / DefaultFrameDelay.</param>
    /// <param name="Repeat">No of times the Gif should repeat... -1 not to repeat, 0 to repeat indefinitely.</param>
    public GifWriter(Stream OutStream, int DefaultFrameDelay = 500, int Repeat = -1)
    {
        if (OutStream == null)
            throw new ArgumentNullException(nameof(OutStream));

        if (DefaultFrameDelay <= 0)
            throw new ArgumentOutOfRangeException(nameof(DefaultFrameDelay));

        if (Repeat < -1)
            throw new ArgumentOutOfRangeException(nameof(Repeat));

        _writer = new BinaryWriter(OutStream);
        this.DefaultFrameDelay = DefaultFrameDelay;
        this.Repeat = Repeat;
    }

    /// <summary>
    /// Creates a new instance of GifWriter.
    /// </summary>
    /// <param name="FileName">The path to the file to output the Gif to.</param>
    /// <param name="DefaultFrameDelay">Default Delay between consecutive frames... FrameRate = 1000 / DefaultFrameDelay.</param>
    /// <param name="Repeat">No of times the Gif should repeat... -1 not to repeat, 0 to repeat indefinitely.</param>
    public GifWriter(string FileName, int DefaultFrameDelay = 500, int Repeat = -1)
        : this(new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Read), DefaultFrameDelay, Repeat) { }

    #region Properties
    /// <summary>
    /// Gets or Sets the Default Width of a Frame. Used when unspecified.
    /// </summary>
    public int DefaultWidth { get; set; }

    /// <summary>
    /// Gets or Sets the Default Height of a Frame. Used when unspecified.
    /// </summary>
    public int DefaultHeight { get; set; }

    /// <summary>
    /// Gets or Sets the Default Delay in Milliseconds.
    /// </summary>
    public int DefaultFrameDelay { get; set; }

    /// <summary>
    /// The Number of Times the Animation must repeat.
    /// -1 indicates no repeat. 0 indicates repeat indefinitely
    /// </summary>
    public int Repeat { get; }
    #endregion

    /// <summary>
    /// Adds a frame to this animation.
    /// </summary>
    /// <param name="Image">The image to add</param>
    /// <param name="Delay">Delay in Milliseconds between this and last frame... 0 = <see cref="DefaultFrameDelay"/></param>
    public void WriteFrame(Image Image, int Delay = 0)
    {
        lock (_syncLock)
            using (var gifStream = new MemoryStream())
            {
                Image.Save(gifStream, ImageFormat.Gif);

                // Steal the global color table info
                if (_firstFrame)
                    InitHeader(gifStream, _writer, Image.Width, Image.Height);

                WriteGraphicControlBlock(gifStream, _writer, Delay == 0 ? DefaultFrameDelay : Delay);
                WriteImageBlock(gifStream, _writer, !_firstFrame, 0, 0, Image.Width, Image.Height);
            }

        if (_firstFrame)
            _firstFrame = false;
    }

    #region Write
    void InitHeader(Stream SourceGif, BinaryWriter Writer, int Width, int Height)
    {
        // File Header
        Writer.Write("GIF".ToCharArray()); // File type
        Writer.Write("89a".ToCharArray()); // File Version

        Writer.Write((short)(DefaultWidth == 0 ? Width : DefaultWidth)); // Initial Logical Width
        Writer.Write((short)(DefaultHeight == 0 ? Height : DefaultHeight)); // Initial Logical Height

        SourceGif.Position = SourceGlobalColorInfoPosition;
        Writer.Write((byte)SourceGif.ReadByte()); // Global Color Table Info
        Writer.Write((byte)0); // Background Color Index
        Writer.Write((byte)0); // Pixel aspect ratio
        WriteColorTable(SourceGif, Writer);

        // App Extension Header for Repeating
        if (Repeat == -1)
            return;

        Writer.Write(unchecked((short)0xff21)); // Application Extension Block Identifier
        Writer.Write((byte)0x0b); // Application Block Size
        Writer.Write("NETSCAPE2.0".ToCharArray()); // Application Identifier
        Writer.Write((byte)3); // Application block length
        Writer.Write((byte)1);
        Writer.Write((short)Repeat); // Repeat count for images.
        Writer.Write((byte)0); // terminator
    }

    static void WriteColorTable(Stream SourceGif, BinaryWriter Writer)
    {
        SourceGif.Position = 13; // Locating the image color table
        var colorTable = new byte[768];
        SourceGif.Read(colorTable, 0, colorTable.Length);
        Writer.Write(colorTable, 0, colorTable.Length);
    }

    static void WriteGraphicControlBlock(Stream SourceGif, BinaryWriter Writer, int FrameDelay)
    {
        SourceGif.Position = 781; // Locating the source GCE
        var blockhead = new byte[8];
        SourceGif.Read(blockhead, 0, blockhead.Length); // Reading source GCE

        Writer.Write(unchecked((short)0xf921)); // Identifier
        Writer.Write((byte)0x04); // Block Size
        Writer.Write((byte)(blockhead[3] & 0xf7 | 0x08)); // Setting disposal flag
        Writer.Write((short)(FrameDelay / 10)); // Setting frame delay
        Writer.Write(blockhead[6]); // Transparent color index
        Writer.Write((byte)0); // Terminator
    }

    static void WriteImageBlock(Stream SourceGif, BinaryWriter Writer, bool IncludeColorTable, int X, int Y, int Width, int Height)
    {
        SourceGif.Position = SourceImageBlockPosition; // Locating the image block
        var header = new byte[11];
        SourceGif.Read(header, 0, header.Length);
        Writer.Write(header[0]); // Separator
        Writer.Write((short)X); // Position X
        Writer.Write((short)Y); // Position Y
        Writer.Write((short)Width); // Width
        Writer.Write((short)Height); // Height

        if (IncludeColorTable) // If first frame, use global color table - else use local
        {
            SourceGif.Position = SourceGlobalColorInfoPosition;
            Writer.Write((byte)(SourceGif.ReadByte() & 0x3f | 0x80)); // Enabling local color table
            WriteColorTable(SourceGif, Writer);
        }
        else Writer.Write((byte)(header[9] & 0x07 | 0x07)); // Disabling local color table

        Writer.Write(header[10]); // LZW Min Code Size

        // Read/Write image data
        SourceGif.Position = SourceImageBlockPosition + header.Length;

        var dataLength = SourceGif.ReadByte();
        while (dataLength > 0)
        {
            var imgData = new byte[dataLength];
            SourceGif.Read(imgData, 0, dataLength);

            Writer.Write((byte)dataLength);
            Writer.Write(imgData, 0, dataLength);
            dataLength = SourceGif.ReadByte();
        }

        Writer.Write((byte)0); // Terminator
    }
    #endregion

    /// <summary>
    /// Frees all resources used by this object.
    /// </summary>
    public void Dispose()
    {
        // Complete File
        _writer.Write((byte)0x3b); // File Trailer

        _writer.BaseStream.Dispose();
        _writer.Dispose();
    }
}

使用系统；
使用系统图；
使用系统、绘图、成像；
使用System.IO；
使用System.Threading.Tasks；
/// 
///使用.Net GIF编码和其他动画标题创建GIF。
/// 
公共类GifWriter:IDisposable
{
#区域字段
const long sourceglobalColorInfo=10，
SourceImageBlockPosition=789；
只读二进制编写器\u编写器；
bool _firstFrame=true；
只读对象_syncLock=新对象（）；
#端区
/// 
///创建GifWriter的新实例。
/// 
///要将Gif输出到的。
///连续帧之间的默认延迟…帧速率=1000/默认帧延迟。
///Gif应重复的次数…-1不重复，0无限期重复。
公共GifWriter（流外扩，int-DefaultFrameDelay=500，int-Repeat=-1）
{
如果（超出流==null）
抛出新ArgumentNullException（nameof（OutStream））；
如果（默认帧延迟0）
{
var imgData=新字节[数据长度]；
SourceGif.Read（imgData，0，dataLength）；
Writer.Write（（字节）数据长度）；
Writer.Write（imgData，0，dataLength）；
dataLength=SourceGif.ReadByte（）；
}
Writer.Write（（字节）0）；//终止符
}
#端区
/// 
///释放此对象使用的所有资源。
/// 
公共空间处置（）
{
//完整文件
_writer.Write（（字节）0x3b）；//文件尾部
_writer.BaseStream.Dispose（）；
_writer.Dispose（）；
}
}

我注意到，答案中还没有列出ImageMagic和NGif的另一个很好的替代方案

可用于从以下位置创建动画GIF：

• 图像（文件）序列
• 现有视频剪辑（如mp4或avi）
• 通过stdin（不使用任何临时文件）以“ravvideo”的形式提供输入数据，从C#位图对象开始

您可以直接从C代码（使用System.Diagnostics.Process）启动ffmpeg.exe，或使用现有的.NET ffmpeg包装器之一：

var ffmpeg = new NReco.VideoConverter.FFMpegConverter();
ffmpeg.ConvertMedia("your_clip.mp4", null, "result.gif", null, new ConvertSettings() );

（此代码示例使用免费-我是此组件的作者，可以随时询问有关其用法的任何问题）

通过降低帧速率和/或帧大小，可以轻松减小GIF大小。 此外，还可以通过生成最佳GIF调色板的双通道方法获得好看的动画GIF。

该软件包可以制作动画GIF

using (var gif = AnimatedGif.AnimatedGif.Create(Path.Combine(outputPath, "output.gif"), 20))
{
    for (var i = 0; i < 10; i++)
    {
        img = Image.FromFile(Path.Combine(outputPath, $"{i.ToString().PadLeft(3, '0')}.png"));
        gif.AddFrame(img, delay: -1, quality: GifQuality.Bit8);
    }
}

使用（var gif=AnimatedGif.AnimatedGif.Create（Path.Combine（outputPath，“output.gif”），20））
{
对于（变量i=0；i<10；i++）
{
img=Image.FromFile（Path.Combine（outputPath，$”{i.ToString（）.PadLeft（3，'0'）}.png））；
添加帧（img，延迟：-1，质量：GifQuality.Bit8）；
}
}

imagemagick似乎仍然有最好的选择（抖动、减色等）。建议的库和其他创建方法质量很差。您是否尝试过任何最终解决方案？未标记答案…是否有办法使用此代码在每帧之间有一定的延迟或设置帧速率？嗯。该代码大量失败。它所做的只是将一组图像放在另一个图像上，并将其保存为单个图像。在上面的解决方案中需要注意的是，您需要处理GDI位图对象可能导致的内存泄漏-这是给定代码中的

bmpImage.GetHbitmap（）

。作为。这是一个如何避免GDI位图对象占用太多内存的代码示例。有趣的是，我为内存泄漏添加了其他代码。在gif创建和显示后，如果有人得到一个黑色矩形，我将使用NReco将多个图像转换为MP4（h.264）格式。我找不到任何可行的例子。你能帮我解决这个问题吗？谢谢您好，您知道我如何将图像与视频合并。合并视频效果很好。但当我试图在两个视频之间进行合并和成像时，它不起作用

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Threading.Tasks;

/// <summary>
/// Creates a GIF using .Net GIF encoding and additional animation headers.
/// </summary>
public class GifWriter : IDisposable
{
    #region Fields
    const long SourceGlobalColorInfoPosition = 10,
        SourceImageBlockPosition = 789;

    readonly BinaryWriter _writer;
    bool _firstFrame = true;
    readonly object _syncLock = new object();
    #endregion

    /// <summary>
    /// Creates a new instance of GifWriter.
    /// </summary>
    /// <param name="OutStream">The <see cref="Stream"/> to output the Gif to.</param>
    /// <param name="DefaultFrameDelay">Default Delay between consecutive frames... FrameRate = 1000 / DefaultFrameDelay.</param>
    /// <param name="Repeat">No of times the Gif should repeat... -1 not to repeat, 0 to repeat indefinitely.</param>
    public GifWriter(Stream OutStream, int DefaultFrameDelay = 500, int Repeat = -1)
    {
        if (OutStream == null)
            throw new ArgumentNullException(nameof(OutStream));

        if (DefaultFrameDelay <= 0)
            throw new ArgumentOutOfRangeException(nameof(DefaultFrameDelay));

        if (Repeat < -1)
            throw new ArgumentOutOfRangeException(nameof(Repeat));

        _writer = new BinaryWriter(OutStream);
        this.DefaultFrameDelay = DefaultFrameDelay;
        this.Repeat = Repeat;
    }

    /// <summary>
    /// Creates a new instance of GifWriter.
    /// </summary>
    /// <param name="FileName">The path to the file to output the Gif to.</param>
    /// <param name="DefaultFrameDelay">Default Delay between consecutive frames... FrameRate = 1000 / DefaultFrameDelay.</param>
    /// <param name="Repeat">No of times the Gif should repeat... -1 not to repeat, 0 to repeat indefinitely.</param>
    public GifWriter(string FileName, int DefaultFrameDelay = 500, int Repeat = -1)
        : this(new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write, FileShare.Read), DefaultFrameDelay, Repeat) { }

    #region Properties
    /// <summary>
    /// Gets or Sets the Default Width of a Frame. Used when unspecified.
    /// </summary>
    public int DefaultWidth { get; set; }

    /// <summary>
    /// Gets or Sets the Default Height of a Frame. Used when unspecified.
    /// </summary>
    public int DefaultHeight { get; set; }

    /// <summary>
    /// Gets or Sets the Default Delay in Milliseconds.
    /// </summary>
    public int DefaultFrameDelay { get; set; }

    /// <summary>
    /// The Number of Times the Animation must repeat.
    /// -1 indicates no repeat. 0 indicates repeat indefinitely
    /// </summary>
    public int Repeat { get; }
    #endregion

    /// <summary>
    /// Adds a frame to this animation.
    /// </summary>
    /// <param name="Image">The image to add</param>
    /// <param name="Delay">Delay in Milliseconds between this and last frame... 0 = <see cref="DefaultFrameDelay"/></param>
    public void WriteFrame(Image Image, int Delay = 0)
    {
        lock (_syncLock)
            using (var gifStream = new MemoryStream())
            {
                Image.Save(gifStream, ImageFormat.Gif);

                // Steal the global color table info
                if (_firstFrame)
                    InitHeader(gifStream, _writer, Image.Width, Image.Height);

                WriteGraphicControlBlock(gifStream, _writer, Delay == 0 ? DefaultFrameDelay : Delay);
                WriteImageBlock(gifStream, _writer, !_firstFrame, 0, 0, Image.Width, Image.Height);
            }

        if (_firstFrame)
            _firstFrame = false;
    }

    #region Write
    void InitHeader(Stream SourceGif, BinaryWriter Writer, int Width, int Height)
    {
        // File Header
        Writer.Write("GIF".ToCharArray()); // File type
        Writer.Write("89a".ToCharArray()); // File Version

        Writer.Write((short)(DefaultWidth == 0 ? Width : DefaultWidth)); // Initial Logical Width
        Writer.Write((short)(DefaultHeight == 0 ? Height : DefaultHeight)); // Initial Logical Height

        SourceGif.Position = SourceGlobalColorInfoPosition;
        Writer.Write((byte)SourceGif.ReadByte()); // Global Color Table Info
        Writer.Write((byte)0); // Background Color Index
        Writer.Write((byte)0); // Pixel aspect ratio
        WriteColorTable(SourceGif, Writer);

        // App Extension Header for Repeating
        if (Repeat == -1)
            return;

        Writer.Write(unchecked((short)0xff21)); // Application Extension Block Identifier
        Writer.Write((byte)0x0b); // Application Block Size
        Writer.Write("NETSCAPE2.0".ToCharArray()); // Application Identifier
        Writer.Write((byte)3); // Application block length
        Writer.Write((byte)1);
        Writer.Write((short)Repeat); // Repeat count for images.
        Writer.Write((byte)0); // terminator
    }

    static void WriteColorTable(Stream SourceGif, BinaryWriter Writer)
    {
        SourceGif.Position = 13; // Locating the image color table
        var colorTable = new byte[768];
        SourceGif.Read(colorTable, 0, colorTable.Length);
        Writer.Write(colorTable, 0, colorTable.Length);
    }

    static void WriteGraphicControlBlock(Stream SourceGif, BinaryWriter Writer, int FrameDelay)
    {
        SourceGif.Position = 781; // Locating the source GCE
        var blockhead = new byte[8];
        SourceGif.Read(blockhead, 0, blockhead.Length); // Reading source GCE

        Writer.Write(unchecked((short)0xf921)); // Identifier
        Writer.Write((byte)0x04); // Block Size
        Writer.Write((byte)(blockhead[3] & 0xf7 | 0x08)); // Setting disposal flag
        Writer.Write((short)(FrameDelay / 10)); // Setting frame delay
        Writer.Write(blockhead[6]); // Transparent color index
        Writer.Write((byte)0); // Terminator
    }

    static void WriteImageBlock(Stream SourceGif, BinaryWriter Writer, bool IncludeColorTable, int X, int Y, int Width, int Height)
    {
        SourceGif.Position = SourceImageBlockPosition; // Locating the image block
        var header = new byte[11];
        SourceGif.Read(header, 0, header.Length);
        Writer.Write(header[0]); // Separator
        Writer.Write((short)X); // Position X
        Writer.Write((short)Y); // Position Y
        Writer.Write((short)Width); // Width
        Writer.Write((short)Height); // Height

        if (IncludeColorTable) // If first frame, use global color table - else use local
        {
            SourceGif.Position = SourceGlobalColorInfoPosition;
            Writer.Write((byte)(SourceGif.ReadByte() & 0x3f | 0x80)); // Enabling local color table
            WriteColorTable(SourceGif, Writer);
        }
        else Writer.Write((byte)(header[9] & 0x07 | 0x07)); // Disabling local color table

        Writer.Write(header[10]); // LZW Min Code Size

        // Read/Write image data
        SourceGif.Position = SourceImageBlockPosition + header.Length;

        var dataLength = SourceGif.ReadByte();
        while (dataLength > 0)
        {
            var imgData = new byte[dataLength];
            SourceGif.Read(imgData, 0, dataLength);

            Writer.Write((byte)dataLength);
            Writer.Write(imgData, 0, dataLength);
            dataLength = SourceGif.ReadByte();
        }

        Writer.Write((byte)0); // Terminator
    }
    #endregion

    /// <summary>
    /// Frees all resources used by this object.
    /// </summary>
    public void Dispose()
    {
        // Complete File
        _writer.Write((byte)0x3b); // File Trailer

        _writer.BaseStream.Dispose();
        _writer.Dispose();
    }
}

var ffmpeg = new NReco.VideoConverter.FFMpegConverter();
ffmpeg.ConvertMedia("your_clip.mp4", null, "result.gif", null, new ConvertSettings() );

using (var gif = AnimatedGif.AnimatedGif.Create(Path.Combine(outputPath, "output.gif"), 20))
{
    for (var i = 0; i < 10; i++)
    {
        img = Image.FromFile(Path.Combine(outputPath, $"{i.ToString().PadLeft(3, '0')}.png"));
        gif.AddFrame(img, delay: -1, quality: GifQuality.Bit8);
    }
}