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diff --git a/DOCS/OUTDATED-tech/formats.txt b/DOCS/OUTDATED-tech/formats.txt deleted file mode 100644 index ee4aa8f6ba..0000000000 --- a/DOCS/OUTDATED-tech/formats.txt +++ /dev/null @@ -1,160 +0,0 @@ -1. Input layer, supported devices, methods: - - plain file, with seeking - - STDIN, without seeking backward - - 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!!!) - - CDDA - raw audio from audio CD-ROM discs (using cdparanoia libs) - - RTP streaming (mpeg-ps over multicast only) - - LIVE555 streaming - support SDP/RTSP (using the LIVE555 libs) - - SMB - file access over samba (experimental) - -2. Demuxer/parser layer, supported file/media formats: - - - MPEG streams (ES,PES,PS. no TS support yet) - note: mpeg demuxer silently ignore non-mpeg content, and find mpeg packets - in arbitrary streams. it means you can play directly VCD images (for example - CDRwin's .BIN files) without extracting mpeg files first (with tools like vcdgear) - It accepts all PES variants, including files created by VDR. - Note: VOB (video object) is simple mpeg stream, but it usually has 01BD - packets which may contain subtitles and non-mpeg audio. Usually found on DVD discs. - - Headers: mpeg streams has no global header. each frame sequence (also called GOP, - group of pictures) contains an sequence header, it describes that block. - In normal mpeg 1/2 content there are groups of 12-15 frames (24/30 fps). - It means you can freely seek in mpeg streams, and even can cut it to - small parts with standard file tools (dd, cut) without destroying it. - - Codecs: video is always mpeg video (mpeg1, mpeg2 or mpeg4). - audio is usually mpeg audio (any layer allowed, but it's layer 2 in most files) - but 01BD packets may contain AC3, DTS or LPCM too. - - FPS: mpeg2 content allows variable framerate, in form of delayed frames. - It's mostly used for playback 24fps content at 29.97/30 fps (NTSC) rate. - (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 23.976 - is recommended. - - - AVI streams. - Two kind of RIFF AVI files exists: - 1. interleaved: audio and video content is interleaved. it's faster and - requires only 1 reading thread, so it's recommended (and mostly used). - 2. non-interleaved: audio and video aren't interleaved, i mean first come - whole video followed by whole audio. it requires 2 reading process or - 1 reading with lots of seeking. very bad for network or cdrom. - 3. badly interleaved streams: mplayer detects interleaving at startup and - enables -ni option if it finds non-interleaved content. but sometimes - the stream seems to be interleaved, but with bad sync so it should be - played as non-interleaved otherwise you get a-v desync or buffer overflow. - - MPlayer supports 2 kind of timing for AVI files: - - bps-based: it is based on bitrate/samplerate of video/audio stream. - this method is used by most players, including avifile and wmp. - files with broken headers, and files created with VBR audio but not - vbr-compliant encoder will result a-v desync with this method. - (mostly at seeking). - - interleaving-based: note: it can't be used togethwer with -ni - it doesn't use bitrate stuff of header, it uses the relative position - of interleaved audio and video chunks. makes some badly encoded file - with vbr audio playable. - - Headers: AVI files has a mandatory header at the begin of the file, - describing video parameters (resolution, fps) and codecs. Optionally - they have an INDEX block at the end of the file. It's optional, but - most files has such block, because it's REQUIRED for seeking. - Btw usually it can be rebuilt from file content, mplayer does it with - the -idx switch. MPlayer can recreate broken index blocks using -forceidx. - As AVI files needs index for random access, broken files with no index - are usually unplayable. - Of course, cutting/joining AVI files needs special programs. - - Codecs: any audio and video codecs allowed, but I note that VBR audio is - not well supported by most players. The file format makes it possible to - use VBR audio, but most players expect CBR audio and fails with VBR, - as VBR is unusual, and Microsoft's AVI specs only describe CBR audio. - I also note, that most AVI encoders/multiplexers create bad files if - using VBR audio. only 2 exception (known by me): NaNDub and MEncoder. - - FPS: only constant framerate allowed, but it's possible to skip frames. - - - ASF streams: - ASF (active streaming format) comes from Microsoft. they developed two - variant of ASF, v1.0 and v2.0. v1.0 is used by their media tools (wmp and - wme) and v2.0 is published and patented :). of course, they differ, - 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. - Asf uses fixed packet size, so it is seekable without any INDEX block, - and broken files are playable well. - - Codecs: video is mostly microsoft's mpeg4 variants: MP42, MP43 (aka DivX), - WMV1 and WMV2. but any codecs allowed. - audio is usually wma or voxware, sometimes mp3, but any codecs allowed. - - FPS: no fixed fps, every video frame has an exact timestamp instead. - I've got stream with up to 3 sec frame display times. - - - QuickTime / MOV files: - They come from Mac users, usually with .mov or .qt extension, but as - MPEG Group chose quicktime as recommended file format for MPEG4, - sometimes you meet quicktime files with .mpg or .mp4 extension. - - At first look, it's a mixture of ASF and AVI. - It requires INDEX block for random access and seeking, and even for - playback, like AVI, but uses timestamps instead of constant framerate - and has more flexible stream options (including network stuff) like ASF. - - Headers: header can be placed at the beginning or at the end of file. - About half of my files have it at the beginning, others have it at the end. - Broken files are only playable if they have header at the beginning! - - Codecs: any codecs allowed, both CBR and VBR. - Note: most new mov files use Sorenson video and QDesign Music audio, - they are patented, closed, secret, (TM)-ed etc formats, only Apple's - quicktime player is able to playback these files (on win/mac only). - - - VIVO files: - They are funny streams. They have a human-readable ascii header at - the beginning, followed by interleaved audio and video chunks. - It has no index block, has no fixed packetsize or sync bytes, and most - files even has no keyframes, so forget seeking! - Video is standard h.263 (in vivo/2.0 files it's modified, non-standard - h.263), audio is either standard g.723 or Vivo Siren codec. - - 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. - - - GIF files: - The GIF format is a common format for web graphics that supports - animation. These are read through libungif or compatible library. - Variable frame delays are supported, but seeking is not supported. - Seeking will be supported once an index of gif frames can be built. |