Video Edit SDK .NET 与 FFmpeg .NET 封装器

using VisioForge.Core.VideoEdit;

var editor = new VideoEditCoreX();

// Add clips to timeline with trim points
editor.Input_AddVideoFile("intro.mp4", TimeSpan.Zero, TimeSpan.FromSeconds(5));
editor.Input_AddVideoFile("main.mp4", TimeSpan.FromSeconds(10), TimeSpan.FromSeconds(60));
editor.Input_AddVideoFile("outro.mp4");

// Configure output
editor.Output_Format = new MP4Output("final.mp4")
{
    Video = { Codec = VideoCodec.H264, Bitrate = 8_000_000 },
    Audio = { Codec = AudioCodec.AAC, Bitrate = 192_000 }
};

// Render with progress
editor.OnProgress += (s, e) => Console.WriteLine($"{e.Progress}%");
await editor.StartAsync();

using FFMpegCore;
using FFMpegCore.Pipes;

// Step 1: Trim each clip to temp files
await FFMpegArguments
    .FromFileInput("intro.mp4")
    .OutputToFile("tmp_intro.mp4", true, o => o
        .WithDuration(TimeSpan.FromSeconds(5)))
    .ProcessAsynchronously();

await FFMpegArguments
    .FromFileInput("main.mp4")
    .OutputToFile("tmp_main.mp4", true, o => o
        .Seek(TimeSpan.FromSeconds(10))
        .WithDuration(TimeSpan.FromSeconds(50)))
    .ProcessAsynchronously();

// Step 2: Create concat file list
File.WriteAllText("list.txt",
    "file 'tmp_intro.mp4'\nfile 'main.mp4'\nfile 'outro.mp4'");

// Step 3: Concatenate
await FFMpegArguments
    .FromFileInput("list.txt", false, o => o
        .WithCustomArgument("-f concat -safe 0"))
    .OutputToFile("final.mp4", true, o => o
        .WithVideoCodec("libx264")
        .WithVideoBitrate(8000)
        .WithAudioCodec("aac")
        .WithAudioBitrate(192))
    .ProcessAsynchronously();

// Cleanup temp files
File.Delete("tmp_intro.mp4");
File.Delete("tmp_main.mp4");
File.Delete("list.txt");

var editor = new VideoEditCoreX();

// Add video with its audio on track 0
editor.Input_AddVideoFile("interview.mp4");

// Add background music on track 1 with reduced volume
editor.Input_AddAudioFile("music.mp3", audioTrack: 1);
editor.Audio_SetTrackVolume(1, 0.15); // 15% volume
editor.Audio_SetTrackFade(1, fadeIn: TimeSpan.FromSeconds(2),
                                      fadeOut: TimeSpan.FromSeconds(3));

editor.Output_Format = new MP4Output("mixed.mp4");
await editor.StartAsync();

// FFMpegCore does not have a native multi-input mixing API.
// You must use custom arguments to access FFmpeg's filter_complex.

await FFMpegArguments
    .FromFileInput("interview.mp4")
    .AddFileInput("music.mp3")
    .OutputToFile("mixed.mp4", true, o => o
        .WithCustomArgument(
            "-filter_complex " +
            "[1:a]volume=0.15," +
            "afade=t=in:st=0:d=2," +
            "afade=t=out:st=58:d=3[bg];" +
            "[0:a][bg]amix=inputs=2:duration=first[aout]" +
            " -map 0:v -map [aout]")
        .WithVideoCodec("copy")
        .WithAudioCodec("aac"))
    .ProcessAsynchronously();

// Note: Calculating the fade-out start time (58s above)
// requires knowing the video duration beforehand.

var editor = new VideoEditCoreX();

editor.Input_AddVideoFile("source.mp4",
    start: TimeSpan.FromMinutes(5),
    stop: TimeSpan.FromMinutes(10));

// Use stream copy mode — no transcoding
editor.Output_Format = new MP4Output("clip.mp4")
{
    Video = { Codec = VideoCodec.Copy },
    Audio = { Codec = AudioCodec.Copy }
};

await editor.StartAsync();

await FFMpegArguments
    .FromFileInput("source.mp4", false, o => o
        .Seek(TimeSpan.FromMinutes(5))
        .WithDuration(TimeSpan.FromMinutes(5)))
    .OutputToFile("clip.mp4", true, o => o
        .WithVideoCodec("copy")
        .WithAudioCodec("copy"))
    .ProcessAsynchronously();

// Note: With -c copy, the actual cut point snaps to the
// nearest keyframe, which may not be frame-accurate.

var files = Directory.GetFiles("input/", "*.avi");

var tasks = files.Select(async file =>
{
    var editor = new VideoEditCoreX();
    editor.Input_AddVideoFile(file);
    editor.Output_Format = new MP4Output(
        Path.Combine("output/", Path.GetFileNameWithoutExtension(file) + ".mp4"))
    {
        Video = { Codec = VideoCodec.H264, Bitrate = 5_000_000 },
        Audio = { Codec = AudioCodec.AAC, Bitrate = 128_000 }
    };
    await editor.StartAsync();
});

await Task.WhenAll(tasks);

var files = Directory.GetFiles("input/", "*.avi");

// Process sequentially to avoid spawning too many ffmpeg processes
foreach (var file in files)
{
    var output = Path.Combine("output/",
        Path.GetFileNameWithoutExtension(file) + ".mp4");

    await FFMpegArguments
        .FromFileInput(file)
        .OutputToFile(output, true, o => o
            .WithVideoCodec("libx264")
            .WithVideoBitrate(5000)
            .WithAudioCodec("aac")
            .WithAudioBitrate(128))
        .ProcessAsynchronously();
}

// Parallel execution is possible but requires manual
// process pool management to avoid resource exhaustion.