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using GLib;
using Gst;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Text;
namespace GstreamerSharp
{
class Program
{
static void Main(string[] args)
{
Gst.Application.Init(ref args);
Element src = ElementFactory.Make("audiotestsrc");
Element convert = ElementFactory.Make("audioconvert");
Element volume = new ExampleVolume();
Element sink = ElementFactory.Make("autoaudiosink");
Pipeline pipeline = new Pipeline();
pipeline.Add(src, convert, volume, sink);
Element.Link(src, convert, volume, sink);
pipeline.SetState(State.Playing);
MainLoop loop = new MainLoop();
loop.Run();
pipeline.SetState(State.Null);
Console.ReadLine();
}
}
class ExampleVolume : Element
{
public ExampleVolume()
{
Volume = 0.5;
_sink = new Pad(__sinkTemplate, "sink");
_sink.ChainFunctionFull = Chain;
_sink.Flags |= PadFlags.ProxyCaps;
AddPad(_sink);
_src = new Pad(__srcTemplate, "src");
_src.Flags |= PadFlags.ProxyCaps;
AddPad(_src);
}
public double Volume { get; set; }
FlowReturn Chain(Pad pad, Gst.Object parent, Gst.Buffer buffer)
{
if (Volume == 1.0)
{
return _src.Push(buffer);
}
buffer.MakeWritable();
MapInfo mapInfo;
buffer.Map(out mapInfo, MapFlags.Read | MapFlags.Write);
ScaleInt16(mapInfo.DataPtr, mapInfo.Size / 2, Volume);
buffer.Unmap(mapInfo);
return _src.Push(buffer);
}
private unsafe void ScaleInt16(IntPtr data, ulong size, double volume)
{
Int16* sample = (Int16*)data;
for (ulong i = 0; i < size; i++)
{
*sample = ClampInt16(*sample * volume);
sample++;
}
}
private Int16 ClampInt16(double d)
{
int i = (int)Math.Round(d);
if (i > Int16.MaxValue)
{
return Int16.MaxValue;
}
else if (i < Int16.MinValue)
{
return Int16.MinValue;
}
else
{
return (Int16)i;
}
}
Pad _src;
Pad _sink;
static ExampleVolume()
{
Caps audioCaps = Caps.FromString("audio/x-raw, format=(string) S16LE, rate=(int) [1, MAX], channels=(int) 2, layout=(string) interleaved");
__srcTemplate = new PadTemplate("src", PadDirection.Src, PadPresence.Always, audioCaps);
__sinkTemplate = new PadTemplate("sink", PadDirection.Sink, PadPresence.Always, audioCaps);
}
static PadTemplate __srcTemplate;
static PadTemplate __sinkTemplate;
}
}
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