Converting standard sound to HD?

Jawad

Jawad

Veteran
I shot some interviews on my p2 card and before I knew it, the p2 card got full and I had to resort to tape on my panasonic hvx200.

Now in one of the interview, half is shot hd and half on tape and another 2 on tape out of 20.

Is there any way to bring all the audios to the same level not hd necessarily but good enough to hear it and especially match the one interview that's in hd and sd?

Also, what's the best way to get rid of room tone and background noise of the room

Thoughts?
 
The audio should not be in a different format, there is no "HD audio" other than marketing hype. Both are probably 48K/ 16 bit Wav or AIFF files, or part of the DV/HDV stream. So you should have no problem using both in the same time line.
Quality is a different issue and doesn't have that much to do with the format, though I heard that many of the HD camcorders have noisier audio sections than their DV brothers and sisters. If there is a big difference in sound it's probably because one camera wasn't set up correctly.

The best way to get rid of unwanted noise is not to record it in the first place. I know that sounds like a snotty answer but there is no "good" way to remove it after the fact. You really need to get rid of it BEFORE you shoot.

OK so it's too late, now what? FCP/ STP has some noise reduction filters than can help with some things like room tone. Noise can be reduced if it's constant. Changing noise like traffic, people talking, kettle boiling, jets over head etc are almost impossible to remove. Some times you can roll off the low end and that helps, expansion helps. There is a box by a company called Cedar that can do some amazing things with BG noise but it runs ~$30,000.
 
Thanks for the response. I appreciate it.

I think the problem is twofold. When you record HD, it records 6 audio tracks as oppose to standard. But with the same camera, same room, same time, there is a difference in background noise

I will try FCP tomorrow as I am shooting all day and let you know but thanks.

Jawad
 
Well I did a little looking and I not quite correct. What you are getting are probably XMF "files". the XMF is a "package" (like a folder but it appears as a file) that holds audio and video and an XML file that links everything together. I couldn't see what the options are for your camera but since it's hiding the Audio file format from you it could be anything. I suspect though that it is not an "uncompressed" format like WAV or AIFF since there are a number of converters out to convert the audio to WAV for editing. You should try to record as few tracks as poss since the storage space is probably fixed so the more tracks the more it will be compressed, though this is just an educated guess at the moment. I'm having dinner with a bunch of folks who should know the answers to this and I'll ask since I do sound and this looks like a nightmare that's going to bite my hiney at some point.
I'll let you know what I find out.
 
thanks. the option of shooting again is not an option at all unfortunately.

So whatever I can do to make the hd footage audio come close to sd or vice versa or bring both closer together
 
OK so here's the scoop from someone who actually knows.
The MXF "package" on the P2 card has 4 audio tracks not 6. Two of those are the onboard mics and two are the external inputs. It's 48/16 but as raw PCM audio rather than AIFF or WAV. Also in the package is the video file and an XML that can assemble the video and audio together and a small still frame from the start of the clip.

The SD will come in as a stereo pair, probably AIFF but I think that depends on how your project is set up.

So both are essentially the same format but one has some extra tracks. Part of your problem may be that with the HD footage, if you were using a boom mic your probably also playing back the onboard mic. If your HD footage came in with only two tracks it is probably the onboard mics and sounds bad, or the four tracks were mixed down to two - and it sounds bad. If you can't get all four to come in as four mono tracks you may have to try and extract the tracks you want from the clips. Many sound editing apps can open raw PCM files as long as you can tell it the SR and BD which you can (48/16).

If above doesn't solve the problem then you may have to do some work on the sound. If you know a sound editor get them to help, they will do a better job. If that isn't an option then you can boost the level of the tracks that are too quiet. The quickest way is to use the volume automation and raise the level. If that isn't enough to fix the problem you will need to use filters, but that is going to be clip by clip. I would raise the level then work on the noise reduction.
 
Huh- what is HD audio? The HVX shoots 4 channels of 16-bit 48Khz PCM audio. Perhaps you are talking about surround sound? That's 6 channels of audio matrixed together to create a 3D effect. You typically never record that though, you create that in your mix.

-Noah
 
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