Help with compression..

[musicmad]

Hi,
being new to digital technology i was wondering if someone could help.
When downloading files from the network, audio or video, i understand at first they need to be encoded/compressed for transportation over the network /internet,
Once these files reach somebody else who wants to download and burn them to disc, they need to decode these files to the correct format for compatibility, this i understand, what i dont understand is, When an audio file is being converted from mp3 back to cda format, is it just changing the file format for compatibility or is it actually affecting the compression rate again??? basically what i mean is, once a cda file has been compressed, its not possible to un-compress it, put the audio back in??? this is where i get confused, to encode compress, to decode un-compress, whats the diffrence..

Musicmad

 

[strangestranger]

once something has been compressed to a lesser quality it can never be turned back, therefore, if all you have a is a 320CBR MP3, that is the best quality you can get from that file.

files do not need to be compressed for transferring but it is handy for space and speed.

why do you ask exactly?

 

[musicmad]

Hi strangestranger thanks for your feedback,
basically.. i just got confused with decode as opposed to encode, if encode means to compress, then decode must mean to un-compress, but obviously from your reply i know now that this is incorrect, so what exactly does decode refer to

 

[rexter]

When an audio file is being converted from mp3 back to cda format, is it just changing the file format for compatibility or is it actually affecting the compression rate again??? basically what i mean is, once a cda file has been compressed, its not possible to un-compress it, put the audio back in??? this is where i get confused, to encode compress, to decode un-compress, whats the diffrence..Musicmad

Easy example: Let say you need to transfer a VHS video tape of your family event onto a DVD. Say you need to Encode to a Mpeg 2 format so if 1 hour of the video tape equals to 5 Gig of hard drive space, would you like to decrease the amount of space used or not. If not then no compression will be made just encoding. If yes then Encoding and compression will be used.

Therefore Encoding is just a tool to transfer one format to another format. And compression does not need to be presented unless space is required for a target.

once something has been compressed to a lesser quality it can never be turned back, therefore, if all you have a is a 320CBR MP3, that is the best quality you can get from that file.

files do not need to be compressed for transferring but it is handy for space and speed.

Because whatever material you have is the only information you can play with.
ee(If you have a bad recording it doesn't matter where you transfer it to, It still a bad recording)

 

[musicmad]

ok, the encoding process is clearly understood know, but with regard to decoding i'm still unsure what this actually refers to, what is to decode???

 

[rexter]

ok, the encoding process is clearly understood know, but with regard to decoding i'm still unsure what this actually refers to, what is to decode???

Means that whatever is encoded it needs to decode so that your computer will process the material. Computers need it to understand the language it's writen on.

Regular DVD movies encoded with Mpeg2, so When your computer does not have mpeg2 decoder, even with windows media player it wont play. so you need to install the codec required to decode and play the movie.

Like jpeg and bitmap. The decoder can read specific format it's design for and process it.

 

[musicmad]

rexter, clearly understood, thanks for all your feedback, much appreciated

Musicmad