<html><body><div style="color:#000; background-color:#fff; font-family:times new roman, new york, times, serif;font-size:12pt"><div><span>Robert,</span></div><div><span><br></span></div><div><span>Much appreciate your insight.</span></div><div><span><br>Regards,</span></div><div><span>Peter<br></span></div><div><br></div> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div style="font-family: times new roman, new york, times, serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Robert Forsman <bob.forsman@ericsson.com><br> <b><span style="font-weight: bold;">To:</span></b> Mailing list for VLC media player developers <vlc-devel@videolan.org> <br> <b><span style="font-weight: bold;">Sent:</span></b> Friday, March 30, 2012 12:46 PM<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: [vlc-devel] How to implement
a filter that skips a portion of the movie?<br> </font> </div> <br>
On Fri, 30 Mar 2012 15:22:53 -0400<br>Peter Tap <<a ymailto="mailto:ptrtap@yahoo.com" href="mailto:ptrtap@yahoo.com">ptrtap@yahoo.com</a>> wrote:<br><br>> Folks,<br>> <br>> My company is in the business of digitization of movies. The digitization process for a movie takes a few days. The final format is mp4.<br>> <br>> Sometimes, when the movie is about to be released, we get a notice that some parts of the movie have been censored. However, there is not enough time for us to re-encode the movie before releasing it.<br>> <br>> As our digitized movie can only be played through VLC, I am thinking I might be able to write a module that tells VLC to skip certain frames. I am wondering how do I go about writing such a module. Is it a video filter that I need to create?<br><br>Two suggestions:<br><br> Recommendation 1 is that this be handled with an 'elst' Edit List<br>Box (ISO 14496-12 section 8.6.6.1). I don't
have any media that<br>includes this box, so I don't know if VLC supports it (my guess is that<br>it is not yet supported). The down side is that the "censored" bits<br>are still in the file and will be played by any player that doesn't<br>correctly implement the 'elst' atom (probably all the players).<br><br>Recommendation 2 is to write some software which can "edit" the<br>MP4 file. Given a source MP4 and an edit list, it is a simple matter<br>to emit a second MP4 file that only contains the audio and video access<br>units that match the edit list. No reencoding is necessary. It is a<br>less simple matter to make sure that the cut point is "clean" (doesn't<br>contain AUs which mathematically depend on removed AUs for proper<br>rendering). <br><br>Clean cut points become more difficult if your GOPs are not closed.<br>Clean cut points become near impossible if you take full advantage of<br>H.264's decoding features where
you can refer to a wide range of<br>reference pictures for interpolation.<br>_______________________________________________<br>vlc-devel mailing list<br>To unsubscribe or modify your subscription options:<br>http://mailman.videolan.org/listinfo/vlc-devel<br><br><br> </div> </div> </div></body></html>