diff options
author | gpoirier <gpoirier@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2005-08-12 13:27:26 +0000 |
---|---|---|
committer | gpoirier <gpoirier@b3059339-0415-0410-9bf9-f77b7e298cf2> | 2005-08-12 13:27:26 +0000 |
commit | 740f19c59ff9dcb08a3eaea9cf161f7b30fd6ca5 (patch) | |
tree | 310775416d57c955e5fad6e1f7b97a8d5b37137b | |
parent | 1c4da1e6747ec427b24e2d311dd057c04add1957 (diff) |
Why multipass is better in a nutshell. Taken from Rich's encoding guide.
git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@16203 b3059339-0415-0410-9bf9-f77b7e298cf2
-rw-r--r-- | DOCS/xml/en/encoding-guide.xml | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/DOCS/xml/en/encoding-guide.xml b/DOCS/xml/en/encoding-guide.xml index 9a01a59730..cdc93edf5c 100644 --- a/DOCS/xml/en/encoding-guide.xml +++ b/DOCS/xml/en/encoding-guide.xml @@ -289,6 +289,19 @@ (CBR), constant quantizer, and multipass (ABR, or average bitrate). </para> +<para> + The complexity (and thus the number of bits) required to compress the + frames of a movie can vary greatly from one scene to another. + Modern video encoders can adjust to these needs as they go and vary + the bitrate. + However, in simple modes such CBR, they cannot exceed the requested + average bitrate for long stretches of time, because they do not know + the bitrate needs of future scenes. + Wiser modes, such as multipass encode can take into account the + statistics from previous passes, which fixes the problem mentioned + above. +</para> + <note><title>Note:</title> <para> Most codecs which support ABR encode only support two pass encode |