hi guys

im confused with the container specifically what it is ?

is it mean the extension like (somthing.***) which tell the OS wich program will run on it and to let people distinguish between diffrent format

im speaking not on audio only but also pic and video too

is it right that the container in fact its don`t do something with the file itself but the important is the algorithm of file or the encoding that made from ?


thanks in advance

Container formats are necessary with respect to

- aligning audio, video and subtitle streams in a single file, so that they stay in sync during playback

- allow tagging of the files ( most tagging standards, like id3v2, can also be seen as a kind of a/v container )

- offer more than one subtitles and audio streams in combination with one, or more video streams, and even using completely different compression formats for them

While audio/video containers, by definition, do have a higher importance for video material, they could also offer a number of advantages for audio compression only, like

1. Allowing app developers to save a lot of time by supporting a big number of different formats, but without the need to code specific support for their different tagging standards, etc.

2. Enabling users to combine their favourite audio compression format with any video streams they have

Unfortunately, all audio compression format developers prefer to create their own containers or framings, instead of setting on a common, existing container standard like MOV, WAV, OGG or MKA.

Christian
matroska project admin
http://www.matroska.org

so not in respect to video...

a container is a method in which to present the audio/visual data. the container will retain vital information regarding the data, and (most) allow for a tagging mechanism. some containers are strictlly a header that provides this function (small overhead), while other containers have a huge overhead.

an extension is (usually) just to provide a simple reference to a file (like .txt for text) - e.g. most *NIX data does not need an extension unless required by the accessing/playback software.


later

I have a container related question.

I see that there's an option to encode FLAC inside an OGG container. I guess this means that the content is lossless, but has an .ogg extension and will play in software and on devices that play OGG files but not FLAC...

Right? When I try this (several times), the resulting file doesn't play. Maybe my understanding is wrong?

I'm using FLAC Installer for Windows 1.1.2a from Mike Wren. Maybe I set the wrong options?

TIA

In general, if something says "Plays Ogg!" it means that it plays Ogg Vorbis, as that is by far the most common use for the Ogg container. What you have are Ogg FLAC files, which is a completely different encoding algorithm and therefore won't play without a FLAC decoder.

I, personally, don't really know why one would want to make Ogg FLAC files, as they are always larger than straight FLAC.

Ogg FLAC is better AFAIK for streaming lossless audio content that pure FLAC.

Christian
matroska project admin

as for any file (in container or not), you need two things:
1) a parser, which parses the file
2) a decoder, which decodes the stream

sounds obvious but this also tells you that an ogg vorbis player might be able to parse an ogg flac file, but will not be able to decode the flac stream inside the container


btw containers are also need for interactive streams (eg enabling menus)