flowframes/Code/Media/FfmpegEncode.cs

using Flowframes.Data;
using Flowframes.IO;
using Flowframes.MiscUtils;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using static Flowframes.AvProcess;
using Utils = Flowframes.Media.FfmpegUtils;

namespace Flowframes.Media
{
    partial class FfmpegEncode : FfmpegCommands
    {
        public static async Task FramesToVideo(string framesFile, string outPath, Interpolate.OutMode outMode, Fraction fps, Fraction resampleFps, float itsScale, VidExtraData extraData, LogMode logMode = LogMode.OnlyLastLine, bool isChunk = false)
        {
            if (logMode != LogMode.Hidden)
                Logger.Log((resampleFps.GetFloat() <= 0) ? "Encoding video..." : $"Encoding video resampled to {resampleFps.GetString()} FPS...");

            IoUtils.RenameExistingFile(outPath);
            Directory.CreateDirectory(outPath.GetParentDir());
            string[] encArgs = Utils.GetEncArgs(Utils.GetCodec(outMode), (Interpolate.currentSettings.ScaledResolution.IsEmpty ? Interpolate.currentSettings.InputResolution : Interpolate.currentSettings.ScaledResolution), Interpolate.currentSettings.outFps.GetFloat());

            string inArg = $"-f concat -i {Path.GetFileName(framesFile)}";
            string linksDir = Path.Combine(framesFile + Paths.symlinksSuffix);

            if (Config.GetBool(Config.Key.allowSymlinkEncoding, true) && Symlinks.SymlinksAllowed())
            {
                if (await Symlinks.MakeSymlinksForEncode(framesFile, linksDir, Padding.interpFrames))
                    inArg = $"-i \"{linksDir}/%{Padding.interpFrames}d{GetConcatFileExt(framesFile)}\"";
            }

            string args = "";

            for(int i = 0; i < encArgs.Length; i++)
            {
                string pre = i == 0 ? "" : $" && ffmpeg {AvProcess.GetFfmpegDefaultArgs()}";
                string post = (i == 0 && encArgs.Length > 1) ? $"-f null -" : outPath.Wrap();
                string fs = (!isChunk && outMode == Interpolate.OutMode.VidMp4) ? $"-movflags +faststart" : "";
                args += $"{pre} -fps_mode 0 {GetFfmpegExportArgsIn(fps, itsScale)} {inArg} {encArgs[i]} {GetFfmpegExportArgsOut(resampleFps, extraData)} -threads {Config.GetInt(Config.Key.ffEncThreads)} {fs} {post} ";
            }

            await RunFfmpeg(args, framesFile.GetParentDir(), logMode, !isChunk);
            IoUtils.TryDeleteIfExists(linksDir);
        }

        public static string GetFfmpegExportArgsIn(Fraction fps, float itsScale)
        {
            fps = fps / new Fraction(itsScale);
            return $"-r {fps}";
        }

        public static string GetFfmpegExportArgsOut (Fraction resampleFps, VidExtraData extraData)
        {
            List<string> filters = new List<string>();
            string extraArgs = "";

            if (resampleFps.GetFloat() >= 0.1f)
                filters.Add($"fps=fps={resampleFps}");

            if (Config.GetBool(Config.Key.keepColorSpace) && extraData.HasAllValues())
            {
                Logger.Log($"Applying color transfer ({extraData.colorSpace}).", true, false, "ffmpeg");
                filters.Add($"scale=out_color_matrix={extraData.colorSpace}");
                extraArgs += $" -colorspace {extraData.colorSpace} -color_primaries {extraData.colorPrimaries} -color_trc {extraData.colorTransfer} -color_range:v \"{extraData.colorRange}\"";
            }

            if (!string.IsNullOrWhiteSpace(extraData.displayRatio) && !extraData.displayRatio.MatchesWildcard("*N/A*"))
                extraArgs += $"-aspect {extraData.displayRatio}";

            return filters.Count > 0 ? $"-vf {string.Join(",", filters)}" : "" + $" {extraArgs}";
        }

        public static string GetConcatFileExt (string concatFilePath)
        {
            return Path.GetExtension(File.ReadAllLines(concatFilePath).FirstOrDefault().Split('\'')[1]);
        }

        public static async Task FramesToFrames(string framesFile, string outDir, int startNo, Fraction fps, Fraction resampleFps, string format = "png", int lossyQ = 1, LogMode logMode = LogMode.OnlyLastLine)
        {
            Directory.CreateDirectory(outDir);
            string inArg = $"-f concat -i {Path.GetFileName(framesFile)}";
            string linksDir = Path.Combine(framesFile + Paths.symlinksSuffix);
            format = format.ToLower();

            if (Config.GetBool(Config.Key.allowSymlinkEncoding, true) && Symlinks.SymlinksAllowed())
            {
                if (await Symlinks.MakeSymlinksForEncode(framesFile, linksDir, Padding.interpFrames))
                    inArg = $"-i {Path.GetFileName(framesFile) + Paths.symlinksSuffix}/%{Padding.interpFrames}d{GetConcatFileExt(framesFile)}";
            }

            string sn = $"-start_number {startNo}";
            string rate = fps.ToString().Replace(",", ".");
            string vf = (resampleFps.GetFloat() < 0.1f) ? "" : $"-vf fps=fps={resampleFps}";
            string compression = format == "png" ? pngCompr : $"-q:v {lossyQ}";
            string codec = format == "webp" ? "-c:v libwebp" : ""; // Specify libwebp to avoid putting all frames into single animated WEBP
            string args = $"-fps_mode 0 -r {rate} {inArg} {codec} {compression} {sn} {vf} \"{outDir}/%{Padding.interpFrames}d.{format}\"";
            await RunFfmpeg(args, framesFile.GetParentDir(), logMode, "error", true);
            IoUtils.TryDeleteIfExists(linksDir);
        }

        public static async Task FramesToGifConcat(string framesFile, string outPath, Fraction rate, bool palette, int colors, Fraction resampleFps, float itsScale, LogMode logMode = LogMode.OnlyLastLine)
        {
            if (rate.GetFloat() > 50f && (resampleFps.GetFloat() > 50f || resampleFps.GetFloat() < 1))
                resampleFps = new Fraction(50, 1);  // Force limit framerate as encoding above 50 will cause problems

            if (logMode != LogMode.Hidden)
                Logger.Log((resampleFps.GetFloat() <= 0) ? $"Encoding GIF..." : $"Encoding GIF resampled to {resampleFps.GetFloat().ToString().Replace(",", ".")} FPS...");
            
            string framesFilename = Path.GetFileName(framesFile);
            string dither = Config.Get(Config.Key.gifDitherType).Split(' ').First();
            string paletteFilter = palette ? $"-vf \"split[s0][s1];[s0]palettegen={colors}[p];[s1][p]paletteuse=dither={dither}\"" : "";
            string fpsFilter = (resampleFps.GetFloat() <= 0) ? "" : $"fps=fps={resampleFps}";
            string vf = FormatUtils.ConcatStrings(new string[] { paletteFilter, fpsFilter });
            string extraArgs = Config.Get(Config.Key.ffEncArgs);
            rate = rate / new Fraction(itsScale);
            string args = $"-f concat -r {rate} -i {framesFilename.Wrap()} -gifflags -offsetting {vf} {extraArgs} {outPath.Wrap()}";
            await RunFfmpeg(args, framesFile.GetParentDir(), LogMode.OnlyLastLine, "error");
        }
    }
}