[MPlayer-dev-eng] [PATCH] formats.html (again)

[Arpi]

Hi,

> Arpi beat me with his checkin of my patch..
I've waited for Gabucino but it seems you're still procmail'ed to /dev/null

-<P>You see, a <B>codec</B> is not the same as a <B>file format</B>.<BR>
+<P>You see, a <B>video codec</B> is not the same as a <B>video
format</B>.<BR>

hey, i've dropped this change BY REASON at first time.
facts:
- video format is not the same as file format
- video codec is the code to en/decode a given video format
- audio codec is the code to en/decode a given audio format
- demuxer is the code to handle a given _file_ format

the difference between audio and video is very different form that you and
Gabu wrote!

in the reality, no video-only file format, which can be played by codec
without using some kind of demuxer. but most (not all) audio-only file
format is the same as teh raw audio steram of a mxued stream, so they
can be played without using any demuxer. in this case we may say: audio
format is the same as audio-only file format. btw it's misleading and i
doubt we should keep such sentence in the docs.

the term 'video format' is also bad... people usually call muxed audio-video
and muxed video-only file formats 'video format' and raw audio-only files
'audio format'. it is not too clean and shouldn't be used in mplayer dox
or must be explained before using these.

from the docs:
+Examples of video <B>codecs</B> are: MPEG1, MPEG2, DivX, Indeo5, 3ivx.<BR>
+Examples of video <B>formats</B> are: MPG, AVI, ASF.<BR>

mpg, avi and asf are really video _file_ formats
mpeg 1/2, divx etc are video formats and can be decoded using video codecs
mp3, aac, ac3 are audio formats and audio file formats
wma, wav are audio _file_ formats but not audio format (.wma/.wav can contain
mp3, aac, pcm etc audio formats muxed)
note that wma file format (a.k.a. asf file format) mostly have audio in wma
audio format, a.k.a divx audio format, but the file format allows to use mp3
pcm or any other win32/acm supported audio format.

i suggest to forget terms audio format and video format.
use raw audio-only and muxed audio-video file format and audio/video
coding/codec. note again that .wma is teh same as .asf, and can contain even
video, it's just renamed to .wma to make that silly windows users happy who
anyway used to click on the attachment _file_ called www.yahoo.com and
are suprised when their computer gets infected by virus...


A'rpi / Astral & ESP-team

--
Developer of MPlayer, the Movie Player for Linux - http://www.MPlayerHQ.hu