public FrameDecoder(RawFrame sampleSource, int targetWidth, int targetHeight, AVPixelFormat targetFormat, int targetBufferSize, int algorithm = ffmpeg.SWS_BICUBIC, int align = 1)
{
var actualTargetBufferSize = ffmpeg.av_image_get_buffer_size(targetFormat, targetWidth, targetHeight, align);
if (actualTargetBufferSize != targetBufferSize)
{
throw new ArgumentOutOfRangeException(nameof(targetBufferSize), FormattableString.Invariant($"Incorrect buffer size - expected {actualTargetBufferSize}"));
}
var format = ImageConvert.ConvertFormat(sampleSource.Format);
var converterContext = ffmpeg.sws_getContext(sampleSource.Width, sampleSource.Height, format, targetWidth, targetHeight, targetFormat, algorithm, srcFilter: null, dstFilter: null, param: null);
try
{
_converterContext = converterContext;
_targetBufferSize = targetBufferSize;
_targetWidth = targetWidth;
_targetHeight = targetHeight;
_targetFormat = targetFormat;
_align = align;
}
catch (Exception)
{
ffmpeg.sws_freeContext(converterContext);
throw;
}
}
public DecodedFrame Convert(RawFrame source, byte *targetBuffer)
{
var destData = new byte_ptrArray4();
var destLineSize = new int_array4();
ffmpeg.av_image_fill_arrays(ref destData, ref destLineSize, targetBuffer, _targetFormat, _targetWidth, _targetHeight, _align).ThrowExceptionIfError(nameof(ffmpeg.av_image_fill_arrays));
var frame = source.Frame;
ffmpeg.sws_scale(_converterContext, frame->data, frame->linesize, 0, frame->height, destData, destLineSize).ThrowExceptionIfError(nameof(ffmpeg.sws_scale));
return(new DecodedFrame(targetBuffer, _targetBufferSize, _targetWidth, _targetHeight, _targetFormat, destData, destLineSize, sharedBuffer: true));
}