// @Override
  @Override
  public int read(byte[] b, int off, int len) throws IOException {
    // TODO: how do we detect IOException?
    fillBuffer();
    if (buffer.getLength() == 0 && buffer.isEOM()) // TODO: will always be
      // EOM if length is 0
      return -1;
    final byte[] data = (byte[]) buffer.getData();

    int lengthToCopy = buffer.getLength() < len ? buffer.getLength() : len;
    System.arraycopy(data, buffer.getOffset(), b, off, lengthToCopy);
    buffer.setOffset(buffer.getOffset() + lengthToCopy);
    buffer.setLength(buffer.getLength() - lengthToCopy);

    return lengthToCopy;
  }
  private void fillBuffer() {
    if (buffer == null) {
      buffer = new Buffer();
      buffer.setFormat(track.getFormat());
    }

    do {
      if (buffer.isEOM()) return;

      if (buffer.getLength() > 0) return; // still have data in buffer
      // TODO: any fields to set?

      track.readFrame(buffer);
      logger.fine("Read buffer from track: " + buffer.getLength());

    } while (buffer.isDiscard());
  }
    public VideoTrack(PullSourceStream stream) throws ResourceUnavailableException {
      super();

      this.stream = stream;
      // set format

      // read first frame to determine format
      final Buffer buffer = new Buffer();
      readFrame(buffer);
      if (buffer.isDiscard() || buffer.isEOM())
        throw new ResourceUnavailableException("Unable to read first frame");
      // TODO: catch runtime exception too?

      // parse jpeg
      final java.awt.Image image;
      try {
        image =
            ImageIO.read(
                new ByteArrayInputStream(
                    (byte[]) buffer.getData(), buffer.getOffset(), buffer.getLength()));
      } catch (IOException e) {
        logger.log(Level.WARNING, "" + e, e);
        throw new ResourceUnavailableException("Error reading image: " + e);
      }

      if (image == null) {
        logger.log(Level.WARNING, "Failed to read image (ImageIO.read returned null).");
        throw new ResourceUnavailableException();
      }

      if (frameContentType.equals("image/jpeg"))
        format =
            new JPEGFormat(
                new Dimension(image.getWidth(null), image.getHeight(null)),
                Format.NOT_SPECIFIED,
                Format.byteArray,
                -1.f,
                Format.NOT_SPECIFIED,
                Format.NOT_SPECIFIED);
      else if (frameContentType.equals("image/gif"))
        format =
            new GIFFormat(
                new Dimension(image.getWidth(null), image.getHeight(null)),
                Format.NOT_SPECIFIED,
                Format.byteArray,
                -1.f);
      else if (frameContentType.equals("image/png"))
        format =
            new PNGFormat(
                new Dimension(image.getWidth(null), image.getHeight(null)),
                Format.NOT_SPECIFIED,
                Format.byteArray,
                -1.f);
      else
        throw new ResourceUnavailableException(
            "Unsupported frame content type: " + frameContentType);
      // TODO: this discards first image. save and return first time
      // readFrame is called.

    }
  // @Override
  @Override
  public int read() throws IOException {
    // TODO: how do we detect IOException?
    fillBuffer();
    if (buffer.getLength() == 0 && buffer.isEOM()) // TODO: will always be
      // EOM if length is 0
      return -1;
    final byte[] data = (byte[]) buffer.getData();
    final int result = data[buffer.getOffset()] & 0xff;
    buffer.setOffset(buffer.getOffset() + 1);
    buffer.setLength(buffer.getLength() - 1);

    return result;
  }
    @Override
    public void readFrame(Buffer buffer) {
      // example data:
      // --ssBoundary8345
      // Content-Type: image/jpeg
      // Content-Length: 114587

      try {
        String line;
        // eat leading blank lines
        while (true) {
          line = readLine(MAX_LINE_LENGTH);
          if (line == null) {
            buffer.setEOM(true);
            buffer.setLength(0);
            return;
          }

          if (!line.trim().equals("")) break; // end of header
        }

        if (boundary == null) {
          boundary = line.trim(); // TODO: we should be able to get
          // this from the content type, but
          // the content type has this
          // stripped out. So we'll just take
          // the first nonblank line to be the
          // boundary.
          // System.out.println("boundary: " + boundary);
        } else {
          if (!line.trim().equals(boundary)) {
            // throw new IOException("Expected boundary: " +
            // toPrintable(line));
            // TODO: why do we seem to get these when playing back
            // mmr files recorded using FmjTranscode?
            logger.warning("Expected boundary (frame " + framesRead + "): " + toPrintable(line));

            // handle streams that are truncated in the middle of a
            // frame:
            final int eatResult = eatUntil(boundary); // TODO: no
            // need to
            // store the
            // data

            logger.info(
                "Ignored bytes (eom after="
                    + (eatResult < 0)
                    + "): "
                    + (eatResult < 0 ? (-1 * eatResult - 1) : eatResult));
            if (eatResult < 0) {
              buffer.setEOM(true);
              buffer.setLength(0);
              return;
            }

            // now read boundary
            line = readLine(MAX_LINE_LENGTH);
            if (!line.trim().equals(boundary)) {
              throw new RuntimeException("No boundary found after eatUntil(boundary)"); // should
              // never
              // happen
            }
          }
        }

        final Properties properties = new Properties();

        while (true) {
          line = readLine(MAX_LINE_LENGTH);
          if (line == null) {
            buffer.setEOM(true);
            buffer.setLength(0);
            return;
          }

          if (line.trim().equals("")) break; // end of header

          if (!parseProperty(line, properties))
            throw new IOException("Expected property: " + toPrintable(line));
        }

        final String contentType = properties.getProperty("Content-Type".toUpperCase());
        if (contentType == null) {
          logger.warning("Header properties: " + properties);
          throw new IOException("Expected Content-Type in header");
        }

        // check supported content types:
        if (!isSupportedFrameContentType(contentType)) {
          throw new IOException("Unsupported Content-Type: " + contentType);
        }

        if (frameContentType == null) {
          frameContentType = contentType;
        } else {
          if (!contentType.equals(frameContentType))
            throw new IOException(
                "Content type changed during stream from "
                    + frameContentType
                    + " to "
                    + contentType);
        }

        // TODO: check that size doesn't change throughout

        final byte[] data;

        final String contentLenStr = properties.getProperty("Content-Length".toUpperCase());
        if (contentLenStr != null) { // if we know the content length, use it
          final int contentLen;
          try {
            contentLen = Integer.parseInt(contentLenStr);
          } catch (NumberFormatException e) {
            throw new IOException("Invalid content length: " + contentLenStr);
          }

          // now, read the content-length bytes
          data = readFully(contentLen); // TODO: don't realloc each
          // time
        } else {
          // if we don't know the content length, just read until we
          // find the boundary.
          // Some IP cameras don't specify it, like
          // http://webcam-1.duesseldorf.it-on.net/cgi-bin/nph-update.cgi
          data = readUntil(boundary);
        }

        // ext
        final String timestampStr = properties.getProperty(TIMESTAMP_KEY.toUpperCase());
        if (timestampStr != null) {
          try {
            final long timestamp = Long.parseLong(timestampStr);
            buffer.setTimeStamp(timestamp);

          } catch (NumberFormatException e) {
            logger.log(Level.WARNING, "" + e, e);
          }
        }

        if (data == null) {
          buffer.setEOM(true);
          buffer.setLength(0);
          return;
        }

        buffer.setData(data);
        buffer.setOffset(0);
        buffer.setLength(data.length);
        ++framesRead;

      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }