some little clarifications and additions

patch by Samuli Kärkkäinen <skarkkai@woods.iki.fi>


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@11781 b3059339-0415-0410-9bf9-f77b7e298cf2
This commit is contained in:
diego 2004-01-12 06:30:30 +00:00
parent 1577824605
commit d7154f34b0
1 changed files with 12 additions and 3 deletions

View File

@ -633,7 +633,7 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
</para>
<para>
There are two ways to avoid this. You can try encoding again using
There are three ways to avoid this. You can try encoding again using
<option>vqscale=4</option> and see if both the resulting file size
and picture quality are acceptable. You can also use
<link linkend="menc-feat-divx4">2 pass encoding</link>.
@ -643,6 +643,14 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
<option>-lavcopts vbitrate=<replaceable>bitrate</replaceable></option>
option without using
<link linkend="menc-feat-divx4">3 pass encoding</link>.
</para>
<para>
The third and possibly the best option may be to slightly scale down
the resolution. The uniform slight softening and loss of detail is
visually more appealing than the blockiness and other artifacts
caused by MPEG compression. Scaling down also effectively reduces the
noise of the picture, which is good, as noise is hard to compress.
</para></sect2>
<sect2 id="menc-feat-dvd-mpeg4-deinterlacing">
@ -701,8 +709,9 @@ vcodec=mpeg2video:intra_matrix=8,9,12,22,26,27,29,34,9,10,14,26,27,29,34,37,
<sect2 id="menc-feat-dvd-mpeg4-scaling">
<title>Scaling and aspect ratio</title>
<para>
For best quality, do not scale the movie while ripping. Scaling
causes artifacts and makes the file larger. Pixels in DVD movies
For best quality, do not scale the movie while ripping. Scaling down
obviously loses detail, and scaling up causes artifacts and obviously
makes the file larger. Pixels in DVD movies
are not square, so DVD movies include info about the correct aspect
ratio. It is possible to store the aspect ratio in the MPEG4 header
of the output file. Most video players ignore this info, but