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using System;
using System.Collections.Generic;
using MediaBrowser.Model.Extensions;
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),
new ResolutionConfiguration(1920, 4000000),
new ResolutionConfiguration(3840, 35000000)
};
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
};
}
}
var resolutionConfig = GetResolutionConfiguration(outputBitrate);
if (resolutionConfig != null)
{
var originvalValue = maxWidth;
maxWidth = Math.Min(resolutionConfig.MaxWidth, maxWidth ?? resolutionConfig.MaxWidth);
if (!originvalValue.HasValue || originvalValue.Value != maxWidth.Value)
{
maxHeight = null;
}
}
return new ResolutionOptions
{
MaxWidth = maxWidth,
MaxHeight = maxHeight
};
}
private static ResolutionConfiguration GetResolutionConfiguration(int outputBitrate)
{
foreach (var config in Configurations)
{
if (outputBitrate <= config.MaxBitrate)
{
return config;
}
}
return null;
}
private static double GetVideoBitrateScaleFactor(string codec)
{
if (StringHelper.EqualsIgnoreCase(codec, "h265") ||
StringHelper.EqualsIgnoreCase(codec, "hevc") ||
StringHelper.EqualsIgnoreCase(codec, "vp9"))
{
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);
}
}
}
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