jellyfin-server/MediaBrowser.Model/Dlna/ResolutionNormalizer.cs
2016-06-06 13:33:55 -04:00

81 lines
2.4 KiB
C#

using System;
using System.Collections.Generic;
namespace MediaBrowser.Model.Dlna
{
public class ResolutionNormalizer
{
private static readonly List<ResolutionConfiguration> Configurations =
new List<ResolutionConfiguration>
{
new ResolutionConfiguration(426, 320000),
new ResolutionConfiguration(640, 400000),
new ResolutionConfiguration(720, 950000),
new ResolutionConfiguration(1280, 2500000)
};
public static ResolutionOptions Normalize(int? inputBitrate,
int outputBitrate,
string inputCodec,
string outputCodec,
int? maxWidth,
int? maxHeight)
{
// If the bitrate isn't changing, then don't downlscale the resolution
if (inputBitrate.HasValue && outputBitrate >= inputBitrate.Value)
{
if (maxWidth.HasValue || maxHeight.HasValue)
{
return new ResolutionOptions
{
MaxWidth = maxWidth,
MaxHeight = maxHeight
};
}
}
foreach (var config in Configurations)
{
if (outputBitrate <= config.MaxBitrate)
{
var originvalValue = maxWidth;
maxWidth = Math.Min(config.MaxWidth, maxWidth ?? config.MaxWidth);
if (!originvalValue.HasValue || originvalValue.Value != maxWidth.Value)
{
maxHeight = null;
}
break;
}
}
return new ResolutionOptions
{
MaxWidth = maxWidth,
MaxHeight = maxHeight
};
}
private static double GetVideoBitrateScaleFactor(string codec)
{
if (string.Equals(codec, "h265", StringComparison.OrdinalIgnoreCase) ||
string.Equals(codec, "hevc", StringComparison.OrdinalIgnoreCase))
{
return .5;
}
return 1;
}
public static int ScaleBitrate(int bitrate, string inputVideoCodec, string outputVideoCodec)
{
var inputScaleFactor = GetVideoBitrateScaleFactor(inputVideoCodec);
var outputScaleFactor = GetVideoBitrateScaleFactor(outputVideoCodec);
var scaleFactor = outputScaleFactor/inputScaleFactor;
var newBitrate = scaleFactor*bitrate;
return Convert.ToInt32(newBitrate);
}
}
}