Welcome to Doom9's Forum, THE in-place to be for everyone interested in DVD conversion. Before you start posting please read the forum rules. By posting to this forum you agree to abide by the rules. |
24th September 2015, 21:05 | #122 | Link |
Registered User
Join Date: Feb 2002
Location: California
Posts: 2,691
|
Does 25p encoded as 50i actually produce a different effect on the screen than would that same content encoded and played at 25p? Since there is no temporal difference between the two fields in a 50i encode that originates from 25p material, part of me thinks that the person viewing the screen would not be able to tell the difference.
|
24th September 2015, 21:13 | #123 | Link | |
Registered User
Join Date: Oct 2012
Posts: 7,903
|
Quote:
nearly all TV have some kind of field matching and will notice that the fields match and it will look the same. BD and DVD doesn't support 25p only 50i. you can just treated a 25p/30p stream as interlaced and nothing will happen with it it's just deintelaced and the result from a pretty normal deinterlacer is 50p with 2:2 |
|
24th September 2015, 22:09 | #125 | Link | |
Registered User
Join Date: Nov 2004
Location: Poland
Posts: 2,843
|
Quote:
If payer/TV is good enough than you get back original 25p, in other cases it may be treated by player/TV as 50i, which is of course not the best, but not the end of the world neither. |
|
24th September 2015, 22:14 | #127 | Link |
Registered User
Join Date: Nov 2004
Location: Poland
Posts: 2,843
|
Chroma placement for progressive and interlaced is different, but I never saw this be a problem when watched even on big TV (maybe it actually gets "corrected" by TV filtering system).
Maybe encoders knowing that source is progressive already "correct" it, eg. when x264 encodes as fake interlaced. |
24th September 2015, 22:19 | #129 | Link |
Registered User
Join Date: Nov 2004
Location: Poland
Posts: 2,843
|
It depends on the master. If master is originally interlaced than it's encoded as interlaced, but many movies etc are shot at 25p (or 24p and speed up, which also happens in Europe) and these are encoded as fake interlaced.
For the Blu-ray is similar thought I always use to ask for 24p masters. When possible I use to speed up/slow down extras to match main movie fps, so such a disc causes less TV switching, which sometimes is slow and annoying. Last edited by kolak; 24th September 2015 at 22:23. |
24th September 2015, 22:35 | #131 | Link | |
Registered User
Join Date: May 2009
Location: Belgium
Posts: 1,743
|
Quote:
There is another solution quickly mentioned on 1st or 2nd page : DGPulldown (if the encoding is for dvd). I believe it allows to encode 25p and play it at 29.97 fps without speed change, thanks to a flag. The main advantage is that the bitrate is higher by frame (compared to 30p or 60i), because there are less frames to encode by second (the maximal bitrate allowed on dvd is always the same, whatever the framerate). Other advantage : the encoding is simpler, there is nothing to do with Avisynth about framerate. |
|
24th September 2015, 22:43 | #133 | Link |
Registered User
Join Date: May 2006
Posts: 3,997
|
DGPulldown is found here:
http://rationalqm.us/dgpulldown/dgpulldown.html As I understand it uses soft-pulldown based on flags and timecode, as opposed to hard-pulldown produced by changefps(). DGPulldown hence preserves the original video. |
24th September 2015, 23:34 | #136 | Link | |
Registered User
Join Date: May 2006
Posts: 3,997
|
Quote:
|
|
25th September 2015, 08:19 | #137 | Link | |
Registered User
Join Date: May 2009
Location: Belgium
Posts: 1,743
|
Quote:
The DGpulldown trick allows to encode in 25p with the mpeg-2 encoder, but as the framerate for the player is 29.97 fps (thanks to DGpulldown's flag), the resolution has to be 720*480, not 720*576. But it's maybe possible if player's resolution is set on 1080p. Because if it's set on 480p, I don't believe the player will be able to send 480p with a 25p (or 50p actually) framerate. edit : actually I believe that the mpeg-2 encoder needs the final framerate (29.97 in this case), thus it has to be fed with 720*480 @ 29.97 fps, not 25 (unless the encoder accepts to encode 720*480 @ 25 fps). But don't use changefps() in avs script to convert 25p in 29.97, use assumefps(30000, 1001), but not for the sound which will keep its 25p speed. DGpulldown's flag will change it (as if assumefps(25) was done) and will add the 29.97 fps flag. It also means the encoding bitrate can be higher than 10 Mbps because of the slowdown made by DGpulldown : 11,5 Mbps @ 29.97 fps means 9,59 Mbps when slowed down @ 25 fps. Last edited by Music Fan; 25th September 2015 at 09:07. |
|
25th September 2015, 10:18 | #139 | Link | |
Registered User
Join Date: May 2006
Posts: 3,997
|
Quote:
...3:2:3:2:2:3:2:3:2:2:3:2:2:3:2:3:2:2:3:2:3:2:2...... or in case of ChangeFPS(30000,1001) the frame pattern becomes ....2:1:1:1:1:2:1:1:1:1:1:2:1:1:1:1:2:1:1:1:1 ..... I don't know if and how these hickups affect the playback, I didn't test on player + TV. It is definitely better to do the pulldown with ChangeFPS(60) or ChangeFPS(30) respectively, and add the slight slowdown AssumeFPS(...) for standards compliance at the end of the script. But kolak wrote that he does not want any speed change, if I remember correctly. |
|
25th September 2015, 10:58 | #140 | Link | |||
Moderator
Join Date: Oct 2001
Location: Hawaii
Posts: 7,406
|
No it doesn't. It'll be output by the DVD player at 59.94 fields per second, just like any other NTSC DVD.
Quote:
Quote:
Quote:
Last edited by manono; 25th September 2015 at 11:01. |
|||
Thread Tools | Search this Thread |
Display Modes | |
|
|