11/06/2010, 09:52 PM
This is like one of the most misunderstood things ever...
I'm going to explain it here, so instead of spending effort to explain this over and over every time, I can simply link them to this thread.
Firstly, what is a container?
In our case, a multimedia container is a wrapper that wraps the video, audio, subtitles, and whatever else together in one file.
So inside a container, wee can have multiple different types of video and audio streams. Support for a container format DOES NOT neccessarily mean support for all the possible video/audio types the container can hold, and conversely, having support for a video/audio format DOES NOT mean support for all container formats that can hold such a video/audio format.
For example...
So why do wee need containers?
To hold our video/audio/subtitles/whatever files together.
Also to store some useful information not contained in the raw video/audio bitstreams, such as chapter information, tags, and synch information so the video and audio play together as they are intended to.
So why is it important to get it right?
Besides for making yourself not sound retarded... ("Hey guise, I downloaded XviD converter, how come I get AVI video not Xvid video?")
It's important because when you ask for help, the person helping you may need to know exactly what you're trying to play. It also lets you diagnose a lot of your support problems so won't end up spamming forums with "OMG, Company xxxxx said this yyyyy can play MP4's, I have this MP4 here and it doesn't play, Please HALP ME, fucking liar bitches, I'll sue you!"
So how do I find out what is what?
Same as how you would find out any other information, use Google/Yahoo/Bing/Ask/whatever, ask someone, many other ways (searching Wikipedia is good).
To save you some effort, here is a list of some common names you hear and what they are...
Container formats - AVI, MP4 (M4A), MKV (MKA), MOV, ASF, OGV (OGM, OGG), WebM (lol rebranded MKV)
Video formats - DivX, XviD, H.264 (AVC), WMV, VP8, Theora
Audio formats - AAC, MP3, WMA, Vorbis, FLAC, AC3, DTS
Notes...
1. File extension doesn't always imply container. Eg. you see .WMV file, that doesn't mean WMV is a container format, WMV is a video format, the container for your .WMV file is ASF.
2. Some video/audio formats have their own container format. Eg. FLAC is both an audio codec, and also it's own container format.
I'm going to explain it here, so instead of spending effort to explain this over and over every time, I can simply link them to this thread.
Firstly, what is a container?
In our case, a multimedia container is a wrapper that wraps the video, audio, subtitles, and whatever else together in one file.
So inside a container, wee can have multiple different types of video and audio streams. Support for a container format DOES NOT neccessarily mean support for all the possible video/audio types the container can hold, and conversely, having support for a video/audio format DOES NOT mean support for all container formats that can hold such a video/audio format.
For example...
- AVI (with XviD + MP3) --» AVI (Audio Video Interleave) = container, XviD = video, MP3 = audio. AVI is NOT the video format, you don't have AVI video, you have XviD video.
- MP4 (with AVC + AAC) --» MP4 = container, AVC (H.264) = video, AAC = audio. Pretty much all devices that support MP4 can play that.
- MP4 (with Dirac + ALAC) --» MP4 = container, Dirac = video, ALAC (Apple Lossless Audio Codec) = audio. And absolutely no device out there that support MP4 can play that.
- OGG Vorbis --» OGG = container, Vorbis = audio.
So why do wee need containers?
To hold our video/audio/subtitles/whatever files together.
Also to store some useful information not contained in the raw video/audio bitstreams, such as chapter information, tags, and synch information so the video and audio play together as they are intended to.
So why is it important to get it right?
Besides for making yourself not sound retarded... ("Hey guise, I downloaded XviD converter, how come I get AVI video not Xvid video?")
It's important because when you ask for help, the person helping you may need to know exactly what you're trying to play. It also lets you diagnose a lot of your support problems so won't end up spamming forums with "OMG, Company xxxxx said this yyyyy can play MP4's, I have this MP4 here and it doesn't play, Please HALP ME, fucking liar bitches, I'll sue you!"
So how do I find out what is what?
Same as how you would find out any other information, use Google/Yahoo/Bing/Ask/whatever, ask someone, many other ways (searching Wikipedia is good).
To save you some effort, here is a list of some common names you hear and what they are...
Container formats - AVI, MP4 (M4A), MKV (MKA), MOV, ASF, OGV (OGM, OGG), WebM (lol rebranded MKV)
Video formats - DivX, XviD, H.264 (AVC), WMV, VP8, Theora
Audio formats - AAC, MP3, WMA, Vorbis, FLAC, AC3, DTS
Notes...
1. File extension doesn't always imply container. Eg. you see .WMV file, that doesn't mean WMV is a container format, WMV is a video format, the container for your .WMV file is ASF.
2. Some video/audio formats have their own container format. Eg. FLAC is both an audio codec, and also it's own container format.