[Mplayer-cvslog] CVS: main/DOCS/tech formats.txt,1.6,1.7
Arpi of Ize
arpi at mplayerhq.hu
Tue Oct 22 03:06:54 CEST 2002
Update of /cvsroot/mplayer/main/DOCS/tech
In directory mail:/var/tmp.root/cvs-serv28585
Modified Files:
formats.txt
Log Message:
updated
docs on realmedia
Index: formats.txt
===================================================================
RCS file: /cvsroot/mplayer/main/DOCS/tech/formats.txt,v
retrieving revision 1.6
retrieving revision 1.7
diff -u -r1.6 -r1.7
--- formats.txt 12 May 2002 00:47:19 -0000 1.6
+++ formats.txt 22 Oct 2002 01:06:32 -0000 1.7
@@ -4,7 +4,11 @@
- network streaming (currently plain wget-like HTTP and MMS (.asx))
- VCD (Video CD) track, by direct CDROM device access (not requires mounting disc)
- DVD titles using .IFO structure, by direct DVD device access (not requires mounting disc)
- - DVD titles using menu navigation (experimental/alpha, not yet finished)
+ - DVD titles using menu navigation (experimental/alpha, not yet finished!!!)
+ - CDDA - raw audio from audio CD-ROM discs (using cdparanoia libs)
+ - RTP streaming (mpeg-ps over multicast only)
+ - Live.com streaming - support SDP/RTSP (using the live.com libs)
+ - SMB - file access over samba (experimental)
2. Demuxer/parser layer, supported file/media formats:
@@ -31,7 +35,7 @@
(so called Telecine or 3:2 pulldown effect)
It means you see 30 frames per second, but there are only 24 different
pictures and some of them are shown longer to fill 30 frame time.
- If you encode such files with mencoder, using -ofps 24 or -ofps 23.98
+ If you encode such files with mencoder, using -ofps 24 or -ofps 23.976
is recommended.
- AVI streams.
@@ -83,6 +87,8 @@
no compatibility at all. (it's just a legality game)
MPlayer supports only v1.0, as nobody ever seen v2.0 files :)
Note, that .ASF files are nowdays come with extension .WMA or .WMV.
+ UPDATE: MS recently released the ASF v1.0 specs too, but it has some
+ restrictions making it illegal to read by us :)
Headers: Stream headers (codecs parameters) can be everywhere (in theory),
but all files i've seen had it at the beginning of the file.
@@ -126,3 +132,23 @@
Note, that microsoft licensed vivo stuff, and included in their netshow
v2.0 program, so there are VfW/ACM codecs for vivo video and audio.
+ - RealMedia files:
+ A mixture of AVI and ASF features. It has mandatory headers at the
+ beginning and an optional INDEX (missing in most files).
+ The file is constructed of variable size chunks, with small header
+ telling the stream ID, timestamp, flags (keyframe...) and size.
+ But it has some features found in ASF files:
+ The video is actually double-muxed, the video chunks are really
+ appended fragments of the video frame. RV30+ supports B frames, so
+ you have to parse some bits of the first fragment to get the real PTS.
+ The audio frames are fixed size (CBR) but using the same scrambling
+ (out-of-order interleaving) as in the ASF files.
+
+ Codecs: Audio is either COOK(er), SIPR(o), ATRAC3 or DNET.
+ The DNET is actually a byte-swapped low-bitrate Dolby AC3 variant :)
+ Video is RV10 (h263 variant), RV20 (rp G2), RV30 (rp v8) or RV40 (rp v9).
+
+ FPS: variable, just like in ASF.
+
+ Note, that similarity of real and asf has some background - they worked
+ together on the (never finished/used) ASF v2 spec for some time.
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