[FFmpeg-devel] [PATCH] avfilter: add compensationdelay filter

Paul B Mahol onemda at gmail.com
Wed Nov 25 16:39:37 CET 2015


On 11/25/15, Moritz Barsnick <barsnick at gmx.net> wrote:
> On Wed, Nov 25, 2015 at 09:48:36 +0100, Paul B Mahol wrote:
>> Patch attached.
>
>> +For example, you have recorded guitar with two microphones placed in
>> +different location. Because the front of sound wave has fixed speed in
>> +normal conditions, the phasing of microphones can vary and depends on
>> +their location and interposition. The best sound mix you will get when
>> +these microphones are in phase (synchronized). Note that distance of
>> +~30 cm between microphones makes one microphone to capture signal in
>> +antiphase to another microphone. That makes the final mix sounding moody.
>> +This filter helps to solve phasing problems by adding different delays
>> +to each microphone track and make them synchronized.
>
>   For example, you have recorded a guitar with two microphones placed
>   in different locations.
>
> This part I don't actually understand (is the fixed speed really the
> reason?), but I fixed the grammar anyway:
>
>   Because the front of sound wave travels at fixed speed in normal
>   conditions, the phasing of microphones can vary and depends on their
>   location and interposition.
>
>   The best sound mix can be achieved when these microphones are in
>   phase (synchronized). Note that a difference of ~30 cm in the
>   distances between source and microphones leads to one microphone
>   capturing its signal in antiphase to the other.
>
>   That makes the final mix sound moody. This filter helps to solve
>   phasing problems by adding different delays to each microphone track
>   and make them synchronized.

You changed logic here, I changed only first part.

>
> I'm not sure "synchronized" is the correct term though, but I'm no
> expert.
>
> Here, I might avoid the "you" form in favor of passive, but I guess
> it's okay as it is:
>
>   The best results can be achieved when you take one track as base and
>   synchronize other tracks one by one with it.
>
>
>> + at item mm
>> +Set millimeters distance. This is compensation distance for fine tuning.
>> +
>> + at item cm
>> +Set cm distance. This is compensation distance for tighten distance
>> setup.
>
> for tightening

Changed.

>
>> + at item m
>> +Set meters distance. This is compensation distance for hard distance
>> setup.
>> +
>> + at item dry
>> +Set dry amount. Amount of unprocessed (dry) signal.
>> +
>> + at item wet
>> +Set wet amount. Amount of processed (wet) signal.
>> +
>> + at item temp
>> +Set temperature degree in Celzius. This is the temperature of the
>> environment.
>
> Celsius

Changed.

>
>> + at end table
>
> Would you like to document the defaults?

Done.

>
> Moritz
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>


More information about the ffmpeg-devel mailing list