ffmpeg-libvorbis vs. oggenc: which one to use?

tauro_kpo · 01-30-2013, 02:59 AM

Hi people

I intend to convert all of my mp3 collection to ogg vorbis, but I don't know which is the best method.

I've recently done a bit of testing:

1. MP3 --> FLAC (via ffmpeg) --> OGG (via oggenc).

ffmpeg original.mp3 -acodec flac test.flac
oggenc -q 6 test.flac -o test-oggenc.ogg

2. MP3 --> OGG (via ffmpeg)
ffmpeg test.mp3 -acodec libvorbis -aq 6 test-ffmpeg.ogg

Results in size:

Code:

 3.8M  original.mp3
 3.8M  test-ffmpeg.ogg
  15M  test.flac
 3.5M  test-oggenc.ogg

Just for testing a bit more, I tried another thing:

3. MP3 --> FLAC (via ffmpeg) --> OGG (via ffmpeg).

ffmpeg original.mp3 -acodec flac test.flac
ffmpeg test.flac -acodec libvorbis -aq 6 test-ffmpeg2.ogg

And the output file was 3.8 M also, apart from that I got a lot of messages saying

Multiple frames in a packet from stream 0
Multiple frames in a packet from stream 0
Multiple frames in a packet from stream 0

and at the end

flac @ 0x84b9ce0]FRAME HEADER not here

So as you can see the one that apparently works better is method 1., but I would like to know about other people's experiences regarding conversion to ogg from mp3, ffmpeg and ogg vorbis, using oggenc, etc.

Also, will mp3 tags be preserved if I use method 1? How would you improve this?

Any other suggestions will be welcome.

headrift · 01-31-2013, 01:36 PM

Your problem is going to be listenability. Both mp3 and ogg are lossy compressions, while flac is lossless. Since you're starting with mp3s, going to flac won't get you better audio quality, and going to ogg (however you get there) from mp3 will decrease your audio quality.

Basically, you're losing audio data every time you do lossy compression. It might be minimal just once, but chances are that it will be noticeable, especially if you're using lower bitrates/qualities. Best thing to do, if possible, is re-rip the CD as ogg instead of mp3.

David the H. · 01-31-2013, 03:49 PM

headrift is right. Always go back to the original if you have it.

But if you have no choice and must convert, remember that others have already blazed the trail for you. A quick debian repository search came up with at least two options, oggconvert and dir2ogg, and I'm sure google will turn up many more.