> -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Steven > M. Schultz > Sent: woensdag 21 juli 2004 0:05 > To: [EMAIL PROTECTED] > Subject: RE: [Mjpeg-users] Mpeg2enc quality? > > On Tue, 20 Jul 2004, Marc Gregoire wrote: > > > > > I'm trying to author lots of slides to a still-show (not a > > > slideshow!) on DVD. > > > > So I need to convert my slides to mpeg stills. I tried several > > > > different parameters for mpeg2enc and came up with > > I knew there was something I forgot to ask... > > The artifacts (ringing) on the edges of the flowers look similar to > what one can get from scaling. Part of the differences in the two > flower encodings may be due to the method used to scale the images > to the DVD frame size. > > What size/resolution are the slides (source .jpg > files)? Are they > from a digital camera (or similar source) and being scaled/resized > to 720x576? mpeg2enc of course needs the correct > frame size on > input but perhaps the other encoder is doing the scaling in a way > that avoids the artifacts.
I had scaled the original image to 720x576 with an external program and used the scaled version for both mpeg2enc and the other encoder. > > Are you scaling the data before running jpeg2yuv and if so how is > that being done? Off the top of my head (which means this is > completely untested - but is similar to what I've done on other > projects): I scaled the image before encoding with another program. (720x576) This scaled image can be seen at: http://www.nuonsoft.com/temp/flower_orig.jpg This scaled version was then used by both encoders, so both encoder got a jpg file of the correct PAL resolution, so they don't need to do any scaling. > You can try setting -q to 3 or less but 4 should give good results. > Raising the bitrate from the default of 7500 can be done with > something like "-b 8400". I tried with raising the bitrate with the -b parameter, but I never got a big increase in size. In response to your other reply: I was using an older version of mpeg2enc as can be seen from the -h parameter which is -H in the latest version. So I downloaded mjpegtools 1.6.2 and compiled it with cygwin without a problem. Using that mpeg2enc version, changing -h to -H I get almost the same results. Even with a -q 1, the filesize just barely increases. Even when I increase the bitrate with -b to 15000 (which is way to high for DVD !) I get a .M2V of barely 100 KB. If you find the time, could you take a look at the original image I posted above that I've used with both encoders and see what you can make of it? Ragards, Marc Gregoire ------------------------------------------------------- This SF.Net email is sponsored by BEA Weblogic Workshop FREE Java Enterprise J2EE developer tools! Get your free copy of BEA WebLogic Workshop 8.1 today. http://ads.osdn.com/?ad_id=4721&alloc_id=10040&op=click _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
