Hello,
I have a question about converting audio OGG (VORBIS) to FLAC.
You could ask: why this convertion?
Because I have many OGG file from ripped CD and I would like to
convert them in another format compatible with my portable audio player.
If I convert OGG to MP3 I have another loss, so I would like to choose a lossless algorithm: FLAC.
But an OGG 6.6 MB file become a 50MB FLAC file.
I understand that FLAC is loss-less, so from CD to FLAC se file size is bigger than from CD to OGG.
Once I have ripped from CD to OGG some informations are lost and after then there’s a compression of data, so file are smaller due to loss.
I dont’ understand why If I only change the compression method, so from OGG(VORBIS) to FLAC, but datas are less than the original CD, files becomes huge.
As you are aware, CD audio uses a huge amount of digital data to represent that analog audio. To be precise, CD audio uses 1411200 bits of data for every second of audio. In other words, it has a “bit rate” of “1411200 bits per second” (1411.2 kbps). This format is commonly known as “PCM”.
In comparison, an Ogg encoded file may represent the same analog sound in around 160 kbps. The way this happens is the the Ogg encoder takes the 1411.2 thousand bits of “PCM” data each second and “encodes” the data cleverly so as to reduce the number of bits to only 160 thousand bits of “Ogg” data per second.
What happens in a media player that supports Ogg playback is that the Ogg file is decoded, so that the 160 kb of Ogg data each second is expanded back to 1411.2 kb of PCM data per second, which can then be played back as analog sound for you to listen to.
In your case, you say that your media player does not support Ogg. In other words, your media player is not able to decode the 160 kb of “Ogg data” back to 14411.2 kb of “PCM” data. However, you also say that your media player does support FLAC format.
FLAC encoding is able to take 1411.2 thousand bits of “PCM” data each second and “encode” the data cleverly so as to reduce the number of bits to somewhere around 700 thousand bits of “FLAC” data per second. On playback, the 700 kb of FLAC data is “decoded” (perfectly) back to 1411.2 kb of PCM data and then played for you to listen to.
The important thing to note is that for both Ogg and Flac, encoding is from PCM to the encoded (Ogg/Flac) format, and decoding is from the encoded (Ogg/Flac) format to PCM.
When you convert from Ogg to Flac, you are actually doing 2 separate steps:
I think you have answered. I resume it in another way to ensure that.
Producing FLAC from OGG is similar as producing it from CD as in both cases the encode process starts from 1411.2 kb.
Form CD I start with all the original informations, from OGG the informations are, in some way, “interpolated” (pass me this expression).
So another problem is that every type of “transcoding” using “lossy” algorithm (e.g. from OGG to MP3) lose more informations as I have to pass through PCM.
Is there a sort of “transcoding” only for the container, without loss?
Fo example OGG is a contanier and the coding is called VORBIS.
In another words, can I change the container without decoding and recoding?
Is there a sort of “transcoding” only for the container, without loss?
Fo example OGG is a contanier and the coding is called VORBIS.
In another words, can I change the container without decoding and recoding?
Not in Audacity.
I know that you can have FLAC encoded audio in an OGG container, but I don’t think you can have Vorbis encoded audio in a FLAC container.