public static SwsContext Create(VideoFormatInfo source, VideoFormatInfo target, SwsFlags flags)
{
var pointer = ffmpeg.sws_getContext(
source.Width,
source.Height,
source.PixelFormat.ToAVFormat(),
target.Width,
target.Height,
target.PixelFormat.ToAVFormat(),
flags: (int)flags,
srcFilter: null,
dstFilter: null,
param: null
);
return(new SwsContext(pointer));
}
public FilterContext AddSource(VideoFormatInfo format)
{
AVFilterContext *sourceFilterContext;
var pixelFormatName = ffmpeg.av_get_pix_fmt_name(format.PixelFormat.ToAVFormat());
var args = string.Format(
"video_size={0}x{1}:pix_fmt={2}:time_base={3}/{4}:pixel_aspect={5}/{6}",
format.Width,
format.Height,
pixelFormatName,
format.TimeBase.Numerator,
format.TimeBase.Denominator,
format.AspectRatio.Numerator,
format.AspectRatio.Denominator
);
var sourceFilter = Filter.FromName("buffer");
ffmpeg.avfilter_graph_create_filter(&sourceFilterContext, sourceFilter.Pointer, "in", args, null, pointer).EnsureSuccess();
return(new FilterContext(sourceFilterContext));
}
public static FilterGraph Create(
Codec decoder,
Codec encoder,
string filterSpecification)
{
if (decoder is null)
{
throw new ArgumentNullException(nameof(decoder));
}
if (encoder is null)
{
throw new ArgumentNullException(nameof(encoder));
}
FilterContext bufferSource = default;
FilterContext bufferSink = default;
var graph = new FilterGraph();
if (decoder is VideoDecoder)
{
var format = new VideoFormatInfo(
decoder.Context.PixelFormat,
decoder.Context.Width,
decoder.Context.Height,
decoder.Context.TimeBase,
decoder.Context.AspectRatio
);
bufferSource = graph.AddSource(format);
bufferSink = graph.AddSink(Filter.FromName("buffersink"));
bufferSink.SetOption("pix_fmts", (int)encoder.Context.PixelFormat.ToAVFormat());
}
else if (decoder is AudioDecoder audioDecoder)
{
if (audioDecoder.Context.ChannelLayout == ChannelLayout.Unknown)
{
throw new Exception("Invalid ChannelLayout:" + audioDecoder.Context.ChannelLayout);
// decoder.Context.ChannelLayout = (ChannelLayout)ffmpeg.av_get_default_channel_layout(decoder.Context.ChannelCount);
}
bufferSource = graph.AddSource(new AudioFormatInfo(
sampleFormat: audioDecoder.Context.SampleFormat,
sampleRate: audioDecoder.Context.SampleRate,
channelCount: audioDecoder.Context.ChannelCount,
channelLayout: audioDecoder.Context.ChannelLayout
));
bufferSink = graph.AddSink(Filter.FromName("abuffersink"));
// $"aresample={resampledAudioFormat.SampleRate},aformat=sample_fmts={sampleFormat}:channel_layouts=stereo,asetnsamples=n=1024:p=0"
// var sampleFormatName = ffmpeg.av_get_sample_fmt_name(encoder.Context.SampleFormat.ToAVFormat());
bufferSink.SetOption("sample_fmts", (int)encoder.Context.SampleFormat.ToAVFormat());
bufferSink.SetOption("channel_layouts", (ulong)encoder.Context.ChannelLayout);
bufferSink.SetOption("sample_rates", encoder.Context.SampleRate);
}
else
{
throw new Exception("Invalid codec");
}
graph.Outputs = new FilterInOut("in", bufferSource);
graph.Inputs = new FilterInOut("out", bufferSink);
graph.bufferSource = bufferSource;
graph.bufferSink = bufferSink;
if (filterSpecification != null)
{
graph.Parse(filterSpecification);
}
else
{
ffmpeg.avfilter_link(bufferSource.Pointer, 0, bufferSink.Pointer, 0);
}
graph.Initialize();
return(graph);
}
public VideoResampler(VideoFormatInfo source, VideoFormatInfo target, SwsFlags flags = SwsFlags.FastBilinear)
{
Source = source ?? throw new ArgumentNullException(nameof(source));
Target = target ?? throw new ArgumentNullException(nameof(target));
Context = SwsContext.Create(source, target, flags);
}
public static int GetBufferSize(this VideoFormatInfo format, int align)
{
return(ffmpeg.av_image_get_buffer_size(format.PixelFormat.ToAVFormat(), format.Width, format.Height, align));
}
public static int[] GetStrides(this VideoFormatInfo format, int align)
{
return(GetStrides(format.PixelFormat, format.Width, align));
}
public VideoFrame(VideoFormatInfo format)
: this(format.PixelFormat, format.Width, format.Height)
{
}
