Re: [backstage] Audio levels on iPlayer material (again)
At least you get the audio all the way though. Several things from Glastonbury were full of audio drop-outs. It was most noticeable on the Pet Shop Boys set. http://www.bbc.co.uk/programmes/b00syz40 Mind you all the BBC Three coverage from Glasto was labelled as 6 Music TV, as you can see. On 9 July 2010 02:15, Christopher Woods chris...@infinitus.co.uk wrote: I posted a while back asking about why iPlayer videos start loud then get quieter a few seconds later... It's hard to hear with most materal, but this programme exhibits the effect beautifully: http://www.bbc.co.uk/iplayer/episode/b00kntl1/The_Birth_of_British_Music_Han del_The_Conquering_Hero/ Listen to how the limiter suddenly kicks in after 1/2 seconds, bringing the overall gain down. The audio level at the start is fine, whereas afterwards it's just too quiet. Cue needlessly having to crank the gain on the computer to compensate. the It seems pointless having to constantly ride the gain when playing a new piece of footage - and it can often deafen you if you have your speakers or headphones turned up to an appropriate level from watching a previous programme! Could this be looked at by someone in the iPlayer team responsible for encodes? Seems like a very odd, pointless oversight and it's affected every video I've watched for at least six months, if not longer. Ta :-) - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/ -- Brian Butterworth follow me on twitter: http://twitter.com/briantist web: http://www.ukfree.tv - independent digital television and switchover advice, since 2002
Re: [backstage] Audio levels on iPlayer material (again)
Christopher Woods wrote: I posted a while back asking about why iPlayer videos start loud then get quieter a few seconds later... A Normalisation stage post encoding ? Obviously that won't help where the 'correction' is made within the programme. Grandmother, Eggs, How to suck ? - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
RE: [backstage] Audio levels on iPlayer material (again)
-Original Message- From: owner-backst...@lists.bbc.co.uk [mailto:owner-backst...@lists.bbc.co.uk] On Behalf Of David Tomlinson Sent: 09 July 2010 09:34 To: backstage@lists.bbc.co.uk Subject: Re: [backstage] Audio levels on iPlayer material (again) Christopher Woods wrote: I posted a while back asking about why iPlayer videos start loud then get quieter a few seconds later... A Normalisation stage post encoding ? The problem is definitely introduced when the material's encoded by Red Bee / the Beeb. Nothing on my system is doing that, I have a proper audio interface with nearfield monitors + sub running off XLR :-) - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
Re: [backstage] Audio levels on iPlayer material (again)
Unless I'm (quite possibly) misunderstanding you here David, I think he was just highlighting a valid issue. Jim On 9 Jul 2010, at 09:33, David Tomlinson wrote: Christopher Woods wrote: I posted a while back asking about why iPlayer videos start loud then get quieter a few seconds later... A Normalisation stage post encoding ? Obviously that won't help where the 'correction' is made within the programme. Grandmother, Eggs, How to suck ? - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/ Jim - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
Re: [backstage] Audio levels on iPlayer material (again)
Jim Tonge wrote: Unless I'm (quite possibly) misunderstanding you here David, I think he was just highlighting a valid issue. I wasn't trying to be critical of anyone, just making a suggestion, while well aware that the BBC has people with far more expertise in this area than I. I wasn't aware that Christopher [Woods] works for the BBC Sorry for any misunderstanding :( - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
RE: [backstage] Audio levels on iPlayer material (again)
I wasn't aware that Christopher [Woods] works for the BBC ...Neither was I ;-) I think I misinterpreted context of your comment, didn't notice the tongue in cheek second line (sorry!) Hopefully it's something relatively simple to fix and it's just an overeager preset default... Hardly the end of the world but it's such an obvious fault I'd be remiss to not point it out. (PS - any Beeb employees with an eye on the internal vacancies, any jobs in the Mailbox going for things like postproduction / editing for National / Regions? Been a longtime goal of mine to work for BBC radio at some point) - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
Re: [backstage] Audio levels on iPlayer material (again)
At the risk of making things worse, normalisation is a technical term, perhaps the correct term I was looking for is replay gain. The BBC 'normalises' it's output to ensure everything is at the same apparent sound level (relative to other output). I was suggesting that some sort of automatic gain control is deciding that the output is too loud and automatically reducing the gain for the rest of the output. This may be particular to the iplayer output, the original or could be the result of many stages of processing (e.g normalising and already normalised input). But then I am sure the staff at the BBC are well aware of this, and it may not be the issue. http://en.wikipedia.org/wiki/Audio_normalization http://en.wikipedia.org/wiki/Replay_Gain Replay Gain works by first performing a psychoacoustic analysis of an entire audio track to measure peak levels and perceived loudness. The difference between the measured perceived loudness and the desired target loudness is calculated; this is considered the ideal replay gain value (the target loudness of most Replay Gain utilities is 89 dB SPL --- 6 dB higher than the Replay Gain specification and SMPTE recommendation[1]). Usually, the gain value and the peak value are then stored as metadata in the audio file, allowing Replay Gain-capable audio players to automatically attenuate or amplify the signal so that tracks will play at a similar loudness level. This avoids the common problem of having to manually adjust volume levels when playing audio files from albums that have been mastered at different levels. Should the audio at its original levels be desired (e.g., for burning back to hard copy), the metadata can simply be ignored. - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
Re: [backstage] Audio levels on iPlayer material (again)
http://en.wikipedia.org/wiki/Replay_Gain No native support is available for Amarok 1, but a Replay Gain script is available for Amarok's script manager. As it is an external script, however, there will be a slight lag between the start of a track and the volume adjustment. This is particularly noticeable when a track starts with a peak loudness. - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
[backstage] Audio levels on iPlayer material (again)
I posted a while back asking about why iPlayer videos start loud then get quieter a few seconds later... It's hard to hear with most materal, but this programme exhibits the effect beautifully: http://www.bbc.co.uk/iplayer/episode/b00kntl1/The_Birth_of_British_Music_Han del_The_Conquering_Hero/ Listen to how the limiter suddenly kicks in after 1/2 seconds, bringing the overall gain down. The audio level at the start is fine, whereas afterwards it's just too quiet. Cue needlessly having to crank the gain on the computer to compensate. the It seems pointless having to constantly ride the gain when playing a new piece of footage - and it can often deafen you if you have your speakers or headphones turned up to an appropriate level from watching a previous programme! Could this be looked at by someone in the iPlayer team responsible for encodes? Seems like a very odd, pointless oversight and it's affected every video I've watched for at least six months, if not longer. Ta :-) - Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, please visit http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. Unofficial list archive: http://www.mail-archive.com/backstage@lists.bbc.co.uk/
