Audio compression in DV/HDV at DVinfo.net

Spike Spiegel · November 21st, 2006, 11:35 PM

Here is something i've been wondering about: a lot of television shows are shot on minidv and hdvcams these days, even on networks such as discovery, etc etc. and theres always a audio guy with a boom pole capturing audio, on their own mixer/recorder.

I understand that this is to avoid the compression that would be present in going straight to the camera tape, but how does the audio quality differ (straight to tape audio vs. independent recorders)? Is it a night and day difference or is it comparable?

I've been wondering about this for a while, hope someone can respond to this. Thanks!

Nate Weaver · November 22nd, 2006, 12:40 AM

If it's a television show, chances are the audio is going from the mixer's mixer to the XLR input on the camera.

TV shows generally don't have the time to sync double system audio, but some do, especially if it helps to keep the camera(s) untethered.

On some shows, they go wireless from the mixer to the camera. I've done that before when I didn't want to slowed down by my sound guy.

Spike Spiegel · November 22nd, 2006, 02:31 AM

If it is meant for television, is it alright to record directly onto the tape that the camera is recording on? I mean, isn't the audio going to be of lower quality, is this acceptable to networks?

Chris Harris · November 22nd, 2006, 10:37 AM

Well, DV audio is uncompressed PCM, 12 or 16bit, 48khz audio at 1536Kbps. HDV audio is 48kHz, 16 bit, at 384Kbps. I don't know what each networks accept, however.

Zulkifli Yusof · November 24th, 2006, 10:38 AM

Quote:

Originally Posted by Chris Harris

Well, DV audio is uncompressed PCM, 12 or 16bit, 48khz audio at 1536Kbps. HDV audio is 48kHz, 16 bit, at 384Kbps. I don't know what each networks accept, however.

Am I reading this right or is it a typo? HDV records audio at a lower bitrate than DV?

Stu Holmes · November 24th, 2006, 10:41 AM

Quote:

Originally Posted by Zulkifli Yusof

Am I reading this right or is it a typo? HDV records audio at a lower bitrate than DV?

Zulkifli - yes you're reading it right. HDV records in compressed audio at 384kbps. DV is, perhaps somewhat ironically, uncompressed audio. That's the way it is.

Matt Davis · November 24th, 2006, 02:03 PM

Quote:

Originally Posted by Stu Holmes

That's the way it is.

Hey Stu - have you ever heard glitches in either DV or HDV audio? Especially stutters?

Stu Holmes · November 24th, 2006, 07:16 PM

Quote:

Originally Posted by Matt Daviss

Hey Stu - have you ever heard glitches in either DV or HDV audio? Especially stutters?

Can't say I have at all really Matt.
Are you experiencing some audio probs with your cam(s) ?

November 21st, 2006, 11:35 PM	#1
Spike Spiegel Major Player Join Date: Feb 2005 Location: Los Angeles, CA Posts: 429	Audio compression in DV/HDV Here is something i've been wondering about: a lot of television shows are shot on minidv and hdvcams these days, even on networks such as discovery, etc etc. and theres always a audio guy with a boom pole capturing audio, on their own mixer/recorder. I understand that this is to avoid the compression that would be present in going straight to the camera tape, but how does the audio quality differ (straight to tape audio vs. independent recorders)? Is it a night and day difference or is it comparable? I've been wondering about this for a while, hope someone can respond to this. Thanks!

November 22nd, 2006, 12:40 AM	#2
Nate Weaver Wrangler Join Date: Oct 2002 Location: Los Angeles, CA Posts: 2,100	If it's a television show, chances are the audio is going from the mixer's mixer to the XLR input on the camera. TV shows generally don't have the time to sync double system audio, but some do, especially if it helps to keep the camera(s) untethered. On some shows, they go wireless from the mixer to the camera. I've done that before when I didn't want to slowed down by my sound guy. __________________ My Work: nateweaver.net

November 22nd, 2006, 02:31 AM	#3
Spike Spiegel Major Player Join Date: Feb 2005 Location: Los Angeles, CA Posts: 429	If it is meant for television, is it alright to record directly onto the tape that the camera is recording on? I mean, isn't the audio going to be of lower quality, is this acceptable to networks?

November 22nd, 2006, 10:37 AM	#4
Chris Harris Major Player Join Date: Mar 2006 Location: San Francisco, California Posts: 487	Well, DV audio is uncompressed PCM, 12 or 16bit, 48khz audio at 1536Kbps. HDV audio is 48kHz, 16 bit, at 384Kbps. I don't know what each networks accept, however.