"Sample Rate" -- extremely important, please read

Comments about LibriVox? Suggestions to improve things? News?
Bronwyn Kate
Posts: 95
Joined: January 13th, 2006, 5:30 pm
Location: Melbourne, Australia
Contact:

Post by Bronwyn Kate »

Would Audacity be able to open recordings at 8000Mz? Oh dear!
ChipDoc
Posts: 1277
Joined: January 4th, 2006, 3:11 am
Location: Tampa, FL
Contact:

Post by ChipDoc »

Yes it can, but the quality is well beyond "awful" - much more into "ludicrous" territory!
-Chip
Retired to Colorado
The man who does not read good books has no advantage over the man who cannot read them.
~Mark Twain
BradBush
Posts: 173
Joined: October 18th, 2005, 3:41 pm
Location: Texas

Post by BradBush »

raynr wrote:Some are recorded with 24000Hz and that sample rate doesn't work with my telephone.
Actually a lot of the 64kbps ones are at 24khz, because it appears that is the default for the archive.org encoder. Do 22.05khz work on your phone?

Brad
Last edited by BradBush on February 14th, 2006, 5:38 pm, edited 1 time in total.
raynr
Posts: 3165
Joined: December 4th, 2005, 3:45 pm
Location: Munich, Germany

Post by raynr »

Yes, it does. But the software on the phone is generally very buggy. It states that it will be able to play the file in spite of the wrong bitrate (just with some quality loss), but then the program crashes. I just wanted to add to the discussion that I already noticed the sample rate issue, but you don't have to change the archive.org default encoder because of me. If I come to such a file I just reencode it with Cdex. I don't mind the quality loss because the mp3 player on the phone is not that good anyway that I notice any difference. But it is very handy that I don't need an extra mp3 player to listen to the audiobooks.
"Everything in the world exists in order to end in a book." (Stéphane Mallarmé)
kayray
Posts: 11828
Joined: September 26th, 2005, 9:10 am
Location: Union City, California
Contact:

Post by kayray »

I just had the bright idea of asking the guy who originally pointed out the sample-rate problem to me (because ch 3-4 of treasure island (48000) wouldn't play for him) to test some of my odd-rate Grimms' Tales, since he obviously has a sensitive mp3 player! I think he might even be a member here now...

Anyway, I asked him to test a 22050 and a 32000... cross your fingers :)

Kara
Kara
http://kayray.org/
--------
"Mary wished to say something very sensible into her Zoom H2 Handy Recorder, but knew not how." -- Jane Austen (& Kara)
BradBush
Posts: 173
Joined: October 18th, 2005, 3:41 pm
Location: Texas

Post by BradBush »

Great. This is a good test. Would also like to know which MP3 Player he has.
kayray
Posts: 11828
Joined: September 26th, 2005, 9:10 am
Location: Union City, California
Contact:

Post by kayray »

according to his email it's an iRiver .mp3 CD/MP3 player.

He says he's never had any other problems with any podcasts or mp3s, so I'll bet the test files will check out ok. And then I'll feel better :)
Kara
http://kayray.org/
--------
"Mary wished to say something very sensible into her Zoom H2 Handy Recorder, but knew not how." -- Jane Austen (& Kara)
ChipDoc
Posts: 1277
Joined: January 4th, 2006, 3:11 am
Location: Tampa, FL
Contact:

Post by ChipDoc »

Just for the record, I've got a Creative Zen Micro and it had no problem with any of the Treasure Island chapters - that was the first book I downloaded here and is essentially what hooked me on this place!
-Chip
Retired to Colorado
The man who does not read good books has no advantage over the man who cannot read them.
~Mark Twain
thistlechick
Posts: 6170
Joined: November 30th, 2005, 12:14 pm
Location: Michigan

Post by thistlechick »

kayray wrote: The standard is 44100kHz or less. Recordings made at a higher sample rate might not play in all mp3 players.
I think there must be a minimum though too as 8000Hz didn't play for me ... so perhaps we need to specify a range.
Last edited by thistlechick on February 15th, 2006, 8:02 pm, edited 1 time in total.
~ Betsie
Multiple projects lead to multiple successes!
vee
Posts: 585
Joined: October 10th, 2005, 7:35 pm
Location: Columbia, MD
Contact:

Post by vee »

I think we should just ask users to use either 22.05 or 44.1. It seems that those are the two most common that are available. 8khz is much too low. If Archive.org is creating 64k 24KHz files from our originals, maybe we should just require 44.1
Chris Vee
"You never truly understand something until you can explain it to your grandmother." - Albert Einstein
BradBush
Posts: 173
Joined: October 18th, 2005, 3:41 pm
Location: Texas

Post by BradBush »

Seems like 22.05 to 44.1 is the right range. I think that's what we settled on, after we realized some were down to 8.

Archive.org actually makes 64kbps 22.05khz files from a 128 22.05 file and 64kbps 24khz from a 128 44 file. Don't ask me. Its strange.
vee
Posts: 585
Joined: October 10th, 2005, 7:35 pm
Location: Columbia, MD
Contact:

Post by vee »

well at least they aren't upsampling, but yeah a 24 from a 44.1 is really weird. You usually downsample by factors of 2.
Chris Vee
"You never truly understand something until you can explain it to your grandmother." - Albert Einstein
thistlechick
Posts: 6170
Joined: November 30th, 2005, 12:14 pm
Location: Michigan

Post by thistlechick »

does this effect file size at all?
~ Betsie
Multiple projects lead to multiple successes!
BradBush
Posts: 173
Joined: October 18th, 2005, 3:41 pm
Location: Texas

Post by BradBush »

vee wrote:well at least they aren't upsampling, but yeah a 24 from a 44.1 is really weird. You usually downsample by factors of 2.
Yep. 24 will give you artifacts from 44.1. Whats strange, is they used to make 22.05 (some of our old books have all 22.05 on the 64kbps files)!
BradBush
Posts: 173
Joined: October 18th, 2005, 3:41 pm
Location: Texas

Post by BradBush »

thistlechick wrote:does this effect file size at all?
The raw files are 1/2 the size, but the MP3's are about the same size. Sample rate from 22.05 at the bit rates we are at, don't really affect too much.
Post Reply