RE: [SLUG] Theme From A Movie

From: Kwan Lowe (kwan@digitalhermit.com)
Date: Sun May 14 2006 - 17:12:19 EDT


>>>>> wav file plays at a significantly slower pace than what was recorded.
>>>>> Is this a known problem?
>>>
>>> It's not a known-to-me problem. I've _never_ seen Audacity do this. You
>>> might want to see why it's doing this, and re-record the music.
>>
>> I've seen this happen often.. It occurs when the recording is done at a
>> faster Hz than the playback. WAV is apparently a fixed speed,
>
> I don't think so. I've recorded 22.05 kHz and 44.1 kHz WAVs, and converted
> between them. The file sizes attest that it's not merely a faked sample
> rate. WAVs may have a limited set of valid rates, though.
>
Yes -- I think we're talking about the same thing. A 22.06 KhZ wav file is exactly
half of a 44.1KhZ wav. How I understand it is that the WAV format is just a series
of measurements taken at x number of intervals per second. It's fixed to what it was
recorded at because each data point is directly equivalent to a sample point unlike
some other formats that encode time and other information in the data/stream.

So to change the sample rate of a WAV you'd need to change the header and downsample
or upsample the data. I.e., if you convert a 22 KhZ to a 44 KhZ you double the
number of samples programmatically or vice versa.

-- 
* The Digital Hermit   http://www.digitalhermit.com
* Unix and Linux Solutions   kwan@digitalhermit.com
-----------------------------------------------------------------------
This list is provided as an unmoderated internet service by Networked
Knowledge Systems (NKS).  Views and opinions expressed in messages
posted are those of the author and do not necessarily reflect the
official policy or position of NKS or any of its employees.



This archive was generated by hypermail 2.1.3 : Fri Aug 01 2014 - 19:01:36 EDT