Starting with version 0.51, ccextractor has a mode that allows frontends and other programs know what the current progress is as well as get information on interesting events, such as a file being open or video information (resolution, frame rate and so on) being found. The Windows GUI source code is good reference implementation. Usage: Add --gui_mode_reports to the command line as the first parameter (this is not essential but because the mode is enabled after this option is parsed, if there is any event regarding the previous parameters you would miss them). When this option is used, ccextractor reports progress and other information to stderr. This does not disable stdout (the regular stuff) reporting. Information it sent to stderr, one line at a time. Information lines that are supposed to be parsed by programs starts with ###. All other lines, if any, must be discarded. stderr is not guaranteed to have only information lines - so do check. After ### the data starts. Tokens are also separated by #. The first token specified the data type, and the rest, if any, are parameters. The following data types are currently defined: VERSION - Get CCExtractor version Program Version Example: ###VERSION#CCExtractor#0.51 PROGRESS - Get processed percentage and current timing Percentage (or -1 for streaming mode) Minutes Seconds Example: ###PROGRESS#45#12#34 (for 45%, 12:34) INPUTFILECLOSED - CCExtractor closed whatever input file it had open (which had been reported before). No parameters. INPUTFILEOPEN - A new file was successfully open for reading. Filename Note that the filename CAN contain #, so don't split the line after the first token and treat the remainder as the filename. Example: ###INPUTFILEOPEN#/tmp/This is # a file.mpg MESSAGE - Something interesting happened. Message text. This can be anything from a fatal error message to something merely informative. Example: ###MESSAGE#Timing broken in this file VIDEOINFO - New video information found Horizontal resolution Vertical resolution Aspect ratio Framerate Example: ###VIDEOINFO#1980#1080#16:9#29.97 SUBTITLE - New subtitle screen Start time End time Line Time is empty if it's the same of the previous line (i.e. they're supposed to appear together). Example: ###SUBTITLE#10:23#10:25#This is 1 ###SUBTITLE###This is 2 Note that time is in MM:SS format. No milliseconds since this is for a preview window. Text is trimmed and there is no color or font information, to save space. TSPROGRAMNUMBER - A multiprogram TS was detected, but no program was manually selected. CCExtractor will send a list of programs so the GUI can show it to the user for selection. Example: ###TSPROGRAMNUMBER#3 XDSPROGRAMNAME - Program Name as received from XDS is available. Example: ###XDSPROGRAMNAME#Star Trek You may receive this more than once per stream. *** TODO : Add the rest of XDS stuff ****