From 56cf1a581c7f0ffc19fca284a13878d231136aaa Mon Sep 17 00:00:00 2001 From: gnattu Date: Sun, 22 Sep 2024 10:01:47 +0800 Subject: [PATCH] Better bitrate and resolution normalization (#12644) --- Jellyfin.Api/Helpers/StreamingHelpers.cs | 8 ++- .../MediaEncoding/EncodingHelper.cs | 8 ++- .../Dlna/ResolutionNormalizer.cs | 69 ++++++++++--------- 3 files changed, 50 insertions(+), 35 deletions(-) diff --git a/Jellyfin.Api/Helpers/StreamingHelpers.cs b/Jellyfin.Api/Helpers/StreamingHelpers.cs index 3cc6a393bc..3a5db2f3fb 100644 --- a/Jellyfin.Api/Helpers/StreamingHelpers.cs +++ b/Jellyfin.Api/Helpers/StreamingHelpers.cs @@ -219,11 +219,17 @@ public static class StreamingHelpers } else { + var h264EquivalentBitrate = EncodingHelper.ScaleBitrate( + state.OutputVideoBitrate.Value, + state.ActualOutputVideoCodec, + "h264"); var resolution = ResolutionNormalizer.Normalize( state.VideoStream?.BitRate, state.OutputVideoBitrate.Value, + h264EquivalentBitrate, state.VideoRequest.MaxWidth, - state.VideoRequest.MaxHeight); + state.VideoRequest.MaxHeight, + state.TargetFramerate); state.VideoRequest.MaxWidth = resolution.MaxWidth; state.VideoRequest.MaxHeight = resolution.MaxHeight; diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs index f8ba8ddd80..788bd03351 100644 --- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs +++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs @@ -2400,7 +2400,7 @@ namespace MediaBrowser.Controller.MediaEncoding return 1; } - private static int ScaleBitrate(int bitrate, string inputVideoCodec, string outputVideoCodec) + public static int ScaleBitrate(int bitrate, string inputVideoCodec, string outputVideoCodec) { var inputScaleFactor = GetVideoBitrateScaleFactor(inputVideoCodec); var outputScaleFactor = GetVideoBitrateScaleFactor(outputVideoCodec); @@ -2424,6 +2424,12 @@ namespace MediaBrowser.Controller.MediaEncoding { scaleFactor = Math.Max(scaleFactor, 2); } + else if (bitrate >= 30000000) + { + // Don't scale beyond 30Mbps, it is hardly visually noticeable for most codecs with our prefer speed encoding + // and will cause extremely high bitrate to be used for av1->h264 transcoding that will overload clients and encoders + scaleFactor = 1; + } return Convert.ToInt32(scaleFactor * bitrate); } diff --git a/MediaBrowser.Model/Dlna/ResolutionNormalizer.cs b/MediaBrowser.Model/Dlna/ResolutionNormalizer.cs index 5d7daa81aa..1a636b2403 100644 --- a/MediaBrowser.Model/Dlna/ResolutionNormalizer.cs +++ b/MediaBrowser.Model/Dlna/ResolutionNormalizer.cs @@ -2,28 +2,33 @@ #pragma warning disable CS1591 using System; +using System.Linq; namespace MediaBrowser.Model.Dlna { public static class ResolutionNormalizer { - private static readonly ResolutionConfiguration[] Configurations = - new[] - { - new ResolutionConfiguration(426, 320000), - new ResolutionConfiguration(640, 400000), - new ResolutionConfiguration(720, 950000), - new ResolutionConfiguration(1280, 2500000), - new ResolutionConfiguration(1920, 4000000), - new ResolutionConfiguration(2560, 20000000), - new ResolutionConfiguration(3840, 35000000) - }; + // Please note: all bitrate here are in the scale of SDR h264 bitrate at 30fps + private static readonly ResolutionConfiguration[] _configurations = + [ + new ResolutionConfiguration(416, 365000), + new ResolutionConfiguration(640, 730000), + new ResolutionConfiguration(768, 1100000), + new ResolutionConfiguration(960, 3000000), + new ResolutionConfiguration(1280, 6000000), + new ResolutionConfiguration(1920, 13500000), + new ResolutionConfiguration(2560, 28000000), + new ResolutionConfiguration(3840, 50000000) + ]; public static ResolutionOptions Normalize( int? inputBitrate, int outputBitrate, + int h264EquivalentOutputBitrate, int? maxWidth, - int? maxHeight) + int? maxHeight, + float? targetFps, + bool isHdr = false) // We are not doing HDR transcoding for now, leave for future use { // If the bitrate isn't changing, then don't downscale the resolution if (inputBitrate.HasValue && outputBitrate >= inputBitrate.Value) @@ -38,16 +43,26 @@ namespace MediaBrowser.Model.Dlna } } - var resolutionConfig = GetResolutionConfiguration(outputBitrate); - if (resolutionConfig is not null) + var referenceBitrate = h264EquivalentOutputBitrate * (30.0f / (targetFps ?? 30.0f)); + + if (isHdr) { - var originvalValue = maxWidth; + referenceBitrate *= 0.8f; + } - maxWidth = Math.Min(resolutionConfig.MaxWidth, maxWidth ?? resolutionConfig.MaxWidth); - if (!originvalValue.HasValue || originvalValue.Value != maxWidth.Value) - { - maxHeight = null; - } + var resolutionConfig = GetResolutionConfiguration(Convert.ToInt32(referenceBitrate)); + + if (resolutionConfig is null) + { + return new ResolutionOptions { MaxWidth = maxWidth, MaxHeight = maxHeight }; + } + + var originWidthValue = maxWidth; + + maxWidth = Math.Min(resolutionConfig.MaxWidth, maxWidth ?? resolutionConfig.MaxWidth); + if (!originWidthValue.HasValue || originWidthValue.Value != maxWidth.Value) + { + maxHeight = null; } return new ResolutionOptions @@ -59,19 +74,7 @@ namespace MediaBrowser.Model.Dlna private static ResolutionConfiguration GetResolutionConfiguration(int outputBitrate) { - ResolutionConfiguration previousOption = null; - - foreach (var config in Configurations) - { - if (outputBitrate <= config.MaxBitrate) - { - return previousOption ?? config; - } - - previousOption = config; - } - - return null; + return _configurations.FirstOrDefault(config => outputBitrate <= config.MaxBitrate); } } }