Am Samstag, 3. Dezember 2005 21:36 schrieb Juergen Bausa: > Dear Sven, > > thank you very much for your detailed answer. Good to hear, what stand > behind dvbcut. I just asked about synchronization because I heard of other > programs that are not got in that. Now I know, that everything is handled > correctly.
The synchronisation usually comes up when you separate video and audio from each other. An MPEG2 video elementary stream has no timestamps in it, the same holds for mp2 or mp3 audio files. Of course, if your audio and video files are in sync at the beginning, there should be in sync everywhere, in theory. However, the philosophy of DVBCUT is to keep the original timing information. > But when I tried to process the video the program crashed without any > hints. Unfortunately I have erased the file so I cant reproduce this. I have already some hints to problems. Most testing so far I did with streams from the same source (MTV2 Europe). For those, DVBCUT works rather stable. But I found it segfaulting when taking video from another source (German TV station ARD, for example). The point is, that the way the streams are constructed seems to differ a little. Somehow I have implicit assumptions in my code that the streams look like the ones from MTV2 ;) But I'm working on it. [...] > Exporting 64415 pictures: 01:24:08.200/00 .. -11:08:17.058/76 > Recoding 2 pictures > putpacket(streampic=129306) returned false > putpacket(streampic=129307) returned false > putpacket(streampic=129308) returned false > ...putpacket(streampic=190618) returned false > putpacket(streampic=190619) returned false > Recoding 2 pictures > Audio channel 1: starts 6.789 milliseconds before video > Audio channel 1: stops 45145252.000 milliseconds after video > Audio channel 1: delayed -8.000 milliseconds > > Saved 158859 pictures (-11:-29:-27.-498) This looks rather bad. The error message "putpacket... returned false" results from a failed call to libavformat (ffmpeg). Since libavformat is very bad documented, I have no real idea where it exactly comes from. Yesterday and today I worked on this problem, and implemented my own MPEG multiplexer inside DVBCUT to replace libavformat. So far it works quite well, for example it solves one "problem" (well, I don't know if it is really a problem): dvbreplex complains about inconsistent PTS and DTS when reading a file created with DVBCUT. But since the same messages appear when running dvbreplex on a FFMPEG generated file, the origin of this oddity is in libavformat. My new multiplexer works fine so far, at least dvbreplex does not complain, and mplayer and xine play the output with no problems. > Besides, there are some other things that might be improved, but they are > not that important: > > - I think, one time mplayer crashed and video/audio were not played any > more. I had to stop dvbcut and kill the mplayer process. After restarting > dvbcut everything was ok. Hmm... pressing the STOP button in DVBCUT should kill the mplayer process. Don't know what happened there. Maybe mplayer was stuck and did not react on SIGTERM anymore. DVBCUT could send SIGKILL if you press the STOP button a second time. > - Aspect ratio was wrong in mplayer. I am not sure if this is maybe an > mplayer problem. Maybe one has to set "-monitoraspect" correctly. MPlayer thinks that my 1280x1024 screen is 4:3, I have to set it to 5:4 in .mplayer/config in order to have the video display with the right aspect ratio. Try to add "monitoraspect=5:4" to .mplayer/config. > - I have a topfield TF-5000PVR where the ts-streams have > the extension .rec. This extension should also be in the 'open file' > dialog. This is subject to a configuration dialog which I should add to DVBCUT soon... > - When saving dvpcut-files and program streams the program should by > default propose 'foo.dvbcut' and 'foo.mpg' when the original file was named > 'foo.rec' Acknowledged. > - Sometimes (very seldom) I have movies from dvb that are to > large for a dvd5. In this case I use 'tcrequant' from transcode to reduce > the size of the mpeg2 video (.mpv) after demuxing and cutting in projectx. > After that I would multiplex the result with mplex (mjpegtools). How can I > do the same with dvbcut? Do I need to produce a complete mpg (audio and > video) with dvbcut, then demux it, tcrequant the video, and then multiplex > again? Maybe it would be good to have an option in dvbcut to output video > and audio in separate files without multiplexing them, to directly requant > the video. I could think of filtering the video throught an external requantizer program in DVBCUT. > - In my normal procedure to go from a ts-stream (.rec from topfield pvr) to > a dvd I use mplex to multiplex audio and video. From the mplex manpage: > > FUNCTION LETTERS > -f|--format format_code > This command allows one of a number of convenient preset > output ...... > 8 - DVD (with NAV sectors). Don't get too excited. This is > really a very minimal mux format. It includes empty versions > of the > peculiar VOBU start sectors DVD VOB's include. This is > enough to > persuade some hardware players to play the stream but is a long > way from > full DVD authoring. > 9 - DVD. As above but without the empty VOBU sectors. > > As I use dvdauthor afterwards I use the format '8' (I think dvdauthor would > not work with '7', but I am not sure). What kind of format does dvbcut use? > Will it work with dvdauthor? Up to version 0.5.1, DVBCUT uses the "dvd" format of libavformat. The name suggests that it is well suited for use with dvdauthor, but I don't know how standards compliant it really is. The next version of DVBCUT will come with my own multiplexer which should produce the right output for dvdauthor. I do add the empty VOBU sectors just like 'mplex -f 8'. So the aim is to produce DVD compliant output of course. It just needs more testing. Maybe I will release the next version of DVBCUT the next weekend, depends on how succesful I am with solving the bugs I find. Bye... -- Sven Over Stephanienstr. 9 76133 Karlsruhe Telefon: 0721-9204199 http://www.svenover.de/ ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://ads.osdn.com/?ad_id=7637&alloc_id=16865&op=click _______________________________________________ DVBCUT-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dvbcut-user
