/// <summary>
/// Checks a collection of x264Settings and modifies them if needed to fit within the level constraints.
/// </summary>
/// <param name="level">the level to enforce</param>
/// <param name="inputSettings">the collection of x264Settings to check</param>
/// <param name="frameSize">the size of the decoded video frame in bytes</param>
/// <returns>A compliant set of x264Settings</returns>
public x264Settings EnforceSettings(int level, x264Settings inputSettings, double frameSize, out AVCLevelEnforcementReturn enforcement)
{
x264Settings enforcedSettings = (x264Settings)inputSettings.Clone();
enforcement = new AVCLevelEnforcementReturn();
enforcement.Altered = false;
enforcement.EnableP4x4mv = true;
enforcement.EnableVBVBufferSize = true;
enforcement.EnableVBVMaxRate = true;
enforcement.Panic = false;
enforcement.PanicString = "";
if (!checkP4x4(level, inputSettings))
{
enforcement.Altered = true;
enforcedSettings.P4x4mv = false;
}
if (checkP4x4Enabled(level, inputSettings))
{
enforcement.EnableP4x4mv = true;
}
else
{
enforcement.EnableP4x4mv = false;
}
// step through various options to enforce the max decoded picture buffer size
while (!this.checkMaxDPB(level, enforcedSettings, frameSize))
{
if (enforcedSettings.BFramePyramid)
{
enforcement.Altered = true;
enforcedSettings.BFramePyramid = false; // try turning off pyramid first
}
else
if (enforcedSettings.NbRefFrames > 1)
{
enforcement.Altered = true;
enforcedSettings.NbRefFrames -= 1; // try reducing the number of reference frames
}
else
if (enforcedSettings.NbBframes > 0)
{
enforcement.Altered = true;
enforcedSettings.NbBframes = 0; // try turning off B frames
}
else
{
enforcement.Panic = true;
enforcement.PanicString = "Can't force settings to conform to level (the frame size is too large)";
// reset output settings to original and set level to unrestrained
enforcedSettings = (x264Settings)inputSettings.Clone();
enforcedSettings.Level = 15;
return(enforcedSettings);
}
}
// Disallow independent specification of MaxBitrate and MaxBufferSize unless Unrestrained
if (level < 15)
{
enforcement.EnableVBVMaxRate = false;
enforcedSettings.VBVMaxBitrate = -1;
enforcement.EnableVBVBufferSize = false;
enforcedSettings.VBVBufferSize = -1;
}
else
{
enforcement.EnableVBVMaxRate = true;
enforcement.EnableVBVBufferSize = true;
}
return(enforcedSettings);
}
/// <summary>
/// Checks a collection of x264Settings and modifies them if needed to fit within the level constraints.
/// </summary>
/// <param name="level">the level to enforce</param>
/// <param name="inputSettings">the collection of x264Settings to check</param>
/// <param name="frameSize">the size of the decoded video frame in bytes</param>
/// <returns>A compliant set of x264Settings</returns>
public x264Settings EnforceSettings(int level, x264Settings inputSettings, double frameSize, out AVCLevelEnforcementReturn enforcement)
{
x264Settings enforcedSettings = (x264Settings) inputSettings.Clone();
enforcement = new AVCLevelEnforcementReturn();
enforcement.Altered = false;
enforcement.EnableP4x4mv = true;
enforcement.EnableVBVBufferSize = true;
enforcement.EnableVBVMaxRate = true;
enforcement.Panic = false;
enforcement.PanicString = "";
if (!checkP4x4(level, inputSettings))
{
enforcement.Altered = true;
enforcedSettings.P4x4mv = false;
}
if (checkP4x4Enabled(level, inputSettings))
enforcement.EnableP4x4mv = true;
else
enforcement.EnableP4x4mv = false;
// step through various options to enforce the max decoded picture buffer size
while (!this.checkMaxDPB(level,enforcedSettings, frameSize))
{
if (enforcedSettings.NbRefFrames > 1)
{
enforcement.Altered = true;
enforcedSettings.NbRefFrames -= 1; // try reducing the number of reference frames
}
else
{
enforcement.Panic = true;
enforcement.PanicString = "Can't force settings to conform to level (the frame size is too large)";
// reset output settings to original and set level to unrestrained
enforcedSettings = (x264Settings)inputSettings.Clone();
enforcedSettings.Level = 15;
return enforcedSettings;
}
}
// Disallow independent specification of MaxBitrate and MaxBufferSize unless Unrestrained
if (level < 15)
{
enforcement.EnableVBVMaxRate = false;
enforcedSettings.VBVMaxBitrate = -1;
enforcement.EnableVBVBufferSize = false;
enforcedSettings.VBVBufferSize = -1;
}
else
{
enforcement.EnableVBVMaxRate = true;
enforcement.EnableVBVBufferSize = true;
}
return enforcedSettings;
}
