public RecordingMetadata ConvertPreviewMedia(ConversionConfiguration config)
{
// generate output directory
if (Directory.Exists(config.OutputDirectory))
{
Directory.Delete(config.OutputDirectory, true);
}
Directory.CreateDirectory(config.OutputDirectory);
// convert file
ConvertVideoFiles(config, true);
// generate recording object
var finalRecording = new RecordingMetadata();
finalRecording.FileName = "slides.mp4";
finalRecording.PresenterFileName = "talkinghead.mp4";
finalRecording.StageVideo = "stage.mp4";
finalRecording.Slides = BuildThumbnails(config, "slides.mp4");
finalRecording.Duration = FFmpegHelper.GetMediaLength(config.SlideVideoPath).TotalSeconds;
FFmpegHelper.ExportThumbnail(5f, Path.Combine(config.OutputDirectory, "stage.mp4"), config.OutputDirectory, "thumbnail");
return(finalRecording);
}
public Slide[] BuildThumbnails(ConversionConfiguration config, string slidesFileName)
{
if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
{
return(BuildThumbnailsUnix(config, slidesFileName));
}
else
{
return(BuildThumbnailsWin(config, slidesFileName));
}
}
private void ConvertZoomVideoFile(ConversionConfiguration config, bool preview)
{
string args = "-i \"" + config.SlideVideoPath + "\" " +
"-f mp4 -vcodec libx264 -crf 23 -preset veryfast -tune stillimage -profile:v baseline -level 3.0 -pix_fmt yuv420p -r 30 " + (preview ? " -t 10 " : "") + "\"" + Path.Combine(config.OutputDirectory, "slides.mp4") + "\" ";
_logger.LogInformation("Execute ffmpeg: {0}", args);
Process p = FFmpegHelper.FFmpeg(args, false);
p.Start();
p.WaitForExit();
}
private void ConvertVideoFiles(ConversionConfiguration config, bool preview)
{
var lenSlideVideo = FFmpegHelper.GetMediaLength(config.SlideVideoPath);
var lenTHVideo = FFmpegHelper.GetMediaLength(config.TalkingHeadVideoPath);
var trimTHVideo = lenTHVideo - lenSlideVideo;
// normalize audio
var audioLevels = FFmpegHelper.GetAudioLevels(config.TalkingHeadVideoPath);
string audioFilter = "[1:a]";
if (audioLevels != null)
{
audioFilter = $"[1:a]loudnorm=I=-23:LRA=11:tp=-1:measured_I={audioLevels.Input_I}:measured_LRA={audioLevels.Input_Lra}:measured_tp={audioLevels.Input_Tp}:measured_thresh={audioLevels.Input_Thresh}:offset={audioLevels.Target_Offset}:linear=true[1a];[1a]";
}
// run processing
string args = "-i \"" + config.SlideVideoPath + "\" " +
"-i \"" + config.TalkingHeadVideoPath + "\" " +
"-i \"" + config.RecordingStyle.TargetDimension.Background + "\" " +
// video filters
"-filter_complex " +
"\"" +
"[1:v]trim=start=" + trimTHVideo.TotalSeconds.ToString("0.00000", CultureInfo.InvariantCulture) + ",setpts=PTS-STARTPTS[1v];" +
audioFilter +
"atrim=start=" + trimTHVideo.TotalSeconds.ToString("0.00000", CultureInfo.InvariantCulture) + ",asetpts=PTS-STARTPTS,asplit=2[1a1][1a2];" +
config.RecordingStyle.getFFmpegFilterString() +
"\" " +
"-map \"[slides1]\" -f mp4 -vcodec libx264 -crf 23 -preset veryfast -tune stillimage -profile:v baseline -level 3.0 -pix_fmt yuv420p -r 30 " + (preview ? " -t 10 " : "") + "\"" + Path.Combine(config.OutputDirectory, "slides.mp4") + "\" " +
"-map \"[th_ck_ct]\" -map \"[1a1]\" -f mp4 -vcodec libx264 -crf 23 -preset veryfast -profile:v baseline -level 3.0 -pix_fmt yuv420p -r 30 -acodec aac -b:a 192k " + (preview ? " -t 10 " : "") + "\"" + Path.Combine(config.OutputDirectory, "talkinghead.mp4") + "\" " +
"-map \"[stage]\" -map \"[1a2]\" -f mp4 -vcodec libx264 -crf 23 -preset veryfast -profile:v baseline -level 3.0 -pix_fmt yuv420p -r 30 -acodec aac -b:a 192k " + (preview ? " -t 10 " : "") + "\"" + Path.Combine(config.OutputDirectory, "stage.mp4") + "\" ";
_logger.LogInformation("Execute ffmpeg: {0}", args);
Process p = FFmpegHelper.FFmpeg(args, false);
p.Start();
p.WaitForExit();
}
public RecordingMetadata ConvertPreviewZoomMedia(ConversionConfiguration config)
{
// generate output directory
if (Directory.Exists(config.OutputDirectory))
{
Directory.Delete(config.OutputDirectory, true);
}
Directory.CreateDirectory(config.OutputDirectory);
// convert file
ConvertZoomVideoFile(config, true);
var targetVideoPath = Path.Combine(config.OutputDirectory, "slides.mp4");
// generate preview
var thumbOutDir = Path.Combine(config.OutputDirectory, "thumbs");
Directory.CreateDirectory(thumbOutDir);
string thumbName = FFmpegHelper.ExportThumbnail(5f, targetVideoPath, Path.Combine(config.OutputDirectory, "thumbs"), "0");
// generate recording object
var finalRecording = new RecordingMetadata();
finalRecording.FileName = "slides.mp4";
finalRecording.Slides = new Slide[] { new Slide
{
StartPosition = 0,
Thumbnail = "thumbs/" + thumbName,
Ocr = ""
} };
finalRecording.Duration = FFmpegHelper.GetMediaLength(targetVideoPath).TotalSeconds;
FFmpegHelper.ExportThumbnail(5f, Path.Combine(config.OutputDirectory, "slides.mp4"), config.OutputDirectory, "thumbnail");
return(finalRecording);
}
private Slide[] BuildThumbnailsUnix(ConversionConfiguration config, string slidesFileName)
{
var thumbOutDir = Path.Combine(config.OutputDirectory, "thumbs");
Directory.CreateDirectory(thumbOutDir);
List <Slide> result = new List <Slide>();
try
{
dynamic projectJson = JsonConvert.DeserializeObject(File.ReadAllText(config.MetadataPath));
int currentId = 0;
var keyframes = new List <TimeSpan>();
keyframes.Add(TimeSpan.Zero);
foreach (string timestamp in projectJson["slides"])
{
keyframes.Add(TimeSpan.Parse(timestamp));
}
foreach (var keyframe in keyframes)
{
TimeSpan?nextKeyframe = null;
if (keyframes.IndexOf(keyframe) != keyframes.Count - 1)
{
nextKeyframe = keyframes[keyframes.IndexOf(keyframe) + 1];
}
else
{
nextKeyframe = FFmpegHelper.GetMediaLength(config.SlideVideoPath);
}
string thumbName = FFmpegHelper.ExportThumbnail((float)nextKeyframe.GetValueOrDefault().TotalSeconds - 2.0f, config.SlideVideoPath, thumbOutDir,
(currentId++).ToString());
var tmpFileName = Path.Combine("/tmp", Path.GetRandomFileName());
var process = FFmpegHelper.BuildProcess("tesseract", Path.Combine(thumbOutDir, thumbName) + " \"" + tmpFileName + "\"", false);
process.Start();
process.WaitForExit();
var ocr = File.ReadAllText(tmpFileName + ".txt");
File.Delete(tmpFileName + ".txt");
var slide = new Slide
{
StartPosition = (float)keyframe.TotalSeconds + 0.2f,
Thumbnail = "thumbs/" + thumbName,
Ocr = ocr
};
if (keyframe.Equals(TimeSpan.Zero))
{
slide.StartPosition = 0.0f;
}
result.Add(slide);
}
}
catch (Exception ex)
{
_logger.LogError(ex.Message);
}
return(result.ToArray());
}
private Slide[] BuildThumbnailsWin(ConversionConfiguration config, string slidesFileName)
{
var thumbOutDir = Path.Combine(config.OutputDirectory, "thumbs");
Directory.CreateDirectory(thumbOutDir);
var ocrEngine = new TesseractEngine(Path.Combine("resources", "tessdata"), "eng", EngineMode.Default);
List <Slide> result = new List <Slide>();
try
{
dynamic projectJson = JsonConvert.DeserializeObject(File.ReadAllText(config.MetadataPath));
int currentId = 0;
var keyframes = new List <TimeSpan>();
keyframes.Add(TimeSpan.Zero);
foreach (string timestamp in projectJson["slides"])
{
keyframes.Add(TimeSpan.Parse(timestamp));
}
foreach (var keyframe in keyframes)
{
TimeSpan?nextKeyframe = null;
if (keyframes.IndexOf(keyframe) != keyframes.Count - 1)
{
nextKeyframe = keyframes[keyframes.IndexOf(keyframe) + 1];
}
else
{
nextKeyframe = FFmpegHelper.GetMediaLength(config.SlideVideoPath);
}
string thumbName = FFmpegHelper.ExportThumbnail((float)nextKeyframe.GetValueOrDefault().TotalSeconds - 2.0f, config.SlideVideoPath, thumbOutDir,
(currentId++).ToString());
var slide = new Slide
{
StartPosition = (float)keyframe.TotalSeconds + 0.2f,
Thumbnail = "thumbs/" + thumbName,
Ocr = PerformOcr(Path.Combine(thumbOutDir, thumbName), ocrEngine)
};
if (keyframe.Equals(TimeSpan.Zero))
{
slide.StartPosition = 0.0f;
}
result.Add(slide);
}
}
catch (Exception ex)
{
_logger.LogError(ex.Message);
}
finally
{
ocrEngine.Dispose();
}
return(result.ToArray());
}
