Reading tag data for Ogg / Flac files

Question

I am working on a C library that reads tag information from music files. I already have ID3v2, but I can’t understand how Ogg files are structured.

I opened the .ogg file in hexadecimal code and I was able to find the tag data because it was all clear to the person. But everything from the beginning of the file to the tag data looked like garbage. How is this data encoded?

I don't need any help with the actual code, I just need help in visualizing what the Ogg header looks like and what encoding it uses so that I can read it. I would like to use a non-hacked approach to reading Ogg files.

I watched the Flac format , which was useful.

The Flac file I'm looking for contains about 350 bytes between the identifier "fLac" and the user-readable "Comments" section, and none of them are human-readable in my hex editor, so I'm sure there must be something important there .

I am using Linux and I am not going to port to Windows or OS X. Therefore, if I need to use the glibc function to convert the encoding, I am fine with it.

Answer 1

As described in the link above, the following metadata blocks can occur between the fLaC marker and the VORBIS_COMMENT metadata block.

• STREAMINFO: , ​​ , , .. . , , , .
• : . 32- . FLAC. . , ID FLAC.
• PADDING: . PADDING . , , ; PADDING , ( ) , ( ).
• SEEKTABLE: . FLAC , , . , . 18 , 1% 2k. SEEKTABLE, . "placeholder", , .

.

, FLAC, ; . -. , .

, ?

- Ogg.

, ?

Answer 2

Ogg . .

libogg, BSD- Ogg .