Integrating id3lib Into Your Next C++ Audio Project

To read and write MP3 tags using id3lib, you interact with a mature, open-source C++ library designed to parse and modify ID3v1 and ID3v2 metadata frames. It structures data into a main ID3_Tag object which contains individual ID3_Frame pieces (such as title, artist, or album). Core Concepts of id3lib

ID3_Tag: The master object representing the entire metadata container of an MP3 file.

ID3_Frame: A specific data container inside the tag (e.g., ID3FID_TITLE for the track title).

ID3_Field: The underlying value holder within a frame, allowing you to get or set text strings, integers, or raw binary data. How to Read MP3 Tags

Reading involves instantiating an ID3_Tag, linking it to your MP3 file, finding the specific frame you want, and pulling the text from its fields.

#include #include int main() { // 1. Create a tag object and link it to the file ID3_Tag myTag(“song.mp3”); // 2. Query specific text frames using Frame IDs ID3_FrameartistFrame = myTag.Find(ID3FID_ARTIST); ID3_Frame* titleFrame = myTag.Find(ID3FID_TITLE); // 3. Extract data from the frames if they exist if (artistFrame != NULL) { char artist[256]; artistFrame->GetField(ID3FN_TEXT)->Get(artist, 256); std::cout << “Artist: ” << artist << std::endl; } if (titleFrame != NULL) { char title[256]; titleFrame->GetField(ID3FN_TEXT)->Get(title, 256); std::cout << “Title: ” << title << std::endl; } return 0; } Use code with caution. How to Write MP3 Tags

To write or update tags, you check if a frame already exists. If it does not, you create a new one, update its text fields, attach it to the tag, and commit the changes back to the storage device.

#include int main() { // 1. Load the existing tag from the file ID3_Tag myTag(“song.mp3”); // 2. Find or create the Artist frame ID3_Frame* artistFrame = myTag.Find(ID3FID_ARTIST); if (artistFrame == NULL) { artistFrame = new ID3_Frame(ID3FID_ARTIST); myTag.AttachFrame(artistFrame); } // Set the text field on the frame artistFrame->GetField(ID3FN_TEXT)->Set(“The Rolling Stones”); // 3. Find or create the Album frame ID3_Frame* albumFrame = myTag.Find(ID3FID_ALBUM); if (albumFrame == NULL) { albumFrame = new ID3_Frame(ID3FID_ALBUM); myTag.AttachFrame(albumFrame); } albumFrame->GetField(ID3FN_TEXT)->Set(“Let It Bleed”); // 4. Update and save the file // ID3_Tag will automatically handle formatting both ID3v1 and ID3v2 tags myTag.Update(); return 0; } Use code with caution. Common ID3 Frame Identifiers

When calling myTag.Find() or creating a new ID3_Frame(), use these standard constants to map your data correctly: Frame ID Constant Metadata Field ID3FID_TITLE Track Title ID3FID_ARTIST Lead Performer / Artist ID3FID_ALBUM Album Title ID3FID_YEAR Release Year ID3FID_TRACKNUM Track Number / Position ID3FID_GENRE Music Genre id3lib – how to use?? – LiveCode Forums.