[Kdenlive-devel] Handling audio

[Simon Eugster]

2010/7/19 Dan Dennedy <dan at dennedy.org>:
> On Sun, Jul 18, 2010 at 11:57 AM, Simon Eugster <simon.eu at gmail.com> wrote:
>> I just wonder whether there is an easy way to access audio raw data.
>> http://kdenlive.org/forum/where-vu-meter
>>
>> Any hint/idea?
>
> Anywhere you have a mlt_frame you can get the uncompressed audio for
> the duration of that frame by calling mlt_frame_get_audio().
> http://www.mltframework.org/doxygen/structmlt__frame__s.html#a7c9154d09b0f61407e6c40f836947c26
>
> One place that may apply for VU meters is in that frame show callback.

So this is finally working (although not because of mine) :)

Still, one question. If I want to show dB values, how do I calculate
them? Can I assume 0 dB to be at the highest possible number of
int16_t (S0), and then calculate the dB of a signal S1 with
10*log(S1/S0)?

Simon