Geschrieben von empty am 17.09.2003 um 22:04:
HA, hat Donald rausgekriegt woran es liegt und gleich gefixt. Tolle Arbeit!
Viele Grüße bb empty
P.S.: Warum eigentlich in das SVCD-Forum, Selur?
*offizielles deutsches flaskmpeg & dvdtoogm board* (http://www.flaskmpeg.info/index.php)
- *sonstige tools* (http://www.flaskmpeg.info/board.php?boardid=30)
-- DGMPGDec / DGIndex updates:) (http://www.flaskmpeg.info/thread.php?threadid=3747)
| Zitat: |
| The widely used tools DVD2AVI and MPEG2DEC suffer from serious problems, including frame loss. This can cause serious problems with audio sync and authoring with some tools. Not only that, but random frame access is not handled correctly and incorrect frames can be returned when navigating on the timeline via MPEG2DEC (and its clones). There are three causes for the frame loss in the faulty versions. DVD2AVI fails to flush out the final frame's digit to the D2V file before writing the 9 and closing. This causes one frame to to be lost at the end. MPEG2DEC cuts two frames from the frame count as a workaround for 3 below. This is a kludgy hack that should not be necessary. Thus, thanks to this and 1 above, 3 frames will always be lost. They are lost at the end. If the opening GOP has B frames before the first P frame (IBBPBBP...), then DVD2AVI generates an incorrect D2V file, in which the first digits for the orphaned B frames are not written and all the remaining digits are written out of place (shifted up by the number of orphaned B frames). Also, MPEG2DEC cannot decode the B frames prior to the first P frame, and so discards them. A number of frames will be lost equal to the number of B frames prior to the first P frame. They are lost at the beginning. So, for example, if you edit a VOB and the resulting file has an IBBPBBP... opening GOP, you will lose a total of 5 frames, with 2 lost at the start and 3 lost at the end. In addition to the lost frames, MPEG2DEC does not implement random frame access correctly. In fact it always throws away the first B frames in the GOP prior to the first P frame. If they are (say) frames 12 and 13 (in display order) and you try to seek to 12, MPEG2DEC will toss them and return frame 14 to you, without any warning or indication about it. Finally, when 3 above applies the TFF/RFF flags in the D2V file are misaligned to the frames. I have created fixed versions of DVD2AVI and MPEG2DEC3 that solve these problems. They are available here: |
| Zitat: |
| To fix these things, I started with DVD2AVI 1.77.3 and the MPEG2DEC3 1.10 from Nic's site. I rewrote the D2V file generation to be correct, even when the first GOP is of the form IBBPBBP.... I added a pop-up message box that appears if the first GOP is open. This warns that the first few frames may be decoded incorrectly. I modified MPEG2DEC to not truncate B frames prior to the first P frame and to not unconditionally reduce the frame count by two. I rewrote the decoding and random access code to work correctly with the D2V files generated by the fixed DVD2AVI. Refer to the file "Readme.txt" included in the distribution for further details. |
Mit der offenen GOP, das verstehe ich nicht. Wie kann denn sowas passieren? Starten die d2v nicht an I-Frames? 
Kann man das nicht ändern? 
@Balm| Zitat: |
| Ein Grund mehr für DVDtoOgm DVD2AVI 1.77 zu unterstützen. |
Forensoftware: Burning Board 2.3.6, entwickelt von WoltLab GmbH