/**
   * Copies the content of the most recently received packet into <tt>data</tt>.
   *
   * @param buffer an optional <tt>Buffer</tt> instance associated with the specified <tt>data</tt>,
   *     <tt>offset</tt> and <tt>length</tt> and provided to the method in case the implementation
   *     would like to provide additional <tt>Buffer</tt> properties such as <tt>flags</tt>
   * @param data the <tt>byte[]</tt> that we'd like to copy the content of the packet to.
   * @param offset the position where we are supposed to start writing in <tt>data</tt>.
   * @param length the number of <tt>byte</tt>s available for writing in <tt>data</tt>.
   * @return the number of bytes read
   * @throws IOException if <tt>length</tt> is less than the size of the packet.
   */
  protected int read(Buffer buffer, byte[] data, int offset, int length) throws IOException {
    if (data == null) throw new NullPointerException("data");

    if (ioError) return -1;

    RawPacket pkt;

    synchronized (pktSyncRoot) {
      pkt = this.pkt;
      this.pkt = null;
    }

    int pktLength;

    if (pkt == null) {
      pktLength = 0;
    } else {
      // By default, pkt will be returned to the pool after it was read.
      boolean poolPkt = true;

      try {
        pktLength = pkt.getLength();
        if (length < pktLength) {
          /*
           * If pkt is still the latest RawPacket made available to
           * reading, reinstate it for the next invocation of read;
           * otherwise, return it to the pool.
           */
          poolPkt = false;
          throw new IOException("Input buffer not big enough for " + pktLength);
        } else {
          byte[] pktBuffer = pkt.getBuffer();

          if (pktBuffer == null) {
            throw new NullPointerException(
                "pkt.buffer null, pkt.length " + pktLength + ", pkt.offset " + pkt.getOffset());
          } else {
            System.arraycopy(pkt.getBuffer(), pkt.getOffset(), data, offset, pktLength);
            if (buffer != null) buffer.setFlags(pkt.getFlags());
          }
        }
      } finally {
        if (!poolPkt) {
          synchronized (pktSyncRoot) {
            if (this.pkt == null) this.pkt = pkt;
            else poolPkt = true;
          }
        }
        if (poolPkt) {
          // Return pkt to the pool because it was successfully read.
          poolRawPacket(pkt);
        }
      }
    }

    return pktLength;
  }
Esempio n. 2
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  /**
   * Blocks and reads into a <tt>Buffer</tt> from this <tt>PullBufferStream</tt>.
   *
   * @param buffer the <tt>Buffer</tt> this <tt>PullBufferStream</tt> is to read into
   * @throws IOException if an I/O error occurs while this <tt>PullBufferStream</tt> reads into the
   *     specified <tt>Buffer</tt>
   * @see AbstractVideoPullBufferStream#doRead(Buffer)
   */
  @Override
  protected void doRead(Buffer buffer) throws IOException {
    /*
     * Determine the Format in which we're expected to output. We cannot
     * rely on the Format always being specified in the Buffer because it is
     * not its responsibility, the DataSource of this ImageStream knows the
     * output Format.
     */
    Format format = buffer.getFormat();

    if (format == null) {
      format = getFormat();
      if (format != null) buffer.setFormat(format);
    }

    if (format instanceof AVFrameFormat) {
      Object o = buffer.getData();
      AVFrame frame;

      if (o instanceof AVFrame) frame = (AVFrame) o;
      else {
        frame = new AVFrame();
        buffer.setData(frame);
      }

      AVFrameFormat avFrameFormat = (AVFrameFormat) format;
      Dimension size = avFrameFormat.getSize();
      ByteBuffer data = readScreenNative(size);

      if (data != null) {
        if (frame.avpicture_fill(data, avFrameFormat) < 0) {
          data.free();
          throw new IOException("avpicture_fill");
        }
      } else {
        /*
         * This can happen when we disconnect a monitor from computer
         * before or during grabbing.
         */
        throw new IOException("Failed to grab screen.");
      }
    } else {
      byte[] bytes = (byte[]) buffer.getData();
      Dimension size = ((VideoFormat) format).getSize();

      bytes = readScreen(bytes, size);

      buffer.setData(bytes);
      buffer.setOffset(0);
      buffer.setLength(bytes.length);
    }

    buffer.setHeader(null);
    buffer.setTimeStamp(System.nanoTime());
    buffer.setSequenceNumber(seqNo);
    buffer.setFlags(Buffer.FLAG_SYSTEM_TIME | Buffer.FLAG_LIVE_DATA);
    seqNo++;
  }
Esempio n. 3
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  /** {@inheritDoc} */
  @Override
  protected int doProcess(Buffer inBuffer, Buffer outBuffer) {
    byte[] inData = (byte[]) inBuffer.getData();
    int inOffset = inBuffer.getOffset();

    if (!VP8PayloadDescriptor.isValid(inData, inOffset)) {
      logger.warn("Invalid RTP/VP8 packet discarded.");
      outBuffer.setDiscard(true);
      return BUFFER_PROCESSED_FAILED; // XXX: FAILED or OK?
    }

    long inSeq = inBuffer.getSequenceNumber();
    long inRtpTimestamp = inBuffer.getRtpTimeStamp();
    int inPictureId = VP8PayloadDescriptor.getPictureId(inData, inOffset);
    boolean inMarker = (inBuffer.getFlags() & Buffer.FLAG_RTP_MARKER) != 0;
    boolean inIsStartOfFrame = VP8PayloadDescriptor.isStartOfFrame(inData, inOffset);
    int inLength = inBuffer.getLength();
    int inPdSize = VP8PayloadDescriptor.getSize(inData, inOffset);
    int inPayloadLength = inLength - inPdSize;

    if (empty && lastSentSeq != -1 && seqNumComparator.compare(inSeq, lastSentSeq) != 1) {
      if (logger.isInfoEnabled()) logger.info("Discarding old packet (while empty) " + inSeq);
      outBuffer.setDiscard(true);
      return BUFFER_PROCESSED_OK;
    }

    if (!empty) {
      // if the incoming packet has a different PictureID or timestamp
      // than those of the current frame, then it belongs to a different
      // frame.
      if ((inPictureId != -1 && pictureId != -1 && inPictureId != pictureId)
          | (timestamp != -1 && inRtpTimestamp != -1 && inRtpTimestamp != timestamp)) {
        if (seqNumComparator.compare(inSeq, firstSeq) != 1) // inSeq <= firstSeq
        {
          // the packet belongs to a previous frame. discard it
          if (logger.isInfoEnabled()) logger.info("Discarding old packet " + inSeq);
          outBuffer.setDiscard(true);
          return BUFFER_PROCESSED_OK;
        } else // inSeq > firstSeq (and also presumably isSeq > lastSeq)
        {
          // the packet belongs to a subsequent frame (to the one
          // currently being held). Drop the current frame.

          if (logger.isInfoEnabled())
            logger.info(
                "Discarding saved packets on arrival of"
                    + " a packet for a subsequent frame: "
                    + inSeq);

          // TODO: this would be the place to complain about the
          // not-well-received PictureID by sending a RTCP SLI or NACK.
          reinit();
        }
      }
    }

    // a whole frame in a single packet. avoid the extra copy to
    // this.data and output it immediately.
    if (empty && inMarker && inIsStartOfFrame) {
      byte[] outData = validateByteArraySize(outBuffer, inPayloadLength, false);
      System.arraycopy(inData, inOffset + inPdSize, outData, 0, inPayloadLength);
      outBuffer.setOffset(0);
      outBuffer.setLength(inPayloadLength);
      outBuffer.setRtpTimeStamp(inBuffer.getRtpTimeStamp());

      if (TRACE) logger.trace("Out PictureID=" + inPictureId);

      lastSentSeq = inSeq;

      return BUFFER_PROCESSED_OK;
    }

    // add to this.data
    Container container = free.poll();
    if (container == null) container = new Container();
    if (container.buf == null || container.buf.length < inPayloadLength)
      container.buf = new byte[inPayloadLength];

    if (data.get(inSeq) != null) {
      if (logger.isInfoEnabled())
        logger.info("(Probable) duplicate packet detected, discarding " + inSeq);
      outBuffer.setDiscard(true);
      return BUFFER_PROCESSED_OK;
    }

    System.arraycopy(inData, inOffset + inPdSize, container.buf, 0, inPayloadLength);
    container.len = inPayloadLength;
    data.put(inSeq, container);

    // update fields
    frameLength += inPayloadLength;
    if (firstSeq == -1 || (seqNumComparator.compare(firstSeq, inSeq) == 1)) firstSeq = inSeq;
    if (lastSeq == -1 || (seqNumComparator.compare(inSeq, lastSeq) == 1)) lastSeq = inSeq;

    if (empty) {
      // the first received packet for the current frame was just added
      empty = false;
      timestamp = inRtpTimestamp;
      pictureId = inPictureId;
    }

    if (inMarker) haveEnd = true;
    if (inIsStartOfFrame) haveStart = true;

    // check if we have a full frame
    if (frameComplete()) {
      byte[] outData = validateByteArraySize(outBuffer, frameLength, false);
      int ptr = 0;
      Container b;
      for (Map.Entry<Long, Container> entry : data.entrySet()) {
        b = entry.getValue();
        System.arraycopy(b.buf, 0, outData, ptr, b.len);
        ptr += b.len;
      }

      outBuffer.setOffset(0);
      outBuffer.setLength(frameLength);
      outBuffer.setRtpTimeStamp(inBuffer.getRtpTimeStamp());

      if (TRACE) logger.trace("Out PictureID=" + inPictureId);
      lastSentSeq = lastSeq;

      // prepare for the next frame
      reinit();

      return BUFFER_PROCESSED_OK;
    } else {
      // frame not complete yet
      outBuffer.setDiscard(true);
      return OUTPUT_BUFFER_NOT_FILLED;
    }
  }