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• Fast video compression like Whatsapp

  5 août 2015, par Douglas Anunciação

  I need to speed up video compression in my Android app. I’m using FFMPEG and it takes 3 minutes to compress 80MB video. Does anyone knows a better solution ?

  The command I’m using is :

  /data/data/com.moymer/app_bin/ffmpeg -y -i /storage/emulated/0/DCIM/Camera/VID_20150803_164811363.mp4 -s 640x352 -r 25 -vcodec mpeg4 -ac 1 -preset ultrafast -strict -2 /storage/emulated/0/DCIM/Camera/compressed_video.mp4

  I’m running this command using FFMPEG for Android from this github repo : https://github.com/guardianproject/android-ffmpeg-java

  The code to use FFMPEG in my project is inside an AsyncTask and is copied below :

      @Override
  
      protected Object doInBackground(Object... params) {
  
  
  
          ItemRoloDeCamera compressedVideo = new ItemRoloDeCamera();
  
  
  
          File videoInputFile = new File(video.getSdcardPath());
  
  
  
          File videoFolderFile = videoInputFile.getParentFile();
  
  
  
          File videoOutputFile = new File(videoFolderFile, "video_comprimido_moymer.mp4");
  
  
  
          if (videoFolderFile.exists())
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video folder exist");
  
          else
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video folder DON'T exist");
  
  
  
          if (videoInputFile.exists())
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video input file exist");
  
          else
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video input file DON'T exist");
  
  
  
          if (videoOutputFile.exists())
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video output file exist");
  
          else
  
              android.util.Log.e("COMPRESS VIDEO UTILS", "video output file DON'T exist");
  
  
  
          FfmpegController ffmpegController;
  
  
  
          try {
  
  
  
              ffmpegController = new FfmpegController(context, videoFolderFile);
  
  
  
              Clip clipIn = new Clip(videoInputFile.getAbsolutePath());
  
  
  
              ffmpegController.getInfo(clipIn, new ShellUtils.ShellCallback() {
  
                  @Override
  
                  public void shellOut(String shellLine) {
  
                      videoInfo.add(shellLine);
  
                  }
  
  
  
                  @Override
  
                  public void processComplete(int exitValue) {
  
                      videoInfo.add(String.valueOf(exitValue));
  
                  }
  
              });
  
  
  
              int rotate = getRotateMetadata();
  
  
  
              Clip clipOut = new Clip(videoOutputFile.getAbsolutePath());
  
              clipOut.videoFps = "24";
  
              clipOut.videoBitrate = 512;
  
              clipOut.audioChannels = 1;
  
              clipOut.width = 640;
  
              clipOut.height = 352;
  
  
  
              if (rotate == 90)
  
                  clipOut.videoFilter = "transpose=1";
  
              else if (rotate == 180)
  
                  clipOut.videoFilter = "transpose=1,transpose=1";
  
              else if (rotate == 270)
  
                  clipOut.videoFilter = "transpose=1,transpose=1,transpose=1";
  
  
  
              millisDuration = getVideoDuration(videoInputFile.getAbsolutePath());
  
  
  
              float secondsDuration = millisDuration / 1000f;
  
  
  
              clipOut.duration = secondsDuration;
  
  
  
              ffmpegController.processVideo(clipIn, clipOut, true, new ShellUtils.ShellCallback() {
  
                  @Override
  
                  public void shellOut(String shellLine) {
  
  
  
                      android.util.Log.e("COMPRESS VIDEO UTILS", "shellOut - " + shellLine);
  
  
  
                      float percentage = getTimeMetadata(shellLine);
  
  
  
                      if (percentage >= 0f)
  
                          publishProgress(percentage);
  
  
  
                  }
  
  
  
                  @Override
  
                  public void processComplete(int exitValue) {
  
                      android.util.Log.e("COMPRESS VIDEO UTILS", "proccess complete - " + exitValue);
  
                  }
  
              });
  
  
  
  
  
          } catch (IOException e) {
  
              e.printStackTrace();
  
          } catch (Exception e) {
  
              e.printStackTrace();
  
          } finally {
  
  
  
              if (videoOutputFile.exists()) {
  
  
  
                  android.util.Log.e("COMPRESS VIDEO UTILS", "finished ffmpeg ---> video output file exist");
  
  
  
                  compressedVideo.setSdcardPath(videoOutputFile.getAbsolutePath());
  
  
  
                  return compressedVideo;
  
  
  
              } else
  
                  android.util.Log.e("COMPRESS VIDEO UTILS", "finished ffmpeg ---> video output file DON'T exist");
  
  
  
          }
  
  
  
          return compressedVideo;
  
  
  
      }
  
  
  
      private float getTimeMetadata(String shellLine) {
  
  
  
          float percentage = -1;
  
  
  
          if (shellLine.contains("time=")) {
  
  
  
              String[] timeLine = shellLine.split("=");
  
  
  
              String time = timeLine[5];
  
              time = time.replace("bitrate", "");
  
              time = time.trim();
  
  
  
  //            String source = "00:10:17";
  
              String[] tokens = time.split(":");
  
              int secondsToMs = (int) (Float.parseFloat(tokens[2]) * 1000);
  
              int minutesToMs = Integer.parseInt(tokens[1]) * 60000;
  
              int hoursToMs = Integer.parseInt(tokens[0]) * 3600000;
  
              long timeInMillis = secondsToMs + minutesToMs + hoursToMs;
  
  
  
              percentage = (timeInMillis * 100.0f) / millisDuration;
  
  
  
          }
  
  
  
          return percentage;
  
  
  
      }
  
  
  
      private int getRotateMetadata() {
  
  
  
          int rotate = 0;
  
  
  
          String durationString = "";
  
  
  
          for (String shellLine : videoInfo) {
  
  
  
              if (shellLine.contains("rotate")) {
  
  
  
                  //rotate          : 270
  
  
  
                  String[] rotateLine = shellLine.split(":");
  
  
  
                  rotate = Integer.parseInt(rotateLine[1].trim());
  
  
  
              }
  
  
  
          }
  
  
  
          return rotate;
  
  
  
      }
  
  
  
      public static long getVideoDuration(String videoPath) {
  
  
  
          MediaMetadataRetriever retriever = new MediaMetadataRetriever();
  
  
  
          retriever.setDataSource(videoPath);
  
  
  
          String time = retriever
  
                  .extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
  
  
  
          long timeInmillisec = Long.parseLong(time);
  
  
  
          return timeInmillisec;
  
  
  
      }

  The only change I made in the processVideo method was to add the following lines when building the commmand :

  cmd.add("-preset");
  
  cmd.add("ultrafast");

• Anomalie #2787 : La compression HTML mange les retour ligne dans les formulaires

  8 août 2012, par nicolas -

  J’ai exactement le même comportement en local sur un Mac avec MAMP et en prod chez AlwaysData, donc j’ai un doute que cela vienne d’une particularité du serveur. Je vais creuser, je vous tiens au courant.

• SNES Hardware Compression

  16 juin 2011, par Multimedia Mike — Game Hacking

  I was browsing the source code for some Super Nintendo Entertainment System (SNES) emulators recently. I learned some interesting things about compression hardware. I had previously uncovered one compression algorithm used in an SNES title but that was implemented in software.

  SNES game cartridges — being all hardware — were at liberty to expand the hardware capabilities of the base system by adding new processors. The most well-known of these processors was the Super FX which allows for basic polygon graphical rendering, powering such games as Star Fox. It was by no means the only such add-on processor, though. Here is a Wikipedia page of all the enhancement chips used in assorted SNES games. A number of them mention compression and so I delved into the emulators to find the details :

  • The Super FX is listed in Wikipedia vaguely as being able to decompress graphics. I see no reference to decompression in emulator source code.
  • DSP-3 emulation source code makes reference to LZ-type compression as well as tree/symbol decoding. I’m not sure if the latter is a component of the former. Wikipedia lists the chip as supporting "Shannon-Fano bitstream decompression."
  • Similar to Super FX, the SA-1 chip is listed in Wikipedia as having some compression capabilities. Again, either that’s not true or none of the games that use the chip (notably Super Mario RPG) make use of the feature.
  • The S-DD1 chip uses arithmetic and Golomb encoding for compressing graphics. Wikipedia refers to this as the ABS Lossless Entropy Algorithm. Googling for further details on that algorithm name yields no results, but I suspect it’s unrelated to anti-lock brakes. The algorithm is alleged to allow Star Ocean to smash 13 MB of graphics into a 4 MB cartridge ROM (largest size of an SNES cartridge).
  • The SPC7110 can decompress data using a combination of arithmetic coding and Z-curve/Morton curve reordering.

  No, I don’t plan to implement codecs for these schemes. But it’s always comforting to know that I could.

  Not directly a compression scheme, but still a curious item is the MSU1 concept put forth by the bsnes emulator. This is a hypothetical coprocessor implemented by bsnes that gives an emulated cartridge access to a 4 GB address space. What to do with all this space ? Allow for the playback of uncompressed PCM audio as well as uncompressed video at 240x144x256 colors @ 30 fps. According to the docs and the source code, the latter feature doesn’t appear to be implemented, though ; only the raw PCM playback.