Difference between revisions of "User:Rtsai1111"

Revision as of 01:29, 25 September 2006

See http://www.tsaiberspace.net/projects/mythtv/

Experimental Commercial Flagging

Code from branches/commdetector2 has been merged back into SVN trunk. To use it, go to the "Setup : TV Settings : General : General (Jobs)" configuration screen, and select the "Experimental" commercial flagging method. The "Strict Commercial Detection" setting does not apply to the "Experimental" commercial flagger. I only have broadcast HDTV in the US, so I expect problems with:

• analog recordings
• premium cable channels (anything not available on broadcast TV)
• non-US stuff (Europe, Asia, Australia, etc.)

To perform any kind of troubleshooting, be sure to run mythbackend/mythcommflag with "-v commflag", and update the following database settings:

INSERT INTO settings (value, data) VALUES ('TemplateFinderDebugLevel', '1');
INSERT INTO settings (value, data) VALUES ('TemplateMatcherDebugLevel', '1');
INSERT INTO settings (value, data) VALUES ('HistogramAnalyzerDebugLevel', '1');
INSERT INTO settings (value, data) VALUES ('BlankFrameDetectorDebugLevel', '1');

Debug levels of 2 or higher will generate more verbose logfile output. The TemplateFinder and TemplateMatcher debug levels can go up to 3 to generate a very large amount of output (~100MB, many JPEG frames for showing logo-detection analysis). The JPEG images are generated with ImageMagick, which will need to be installed on the system.

These debugging settings will generate "*-debug" directories in your MythTV recordings directory; they will not be automatically cleaned up when your recordings are deleted, so you will have to periodically clean them up yourself.

The extra debugging output in the backend/mythcommflag logfile should be useful to non-developers; it identifies exactly where the various kinds of breaks are. If you then use the "Edit Recordings" UI to examine your recording, you can get an idea of why or why not a particular segment was flagged in a certain way. It is recommended that an OSD theme using a "framedisplay" element be used (e.g., Gray-OSD).

For more detail, one may examine the extra debugging files in the "*-debug" directories. These files contain the results of the commercial-flagging analysis. Subsequent runs of mythcommflag on the same recording will run much more quickly; these files will be re-read for analysis, rather than re-processing all the video frames. The debugging output files are structured such that each line of output corresponds to the information for that frame number (line 1 represents the first frame, line 2 represents the second frame, etc.). In "vi", one can do ":set nu" to turn on line numbers. The format of each file is rather simple; search for "readData" or "writeData" in the various *Analyzer.cpp source code files.

To run the experimental code on the commandline outside of Myth, use the "--method 511" option.