VideoEncoderService/Encoder/Strategies.cs

using FFMpegCore;
using FFMpegCore.Enums;

namespace Encoder;

public struct EncodingProgress {
    public TimeSpan progress;
    public TimeSpan duration;
    public float framerate;
    public EncodingJob job;
    public string inputPath;
    public string outputPath;
}

public class EncodingStrategyAttribute(EncoderType encoderType) : Attribute {
    public EncoderType EncoderType { get; } = encoderType;
}

public interface IEncodingStrategy {
    public string InputFilePath { get; set; }
    public string OutputFilePath { get; set; }
    public Task<bool> ExecuteAsync(CancellationToken cancellationToken, Action<EncodingProgress> onProgress);
}

[EncodingStrategy(EncoderType.AV1)]
public class AV1EncodingStrategy(string inputFilePath, string outputFilePath, EncodingJob job) : IEncodingStrategy {
    public string InputFilePath { get; set; } = inputFilePath;
    public string OutputFilePath { get; set; } = outputFilePath;
    
    private static readonly Tuple<int, int>[] QPTable = new Tuple<int, int>[] {
        new(1280*720,  64),
        new(1920*1080, 96),
        new(3840*2160, 128),
        new(5760*2880, 96), //VR6K
        new(8128*4096, 120) //VR8K
    }.OrderBy(t => t.Item1).ToArray();

    public async Task<bool> ExecuteAsync(CancellationToken cancellationToken, Action<EncodingProgress> onProgress) {
        var mediaInfo = await FFProbe.AnalyseAsync(InputFilePath, cancellationToken: cancellationToken);
        if (mediaInfo.PrimaryVideoStream == null) return false;
        int W = mediaInfo.PrimaryVideoStream.Width;
        int H = mediaInfo.PrimaryVideoStream.Height;
        int qp = Utils.ToQPValue(W, H, QPTable);
        return await FFMpegArguments
            .FromFileInput(InputFilePath, true, args => args.WithHardwareAcceleration())
            .OutputToFile(OutputFilePath, true, args => args
                .CopyChannel(Channel.Audio)
                .CopyChannel(Channel.Subtitle)
                .WithVideoCodec("av1_nvenc")
                .WithArgument(new NvencSpeedPreset(NvencSpeed.p2))
                .WithArgument(new NvencTuneArgument(NvencTune.hq))
                .WithArgument(new NvencHighBitDepthArgument(true))
                .WithArgument(new NvencQPArgument((byte)qp))
                .WithFastStart()
            )
            .NotifyOnProgress(progress => onProgress(new() {
                progress = progress,
                duration = mediaInfo.Duration,
                framerate = (float)mediaInfo.PrimaryVideoStream.FrameRate,
                job = job,
                inputPath = InputFilePath,
                outputPath = OutputFilePath
            }))
            .CancellableThrough(cancellationToken)
            .ProcessAsynchronously();
    }
}

[EncodingStrategy(EncoderType.HEVC)]
public class HEVCEncodingStrategy(string inputFilePath, string outputFilePath, EncodingJob job) : IEncodingStrategy {
    public string InputFilePath { get; set; } = inputFilePath;
    public string OutputFilePath { get; set; } = outputFilePath;
    
    //TODO: needs to be adjusted
    private static readonly Tuple<int, int>[] QPTable = new Tuple<int, int>[] {
        new(1280*720,  0),
        new(1920*1080, 0),
        new(3840*2160, 0),
        new(5760*2880, 0), //VR6K
        new(8128*4096, 0) //VR8K
    }.OrderBy(t => t.Item1).ToArray();

    public async Task<bool> ExecuteAsync(CancellationToken cancellationToken, Action<EncodingProgress> onProgress) {
        var mediaInfo = await FFProbe.AnalyseAsync(InputFilePath, cancellationToken: cancellationToken);
        if (mediaInfo.PrimaryVideoStream == null) return false;
        int W = mediaInfo.PrimaryVideoStream.Width;
        int H = mediaInfo.PrimaryVideoStream.Height;
        int qp = Utils.ToQPValue(W, H, QPTable);
        return await FFMpegArguments
            .FromFileInput(InputFilePath, true, args => args.WithHardwareAcceleration())
            .OutputToFile(OutputFilePath, true, args => args
                .CopyChannel(Channel.Audio)
                .CopyChannel(Channel.Subtitle)
                .WithVideoCodec("hevc_nvenc")
                .WithArgument(new NvencSpeedPreset(NvencSpeed.p2))
                .WithArgument(new NvencTuneArgument(NvencTune.hq))
                .WithArgument(new NvencHighBitDepthArgument(true))
                .WithArgument(new NvencQPArgument((byte)qp))
                .WithFastStart()
            )
            .NotifyOnProgress(progress => onProgress(new() {
                progress = progress,
                duration = mediaInfo.Duration,
                framerate = (float)mediaInfo.PrimaryVideoStream.FrameRate,
                job = job,
                inputPath = InputFilePath,
                outputPath = OutputFilePath
            }))
            .CancellableThrough(cancellationToken)
            .ProcessAsynchronously();
    }
}

[EncodingStrategy(EncoderType.H264)]
public class H264EncodingStrategy(string inputFilePath, string outputFilePath, EncodingJob job) : IEncodingStrategy {
    public string InputFilePath { get; set; } = inputFilePath;
    public string OutputFilePath { get; set; } = outputFilePath;
    
    //TODO: needs to be adjusted
    private static readonly Tuple<int, int>[] QPTable = new Tuple<int, int>[] {
        new(1280*720,  0),
        new(1920*1080, 0),
        new(3840*2160, 0),
        new(5760*2880, 0), //VR6K
        new(8128*4096, 0) //VR8K
    }.OrderBy(t => t.Item1).ToArray();

    public async Task<bool> ExecuteAsync(CancellationToken cancellationToken, Action<EncodingProgress> onProgress) {
        var mediaInfo = await FFProbe.AnalyseAsync(InputFilePath, cancellationToken: cancellationToken);
        if (mediaInfo.PrimaryVideoStream == null) return false;
        int W = mediaInfo.PrimaryVideoStream.Width;
        int H = mediaInfo.PrimaryVideoStream.Height;
        int qp = Utils.ToQPValue(W, H, QPTable);
        return await FFMpegArguments
            .FromFileInput(InputFilePath, true, args => args.WithHardwareAcceleration())
            .OutputToFile(OutputFilePath, true, args => args
                .CopyChannel(Channel.Audio)
                .CopyChannel(Channel.Subtitle)
                .WithVideoCodec("h264_nvenc")
                .WithArgument(new NvencSpeedPreset(NvencSpeed.p2))
                .WithArgument(new NvencTuneArgument(NvencTune.hq))
                .WithArgument(new NvencHighBitDepthArgument(true))
                .WithArgument(new NvencQPArgument((byte)qp))
                .WithFastStart()
            )
            .NotifyOnProgress(progress => onProgress(new() {
                progress = progress,
                duration = mediaInfo.Duration,
                framerate = (float)mediaInfo.PrimaryVideoStream.FrameRate,
                job = job,
                inputPath = InputFilePath,
                outputPath = OutputFilePath
            }))
            .CancellableThrough(cancellationToken)
            .ProcessAsynchronously();
    }
}