public async Task <Stream> EncodeImage(ImageEncodingOptions options, CancellationToken cancellationToken)
{
ValidateInput(options);
await ResourcePool.WaitAsync(cancellationToken).ConfigureAwait(false);
try
{
return(await EncodeImageInternal(options, cancellationToken).ConfigureAwait(false));
}
finally
{
ResourcePool.Release();
}
}
private string GetArguments(ImageEncodingOptions options, string inputFilename)
{
var vfScale = GetFilterGraph(options);
var outputFormat = GetOutputFormat(options.Format);
var quality = (options.Quality ?? 100) * .3;
quality = 31 - quality;
var qualityValue = Convert.ToInt32(Math.Max(quality, 1));
return(string.Format("-f image2 -i file:\"{3}\" -q:v {0} {1} -f image2pipe -vcodec {2} -",
qualityValue.ToString(_usCulture),
vfScale,
outputFormat,
inputFilename));
}
private string GetFilterGraph(ImageEncodingOptions options)
{
if (!options.Width.HasValue &&
!options.Height.HasValue &&
!options.MaxHeight.HasValue &&
!options.MaxWidth.HasValue)
{
return(string.Empty);
}
var widthScale = "-1";
var heightScale = "-1";
if (options.MaxWidth.HasValue)
{
widthScale = "min(iw\\," + options.MaxWidth.Value.ToString(_usCulture) + ")";
}
else if (options.Width.HasValue)
{
widthScale = options.Width.Value.ToString(_usCulture);
}
if (options.MaxHeight.HasValue)
{
heightScale = "min(ih\\," + options.MaxHeight.Value.ToString(_usCulture) + ")";
}
else if (options.Height.HasValue)
{
heightScale = options.Height.Value.ToString(_usCulture);
}
var scaleMethod = "lanczos";
return(string.Format("-vf scale=\"{0}:{1}\"",
widthScale,
heightScale));
}
public Task <Stream> EncodeImage(ImageEncodingOptions options, CancellationToken cancellationToken)
{
return(new ImageEncoder(FFMpegPath, _logger, _fileSystem, _appPaths).EncodeImage(options, cancellationToken));
}
public Task <Stream> EncodeImage(ImageEncodingOptions options, CancellationToken cancellationToken)
{
throw new NotImplementedException();
}
private async Task <Stream> EncodeImageInternal(ImageEncodingOptions options, CancellationToken cancellationToken)
{
ValidateInput(options);
var inputPath = options.InputPath;
var filename = Path.GetFileName(inputPath);
if (HasDiacritics(filename))
{
inputPath = GetTempFile(inputPath);
filename = Path.GetFileName(inputPath);
}
var process = new Process
{
StartInfo = new ProcessStartInfo
{
CreateNoWindow = true,
UseShellExecute = false,
FileName = _ffmpegPath,
Arguments = GetArguments(options, filename),
WindowStyle = ProcessWindowStyle.Hidden,
ErrorDialog = false,
RedirectStandardOutput = true,
RedirectStandardError = true,
WorkingDirectory = Path.GetDirectoryName(inputPath)
}
};
_logger.Debug("ffmpeg " + process.StartInfo.Arguments);
process.Start();
var memoryStream = new MemoryStream();
#pragma warning disable 4014
// Important - don't await the log task or we won't be able to kill ffmpeg when the user stops playback
process.StandardOutput.BaseStream.CopyToAsync(memoryStream);
#pragma warning restore 4014
// MUST read both stdout and stderr asynchronously or a deadlock may occurr
process.BeginErrorReadLine();
var ranToCompletion = process.WaitForExit(5000);
if (!ranToCompletion)
{
try
{
_logger.Info("Killing ffmpeg process");
process.Kill();
process.WaitForExit(1000);
}
catch (Exception ex)
{
_logger.ErrorException("Error killing process", ex);
}
}
var exitCode = ranToCompletion ? process.ExitCode : -1;
process.Dispose();
if (exitCode == -1 || memoryStream.Length == 0)
{
memoryStream.Dispose();
var msg = string.Format("ffmpeg image encoding failed for {0}", options.InputPath);
_logger.Error(msg);
throw new ApplicationException(msg);
}
memoryStream.Position = 0;
return(memoryStream);
}
private void ValidateInput(ImageEncodingOptions options)
{
}
