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• Memory issues when using ffmpeg and gloss to play videos

  21 décembre 2015, par Noughtmare

  I’m trying to make a video player with haskell using ffmpeg-light, JuicyPixels and gloss. I’m now able to play video, but frames that have been played stay in memory. This causes major memory issues. How can I avoid storing all the frames in memory ?

  Here is my code :

  {-# LANGUAGE FlexibleContexts #-}
  
  module Main where
  
  
  
  -- For my own code:
  
  import Graphics.Gloss
  
  import Codec.FFmpeg
  
  import Codec.FFmpeg.Juicy
  
  import Codec.Picture
  
  import Control.Applicative
  
  import Data.Maybe
  
  import Graphics.Gloss.Juicy
  
  import Control.Monad (when, join)
  
  import Codec.FFmpeg.Decode
  
  import Codec.FFmpeg.Enums
  
  import Control.Monad.Error.Class
  
  import Control.Arrow (first)
  
  import Control.Monad.Except (runExceptT)
  
  import Graphics.Gloss.Interface.IO.Animate
  
  import Data.IORef
  
  
  
  -- Temporary hardcoded resolution
  
  resolution :: (Int,Int)
  
  resolution = (640, 360)
  
  
  
  main :: IO ()
  
  main = do
  
      -- First initialize ffmpeg, this needs to be run before other ffmpeg functions
  
      initFFmpeg
  
      -- Open the samplevideo for reading. video :: IO (IO (Maybe (AVFrame, Double)), IO ())
  
      video <- runExceptT $ frameReaderTime' avPixFmtRgb24 "SampleVideo_640x360_1mb.flv"
  
      either
  
            -- This code gets called when the frameReader reports an error
  
            (const $ putStrLn "Can't read file")
  
            -- This opens a new window and plays the video in it on a white background
  
            (animateFixedIO (InWindow "Nice Window" resolution (10, 10)) white . frameAtWait . fst)
  
  
  
            video
  
  
  
  -- This finds the frame at given time
  
  frameAtWait :: IO (Maybe (AVFrame, Double)) -> Float -> IO Picture
  
  frameAtWait getFrame time = do
  
      -- This gets the next frame from the video
  
      (frame, t) <- fromJust <$> getFrame
  
      -- t has to be converted from Double to Float
  
      let t' = realToFrac t
  
          -- The difference between the requested time and the actual frame time
  
          difference = t' - time
  
      -- If the frame is not yet supposed to be shown
  
      if difference > 0 then do
  
          -- Wait until it is
  
          threadDelay . round . (* 1000000) $ difference
  
          -- then return it
  
          fromJust <$> frameToPicture frame
  
      else
  
          -- return it immediately
  
          fromJust <$> frameToPicture frame
  
  
  
  -- This function converts a ffmpeg internal AVFrame to a gloss picture
  
  frameToPicture :: AVFrame -> IO (Maybe Picture)
  
  frameToPicture frame = do
  
      -- convert it to a juicypixels dynamicimage
  
      dynImage <- toJuicy frame
  
      -- then convert it to a gloss picture and return it
  
      return . join $ fmap fromDynamicImage dynImage

• Stream webcam through FFMPEG in VB.NET

  4 mars 2014, par M.Yazdian

  I want to stream my webcam on RTMP through FFMPEG. I use FFMPEG in ProcessStartInfo, when I start this process FFMPEG run in new window and my web cam Images stream in RTMP correctly.

  But I have problems in this case :

  1. When I start to process, FFMPEG runs in the new window (cmd), I don’t need this window. I would like FFMPEG to work in background.
  2. When the FFMPEG in working I can't access to my forms. My vb.net forms are locked until FFMPEG process is done.
  3. I have 3 webcam in my computer and I like to stream these 3 webcams on the RTMP such as webcam1 , webcam2 , webcam3, But when I start stream from webcam1, I can't access to start other webcams to stream.

  I use this code to stream webcam on RTMP :

  Dim camName = DirectCast(sender, Button)
  
  Dim psi As ProcessStartInfo = New ProcessStartInfo("c:\ImageMagick\ffmpeg.exe")
  
  Dim proc As Process = Process.Start(psi)
  
  psi.UseShellExecute = False
  
  psi.CreateNoWindow = False
  
  psi.Arguments = " -f dshow -i video=""" & camName.Name & """ -threads 1 -preset ultrafast -vcodec libx264 -b:v 640k -acodec copy -f flv rtmp://192.168.1.2/live/sample2 "
  
  proc = Process.Start(psi)
  
  proc.WaitForExit()

  Please advice me to solve these issues

• How to execute commands on a bat file from c++

  2 avril 2015, par AK47

  I’m working in a c++ project and I need to call ffmpeg command prompt(ff-promt) from my c++ code and execute commands on that bat command line. I have already opened the window. but not functioning the command running on that bat window. Can anyone please guide me how to do it.
  for opening I have used following command

  FILE *bat = _popen("ffmpeg-2.5.2-win64-static\\ff-prompt", "w");

  I used following command to write the command on that and enter

  fprintf(bat, "ffmpeg -i Sample.avi -vn -ar 44100 -ac 2 -ab 192k -f mp3 Sample.mp3\r");

  please guide me soon. Thanks