Converting from ASF to OGG and some tunebite questions

I’ve got a few questions about napster and tunebite. I’m looking for some information on the format napster uses. From the sample files I’ve checked it appears they are asf files with a 192k bitrate. Not knowing anything about asf files can someone tell me (or direct me to a way to find this) what bitrate in ogg or mp3 this is comparable to? Currently I’m trying to use tunebite to transcode the audio and I’m set to 192-256k VBR ogg and I’m thinking that’s a bit overkill, but I don’t know. Maybe 160-192k VBR or even 160k CBR would be more than enough to maintain the quality level without wasting space. Anyone know what an optimum setting would be?
ie 128kbps MP3 is not the same as 128kbps OGG, 128k OGG has much better quality for the bits used. What OGG encoding settings would be close to the napster ASF settings? It looks to be a 192k constant bitrate. But, I don’t know if all napster songs are encoded the same.

Also, what are folks thoughts on tunebite’s high speed digital dub? It’s been something I’d been curious why it was never done before. I’ve played around with tunebite’s high speed dub and it’s interesting, but I’m not sure it’s 100% reliable. Anyone have a location where folks have discussed this feature?

Napster uses the Windows Media Audio format at 128kbps from what I recall. ASF is the abbreviation for Active Streaming Format and is generally only used with Windows Media Audio and/or Video.

To find out what the bitrate is, first look through your Napster downloaded collection for a song that is as close to 4 minutes as possible (±15 seconds if need be) and then get its file size in MB. Based on the file size of that ~4 minute song, the file size will indicate the bitrate as follows: ~3.75MB => 128kbps, ~4.69MB => 160kbps, ~5.63MB => 192kbps, ~6.56MB => 224kbps and ~7.5MB => 256kbps. :wink:

There have been many debates on whether WMA at 128kbps sounded better or worse than MP3, however going by a past Audio codec comparison test (dating May 2004), out of 6 finely tuned codec’s tested at 128kbps (OGG, MPC, Lame, iTunes, Atrac3, WMA), the WMA codec came out 2nd worst after Atrac3. However, the encoder behind each codec has likely improved since, for example several new updates have been made to the OGG codec, while the MPC codec has not been worked on for many years.

My recommendation would be to use a good pair of over-ear headphones and try re-encoding a few tracks using Tunebite and see how they compare with the original. Unfortunately, no matter what codec you use, you will not get the exact quality of that produced by WMA, even though WMA itself does not do the best at encoding. For example, if you re-encode a WMA track to MP3, you will end up with the audio artefacts (unwanted sounds) from both formats as well as the information ‘lost’ during the original encoding process to WMA as well as the re-encoding process to MP3. A good real life comparison would be like taping a slightly dusty record. You will end up with the crackles & pops of the record along with tape hiss as well as the combined frequency responses and high/low frequency cut-off’s from each. :rolleyes:

Unfortunately, as I never used Napster, let alone Tunebite, I am unable to comment on its high speed dubbing. On the other hand, I could not imagine any issue with it, especially since it is a direct digital re-encoding. :stuck_out_tongue:

Thanks Sean.

The file size of some ~4:00 songs is in the 5.5-6MB range, so it looks like 192k.
I’ll try the listening test, but that’s not an easy thing to do at the moment…

The codec comparison was something I had checked in my research, that’s where I came up with it looking like OGG was using a bit more bitspace at 128k encoding bitrate than WMA. OGG was almost always was rated better sounding than WMA.

Any idea on the relationship in general between WMA to OGG? Would a 160k OGG generally sound as good as a 192k WMA file? I’m pretty sure that a OGG in VBR at a rate of 160-224 would at least be as good as the source, or is that wasteful and would 128-192 be a better option? I know OGG is pretty good with working in smaller space and I think 192k or 224k is a high bitrate for OGG.

I understand compression/decompression and all the artifacting stuff, I’ve coded a few MP3 decoders so I understand the tech stuff on MP3 and audio compression. The stuff about encode, decode and reencoding I understand. That’s the real reason for the questions as I don’t want to bottleneck the bitstream on the second encode, but I don’t want to waste bitspace either.

As to the tunebite digital copy, you’d really think it should be an easy thing to do, but it’s not appearing that easy. I tried 4x and bumped that down to 2x after 4x having some popping and skipping issues. Turns out 2x worked great for a few songs, but others have failed big time. I figure if I need to recheck all the work after it’s done I might as well do the 1x dub and just waste the time… I searched but didn’t find too much talk about the high speed dub feature. :frowning: