code: private HashMap<String, String> parseProgressInfoLine(String line) {
          HashMap<String, String> table = null;
          Matcher m = PROGRESS_INFO_PATTERN.matcher(line);
          while (m.find())
          {
              if (table == null)
              {
                  table = new HashMap<>();
              }
              String key = m.group(1);
              String value = m.group(2);
              table.put(key, value);
          }
          return table;
      }
docs: Private utility. Parse a line and try to match its contents against the
  {@link Encoder#PROGRESS_INFO_PATTERN} pattern. It the line can be parsed,
  it returns a hashtable with progress informations, otherwise it returns
  null.
  
  @param line The line from the ffmpeg output.
  @return A hashtable with the value reported in the line, or null if the
  given line can not be parsed.