//returns tuple of start and end timestamps for best frame range to splice from existing mp4
private Tuple <long, long> ProcessAllFrames()
{
var coreframeslength = _fps * 2; //core sample of frames will be two seconds of video might in future vary depending on user settings
var computelimit = _framelist.Count - coreframeslength; //this will keep walking average calcs only happening within range
try
{
if (_framelist != null)
{
for (var i = 0; i < _framelist.Count; i++)
{
var currenttimestamp = _framelist.Keys[i];
if (i < computelimit) //makes sense to compute because we will can use it
{
var coreframesrange = _framelist.ToList().GetRange(i, coreframeslength);
var listofscores = new SortedList <long, double>();
foreach (var kvp in coreframesrange)
{
listofscores.Add(kvp.Key, kvp.Value.Size() != 0 ? GetImageUsability(Utils.GetSparseFace(kvp.Value)) : -1); //return -1 for usabilty if no face exists
}
var avg = listofscores.Average(x => x.Value);
var sumOfSquaresOfDifferences = listofscores.ToList().Select(val => (val.Value - avg) * (val.Value - avg)).Sum();
var stdev = Math.Sqrt(sumOfSquaresOfDifferences / coreframesrange.Count);
Coreframesavg.Add(currenttimestamp, avg - stdev); //avg - std dev should give those with best avg score and lowest deviation
}
else //can't use computations past this point so just need timestamps
{
Coreframesavg.Add(currenttimestamp, 0); //avg - std dev should give those with best avg score and lowest deviation
}
//Log.Info(TAG, "moving average index" + i);
}
}
var bestframegroupkey = Coreframesavg.Aggregate((l, r) => l.Value > r.Value ? l : r).Key; //gets key of max value (avg-stdev) from dictionary
bestTSRange = new Tuple <long, long>(bestframegroupkey, Coreframesavg.Keys[Coreframesavg.IndexOfKey(bestframegroupkey) + GetFrameTotal()]);
return(bestTSRange);
}
catch (Exception e)
{
Log.Error(TAG, "Frames Processing messed up", e);
throw;
}
}
private Tuple <long, long> ProcessAllFramesold()
{
var coreframeslength = _fps * 2; //core sample of frames will be two seconds of video
try
{
if (_framelist != null)
{
for (var i = 0; i < _framelist.Count - coreframeslength; i++)
{
var currenttimestamp = _framelist.Keys[i];
var range = _framelist.ToList().GetRange(i, coreframeslength);
var listofscores = new SortedList <long, double>();
foreach (var kvp in range)
{
listofscores.Add(kvp.Key, kvp.Value.Size() != 0 ? GetImageUsability(Utils.GetSparseFace(kvp.Value)) : -1); //return -1 for usabilty if no face exists
}
var avg = listofscores.Average(x => x.Value);
var sumOfSquaresOfDifferences = listofscores.ToList().Select(val => (val.Value - avg) * (val.Value - avg)).Sum();
var stdev = Math.Sqrt(sumOfSquaresOfDifferences / range.Count);
Coreframesavg.Add(currenttimestamp, avg - stdev); //avg - std dev should give those with best avg score and lowest deviation //todo can make this leaner later
//Log.Info(TAG, "moving average index" + i);
}
}
var bestframegroupkey = Coreframesavg.Aggregate((l, r) => l.Value > r.Value ? l : r).Key; //gets key of max value (avg-stdev) from dictionary
var frameoffset = coreframeslength / 2; //will get offset to put coreframes in middle of total frames for entire video.
if (frameoffset > Coreframesavg.IndexOfKey(bestframegroupkey)) //fix for when best frame is at beggining of video
{
frameoffset = 0;
}
var bestlist = Coreframesavg.ToList().GetRange(Coreframesavg.IndexOfKey(bestframegroupkey) - frameoffset, GetFrameTotal());//.ToDictionary(x => x.Key, y => y.Value);
bestTSRange = new Tuple <long, long>(bestlist.Select(x => x.Key).First(), bestlist.Select(x => x.Key).Last());
return(bestTSRange);
}
catch (Exception e)
{
Log.Error(TAG, "Frames Processing messed up", e);
throw;
}
}
