[FFmpeg-user] Increasing audio

[Cecil Westerhof]

On Monday  3 Apr 2017 21:06 CEST, Paul B. Mahol wrote:

> On 4/3/17, William Caulfield <william.caulfield at contentbridge.tv> wrote:
>> On Sat, Apr 1, 2017 at 1:21 PM, Cecil Westerhof <Cecil at decebal.nl> wrote:
>>
>>> I was asked to make videos during a ToastMasters contest. I had
>>> ordered a microphone for this, but sadly it did not arrive in
>>> time. So I needed to use the internal microphone from my Canon
>>> HS60 SX. Being away about ten meters from the speakers, their
>>> voices are much to soft. So I needed to pump up the audio. I did
>>> this with: ffmpeg -y -i speaker.MP4 -vcodec copy -af volume=3
>>> speakerAudioInc.MP4
>>>
>>> Is that the correct way, or is there a better way?
>>>
>>>
>>>
>>> --
>>> Cecil Westerhof
>>> Senior Software Engineer
>>> LinkedIn: http://www.linkedin.com/in/cecilwesterhof
>>> _______________________________________________
>>>
>>
>>
>>
>> Not really an answer to your question, but speaking as an audio
>> engineer:
>>
>> The boost you want is around 2.5Khz. That's where vocals are
>> understood. 700hz up to 3.5khz is probably a good range. Avoid
>> boosting below 400hz (muddy) and above 10Khz (zingy).
>>
>> I guess I'm suggesting some sort of EQ before the volume increase.
>> Not sure how that is done in FFMPEG.

I tried several things. For example:
    -af equalizer=f=2500:width_type=h:width=999:g=40

But just volume=3 sounds (mostly) better.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof