Re: [SoX-users] Problem obtaining frequent RMS measurements

[Aaron \Caustik\ R. <ca...@gm...>]

for what it's worth, I've figured out how to tease sox into doing it right.
setting the buffer size to equate to half the window size I want (so, 50ms /
2 = 25ms of buffer) does the trick.

i've had to move the lowpass/bandpass/highpass into a separate step since
i'm not sure about the window size / delay requirements and how that
interacts with the 'trim' filter. i'm guessing it would screw things up.

On Wed, Apr 28, 2010 at 3:40 PM, Aaron "Caustik" Robinson <ca...@gm...
> wrote:

> I'll donate $100 to you if you can look at this issue.
>
>
> On Wed, Apr 21, 2010 at 7:50 AM, Aaron "Caustik" Robinson <
> ca...@gm...> wrote:
>
>> I'm attempting to split an input audio file into 3 bands, and measure the
>> RMS for each band at 50ms intervals.
>>
>> Seems easy enough with the filters sox provides, however for some reason I
>> can't seem to actually get 50ms resolution. I get about half of that
>> (~100ms). Here's the calls I'm making:
>>
>> ./sox decoded.wav -n lowpass 500 stats trim 0 0.05 : restart 2>
>> low-stats.txt
>> ./sox decoded.wav -n bandpass 1000 1000 stats trim 0 0.05 : restart 2>
>> mid-stats.txt
>> ./sox decoded.wav -n highpass 2000 stats trim 0 0.05 : restart 2>
>> high-stats.txt
>>
>> The window for 'stats' is quoted as 50ms. I attempt to send trim to 50ms,
>> and use restart to force stats to frequently spew it's data.
>>
>> Is there something I'm doing wrong here? Is there a better way to pull
>> this off?
>>
>> caustik
>>
>>
>