aidewoode / wahwah

Ruby gem for reading audio metadata

WahWah

WahWah is an audio metadata reader Ruby gem, it supports many popular formats including mp3(ID3 v1, v2.2, v2.3, v2.4), m4a, ogg, oga, opus, wav, flac and wma.

WahWah is written in pure Ruby, and without any dependencies.

Installation

Add this line to your application's Gemfile:

gem "wahwah"

And then execute:

$ bundle

Or install it yourself as:

$ gem install wahwah

Compatibility

WahWah support Ruby 2.7+

Usage

WahWah is so easy to use.

require "wahwah"

# Get metadata from an audio file

tag = WahWah.open("/files/example.wav")

tag.title       # => "song title"
tag.artist      # => "artist name"
tag.album       # => "album name"
tag.albumartist # => "albumartist name"
tag.composer    # => "composer name"
tag.comments    # => ["comment", "another comment"]
tag.track       # => 1
tag.track_total # => 10
tag.genre       # => "Rock"
tag.year        # => "1984"
tag.disc        # => 1
tag.disc_total  # => 2
tag.lyrics      # => "song lyrics"
tag.duration    # => 256.1 (in seconds)
tag.bitrate     # => 192 (in kbps)
tag.sample_rate # => 44100 (in Hz)
tag.bit_depth   # => 16 (in bits, only for PCM formats)
tag.file_size   # => 976700 (in bytes)
tag.images      # => [{ :type => :cover_front, :mime_type => 'image/jpeg', :data => 'image data binary string' }]


# Get all support formats

WahWah.support_formats # => ["mp3", "ogg", "oga", "opus", "wav", "flac", "wma", "m4a"]

wahwah's Issues

Support for writing

Would it be possible to return the Duration as a float instead of as an integer?

Some of us are doing very specific time calculations.

M4A files not recognized

I have several albums where no artist/album is recognized by wahwah, but MP4Info does recognize and extract the correct information, so I know it's in there.

MP4Info has several m4a files in its test directory that wahwah doesn't pull all the information for correctly. I'm not very familiar with the m4a format or parsing out atoms and such, but I could write failing tests for those files if that would be helpful.

However, wahwah does seem to pull the artist/album names correctly for those test files where with my files it does not. I could send you a sample file if that would be helpful too.

Could get zero duration on wav file

I have some wav file, it can play on vlc, but when I use WahWah to get the duration of the file. I get zero

Support get bit depth for ALAC encoded format

This can solve this issue blackcandy-org/black_candy#175 . I can use bit depth to determine if the audio file is lossless or not.

Support for chapters

I'm looking to use WahWah as part of a Jekyll-based podcast publishing tool, and to that end, it would be mighty helpful if it supported chapters (which are finally – over a decade since their introduction – seeing some adoption among player software).

Ogg's chapters are documented here, and ID3v2's chapters are documented here. There's also reportedly a proprietary chapter encoding used by Apple in their M4A files, but I might argue that supporting that is a secondary or… tertiary or… quaternary priority. (I haven't surveyed how much use they see in the wild, however, so I can't say for entirely certain.)

Thank you ever so much for the wonderful library! 😊 I can't tell you how much of a relief it is to have a library that unifies the API for all these formats successfully!

Add support for AAIF files.

This library does not yet support AAIF files which is another lossless audio codec which stores metadata. Support for this would be very useful.

Add bit depth attribute

It would be great if this library would return the bit depth of the audio file. Since you already use bits_per_sample internally, it wouldn't make a big change to rename this to bit_depth and expose the property. I got this to work locally for both flac and wav.

However, files with lossy compression don't have a bit depth. I'd propose to just leave this nil.
The only encoding I'm unclear on is ASF since WMA can be both lossy and lossless.

It be happy to work on a PR for this, but wanted to check-in first.

Flac files with vorbis tags aren't always recognized

I've noticed a problem with flac files that contain vorbis tags. While they are by a lot of other libraries (ffprobe, EasyTag), they aren't recognized by WahWah (giving a result like <WahWah::FlacTag:0x5000 title= artist= album= albumartist= composer= track= track_total= genre= year= disc= disc_total= duration=933 bitrate=705 sample_rate=44100 bit_depth=16>).

If I reencode the file (without changing any of the tags), it is recognized by wahwah. The files might have slight fault or problems in encoding, but it would be nice to make the library more robust.

I can send a few sample files in private if this would help.

Test coverage reach to 100%

Support for retrieving lyrics from metadata