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• Evolution #4391 : Squelettes de la dist : améliorer le markup et passer à BEM

  18 octobre 2019, par RastaPopoulos ♥

  Cela fait mal mal d’années que ça a changé, moi perso je préfère 1000 fois le truc à jour, c’est bien plus carré : ya UN caractère dédié à séparer les mots d’une même entité ("-" : mon-super-module) et UN caractère dédié à séparer les concepts BEM, block, element et modifier ("_" : mon-super-module__item_alt). Plus de mélange, c’est bien plus cohérent.
  (Et ici on n’est pas dans un éditeur de code, normalement tout ça on le lit en monospace, donc ya pas de gros soucis à voir le nombre de caractères.)

• How to get 20 screenshots from a video with tile or mosiac effect ffmpeg ?

  2 octobre 2019, par Nane

  I am trying to get 20(Will take screens at 5%, 10%, 15%, 20%,.., of the video) screenshot which will be arranged in a single image like this Link

  I found this command but it is taking screenshot based on frames like 1000 I want to get evenly distributed 20 screenshots of the entire video

  ffmpeg -ss 00:00:10 -i movie.avi -frames 1 -vf "select=not(mod(n\,1000)),scale=320:240,tile=2x3" out.png

• Send AVPacket over Network

  2 décembre 2019, par Yondonator

  I’m generating AVPackets with an encoder with ffmpeg and now I want to send them with UDP to another Computer and show them there.
  The problem is I don’t know how to convert the packet to bytes and back. I tried this to copy the package :

  AVPacket newPacket = avcodec.av_packet_alloc();
  
  
  
  
  
  ByteBuffer byteBuffer = packet.buf().buffer().asByteBuffer();
  
  int bufferSize = byteBuffer.capacity();
  
  byte bytes[] = new byte[bufferSize];
  
  byteBuffer.get(bytes);
  
  AVBufferRef newBufferRef = avutil.av_buffer_alloc(bufferSize);
  
  newBufferRef.data(new BytePointer(bytes));
  
  newPacket.buf(newBufferRef);
  
  
  
  
  
  ByteBuffer dataBuffer = packet.data().asByteBuffer();
  
  int dataSize = dataBuffer.capacity();
  
  byte dataBytes[] = new byte[dataSize];
  
  dataBuffer.get(dataBytes);
  
  BytePointer dataPointer = new BytePointer(dataBytes);
  
  newPacket.data(dataPointer);
  
  
  
  
  
  newPacket.dts(packet.dts());
  
  newPacket.duration(packet.duration());
  
  newPacket.flags(packet.flags());
  
  newPacket.pos(packet.pos());
  
  newPacket.pts(packet.pts());
  
  newPacket.side_data_elems(0);
  
  newPacket.size(packet.size());
  
  newPacket.stream_index(packet.stream_index());
  
  
  
  
  
  videoPlayer.sendPacket(newPacket);

  This gives me this Error :

  [h264 @ 0000018951be8440] Invalid NAL unit size (3290676 > 77).
  
  [h264 @ 0000018951be8440] Error splitting the input into NAL units.
  
  [h264 @ 0000018951bf6480] Invalid NAL unit size (15305314 > 163).
  
  [h264 @ 0000018951bf6480] Error splitting the input into NAL units.

  The problem is newPacket.data(). When I set it directly : newPacket.data(packet.data())
  it works. Also packet.data().asByteBuffer().capacity() returns 1 and packet.data().capacity() returns 0.

  This is my method that creates the decoder :

  private void startUnsafe() throws Exception
  
      {
  
          int result;
  
  
  
          convertContext = null;
  
          codec = null;
  
          codecContext = null;
  
          AVFrame = null;
  
          RGBAVFrame = null;
  
          frame = new Frame();
  
  
  
          codec = avcodec_find_decoder(codecID);
  
          if(codec == null)
  
          {
  
              throw new Exception("Unable to find decoder");
  
          }
  
  
  
          codecContext = avcodec_alloc_context3(codec);
  
          if(codecContext == null)
  
          {
  
              releaseUnsafe();
  
              throw new Exception("Unable to alloc codec context!");
  
          }
  
  
  
          AVCodecParameters para = avcodec_parameters_alloc();
  
          para.bit_rate(streamBitrate);
  
          para.width(streamWidth);
  
          para.height(streamHeight);
  
          para.codec_id(codecID);
  
          para.codec_type(AVMEDIA_TYPE_VIDEO);
  
          try
  
          {
  
              byte extradataByte[] = Files.readAllBytes(new File("extradata.byte").toPath());
  
              para.extradata(new BytePointer(extradataByte));
  
              para.extradata_size(extradataByte.length);
  
          }
  
          catch (IOException e1)
  
          {
  
              e1.printStackTrace();
  
              throw new Exception("extradata file not available");
  
          }
  
  
  
          result = avcodec_parameters_to_context(codecContext, para);
  
          if(result < 0)
  
          {
  
              throw new Exception("Unable to copy parameters to context! [" + result + "]");
  
          }
  
  
  
          codecContext.thread_count(0);
  
  
  
          result = avcodec_open2(codecContext, codec, new AVDictionary());
  
          if(result < 0)
  
          {
  
              releaseUnsafe();
  
              throw new Exception("Unable to open codec context![" + result + "]");
  
          }
  
  
  
          AVFrame = av_frame_alloc();
  
          if(AVFrame == null)
  
          {
  
              releaseUnsafe();
  
              throw new Exception("Unable to alloc AVFrame!");
  
          }
  
  
  
          RGBAVFrame = av_frame_alloc();
  
          if(RGBAVFrame == null)
  
          {
  
              releaseUnsafe();
  
              throw new Exception("Unable to alloc AVFrame!");
  
          }
  
          initRGBAVFrame();
  
  
  
          TimerTask task = new TimerTask() {
  
  
  
              @Override
  
              public void run()
  
              {
  
                  timerTask();
  
              }
  
          };
  
          timer = new Timer();
  
          timer.scheduleAtFixedRate(task, 0, (long) (1000/streamFramerateDouble));
  
  
  
          window.setVisible(true);
  
      }

  The file extradata.byte has some bytes that I got from another video, because without them it doesn’t work too.

  EDIT :

  package org.stratostream.streaming;
  
  
  
  import java.nio.ByteBuffer;
  
  
  
  
  
  import org.bytedeco.javacpp.BytePointer;
  
  import org.bytedeco.javacpp.Pointer;
  
  import org.bytedeco.javacpp.avcodec;
  
  import org.bytedeco.javacpp.avutil;
  
  import org.bytedeco.javacpp.avcodec.AVPacket;
  
  import org.bytedeco.javacpp.avcodec.AVPacketSideData;
  
  
  
  
  
  public class PacketIO {
  
  
  
  
  
      public static final int SIDE_DATA_FIELD = 0;
  
      public static final int SIDE_ELEMENTS_FIELD = 4;
  
      public static final int SIDE_TYPE_FIELD = 8;
  
      public static final int DTS_FIELD = 12;
  
      public static final int PTS_FIELD = 20;
  
      public static final int FLAGS_FIELD = 28;
  
      public static final int DATA_OFFSET = 32;
  
  
  
      public static byte[] toByte(AVPacket packet) throws Exception
  
      {
  
          int dataSize = packet.size();
  
          ByteBuffer dataBuffer = packet.data().capacity(dataSize).asByteBuffer();
  
          byte dataBytes[] = new byte[dataSize];
  
          dataBuffer.get(dataBytes);
  
  
  
          AVPacketSideData sideData = packet.side_data();
  
          int sideSize = sideData.size();
  
          ByteBuffer sideBuffer = sideData.data().capacity(sideSize).asByteBuffer();
  
          byte sideBytes[] = new byte[sideSize];
  
          sideBuffer.get(sideBytes);
  
  
  
          int sideOffset = DATA_OFFSET + dataSize;
  
          int resultSize = sideOffset + sideSize;
  
          byte resultBytes[] = new byte[resultSize];
  
          System.arraycopy(dataBytes, 0, resultBytes, DATA_OFFSET, dataSize);
  
          System.arraycopy(sideBytes, 0, resultBytes, sideOffset, sideSize);
  
          resultBytes[SIDE_DATA_FIELD] = (byte) (sideOffset >>> 24);
  
          resultBytes[SIDE_DATA_FIELD+1] = (byte) (sideOffset >>> 16);
  
          resultBytes[SIDE_DATA_FIELD+2] = (byte) (sideOffset >>> 8);
  
          resultBytes[SIDE_DATA_FIELD+3] = (byte) (sideOffset >>> 0);
  
  
  
          int sideType = sideData.type();
  
          intToByte(resultBytes, SIDE_TYPE_FIELD, sideType);
  
  
  
          int sideElements = packet.side_data_elems();
  
          intToByte(resultBytes, SIDE_ELEMENTS_FIELD, sideElements);
  
  
  
          long dts = packet.dts();
  
          longToByte(resultBytes, DTS_FIELD, dts);
  
  
  
          long pts = packet.pts();
  
          longToByte(resultBytes, PTS_FIELD, pts);
  
  
  
          int flags = packet.flags();
  
          intToByte(resultBytes, FLAGS_FIELD, flags);
  
  
  
          return resultBytes;
  
      }
  
  
  
      public static AVPacket toPacket(byte bytes[]) throws Exception
  
      {
  
          AVPacket packet = avcodec.av_packet_alloc();
  
  
  
          int sideOffset = byteToInt(bytes, SIDE_DATA_FIELD);
  
          int sideElements = byteToInt(bytes, SIDE_ELEMENTS_FIELD);
  
          int sideType = byteToInt(bytes, SIDE_TYPE_FIELD);
  
          int dataSize = sideOffset - DATA_OFFSET;
  
          int sideSize = bytes.length - sideOffset;
  
  
  
          long pts = byteToLong(bytes, PTS_FIELD);
  
          long dts = byteToLong(bytes, DTS_FIELD);
  
          int flags = byteToInt(bytes, FLAGS_FIELD);
  
  
  
          packet.pts(pts);
  
          packet.dts(dts);
  
          packet.flags(flags);
  
  
  
  
  
          Pointer newDataPointer =  avutil.av_malloc(bytes.length);
  
          BytePointer dataPointer = new BytePointer(newDataPointer);
  
          byte dataBytes[] = new byte[dataSize];
  
          System.arraycopy(bytes, DATA_OFFSET, dataBytes, 0, dataSize);
  
          dataPointer.put(dataBytes);
  
          packet.data(dataPointer);
  
          packet.size(dataSize);
  
  
  
          Pointer newSidePointer = avutil.av_malloc(sideSize);
  
          BytePointer sidePointer = new BytePointer(newSidePointer);
  
          byte sideBytes[] = new byte[sideSize];
  
          System.arraycopy(bytes, sideOffset, sideBytes, 0, sideSize);
  
          sidePointer.put(sideBytes);
  
          AVPacketSideData sideData = new AVPacketSideData();
  
          sideData.data(sidePointer);
  
          sideData.type(sideType);
  
          sideData.size(sideSize);
  
          //packet.side_data(sideData);
  
          //packet.side_data_elems(sideElements);
  
  
  
          return packet;
  
      }
  
  
  
      private static void intToByte(byte[] bytes, int offset, int value)
  
      {
  
          bytes[offset] = (byte) (value >>> 24);
  
          bytes[offset+1] = (byte) (value >>> 16);
  
          bytes[offset+2] = (byte) (value >>> 8);
  
          bytes[offset+3] = (byte) (value >>> 0);
  
      }
  
  
  
      private static void longToByte(byte[] bytes, int offset, long value)
  
      {
  
          bytes[offset] = (byte) (value >>> 56);
  
          bytes[offset+1] = (byte) (value >>> 48);
  
          bytes[offset+2] = (byte) (value >>> 40);
  
          bytes[offset+3] = (byte) (value >>> 32);
  
          bytes[offset+4] = (byte) (value >>> 24);
  
          bytes[offset+5] = (byte) (value >>> 16);
  
          bytes[offset+6] = (byte) (value >>> 8);
  
          bytes[offset+7] = (byte) (value >>> 0);
  
      }
  
  
  
      private static int byteToInt(byte[] bytes, int offset)
  
      {
  
          return (bytes[offset]<<24)&0xff000000|(bytes[offset+1]<<16)&0x00ff0000|(bytes[offset+2]<<8)&0x0000ff00|(bytes[offset+3]<<0)&0x000000ff;
  
      }
  
  
  
      private static long byteToLong(byte[] bytes, int offset)
  
      {
  
          return (bytes[offset]<<56)&0xff00000000000000L|(bytes[offset+1]<<48)&0x00ff000000000000L|(bytes[offset+2]<<40)&0x0000ff0000000000L|(bytes[offset+3]<<32)&0x000000ff00000000L|(bytes[offset+4]<<24)&0x00000000ff000000L|(bytes[offset+5]<<16)&0x0000000000ff0000L|(bytes[offset+6]<<8)&0x000000000000ff00L|(bytes[offset+7]<<0)&0x00000000000000ffL;
  
      }
  
  
  
  }

  Now I have this class that works fine on the same programm, but when I send the bytes over the network I get a bad output and this error is printed to the console :

  [h264 @ 00000242442acc40] Missing reference picture, default is 72646
  
  [h264 @ 000002424089de00] Missing reference picture, default is 72646
  
  [h264 @ 000002424089e3c0] mmco: unref short failure
  
  [h264 @ 000002424081a580] reference picture missing during reorder
  
  [h264 @ 000002424081a580] Missing reference picture, default is 72652
  
  [h264 @ 000002424082c400] mmco: unref short failure
  
  [h264 @ 000002424082c400] co located POCs unavailable
  
  [h264 @ 000002424082c9c0] co located POCs unavailable
  
  [h264 @ 00000242442acc40] co located POCs unavailable
  
  [h264 @ 000002424089de00] mmco: unref short failure

  I think its because I dont set the sidedata field but when I try to set it the encoder crashes with the second packet.

  The output looks like this :
  Decoder Output