private static WritableLockBitImage GetFrameFromVideo(VideoFingerPrintWrapper video, int frameNumber)
{
using (MediaInfoProcess mediaInfoProcess = new MediaInfoProcess(video.FilePath))
{
MediaInfo mediaInfo = mediaInfoProcess.Execute();
if (mediaInfo.GetFramerate().Numerator == 0)
{
throw new Exception("Did not get valid frame rate");
}
int width = mediaInfo.GetWidth();
int height = mediaInfo.GetHeight();
var ffmpegProcessSettings = new FFMPEGProcessVideoSettings(
video.FilePath,
mediaInfo.GetFramerate().Numerator,
mediaInfo.GetFramerate().Denominator * 4,
FFMPEGMode.SeekFrame
);
ffmpegProcessSettings.TargetFrame = frameNumber;
byte[] frameBytes = new byte[width * height * 3];
int offset = 0;
using (
var ffmpegProcess = new FFMPEGProcess(
ffmpegProcessSettings,
(stdoutBytes, numBytes) =>
{
Buffer.BlockCopy(stdoutBytes, 0, frameBytes, offset, numBytes);
offset += numBytes;
},
false
)
)
{
ffmpegProcess.Execute();
if (offset != 3 * width * height)
{
throw new Exception("Did not get all bytes to produce valid frame");
}
WritableLockBitImage videoFrame = new WritableLockBitImage(width, height, frameBytes);
videoFrame.Lock();
return(videoFrame);
}
}
}
/// <summary>
/// Index a video file by continuously dumping Y4M raw video and indexing it
/// </summary>
/// <param name="videoFile"></param>
/// <returns></returns>
public static VideoFingerPrintWrapper IndexVideo(string videoFile, long maxMemory)
{
using (var mediaInfoProcess = new MediaInfoProcess(videoFile))
{
MediaInfo info = mediaInfoProcess.Execute();
if (info.GetFramerate().Numerator == 0)
{
throw new InvalidOperationException("Invalid framerate for: " + videoFile);
}
return new VideoFingerPrintWrapper
{
FilePath = videoFile,
FingerPrints = IndexVideo(videoFile, info, maxMemory).ToArray(),
};
}
}