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Topic: DBfs

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	DBFS - Wikipedia, the free encyclopedia
		There is still the potential for ambiguity with RMS amplitude measurements, since some use the RMS value of a full-scale square wave for 0 dBFS (which corresponds with a 0 dBFS peak amplitude measurement), and some use a full-scale sine wave (which corresponds with typical analog RMS measurements).
		In the case of a FS sine wave = 0 dBFS, a FS square wave would be at +3 dBFS.
		The term dBFS was first coined in the early 1980’s by James Colotti, an analog engineer that pioneered some of the dynamic evaluation techniques of high-speed A/D and D/A Converters.
	en.wikipedia.org /wiki/DBFS (369 words)

	Inferno's DBFS(4) (Site not responding. Last check: 2007-11-02)
		The filesystem provided by both dbfs and rawdbfs is substantially the same: when started, mountpoint is populated with numbered files, one for each record found in file.
		Dbfs and rawdbfs differ in the way that they store their data.
		Dbfs stores its records in file in a simple text format: the end of a record is indicated by an empty line.
	www.vitanuova.com /inferno/man/4/dbfs.html (422 words)

	PeekDBF User's Manual
		DBFs are binary database table files produced by many database management programs.
		In DBFs, binary fields have a standard width that is specific to the internal representation of the data type.
		If the DBF was created by Visual FoxPro, the next 263 bytes describes the table's relationship to other files in a multi-file database.
	labrocca.com /peekdbf/peekuserman.html (1338 words)

	OSNews.com
		dbfs seems like a lot of overhead for /var, /boot and so forth, dbfs seems like a decent idea for users but not system wide.
		And by the way, DBFS seems a bad idea to me. This sort of things definitely belong to userland, there is no need to bloat the kernel with such nonsense.
		I think the primary problem of layering a DBFS on top of a traditional filesystem is that it prevents the database layer from taking advantage of the on-disk format of the FS layer to optimize searches.
	www.osnews.com /comment.php?news_id=8277&limit=no (2735 words)

	Bobsguide - DBFS Ltd: DBFS - Bespoke Application Development Service
		DBFS are the leading provider of bespoke software development and support for all divisions of Asset Management institutions, offering a cost effective alternative to in-house or solutions provided by individual contractors.
		DBFS can take responsibility for a Clients entire development requirements or a single project.
		DBFS have successfully delivered over 200 solutions in the city.
	www.bobsguide.com /guide/prod/5-1868.html (147 words)

	Why are some decibel readings expressed as negative numbers? (Site not responding. Last check: 2007-11-02)
		This one is a little strange because, unlike all the other dB varieties, the reference level isn't at the bottom, or somewhere near the middle, but at the very top possible measurement.
		This means that "0 dBFS" designates the highest possible level, and that all other measurements expressed in terms of dBFS will always be less than 0 dB -- in other words, a negative number.
		This is why, on digital gear using VU meters (where 0 dBVU means 0 dBFS), the "0" is at the top of the scale, and the meter can never read higher than that.
	www.answerbag.com /a_view.php/13085 (655 words)

	EDN Access--04.10.97 Understanding, enhancing, and measuring PC-audio quality
		Adjust the record path's gain until the ADC output is as large as possible without clipping.
		Using an audio analyzer, apply the swept sine wave at an amplitude of 20 dBFS to an analog input.
		Establish a 0- dBFS level by increasing the signal input until the analog-output signal clips.
	www.edn.com /archives/1997/041097/08df_06.htm (5375 words)

	Linux Desktop Distribution of the Future Follow-up Part 2
		Of all the concepts presented in the original article, the DBFS is probably the least developed in the OSS community.
		Assuming that the “files” database key was a “long” integer, and that the average file name size was 50 bytes, the DBFS would have to search through 7.8 megabytes of data to find all the files created within the last 30 days.
		A DBFS not only advances the user’s ability to interact with a file system, it should advance the ability of applications as well.
	akaimbatman.intelligentblogger.com /wordpress/archives/category/uncategorized (2873 words)

	Mastering (Site not responding. Last check: 2007-11-02)
		The highest possible level in a digital encoding is called 0 dBFS (or Full Scale Digital, FSD), and the only thing to be concerned about is not to hit that ceiling with too many samples in a row.
		If frequent 0 dBFS+ peaks are present, he should make sure to get rid of them before doing anything else, including sample rate conversion.
		Together with the academic community, TC has produced a new, meaningful loudness measure that can be used on both music and speech, and which can be used for display as well as processing control purposes.
	www.tcelectronic.com /Default.asp?Id=4391 (1090 words)

	DVX100-audio (Site not responding. Last check: 2007-11-02)
		The topmost (larger) red VU mark is less than 1 dB away from 0 dBfs, the full-scale point beyond which you get severe digital clipping.
		Note the maximum record level, 0 dBfs (digital full-scale) corresponds to +4 dBu on the analog audio line-out (RCA jacks).
		With ALC on, the input is also linear up to -5 dBfs at which point the limiting circuit starts acting to reduce gain such that the input does not exceed -4.5 dBfs steady-state.
	www.bealecorner.com /dvx100/a-levels/audio-levels.html (605 words)

	DBFS - TECH.inhelsinki.nl (Site not responding. Last check: 2007-11-02)
		The DBFS tries to place the responsibility of finding files at the computer, so you don't have to remember where you stored it.
		The DBFS does not actually store files, it holds references to files on the underlying hierarchy based file system.
		The DBFS allows the desktop to do away with that dualistic nature of the computer by just saving every file you start.
	tech.inhelsinki.nl /dbfs (1310 words)

	Sweetwater inSync
		It is important to distinguish between O dBFS and Overs; they are not the same.
		O dBFS is the absolute highest voltage level that any particular A/D can convert.
		Everyone agrees that very brief excursions beyond 0 dBFS (producing digital clipping) cannot be heard; however no such agreement exists as to just how many samples it takes before an Over is audible.
	www.sweetwater.com /insync/word.php?find=Overs (222 words)

	Amazon.com: DBFS (Site not responding. Last check: 2007-11-02)
		DBF prototype array development by E. J Holder (Unknown Binding - 1987)
		D, the triangles DBF, EFC are also equal (being...
		Database file formats DBF files are single-table database files...
	www.amazon.com /s?ie=UTF8&platform=gurupa&keywords=DBFS&search-type=ss&tag=vepoware14-20&index=blended&link_code=qs&page=1 (520 words)

	Public Radio Satellite System
		If your program is recorded so that the peak level approaches 0 dBFS, then the Reference Tone must be recorded at -12 dBFS.
		When Reference Tone is -18 dBFS, then the cue tone level is -23 dBFS.
		When Reference Tone is -12 dBFS, then the cue tone level is -17 dBFS.
	www.prss.org /producers/preparing/recording/digital.cfm (487 words)

	The Case for NOT going above 0 dBFS For Digital Playback Systems
		I first became aware of this issue back in the early 90’s when I was testing a DAC that used a Burr-Brown Digital Filter and D/A Converter.
		When I explained to the applications engineer exactly what I was observing he remarked that this test went over the 0 dBFS limit and was clipped by the digital filter.
		If the signal is not clipped by the digital filter, and goes above the 0 dBFS level than the signal exhibits gross distortion.
	www.audioholics.com /techtips/specsformats/0dbfsdigitalclipping.php (668 words)

	DBFs
		With ClusterSeer, you can now import dbase files DBF for all methods except Moran's I, local Moran, Oden's IPop, and Grimson's method.
		For spatial and spatio-temporal methods, when you import a DBF, ClusterSeer will prompt you to select which columns in the data file hold the relevant information.
		Modified CuSum is currently the only method that does not require a label.
	www.terraseer.com /products/cSR/help/data/dbf_files.htm (151 words)

	Maximum Conversion
		You may, in fact, find that a reference level of -12, or even -10 dBFS, works better for recording ultraquiet sources in which an additional 2 or 4 dB of gain is needed at the A/D's inputs.
		Instead of using +4 dBu as your analog reference level, calculate which analog level would be needed to deliver 0 dBFS and use that level for your oscillator's output to align your A/D to a full-scale reading.
		To obtain an exact 0 dBFS reading on a given Rosetta channel, I simply turn the channel's calibration pot clockwise until the corresponding Over LED lights up, and then back off the pot barely enough to make the Over LED go out when I clear the meters.
	emusician.com /mag/emusic_maximum_conversion (2534 words)

	dBase headers corrupting, invalid data in DBFs on network - dBforums
		I wonder if part of the problem is that much of the original code has the users editing the actual fields on the screen or by BROWSE.
		Checking all DBFs every night catches these errors, but this cannot continue.
		Softie makes their new OS just incompatible enough with Novell's server to make users give up in frustration, not to mention their undercutting Novell's user license prices.
	dbforums.com /t628557.html (1190 words)

	Making the Case: Chapter 10
		Input files for statistical calculation were in dBase Data Format, with the extension ".dbf." Accordingly, unless it would create confusion, I use the acronym "DBF" to denote input files obtained for me by programmer queries on the source database.
		There were DBFs for which we had no further use, and with every step developing new possibilities, we decided not to update old DBFs (those with no further use).
		When the programmer got my list of still-useful DBFs, he updated them, and, when completed, passed the checked list to me. By the time the CEH report was finished, only about 20% of all the DBFs created in the whole process had been updated.
	shr.aaas.org /mtc/chap10.html (6024 words)

	trance.nu \| View topic - Dummy Head
		It may mean the woosh will end up around -10 dBFS or -15 dBFS (I really have no idea, so use your ears).
		As for the final mix, if you start out with your kick peaking around -8.5 dBFS, you should end up with a mix peak level no higher than -3.0 dBFS, and you shouldn't get any clipping that way.
		If your kick is peaking at -3.0 dBFS prior to mastering, adding the bass or lead will surely clip the waveform - or they're sitting too low in the mix.
	trance.nu /v3/forum_viewtopic.php?topic=131853&forum=14 (971 words)

	Pinter Consulting Website Article - www.LesPinter.com
		When you design a form, you drag fields from a DBF in the data environment to the screen, thus automatically setting the ControlSource of each field.
		But the SQL syntax for creating a DBF is almost identical to that of VFP.
		The reason is that, even though you're going to use cursors for your tables, you need to open a DBF and add it to the form's Data Environment in order to use Drag-and-Drop to place fields on the form.
	www.lespinter.com /PC/ShowArticle.aspx?ArtNum=251 (3687 words)

	Understanding dB
		0 dBFS represents the highest possible level in digital gear.
		All other measurements expressed in terms of dBFS will always be less than 0 dB (negative numbers).
		0 dBFS indicates the digital number with all digits ="1", the highest possible sample.
	www.jimprice.com /prosound/db.htm#dBFS (595 words)

	iZotope, Inc - Dave Moulton: Engineer, educator and Golden Ears author offers tips on mastering
		If we take a 0 dBFS sine wave and amplify it by, say, 60 dB, it will become a 1 kHz.
		I recently auditioned the new Gloria Estafan CD and found that its levels cruised between -3 and 0 dBFS, while a 3-year old Toni Braxton CD is equally whacked.
		I recommend (and use) -14 dBFS as a nominal signal level, and I calibrate all analog gear so that level is equal to +4 dBu.
	www.izotope.com /artists/dave_moulton.asp?id=2 (2526 words)

	TVTechnology - Inside Audio
		According to the Dolby specification for metadata, the target level for such dialogue within digital broadcasts is -31 dBFS Leq(A) for a decoder operating in Line mode and -20 dBFS Leq(A) for a decoder operating in RF mode.
		Voila, your dialogue is at the "correct" level, which is to say that it will be at the same level as everybody else's dialogue, at least those who also measured their dialogue levels correctly and then entered that value into the dialnorm setting.
		Taking the earlier example, if your dialogue is actually -19 dBFS Leq(A) and the dialnorm setting is left at the default -27 dBFS, then at the set-top box outputs the signal will be attenuated by 4 dB and your dialogue will be at -23 dBFS Leq(A), 8 dB above the target level.
	www.tvtechnology.com /features/Inside-Audio/f_dm_inside_audio-12.10.03.shtml (1272 words)

	GUIDE: How To Properly Encode Dolby Digital Audio (AC3) - Doom9's Forum
		Meeting the other end of the requirement, that the consumer should be able to listen to quiet and loud sections of the program without having to adjust volume levels, requires a decrease in the dynamic range of the program.
		A movie, with whispers at -50 dbFS and explosions at -5 dBFS can't be comfortably listened to in the average home.
		For example, if you make a left/right.wav, and find the RMS is -18 dBFS, and there is a pretty good amount of surround and center, assume the RMS level is 3 dB higher then that.
	forum.doom9.org /showthread.php?t=56020 (4130 words)

	Pinter Consulting Website Article - www.LesPinter.com
		So several users can copy the production dbfs to their own workstations, clean the data whenever they have time, then consolidate their CHANGES.DBF tables before running a final cleanup on the production tables one fine Friday evening.
		The first combobox lists all DBFs in the current directory; after you pick a table name, the second combobox displays all of the fields in the selected table.
		As mentioned earlier, several users can copy the production DBFs to their computers and do this work at their leisure.
	www.lespinter.com /PC/ShowArticle.aspx?ArtNum=259 (978 words)

	TVTechnology - Inside Audio
		The basic point I made was that dialnorm is not so much a specification as an active level calibration protocol that establishes a reference decode level of -31 dBFS LeqA (Line Mode operation) for dialogue.
		So, instead of calibrating using a traditional "nominal" (or alignment) level such as +4 dBu or -20 dBFS with a sine wave at 1 kHz, we need to use the longterm Leq (A-weighted) of dialogue as our reference "nominal" signal level, and we tie it to -31 dBFS LeqA.
		However there may be circumstances in which the listener may prefer to use RF mode (at the line-level outputs); for instance for late-night viewing or to avoid disturbing the neighbors.
	www.tvtechnology.com /features/Inside-Audio/f_inside_audio.shtml (1648 words)

	RedOrbit - Science - Disinfection By-Products (Site not responding. Last check: 2007-11-02)
		It reacts with organic matter present in water and forms a series of compounds that have been linked to cancer in animals.
		Disinfectants form DBFs in one of two reactions: 1) Chlorine and chlorine-based compounds (halogens) react with organics in water, causing the chlorine atom to substitute for other atoms and resulting in halogenated by-products.
		Because the pH determines in part which DBF will be formed, setting the pH entails risks and risk tradeoffs.
	www.redorbit.com /news/science/528632/disinfection_byproducts/index.html?source=r_science (1030 words)

	soundberry Decoder esterno hi-end
		THD+N is an astonishing low -106 dB (0.0005%) measured at 0 dBFS, at any playback frequency, at any sample rate, with any degree of input jitter, and it just gets better from there.
		The audio output levels may be controlled from the front panel by the same gain control that feeds the headphone amplifier or it may be preset to a precise level with multi-turn trims.
		The preset gain range is +10 dBu to +29 dBu at 0 dBFS.
	www.soundberry.com /0-00021f.html (1349 words)

	Using dBASE III PLUS on DBFs after 01 Jan 2001 (Site not responding. Last check: 2007-11-02)
		If you are using dBASE III PLUS on DBF files, in conjunction with other Xbase products, you may encounter an error in opening the file after 01 Jan 2001.
		What happens is that the year information "date last updated" information in the DBF header is handled differently between dBASE III PLUS and older products.
		Once the DBF is opened by another product, the "date last updated" information is written in such a way that dBASE III PLUS cannot recognize it, and therefore cannot open the file.
	www.dbase.com /KnowledgeBase/faq/y2kplus1.htm (221 words)

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