@browj2 @AAProds @emmrecs @john-x
Hi John.
As for 0 crossing, is not the original start of a video clip at 0?
That's a good question. Often the answer is no in my experience. A lot depends on the gear being used and its use. For instance, an action cam being used in a continuous recording mode but splits the clips into 4GB chunks will often have loud start and stop sections that can prove problematic. If a microphone is not already on when a recoding starts it will more often than not produce a pop or click when switched on. A lot will also depend on the quality and design of the recording source.
Ray.
If you do need to make a soft start with audio it is much easier to produce a volume curve making sure your first two points are set to zero volume,
Ray, now I'm confused. You say to use the volume curve, but from Jeff's comments it appears the volume has nothing to do with this zitting: it's because a sound wave is being chopped at a non-null position, the wave itself not having bearing on the volume.
This sound wave concept does make sense with the occasional zit on a butt join; I have just trimmed off a few frames and it was fixed. I must have been trimming off to a null (or almost null) position on the wave without knowing why it worked.
Still haven't watched John's tute but have found that I can also drag the actual ends of a grouped object independently holding down the ALT key. Marvellous. Wish I'd known that 15 years ago.
@AAProds @emmrecs @browj2 @john-x
Hi Al.
Sorry for the late reply, I've been away.
As far as I'm aware Jeff and my replies have not contradicted each other but your assumption that the wave itself has no bearing on the volume is slightly wrong as you are looking at a point in time that is measured in milliseconds when editing at a zero point and has nothing to do a change in frequency that can happen at between the two points of a butt join.
If you are starting a video with a clip that produces some form of audio distortion at the beginning then the best solution is to make a volume curve to ramp up the volume over the shortest distance and so hiding the offending sound as it could be made sooner than using another method. It may not be, dependant on how long that offending noise lasts. The same can be true if you are not fading your audio at the end of a video and the same annoyance happens.
If you butt join two clips together that are troublesome then a cross fade is often more effective than taking out offending frames as often one frame taken from the end of the first clip and the start of the next clip to blend the two together without causing a noticeable change or annoying sound can be done sooner than finding a zero crossover point that may not work anyway.
The difference of how much needs to be kept at zero volume is strongly linked to the frequencies and amplitude of the various sounds involved and in both cases and up to a point, the sound system involved and an individual persons' hearing.
Where you trimmed to where it worked I suspect had more to do with the frequency and amplitude at that point than how close it was to a null point but that could also be true.
There are also times when there can visually be large changes in the amplitude and frequencies when joining two clips together and little difference is heard. Such as when a video camera has been running continuously and produced more than one file as it reached its 4GB limit. As it is not easily heard it is seldom checked. It doesn't mean there is no difference between the sounds or that there is nothing going on at that point but our ears have not detected the problem.
Here are two clips butt joined from a concert I attended earlier this year.
And the result as heard on the video. (It also exports without a problem).
On the other hand if I'm producing a stereo loop that has a strong transient at it's start then it can produce a tick or pop at the start or end if I'm not careful and may not be cured by trimming. In which case I would need to produce a volume curve for it to work. In this instance I can't remove the tick on the left hand channel of a harp recording I want to loop.
So I have to produce a curve at the start to remove it.
It gets more complicated the more layers get involved as it can also happen if using several separate audio tracks in any editor. and is always best practice to edit on zero crossing points of each audio track involved before producing a final file where it becomes more difficult to deal with.
So here I have three different wave forms I wish to blend but at varying sound pressure levels that are represented as darker and lighter areas dependant on the amplitude at that point.
As I expand the timeline down to milliseconds you begin to see the differences in the wavelengths of the various sounds involved.
and I need a point where the energy levels are at their most relaxed as possible to produce an audio file with least amount of problems when I add it to a project.
I hope that explanation helps Al.
Ray.