After selecting (and probably ripping) a DVD title it's time to adjust the
clipping and zooming parameters. transcode supports three processing
stages for this task, in this order:
Often you don't need to use all three steps, particulary the last
clipping step may be omitted. Anyway it's very easy to define the
correct parameters with this model.
- Clip the video
- Zoom or shrink the clipped video
- Clip again the result of the zoom/shrink process
dvd::rip should have taken a preview frame for you already after
ripping. If not (e.g you're not using the ripping mode) or the
image isn't representative enough you can
grab an arbitrary preview frame by entering its number and pressing
Grab frame. For ripped titles this needs a few seconds. For
on-the-fly and DVD image modes it needs the longer the higher your
frame number is.
Adjusting clipping and sizing
The grabbed image will appear in the preview section three times.
The first shows the image after the first clipping, the second after
resizing and the third after the second clipping.
Note: preview frame grabbing is rather slow for on-the-fly and
DVD image projects, because all prior frames must be decoded.
Fast movie navigation is available for ripped movies only.
You can click on any preview image to view it in its original size in
a separate window. Additionally, the clipping images will show up
with markers for defining the clipping area.
In ripping mode you can use the button Show video from here
to start the
movie player you configured
for STDIN playing starting at the frame number you entered.
Note: this function is available only for ripped movies.
It's disabled for on-the-fly and DVD image projects.
It's strongly suggested to use the offered Clip & Zoom presets. By default
dvd::rip applies the Autoadjust, Medium Frame Size, Fast Resize
preset, which gives very good results by adequate transcoding speed.
The presets are divided into two classes:
The autoadjusting presets determine the black bars of a letterbox movie
automatically and set the clipping values accordingly. They are available for
three target frame sizes (Small, Medium and Big) and with or without
fast resizing (see below for details). Big only corrects the aspect
ratio, medium scales the image somewhat down and small somewhat more.
(S)VCD / CVD presets
- Fixed values
The fixed presets are currently for (S)VCD and CVD modes only. They're available
two times, once for NTSC and once for PAL. You must select the correct
entry for your format.
For VCD you don't have a lot of choices: 4:3 or 16:9, depending on the aspect ratio of your movie. SVCD is anamporph encoded. For 16:9 movies you can create a 4:3 format. This will cut off some of the letterbox black bars and keep more space for the real movie. CVD has a fixed frame size, anamorph encoded.
After applying a preset the preview images are regenerated automatically.
Note: for SVCD and CVD the aspect ratio information printed under the preview images is mostly useless, because SVCD/CVD is always anamorph encoded. The player stretches the image to 4:3 resp. 16:9, depending on what you've chosen. So forget about the values printed there, they don't take the rescaling of the player into account. This may be fixed in future releases.
dvd::rip let you do the hard job, if that's what you want ;), so you can enter
all values which affect clipping and resizing manually.
You must press the Generate preview images button after
changing values by hand, otherwise the displayed thumbnails
won't show up with your settings.
You can enter arbitrary values in the correspondent entries or
click on the preview image to get a full sized version with markers,
which define the clipping area. This way you can adjust
a custom clipping easily by drag'n'drop.
You can specify negative values, if you want to add corresponding
black bars. This may be needed for (S)VCD formats or if you like to
render subtitles on black bars for a 4:3 movie, which originally has no
Enter arbitrary values into the width and height entries. Currently
no drag'n'drop is available for this. You may leave both fields empty,
which means not to resize anything.
Fast resizing is a special algorithm for resizing the frame which
is much faster than high quality resizing. The quality isn't that
good, but in my opinion the difference isn't visible, at least
with DVD source material.
When you enable fast resizing, there are two rules which must be complied with:
Beside these rules, two more rules must be fulfilled (at least for
the video codecs actually known), even if you don't use fast resizing.
If you break with these
rules you may get colored artefacts in the transcoded movie:
- Zoom width and height must be divisible by 8
- Both axes must shrink or expand simultaneously. You can't
expand the width while shrinking the height and vice versa.
- Resulting frame sizes must be divisible by 16
- Don't clip on odd values
If you turned fast resizing on, a message will be printed
besides the Zoom entries, if one of this rules is violated. If you
transcode anyway, you'll get an error message.
All presets follow these rules.
If you change any value by hand you must hit the
Generate preview images button, otherwise the displayed thumbnails
won't show up with your settings.
If you want to have a specific width or height for your movie while
keeping the correct aspect ratio, you can use these buttons. E.g.
you want to define the height, then enter
your value to the Height entry and press Calc width
afterwards. The same applies vice versa, if you want to define the width
and like to have the proper height calculated.
This is a special function of the early days, where no auto-adjusting
presets were present... ;) If you don't use
fast resizing and don't have any clip1 values you can transfer your
clip2 settings into clip1 settings. The aspect ratio will remain the same,
dvd::rip automatically calculates the correct clip1 and zoom parameters
for you (clipping before zooming has the advantage, that the zoom
stage works with less pixels, which is somewhat faster).
This buttons opens the Zoom calculator window, which is
described in it's own