[Mplayer-cvslog] CVS: main/DOCS/tech formats.txt,NONE,1.1

[Felix Buenemann]

On Thursday, 8. November 2001 00:01, you wrote:
> Update of /cvsroot/mplayer/main/DOCS/tech
> In directory mplayer:/var/tmp.root/cvs-serv32764
>
> Added Files:
> 	formats.txt
> Log Message:
> extended ascii version of formats.html
>
> --- NEW FILE ---
> 1. Input layer, supported devices, methods:
>   - plain file, with seeking
>   - STDIN, without seeking backward
without seeking forward in avis with index.


>     Codecs: video is always mpeg video (mpeg1, mpeg2 or mpeg4).
hmm, I've never seen raw mpeg4 stream...


>     - bps-based: it is baed on bitrate/samplerate of video/audio steram.
>       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.
usually with vbr audio -bps has better sync then -nobps, but it helps with 
other badly interleaved avis.

>
>     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 REQUIRES for seeking.
>     Btw usually it can be rebuild from file content, mplayer does it with
>     the -idx switch. Mplayer can fix broken index blocks using -forceidx.
should be recreate not fix.

>     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, but any codecs allowed.
maybe add mpeg1layer3 here, too.

>   - QuickTime / MOV files:
>     They come from Mac users, usually with .mov or .qt extension, but as
>     MPEG Group choose quicktime as recommended file format for MPEG4,
>     sometimes you meet quicktime files with .mpg extension.
they have .mp4 extension not .mpg

>
>     Codecs: any codecs allowed, both CBR and VBR.
>     Note: most new mov files use Sorenson video and audio, they are
there's no sorenson  audio, they use QDesign Music codec by QDesign but it's 
also patented to apple it seems.

>     patented, closed, secret, (TM)-ed etc formats, only Apple's quicktime
>     player is able to playback these files (on win/mac only).
>

-- 
Best Regards,
	Atmos

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