h.263 codec

Hello, again, everyone.

After searching and searching and reading a bit on a few websites and the book "Voice and Data Communications Handbook" by Regis J. Bates and Donald W. Gregory, I've finally given up.

I'm just not getting what this codec is for, or specifics about what a codec, in general, truly is. Would someone care to explain in a sort of dumbed down way? Also, would you kindly provide some reference as to where I can download it for so that I can use it with ffmpeg specifically (trying to decode to .h263 from .avi and vice-versa, for example). Hope this codec is open source and free/legal...

codec = encoder / decoder
Have you looked up "codec" and "h.263" on Wikipedia?

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Originally Posted by oogabooga

codec = encoder / decoder
Have you looked up "codec" and "h.263" on Wikipedia?

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Yes, I have. Just didn't get it. And still kinda don't. I think my brain is stuck on wanting to think it is something other than it actually isn't and it's just confusing me. I'll look into "encoding" and "decoding" specifically, maybe that'll help. But now that you put it that way, it does answer a question. A codec is a program in itself of sorts. Am I right?

Also, at least I saw that using libavcodec it is legal to encode/decode h263 (unless it isn't original video, I can assume, I guess. Won't be a problem cause I'm making my own video).

A codec will often be a program, but may be entirely implemented in hardware.
I was wrong about "encoder / decoder", it's actually "COmpressor / DECompressor".

Also, to clarify, I have a method which uses libavcodec.

However, avcodec_find_decoder(CODEC_ID_H263) always returns null, however, which is what leads me to believe that despite having downloaded the library, I have to download the codecs separately. Am I on the right track there too? Anybody done this? Because I found a h263.c source file on ffmpeg's website, for example, but don't know if I have to compile it or what other files I need to be able to use it (besides the obvious h263.h). I think I see it requires other header files I don't have either. Any idea?

Quote:

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Originally Posted by oogabooga

A codec will often be a program, but may be entirely implemented in hardware.
I was wrong about "encoder / decoder", it's actually "COmpressor / DECompressor".

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Oh, ok, compression/decompression. That makes sense for my purposes, since I'm trying to compress to h263 and possibly decompress back to mpeg/avi.

I hate to nitpick, but the traditional meaning of CODEC is COder/DECoder

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possibly decompress back to mpeg/avi

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That would require another encoding.

Video, in the simplest form, is a series of images, each with a RGB value for each pixel.

Obviously, that's not very efficient to store, so people encode them into more efficient formats like H.263.

But when the video needs to be played, it needs to be decoded back to the primitive format, and that's the job of the decoder.

As long as the encoder and decoder agree on the "encoded format", the original video can be recovered (maybe with intentional quality loss). That's why they usually come in pairs, hence codec.