feat: add avformat and avdictionary wrapper

FfMpegLib.Net/DataStructs/AvDictionaryWrapper.cs

@@ -0,0 +1,78 @@
+using System.Runtime.InteropServices;
+using FFmpeg.AutoGen.Abstractions;
+using FfMpeg.AutoGen.Wrapper.Extensions;
+
+namespace FfMpeg.AutoGen.Wrapper.DataStructs;
+
+public class AvDictionaryWrapper : WrapperBase<AVDictionary>
+{
+    public string this[string key]
+    {
+        get => GetValue(key);
+        // ReSharper disable once NullCoalescingConditionIsAlwaysNotNullAccordingToAPIContract
+        set => SetValue(key, value ?? string.Empty);
+    }
+
+    public string GetValue(string key, AvDictionaryFlag flag = DefaultFlag)
+    {
+        var val = GetValueCore(key, flag);
+        if (val is null)
+            throw new ArgumentOutOfRangeException(nameof(key));
+
+        return val;
+    }
+
+    public bool TryGetValue(string key, out string? val, AvDictionaryFlag flag = DefaultFlag)
+    {
+        val = GetValueCore(key, flag);
+        return val is not null;
+    }
+
+    private string? GetValueCore(string key, AvDictionaryFlag flag = DefaultFlag)
+    {
+        unsafe
+        {
+            var entry = ffmpeg.av_dict_get(UnmanagedPointer, key, null, (int)flag);
+            return entry is null
+                ? null
+                : Marshal.PtrToStringAuto((IntPtr)entry->value);
+        }
+    }
+
+    public void SetValue(string key, string value, AvDictionaryFlag flag = DefaultFlag)
+        => SetValueCore(key, value, flag).ThrowExceptionIfError();
+
+    public bool TrySetValue(string key, string value, AvDictionaryFlag flag = DefaultFlag)
+        => SetValueCore(key, value, flag) >= 0;
+
+    private int SetValueCore(string key, string? value, AvDictionaryFlag flag = DefaultFlag)
+    {
+        unsafe
+        {
+            var ptr = UnmanagedPointer;
+            return ffmpeg.av_dict_set(&ptr, key, value, (int)flag);
+        }
+    }
+
+    public void Remove(string key, AvDictionaryFlag flag = DefaultFlag)
+        => SetValueCore(key, null, flag)
+            .ThrowExceptionIfError();
+
+    public bool TryRemove(string key, AvDictionaryFlag flag = DefaultFlag)
+        => SetValueCore(key, null, flag) >= 0;
+
+    private const AvDictionaryFlag DefaultFlag = AvDictionaryFlag.MatchCase;
+}
+
+[Flags]
+public enum AvDictionaryFlag
+{
+    None = 0x00,
+    MatchCase = ffmpeg.AV_DICT_MATCH_CASE,
+    IgnoreSuffix = ffmpeg.AV_DICT_IGNORE_SUFFIX,
+    DoNotStrDupKey = ffmpeg.AV_DICT_DONT_STRDUP_KEY,
+    DoNotStrDupVal = ffmpeg.AV_DICT_DONT_STRDUP_VAL,
+    DoNotOverwrite = ffmpeg.AV_DICT_DONT_OVERWRITE,
+    Append = ffmpeg.AV_DICT_APPEND,
+    MultiKey = ffmpeg.AV_DICT_MULTIKEY
+}

FfMpegLib.Net/DataStructs/AvFormatContextWrapper.cs

@@ -0,0 +1,70 @@
+using FFmpeg.AutoGen.Abstractions;
+using FfMpeg.AutoGen.Wrapper.Extensions;
+
+namespace FfMpeg.AutoGen.Wrapper.DataStructs;
+
+public class AvFormatContextWrapper : WrapperBase<AVFormatContext>
+{
+    public unsafe AvFormatContextWrapper()
+        : base(ffmpeg.avformat_alloc_context()) { }
+
+    public unsafe AvFormatContextWrapper(AVFormatContext* context)
+        : base(context) { }
+
+    public bool IsOpen { get; set; }
+
+    public unsafe void Open(string url, AVInputFormat* format, AVDictionary* option)
+        => OpenCore(url, format, option).ThrowExceptionIfError();
+
+    public unsafe bool TryOpen(string url, AVInputFormat* format, AVDictionary* option)
+        => OpenCore(url, format, option) == 0;
+
+    private unsafe int OpenCore(string url, AVInputFormat* format, AVDictionary* option)
+    {
+        var formatCtx = UnmanagedPointer;
+
+        var result = ffmpeg.avformat_open_input(&formatCtx, url, format, &option);
+        IsOpen = result == 0;
+        return result;
+    }
+
+    public void Close()
+    {
+        if (IsOpen)
+        {
+            unsafe
+            {
+                var formatCtx = UnmanagedPointer;
+                ffmpeg.avformat_close_input(&formatCtx);
+            }
+        }
+    }
+
+    public unsafe bool TryFindStreamInfo(AVDictionary* option = null)
+        => FindStreamInfoCore(option) >= 0;
+
+    public unsafe void FindStreamInfo(AVDictionary* option = null)
+        => FindStreamInfoCore(option).ThrowExceptionIfError();
+
+    private unsafe int FindStreamInfoCore(AVDictionary* option)
+    {
+        ffmpeg.avformat_find_stream_info(UnmanagedPointer, &option)
+            .ThrowExceptionIfError();
+    }
+
+    public override void Dispose()
+    {
+        unsafe
+        {
+            if (!IsOpen)
+            {
+                var formatCtx = UnmanagedPointer;
+                ffmpeg.avformat_close_input(&formatCtx);
+            }
+
+            ffmpeg.avformat_free_context(UnmanagedPointer);
+        }
+
+        GC.SuppressFinalize(this);
+    }
+}