From 14f1f2d212032c4f09808f10aa91b6136f634816 Mon Sep 17 00:00:00 2001 From: arpi Date: Tue, 22 Oct 2002 01:06:32 +0000 Subject: [PATCH] updated docs on realmedia git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@7832 b3059339-0415-0410-9bf9-f77b7e298cf2 --- DOCS/tech/formats.txt | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/DOCS/tech/formats.txt b/DOCS/tech/formats.txt index 85503c59f9..8b80c672b4 100644 --- a/DOCS/tech/formats.txt +++ b/DOCS/tech/formats.txt @@ -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.