Needing a program to de-noise the audio track of a video

Discussion in 'other software & services' started by wtsinnc, Feb 9, 2015.

  1. wtsinnc

    wtsinnc Registered Member

    Joined:
    Oct 3, 2008
    Posts:
    943
    Hello. I am hoping someone here at Wilder's can provide a recommendation for a software application which can de-noise the audio track of an old video without altering the video.

    I have several old video recordings that have a very high noise level (hiss) on the audio track which is composed entirely of speech- several people involved in Q&A at a business function which I attended some years ago. Those individuals were on a stage and the recording was made at a distance of about 100 feet.
    Those VHS recordings were transferred to DVD about 15 years ago.
    The video is fine.
    Is there a program, preferably freeware/open source than can remove the noise without serious degradation of the recorded voices ?

    If such a program exists, I plan to download the recordings to my computer for the editing.

    Thank you for any reply.
     
  2. CloneRanger

    CloneRanger Registered Member

    Joined:
    Jan 4, 2006
    Posts:
    4,833
    Hi, whichever solution you use, keep in mind these. Because they were recorded @ such a distance, they will need more than de-noising ! If they were in stereo i would convert to mono. Even if not, de-noise them with a Low Pass Filter. Experiment on a short passage/s, trying different cutoff frequencies. 8kHz should be a good starting point, but somewhere between 5kHz - 10kHz i would suggest. Then process with a High Pass Filter @ 80Hz, which will help to greatly reduce unwanted low frequency noises etc. Finally use a compressor to even out the variations in volume. Again experimenting with the controls will be beneficial. If you're not sure how to use one, a web search should help.

    All the above are available in software, & i "think" that for eg VLC "might" be able to achieve All you want, in one program !
     
  3. roger_m

    roger_m Registered Member

    Joined:
    Jan 25, 2009
    Posts:
    5,248
    Dart Pro works very well but it is not free.
     
  4. wtsinnc

    wtsinnc Registered Member

    Joined:
    Oct 3, 2008
    Posts:
    943
    Thank you CloneRanger and roger m.
    I was unaware that VLC Player was capable of that type of editing.
    I have no knowledge of Dart Pro but will take a look at it.
    Because it is a free application, I will first try VLC Player.

    I see that Dart Pro offers a 30 day trial.
    Although I am reluctant to use their software when I have no intention to buy it, I will at least give it a try.

    Again, thanks to both of you for the advice.
     
  5. CloneRanger

    CloneRanger Registered Member

    Joined:
    Jan 4, 2006
    Posts:
    4,833
    @ wtsinnc

    From you're first post it appeared that you wanted to work on the audio whilst viewing/including the video together. If you only want to improve the audio on it's own, then you could do either of the following.

    1 - Export/Rip the audio from the video & work on it seperately, & then just use that without the video.

    2 - As in 1, but then overwrite the audio track in the video.

    I would use for eg the very good free Audacity to enhance the audio, using it's inbuilt tools/effects as i described earlier.

    If you're not totally sure how to do ALL that, then i would be happy to do it for you. If you're interested then upload the audio track/s somewhere such as Rapidshare for eg, in mp3 format, & let me have the code via PM.
     
  6. Mrkvonic

    Mrkvonic Linux Systems Expert

    Joined:
    May 9, 2005
    Posts:
    8,698
    Try Audacity or Kdenlive/audio effects.
    Mrk
     
  7. wtsinnc

    wtsinnc Registered Member

    Joined:
    Oct 3, 2008
    Posts:
    943
    Hello CloneRanger.
    I downloaded Audacity yesterday morning and am experimenting with it in my free time. Between my job and time necessary to do some renovation work on a house I recently bought, "free time" is something of a luxury.
    Thanks for the offer. As of now, I feel I should do this myself so to learn the program and have that knowledge and experience for possible future use. If this takes a month or two months- no big deal.
    Should I need the answer to a specific question/issue, I will PM you if that is alright.

    Mrkvonic:
    thanks for the suggestions.
     
  8. roger_m

    roger_m Registered Member

    Joined:
    Jan 25, 2009
    Posts:
    5,248
    I can't comment on the other software, but where DART excells is that you can select a part of the recording that just has hiss, and DART will remove noise from the recording based on what you selected. This maybe not be the best explanation, but results are excellent.
     
  9. CloneRanger

    CloneRanger Registered Member

    Joined:
    Jan 4, 2006
    Posts:
    4,833
    I agree, if you're able to learn how to use whatever you choose, & achieve the results you desire, that's good. If you have any questions/problems, PM me so i'm made aware of your post/s.

    An issue you "may" discover due to the recording distance, with a denoiser such as DART etc, is that the sampled area of noise "might" not be very consistant, & therefore make matters worse. The only way to know is to try it. If the results are not as you hoped for, then using a LPF as i suggested earlier would be better. With either approach, also using a HPF & compressor will help.

    All the best with it !
     
  10. wtsinnc

    wtsinnc Registered Member

    Joined:
    Oct 3, 2008
    Posts:
    943
    Update:
    Results are good- considering.
    I ripped the audio track and processed it first by (as suggested by Cloneranger) converting it to monaural, then experimented with Audacity and after several trial runs was able to get acceptable quality sound.
    The original recording was made using a JVC VHS-C camcorder, stereo audio with Dolby noise reduction. Part of the problem was that during the transfer to a full size VHS tape, apparently non-dolby playback was employed thus raising the noise level even further and even obscuring the voices in some parts. This VHS-C to VHS dub was eventually transferred to DVD which was what I had to work with. I had nothing to do with the original recording or the transfers but do have knowledge of most of the hardware employed.

    Many thanks to CloneRanger, roger m, and mrkovonic for your advice and offers of assistance.
     
Loading...