> Can someone make the following available for downloading: > > I need two NTSC captures from a movie (NOT a 'made for TV' movie but > a 'real' movie that was made for movie theatres). I think that it is > best that it is from a recent movie (say from the last 3-4 years). > > First run 'v4l2-ctl -c video_pulldown=0'. Then make the first > capture: the first capture should be about a minute and captured with > a plain 'cat /dev/video0 >1.mpg'. To make the second capture first > issue this command: 'v4l2-ctl -c video_pulldown=1', then start > capturing another minute with 'cat /dev/video0 >2.mpg'. > > Capture from a decent quality channel with a clear picture and should > be 720x480 (so no scaling). > > I want to compare two such streams to see if the 3:2 pulldown control > really works (and if so, if it does what I think it does). > > But since this control is NTSC-only I need some help here!
> Of course, if you have two cards in the same box with equally good > picture quality, then it would be even better if each records the same > picture but with different video_pulldown settings. Although for the > purposes of this test both cards should have the same digitizer > (saa7115 vs cx2584x). So either both cards are a PVR250/350 or both are > a PVR150/500. Well, I've got 2 1 minute captures from LOTR and 2 48 second captures >From Star Wars Episode 1. I used a Panasonic DVD player feeding video into Composite Input 2 of my PVR-150 MCE. The files are huge: [EMAIL PROTECTED] ~]$ ls -altr *mpg -rw-rw-r-- 1 andy andy 39092160 Dec 24 13:46 pulldown-0.mpg -rw-rw-r-- 1 andy andy 39409600 Dec 24 13:47 pulldown-1.mpg -rw-rw-r-- 1 andy andy 49358784 Dec 24 14:02 lotr-0.mpg -rw-rw-r-- 1 andy andy 49721280 Dec 24 14:03 lotr-1.mpg so my 33.6 kbps dial-up upload to somewhere is probably not an option. Plus I'm not sure this would count as fair use under US Copyright law (I prefer to stay well beyond reproach on legal issues...) So what specifically are you looking for in these files? Maybe I could analyze them for you. I assume you're looking for evidence of inverse telecine as Conexants brochure on the MPEG encoder touts. Here are some observations: 1. Computer generated stuff doesn't gzip well, and captures with video_pulldown = 1 compress better (indicating slightly greater redundancy): 1 minute from the middle of the incredibles [EMAIL PROTECTED] ~]$ gzip -9 -v pulldown-0.mpg pulldown-1.mpg pulldown-0.mpg: 6.0% -- replaced with pulldown-0.mpg.gz pulldown-1.mpg: 6.4% -- replaced with pulldown-1.mpg.gz 48 seconds from the beginning of Star Wars Episode 1 [EMAIL PROTECTED] ~]$ gzip -v -9 pulldown-*.mpg pulldown-0.mpg: 13.7% -- replaced with pulldown-0.mpg.gz pulldown-1.mpg: 14.1% -- replaced with pulldown-1.mpg.gz 1 minute from the beginning of the The Fellowship of the Rings [EMAIL PROTECTED] ~]$ gzip -v -9 lotr-* lotr-0.mpg: 70.9% -- replaced with lotr-0.mpg.gz lotr-1.mpg: 71.2% -- replaced with lotr-1.mpg.gz 2. The ivtv driver outputs stuff on 0x800 byte boundaries, making quick and dirty frame counts pretty simple: [EMAIL PROTECTED] ~]$ xxd -c 32 lotr-0.mpg | grep '[08]00: ' | grep -v '01e0 07ec' | grep '0000 01e0' | wc -l 1807 [EMAIL PROTECTED] ~]$ xxd -c 32 lotr-1.mpg | grep '[08]00: ' | grep -v '01e0 07ec' | grep '0000 01e0' | wc -l 1816 But for reference here's what mpeg2dec says: [EMAIL PROTECTED] ~]$ mpeg2dec -o null -s lotr-0.mpg mpeg2dec-0.4.0 - by Michel Lespinasse <[EMAIL PROTECTED]> and Aaron Holtzman 1689 frames in 5.98 sec (282.44 fps), 148 last 0.50 sec (296.00 fps) 1811 frames decoded in 6.38 seconds (283.86 fps) [EMAIL PROTECTED] ~]$ mpeg2dec -o null -s lotr-1.mpg mpeg2dec-0.4.0 - by Michel Lespinasse <[EMAIL PROTECTED]> and Aaron Holtzman 1796 frames in 5.46 sec (328.94 fps), 152 last 0.50 sec (304.00 fps) 1824 frames decoded in 5.56 seconds (328.06 fps) 3. "cat /dev/video | mplayer -" with the intro to LOTR seems to tax my system noticeably more with video_pulldown = 1 than with video_pulldown = 0 4. If video_pulldown = 0 really means inverse telecine enabled, the MPEG decoder gets it wrong for a few frames at the beginning of the LOTR, where I can see a horizontal "comb" of lines in the fire to the right of the cup of molten gold. R, Andy _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
