About how many hours of voice recording would fit on a CD or DVD?
I imagine it might depend on sound quality.
The job is presently being done by compact cassette, so the recording would need to match or exceed that level of fidelity.
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74-80 Minutes on a Standard Audio CD that will play in any CD player.
Lots more on a MP3 CD (depending on quality) that will only play in MP3 enabled CD players or PC/MAC.
HTH
Last edited by: Redviper on Fri 19 Nov 10 at 11:53
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I bet your phone does voice recording. Try that for quality, see what you think. As for duration, depends on free storage in phone but you could probably add a microSD card. Say ten hours /GB (?) assuming it's in some form of MP3.
John
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For me it'd be the mobile phone too, although if the macbook pro's is an option, it's pretty capable out of the box for this kind of thing.
Open garage band, choose new project -> Voice. Choose the compressor plugin to massively improve the quality (cheaper than buying a real compressor).
Don't use a plugin microphone unless it's USB or Firewire type though. Using the line in socket directly to a mic wont give very good results.
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Thanks for the replies.
To explain a little, the query relates to the recording - logging - of proceedings in court.
The people who do this used to be shorthand writers, but are now known as 'loggers'.
They use a twin cassette tape machine, and there are various ideas on the go as to how this will be updated.
I'm not directly involved, although a couple of friends of mine may lose their jobs, depending on how automated the task becomes.
One of the issues, believe it or not, is the overlap during proceedings, when one tape finishes and another must begin.
Switching tapes is one of the main jobs for the loggers, so they are curious to know how many hours could be recorded onto a DVD.
It might be possible, for all I or they know, to set a DVD away at 10am and not need to touch it for the rest of the day.
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"Switching tapes is one of the main jobs for the loggers"
good grief - what other onerous tasks do they perform?
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"Switching tapes is one of the main jobs for the loggers"
Crumbs!! I'm sorry to see anyone lose their job but blimey! Is that a responsible use of taxpayers money? Do they still have punka whallas (spelling?) or have they switched over to electric fans? Even CDs are out of date, but hey, that's government / government agencies for you (in my experience).
Sorry Iffy I'm just a bit gobsmacked.
John
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...I'm just a bit gobsmacked...
They also keep a written log of the proceedings against the tape's counter.
Essential, because proceedings are sometimes transcribed and you can't do that if you don't know who is speaking and what their role is.
The logging job only pays a low wage and is usually carried out by semi-retired people who do a couple of days a week.
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The continued use of tapes is almost certainly due to the goverment's unwillingness to invest in anything better.
I don't know what level of court Iffy works in but once you're in Crown Ct there are some (understandably) onerous requirements about the security and keeping the judges properly provided for & onside. Any change will be a big project almost certainly let to an outside contractor. Whether the exisiting staff, probably themselves contracted, can be TUPE'd over will be another question.
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My query does relate to the crown court.
I didn't want to go too deeply into it because it soon becomes all rather internal and boring, but briefly....
There are one or two pilot projects - Leeds is one - where the logging has been computer/DVD-ised and the operation handed over to the clerks.
Apparently that has not been a success, with several examples of carefully recorded discs turning out to be blank when it comes to transcription time.
Not ideal when some punter's conviction and/or stretch inside depends on it.
As Bromp says, the remaining loggers work as part of a contract the court awards to a private company.
As others have identified, the loggers' job is far from onerous, and the technology they use is outmoded, so you can see why the court managers are looking at ways of modernising.
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A DVD will very easily record a day of proceedings.
If there are problems, then they will be procedural ones, not technological.
I would have thought that storage such as flash memory would have been better.
Backup and storage will be critical in any case - paper transcriptions would still be a good idea IMO.
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I once attended a live transcription demo by, IIRC, wordwave. Posh London Hotel with drinks and canapes to follow.
Impressive technology but at a very significant cost.
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The FSA have just told the banks that they have to record mobile calls. Apparently land line calls are already recorded. These are, I understand, transcribed, or can be when/if needed. I have no idea how, voice recognition I guess. I wonder how the systems used by, say, insurance companies, work when you ring up.
CDs sound a bit low tech / outdated before you start. I'd have thought recording to a central server, saved on disk, off site copy if needed, is the way to go.
I would guess that there are commercial solutions readily available and the sensible solution would be to buy one of them and (please!!!) don't tailor it so that you are stuck on version 3.4.5 for the next 20 years thus meaning that you can't update the o.s and hence meaning that you cannot replace the hardware. Sorry. Been there, done that.
Which leaves someone to do the voiceover when the speaker changes.
John
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...A DVD will very easily record a day of proceedings....
FT,
Thanks for that.
What happens at present is the tape is the only 'live' record and is stored for future use.
Routinely, a transcription is needed for an appeal, which might be lodged a few weeks or months later.
The request for a transcript arrives from the Court of Appeal, someone roots out the tape and it is transcribed by a skilled secretary, not by one of the semi-retired loggers.
The paper log of proceedings is crucial, because without it, the secretary cannot make any sense of the recording.
A portable media is used because the secretaries tend to work from home.
Speculation is this might be centralised if the job is ever fully computerised.
Court Transcripts Agency anyone?
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Just doing a bit of maths.
CD audio is 16 bit stereo sampled at 44.1kHz
Telephone quality is 8 bit mono sampled at 8kz
so CD is 16 x 2 x 44100 bits per second = 1411200 bits per second
Telephone is 8 x 1 x 8000 = 64000 bits per second (as used in pretty much all landline telecomms)
So you'd get 22 times more telephone quality speech on a disk = around 24 hours.
I'm ignoring the interleaving of data on a CD 'cos it's been a long day.
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>> So you'd get 22 times more telephone quality speech on a disk = around 24
>> hours.
>>
>> I'm ignoring the interleaving of data on a CD 'cos it's been a long day.
>>
But recording on standard audio CD its 74 -80 Min regardless of the quality
Data on a standard Audio CD differs from MP3/Computer Recorded Data
Its only when recorded as MP3's and these files are saved onto a DATA CD does filse sizes come into play, not forgetting that only Audio CD players that equipped to read these files can do so.
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>>
>> But recording on standard audio CD its 74 -80 Min regardless of the quality
>> Data on a standard Audio CD differs from MP3/Computer Recorded Data
>>
>> Its only when recorded as MP3's and these files are saved onto a DATA CD
>> does filse sizes come into play, not forgetting that only Audio CD players that equipped
>> to read these files can do so.
>>
Yes by definition an audio CD is always 74-80 minutes as it's always 16 bit stereo linear PCM.
Agreed you probably wouldn't be able to play back an 8bit WAV (i.e. linear PCM as per CD Audio but at 64kbps bitrate) file on a standard CD player, a PC would handle it OK though.
Yes in reality compressing to MP3 or similar would be a more sensible idea in practice than leaving the linear PCM format and just reducing the sample size and frequency like I did.
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Iffy,
We recorded our annual conference on CD. Mpeg layer 3 audio @ 128kbs. Each two hour session comes in at around 120mb. As it's just speech we could clearly have got away with a lower rate. 128 was probably the venue's default as there will be other events where there is music and stuff & the quality needs to be good enough to be replayed in public. We just need something to refer to in the post event write up & perhaps to capture delegate Q&A verbatim.
The problem in court, as you've identified, is assured fast retrieval and the capacity to 'go to' the point where, for example, a specific witnesses evidence or the Judge's summing up commence. Doing it properly is not going to be cheap and the staff who do it are probably not classed as front line.
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a nice grundig tk45 would be ideal as you could keep your eye on the magic eye and also use the tape counter record for the juicy bits------ ;-)
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However you move the recording process into the current millenium, it really aught to be done in duplex as it's important from a legal standpoint: two machines, two recordings.
If the companies involved with the trials don't understand this they shouldn't be doing the job.
Regarding the data rate, as discussed, a DVD would run around 10 hours with 128kb MP3 files
(4.7 gb / 128kb/sec ~ 36718 sec)
But it's debatable if DVD is a good idea in the long term - you'll be back in a few years, wondering what to do about a(nother) obsolete format - central server(s) with RAID storage is probably the way (and diverse networked back-up off site).
There also a job for all the old (tape) stuff to be transfered onto the new solution too.
IMHO
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Voice recording - Redviper
