Album art can be embedded into MP3 files fairly easily using ID3 tags. However, before you start filling up all of your MP3 files with works of art, there are a few things that you should stop to consider first.
While MP3 files were not originally intended to store additional metadata within them, the release of the ID3 tag protocol in 1996 suddenly made this a possibility. However, it wasn’t until version 2 of the protocol became available that MP3 files could actually contain embedded album art.
So, before you start cutting and pasting huge graphics and adding them into your collection of MP3 tracks, what do you need to consider to avert potential disaster?
ID3 Tags and MP3 Files
A standard MP3 file only contains audio data, with no additional information about the artist or type of audio contained within it. To include such extra information in an MP3 track, tag data is usually added to the beginning or end of the audio file in ID3 format.
ID3 tags allow you to store additional information within your MP3 files such as the track title, artist name and even album art. If you’re not familiar with ID3 tags, you may find my previous article on What are ID3 tags in MP3 files? helpful.
While the ID3v2 tag standard allows any type of image to be embedded in an MP3 file, it does advise that either PNG or JPEG formats should be used when interoperability with playback devices is required. Practically speaking JPEG images have been adopted as the de facto standard in this respect.
The ID3 standard is very flexible with regards to the type and number of images that can be embedded in a MP3 single file. The full list of different images that can be embedded are:
- $00 – Other
- $01 – 32×32 pixels ‘file icon’ (PNG only)
- $02 – Other file icon
- $03 – Cover (front)
- $04 – Cover (back)
- $05 – Leaflet page
- $06 – Media (e.g. label side of CD)
- $07 – Lead artist/lead performer/soloist
- $08 – Artist/performer
- $09 – Conductor
- $0A – Band/Orchestra
- $0B – Composer
- $0C – Lyricist/text writer
- $0D – Recording Location
- $0E – During recording
- $0F – During performance
- $10 – Movie/video screen capture
- $11 – A bright coloured fish
- $12 – Illustration
- $13 – Band/artist logotype
- $14 – Publisher/Studio logotype
Quite an exhaustive list, and while a single MP3 file could embed all of the above images, in practice only one image is ever usually embedded.
Unfortunately, any additional information that you add to an MP3 file will increase its file size and this is of particular importance when adding images due to their potential size, even with compressed images such as JPEGs.
However, this does need to be taken in context. For example, adding an 80kB JPEG image to a single 8MB podcast won’t have a significant effect; it’s only a 1% increase in file size.
If on the other hand you add an 80kB album image to every single track in your MP3 collection, let’s say of 1,000 songs, then you’ll need any additional 80MB of storage, which could otherwise hold a further 20 songs or so (another 2 albums).
Current Media Player Support
Windows Media Player embeds album artwork as 200 x 200 pixel images, although will display larger images if they are embedded in the playing file as a larger size. iTunes currently displays album art as 200 x 200 pixel images. The picture to the right is sized at 200 x 200 pixels by way of example and is 35kB in file size.
The resolution of the iPod nano and iPod classic screens is 320 x 240 pixels. The iPod touch screen is 480 x 320 pixels, more than sufficient to display images of 200 x 200 pixels.
The Current Standard
The picture to the right is sized at 300 x 300 pixels and is 62kB in file size by way of example.
JPEG images of these dimensions will vary in file size (dependant on the compression ratio used and image complexity) from around 10kB to 80kB or so. A 300 x 300 pixel image is actually over twice the size of a 200 x 200 image, and will consequently lead to approximately double file sizes.
Adding Your Own Pictures
So if you’re producing your own podcast and want to enhance it with your own logo, or just want to embellish some of the tracks that you already have in your MP3 collection with album art, what’s the best way forward?
It’s probably best to standardise on JPEG images to ensure that your artwork can be seen on the majority of possible playback devices.
Image sizes are probably best set at 300 x 300 pixels to display in reasonable quality on most playback systems. However, if you’re concerned about the space taken up by these images, 200 x 200 pixel images may be the better option for you, reducing the image file size to about half that of a 300 x 300 pixel image. The BBC (a useful technical yardstick I’ve always found) embed 300 x 300 images in their podcasts.
If your current software doesn’t allow you to embed or add images to your MP3 files directly, then standalone tag editing software should offer you this functionality. Some useful examples of such are: