Video Headroom Discrepancy?

[wheatus]

Hi Slutz,

We got a complaint back from one of our digital vendors that the audio on the video we submitted to them is peaking....specifically, that the bass was: "blown out and distorted".

This particular DV file tested perfect on several DVD players and on several laptops and is currently streaming on other sites with no complaints from anyone, including several of the people here who have seen it.

Aside from it needing to be 48K, which it is, is there something I don't know about audio for video that needs to be addressed? Is the RMS meant to be lower for video? is there a standard I am ignorant to?

Please know...the bass (INSTRUMENT) IS distorted, on purpose...as are the drums a bit...It's overall pretty nasty but mastered low...simply because I liked the sound at that volume.

Please advise...

thanks,
brendan b brown
wheatus.com

[24-96 Mastering]

A lot of broadcast and video equipment expects levels of -9 or -12 dBfs and will pump or distort if fed significant peaks above it. That may be what's happening, if you suppliad a file peaking at 0dBfs, who knows. Try submitting a file peaking at -9 dBfs and see if the problem persists. When I have to supply sound for video and am not given any instructions on levels, I usually supply both at 0dBfs and at -9.

(Maybe someone with better knowledge of broadcast/video can chime in and post which formats exactly require which levels)

[wheatus]

Woops....that sounds like my problem...can you elaborate at all...why is this a problem on SOME broadcast gear and not all?

So are you saying that, when a conventional video goes to TV it's dropped down to -9 from 0?

If so, which do you send to a streaming site and which do you send to a digital vendor?...Incidentally, the vendor provided no db requirement.

Is that done at mastering or do video people typically do that after the final cut?

thanks for the insight!

brendan b brown
wheatus.com

[24-96 Mastering]

Originally Posted by wheatus

Woops....that sounds like my problem...can you elaborate at all...why is this a problem on SOME broadcast gear and not all?

So are you saying that, when a conventional video goes to TV it's dropped down to -9 from 0?

If so, which do you send to a streaming site and which do you send to a digital vendor?...Incidentally, the vendor provided no db requirement.

Is that done at mastering or do video people typically do that after the final cut?

thanks for the insight!

brendan b brown
wheatus.com

I'm out of my league here, I hope someone more knowledgable chimes in. If not, try the Gearslutz post production forum at http://www.gearslutz.com/board/post-production-forum/

PS: After some quick research, I believe the intended standard for DV is that 0VU = -20dBfs & 0 PPM = -9dBfs. I.e. peak to around -9dBfs. If you have a PPM meter around (is there a PPM meter plugin by the way), use that. If I'm wrong here, please someone correct me

[wheatus]

Originally Posted by 24-96 Mastering

I'm out of my league here, I hope someone more knowledgable chimes in. If not, try the Gearslutz post production forum at http://www.gearslutz.com/board/post-production-forum/

PS: After some quick research, I believe the intended standard for DV is that 0VU = -20dBfs & 0 PPM = -9dBfs. I.e. peak to around -9dBfs. If you have a PPM meter around (is there a PPM meter plugin by the way), use that. If I'm wrong here, please someone correct me

Where did you find that info? I'll continue the research...

Thanks again...you rule.

brendan b brown
wheatus.com

[24-96 Mastering]

Originally Posted by wheatus

Where did you find that info? I'll continue the research...

Thanks again...you rule.

brendan b brown
wheatus.com

Thanks, but I'm not very knowledgable on this, so please double check any details given here before relying on them. And unfortunately, I don't remember where I found the info. Google for something like: DV dBfs peak RMS PPM level standard --- or some combination thereof

Either way, the general consensus of what I read seemed to be that ideally, you should be working not to dBfs peak, but to RMS or PPM metering.
So it seems that all digital equipment should be able to take the peaks right up to 0dBfs, but that the question is what happens when a device plays it back through analog. I.e. if a RMS of around -20 is nominal level for a DV cam or some other playback unit, it might overload internally when you make it play back a source that instead has an RMS of -10dBfs (which is unfortunately quite realistic for your average tune on CD these days.)

[Jarp2600]

Indeed, the video broadcasting standards are -9,0 dB peaks, -20/-24 dB RMS. That's the guideline I use for my AV client's projects, never had any complaints about the volume!

[Whitecat]

Originally Posted by Jarp2600

Indeed, the video broadcasting standards are -9,0 dB peaks, -20/-24 dB RMS. That's the guideline I use for my AV client's projects, never had any complaints about the volume!

-10 is the ceiling in the UK.

Very difficult to achieve that sort of RMS though with modern music!! It's so slammed it often ends up at -15/-16 even when peaking at PPM6.

Here's a recent thread I started about a very similar topic in case the OP is interested... it's more me moaning about the use of dialnorm measurement on music videos which I believe is unnecessary, but then what do I know

Music video master levels

[Jarp2600]

Originally Posted by terminal3

-10 is the ceiling in the UK.

Very difficult to achieve that sort of RMS though with modern music!! It's so slammed it often ends up at -15/-16 even when peaking at PPM6.

Here's a recent thread I started about a very similar topic in case the OP is interested... it's more me moaning about the use of dialnorm measurement on music videos which I believe is unnecessary, but then what do I know

Music video master levels

Good to remember that... Not that I'm hitting the ceiling that much tough, since the final leveling usually happens at the video editor's. But indeed, especially with modern music, it's kinda hard to not end up in heavily compressed tracks... Aah, that damn loudness race everywhere in the business...