Easily convert your music library from mp3 to ogg

[maddog39]

Hello all,

Well I've been wanting to convert all my music from mp3 to ogg and quickly found that there was no real easy way to do it. So I made a small command line utility to do exactly that. Because I really hate mp3 and proprietary formats because they are such a pain in the butt and in the US (as far as I know) they are illegal or so I thought. Well anyway, I was just reading reading the topic about how many songs you have in your library and I think everyone who replied to that topic had their entire library in mp3 and Im sure that alot of people would like to support the open format, if it were only easier.

So I called my utility am2o (auto mp3 to ogg) and its written in PHP (no it does NOT require a webserver what so ever, its a command line utility). I purposely wrote it in PHP to show people that PHP is just like any other scripting language and to debunk the misconception that its only for websites. It also wraps around ffmpeg to do the transcoding.

My personal need for it was to take all the music that I download from gnutella (frostwire/limewire/gtk-gnutella/etc) and convert it to ogg and put it in my music directory and when you download alot of mp3's you keep them in the same folder and when you rerun the command you dont want to re-transcode all of the music thats already transcoded, so it supports filename caching for each unique directory. You may optionally disable caching as well.

To run it you need the ffmpeg and php5-cli packages from the repository. You can get them from Synaptic, or by command line.

sudo apt-get install ffmpeg php5-cli

The package itself is attached to this post. To install it just unpack the tarball then run:

cd am2o
sudo ./install.sh

Examples on how to use the program are included in the readme but heres one for a quickstart, its really easy.

am2o -i ./Shared -o ./Music

We use -c to enable filename caching (this flag is require, to disable use -c=no), and ./Shared is our input folder (where we will pull mp3's from) and ./Music is the output folder (where we put the transcoded ogg's).
NOTE: As of version 0.2, the -c flag is no longer required and will automatically default to yes if left out.

If you have a big music library that you are transcoding, and you have a multi or dual core CPU system, I dont recommend running multiple instances as this will probably cause it to clash if you are running it on the same directories. Maybe in the future, if people like this tool, I will add support for multiple ffmpeg instances to encode multiple files at a time.

I hope this tool inspires you to convert to and use ogg to support it as an open format.

[Edit]
I have released am2o v0.2 with support for lossless flac and flexible flags and arguments. You may use all flags/arguments in any order but you must use the -i and -o flags to specify input and output directories respectively. The default transcode format is ogg, if you would like to transcode to flac, you must use the '-f flac' flag. Refer the '-h' or the readme for more information.

Enjoy!
-maddog39

[user1397]

Wow! Thanks so much!

Again, open-source at its best!

[Arathorn]

I hope this tool inspires you to convert to and use ogg to support it as an open format.

I'm sorry to say this after all your hard work, but I hope it doesn't. Transcoding from a lossy format to another lossy format results in huge quality loss, and the mp3's you can download with p2p networks are often bad quality already. If you're an open-source zealot I don't think you'll care, but if you love music you will.

[Erik Trybom]

As Arathorn said, DON'T convert between the two formats if you care about the music quality.

Mp3, as well as ogg, is a lossy format. This means some of the information in the raw music files are thrown away to save disk space. That is generally a good thing, because otherwise the files would have been some 5-10 times larger. However, it also lowers the quality of the music. The more compression, the worse it gets. At 192 kbit/s it's almost always impossible to hear any difference, at 128 kbit/s you can hear it if you've got some good equipment and at lower bitrates it's generally quite easy to hear the difference from a CD.

The mp3-making application chooses which part of the music to discard based on an algorithm. It's designed to keep the audible sound and discard the sound that you cannot hear anyway (there's a lot of that in a regular pop song). Ogg Vorbis has a similar algorithm but it's a bit different, which means if you convert from mp3 to ogg you will get the losses of both compression algorithms. The result is a file that may sound considerably worse than the original mp3.

If you want to use ogg, then use it when you rip your CDs. Then you'll only get the compression losses from the ogg algorithm and not from the mp3 algorithm as well.

[Arathorn]

Or just use FLAC. You can even find quite a lot of that on P2P, but it will take longer to get, because there are less sources and the files are bigger.

[mrgnash]

Nice work

[diesel1]

I'm sorry to say this after all your hard work, but I hope it doesn't. Transcoding from a lossy format to another lossy format results in huge quality loss, and the mp3's you can download with p2p networks are often bad quality already. If you're an open-source zealot I don't think you'll care, but if you love music you will.

This is exactly why I am re-ripping my entire collection again!

Diesel1.

[FoolsGold_MKII]

Now all I need to do is buy a media player that supports OGG and I'll be set.

I'll just throw away this perfectly good MP3 player and spend money for one that supports OGG. Thank goodness for open source!

[maddog39]

Heh, well I do realize that both mp3 and ogg are lossy formats and that you may lose some quality, but all the songs that I transcoded sound awsome, and I play them on studio headphones fairly loud. There are only a few songs where i can notice it. Perhaps adding a function to transcode to flac would make a difference?

[tbroderick]

Well I've been wanting to convert all my music from mp3 to ogg and quickly found that there was no real easy way to do it. So I made a small command line utility to do exactly that.

There's also mp32ogg and dir2ogg in the the repos. mp32ogg can convert songs or entire folders and it preserves the tags.