Combining Audio and video

[patronus]

Hello, so I have currently a pretty good audio microphone that I would like to use if I need to audition for anything, but it doesn't record video at all, so for things I need a video recording for, I need a camera. Is it allowed to combine the audio file and the video file into one big file? I understand that rules usually don't allow editing, but normally that's "snipping" separate fragments together, while I just want to overlay my own bad audio with a better audio in the microphone.

Do you think this will be okay, and have any of you done it before?

[indianajo]

Cameras usually have bad microphones, if they have one at all.  U-tube is cluttered with bad music recordings made with camcorders.  It has gotten usual this decade to record with a high end cell phone, with IMHO better but still bad results.
A video editiing software has ways to import audio recordings, as the sound recording is usually done with different equipment.  The two sources are synchronized with the famous "clapper" board you see with the stripes and label.  The pop made by the dropping of the clapper is not only traditional, it is the way the sound and video are started together.
Real recording equipment has SMTP timecode on both the audio file and video file, to allow excellent synchronization by special pro editing software.  Those of us who are amateurs just have to hope synchronization is maintained.    
I use a audio/video editing suite from ubuntu, a linix operating system for IBM heritage PC's, which allegedly can merge the sound and video. I haven't done it yet. My audio recordings are pretty good with audacity doing the recording, or ardour if you want to modify the sound more.  My video recordings are pretty bad, with video from a wide angle sports camera suitable for mounting on a helmet when jumping off a cliff, but not providing any sort of realistic concert video.  
People claim that Apple Mac PC's are good at video editing.  Microsoft claims their latest Windows 7 or 10 systems are as good, not to be backed up by any personal experience.  I do hear that Win 10 has a severe latency problem in making the actual recording.  Buyer beware.  
This certainly is not the website to find a lot of expertise on this.  There are various schools around where people are trained to do this, and U-tube has certainly evidence that a lot of people do video recording of concerts badly.  Having decent hearing and some amateur concert stage experience, I find cellphone recordings with the gain auto-set to be laughable, and not entertaining.  
I you are making audition video for a school, then I would expect the school would be used to the limitations of the cell phone sound, and more interested in your performance traits than in the quality of the sound itself. 
Good luck in your endeavors.  

[Bob]

Sure, I would think so.  You have to do some editing, the beginning and end so the audio isn't chopped.  That creates an impression too.  If it's all consistent and audio lines up with image, no one will complain about it.

If you wanted to, include the specs.  Recorded with x-camera and y-microphone.  Prepared using z-software.


If it's serious, they're going to call you in in person anyway.