>On Thu, May 26, 2011 at 05:48:07PM -0700, Dan Dennedy wrote: >> On Thu, May 26, 2011 at 5:38 PM, Ian Lynagh <[email protected]> wrote: >> > On Thu, May 26, 2011 at 11:47:49AM -0700, Dan Dennedy wrote: >> >> >> >> And it is not capable of interlacing/weaving a 50p input into a 50i >> >> output. >> > >> > But it can do 50p -> 25i (e.g. DVD)? >> >> Yes, from 50p *AV file* to a 25 fps interlaced project/encoding (50i >> means the same but refers to vertical frequency in Hz, not frames per >> second). > >Ah, sorry, I think I was confused and PAL DVDs are 50i, not 25i. This >stuff makes my head hurt! > >So if I understand correctly, MLT can do the conversion, but other tools >might do it better. Another advantage of rendering as 50p with >kdenlive/melt, and then having the option of using another tool to >convert to DVD format, I guess!
Not exactly. MLT can do the conversion just fine. MLT can convert the source frame rate to match the profile frame rate (the project profile in Kdenlive). But MLT can not convert the profile frame rate to be different on the output (renderer). Basically, make sure your renderer frame rate matches your profile frame rate. So, if you want to maintain your project profile as 1080p50 (which I think you do), then after you render the output at 1080p50, your options are: * transcode the rendered 1080p50 file to PAL DVD using another transcoding tool * import the rendered 1080p50 file back into Kdenlive using PAL DVD profile as the project profile - and then render to PAL DVD. >I'm still having trouble rendering, though. I'd like to make a lossless >1080/50p profile, so I tried various things, e.g. using x264 with crf=0 >(mentioned on http://mltframework.org/twiki/bin/view/MLT/ConsumerAvformat) >like so: > > melt untitled.mp4 -profile atsc_1080p_50 -consumer >avformat:/home/ian/kdenlive/untitled2.mp4 progress=1 f=mp4 acodec=ac3 ab=448k >ar=48000 ac=2 vcodec=libx264 crf=0 preset=placebo no-interlaced >profile=atsc_1080p_50 threads=1 real_time=-1 > >but the result is definitely lossy. In fact, even if I do > > melt -verbose script003.sh.mlt -profile atsc_1080p_50 trellis=0 -consumer >avformat:/home/ian/kdenlive/untitled2.mp4 trellis=0 progress=1 f=mp4 trellis=0 >vcodec=libx264 trellis=0 > >the output includes "trellis=1", so I think I must be passing arguments >incorrectly? > >Hmm, using cqp=0 looks a lot better, but still isn't lossless according >to ffmpeg -f framemd5. Your probably don't REALLY want lossless because the files will be HUGE. But you can try this if you want: http://www.kdenlive.org/dnxhd-1920x1080-220-mbs Otherwise, create an H.264 renderer based on one of the existing renderers, but use the -sameq flag. This is probably closer to what you want. Depending on your quality criteria, H.264 at 25Mbps may be close enough to lossless for you. It is for me. >I also see that atsc_1080p_50 has colorspace 709, while dv_pal_wide has >601. Is that going to cause me any problems? How can I tell what >colourspace my inputs use? Generally: HD=709, SD=601 (especially if captured from an analog source). Your content is 1080p. So it should be 709. For an HD render, you want the colorspace to be unchanged. For an SD render intended for DVD playback, you would want the colorspace to be converted to 601 (although, I would defy you to tell the difference by visual inspection). I don't know if MLT or FFMPEG perform 709 to 601 colorspace conversions when downscaling from HD to SD. ~Brian ------------------------------------------------------------------------------ vRanger cuts backup time in half-while increasing security. With the market-leading solution for virtual backup and recovery, you get blazing-fast, flexible, and affordable data protection. Download your free trial now. http://p.sf.net/sfu/quest-d2dcopy1 _______________________________________________ Mlt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mlt-devel
