Wikipedia:Reference desk/Archives/Computing/2014 November 12

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November 12

I just want to get this .avi to burn to a DVD

It's 2014. I have a PC (Windows 8) and a Mac (10.6.8), and for the life of me, I cannot get this .avi file (I captured with Hypercam) to convert to a proper file and burn it to a DVD. I've got IDVD, IMovie, VLC, I downloaded Burn and DVD Flik and I've been screwing around all night with them and haven't made any progress. All I want is this 23 minute video to keep its quality and be able to repeat (endlessly) playing on a standard DVD player...can you help this poor fool out? Where do I start? 74.69.117.101 (talk) 05:06, 12 November 2014 (UTC)

The DVD needs to be in DVD-Video format. This means there must be files with names like VIDEO_TS.VOB in a folder named VIDEO_TS, and they must be written contiguously in a particular order to the disc, and the file system needs to be UDF. Any DVD authoring program, like DVD Flick, will create the files for you, but you also need a DVD-Video-aware burning program that will write them in the correct way. There may be a check box somewhere in an options dialog that you need to check to enable DVD-Video support. Alternately, if the DVD authoring program can produce a disc image (probably with a .iso extension) instead of individual files, you can use any image burning program to burn it. -- BenRG (talk) 05:47, 12 November 2014 (UTC)

Example of how to define a URI for an XHTML/XML Document

Could anyone site an example of a URI for an XHTML/XML document.I tried looking google but couldn't get one.I haven't seen an URI which describes the XML namespace.

QUESTION

This an example taken from http://www.w3schools.com/xml/xml_namespaces.asp.

XML FILE

   <root>
   <h:table xmlns:h="http://www.w3.org/TR/html4/">
   <h:tr>
   <h:td>Apples</h:td>
   <h:td>Bananas</h:td>
   </h:tr>
   </h:table>

    <f:table xmlns:f="http://www.w3schools.com/furniture">
    <f:name>African Coffee Table</f:name>
    <f:width>80</f:width>
    <f:length>120</f:length>
    </f:table>
    </root> 

Could anyone explain how to define the namespace:"http:www.w3schools.com/furniture".I just wanted to know how could we define an namespace.More specifically should we define it using DTD or schema or whether it should have some other elements. Because if you need to write an XML file and if you don't know how to define the namespace I think it might only be possible to read an XML file. JUSTIN JOHNS (talk) 08:46, 12 November 2014 (UTC)

Changed ref to inline link to avoid confusion with later question. AndrewWTaylor (talk) 09:11, 12 November 2014 (UTC)

To editor JUSTIN JOHNS: The xmlns URL is arbitrary; it's determined by whoever makes a standard. You could make up a URL for your own format if you wanted. Anon126 (notify me of responses! / talk / contribs) 00:21, 14 November 2014 (UTC)

And yes, you should probably include a DTD or schema, too. Anon126 (notify me of responses! / talk / contribs) 00:22, 14 November 2014 (UTC)

SQL

I have something like such table in Access

NAME	YEAR	RANK
FFF	2014	1
BBB	2014	2
CCC	2014	3
FFF	2013	2
BBB	2013	1
CCC	2013	3
FFF	2012	3
BBB	2012	2
CCC	2012	1

Is it possible with SQL (I would like to stick to the Access) to get something like this:

NAME	2014	2013	2012
FFF	1	2	3
BBB	2	1	2
CCC	3	3	1

This is just an example. The real table could contain much more rows with different and with more years.

I currently have such code (which works for the table):

SELECT DISTINCT A.NAME,
(select B.RANK from Table1 B where A.NAME=B.NAME and YEAR=2014) AS 2014,
(select B.RANK from Table1 C where A.NAME=B.NAME and YEAR=2013) AS 2013,
(select B.RANK from Table1 D where A.NAME=B.NAME and YEAR=2012) AS 2012
FROM Table1 AS A;

How I can make better code, to not write a new code for each year? --Aswan fan (talk) 09:01, 12 November 2014 (UTC)

This is called a cross-tab query, and they can be created in Access - see here for example, or searching the Access help for cross-tab should find it (I don't have it installed so can't confirm this). I've used a generic stored procedure that I found here to create crosstabs in MS-SQL. AndrewWTaylor (talk) 09:09, 12 November 2014 (UTC)

There will be more than one step, as I understand it. You will need to CREATE your new table (if it doesn't already exist), and add columns using ALTER TABLE, for any columns that don't already exist (using IF EXISTS). When I have needed to do this it has been a one-shot, so I hacked something using the perl DBI, but a dynamic SQL only solution obviously has many attractions. All the best: Rich Farmbrough, 13:17, 12 November 2014 (UTC).

For this particular query, I think a basic crosstab would work. You would put NAME in the Row, YEAR in the Column (selecting Group By for both), and RANK in the Value. If you only have one rank for each combination of NAME and YEAR, then you can select Min (or Max, or First, etc.) to get the correct results. If you have more than one rank, then you should select whichever function you want to apply to the data (i.e. do you want the maximum ranking, the first ranking, etc.).108.59.48.1 (talk) 13:32, 12 November 2014 (UTC)

Audio cassette -> PC

I have some old audio cassette tapes (family recordings) that I need to digitize (probably using Audacity on a Linux desktop machine).

I bought an old (circa 1970's or maybe 1980's) dual-deck cassette player (no amplifier...just the deck) from the GoodWill store - and plugging headphones into the jack on the front produces good audio. But I'm having a hard time getting the PC to pick up a decent signal.

I'm betting that the answer lies in some kind of horrible impedence mismatch - and probably on which output on the deck (headphones/line) and which input on the PC (line/mic) I use. I'm having a hard time getting the right sets of cables to just try all of the possibilities...so rather than guessing, I'm hoping that someone here actually KNOWS what I should do!

TIA SteveBaker (talk) 16:13, 12 November 2014 (UTC)

@SteveBaker: As you surmise, it's a question of impedance; but also sensitivity - voltage levels and the like, see Line level. I would first try connecting line out on the deck to line in on the PC. These should match fairly well. Some cassette decks have the annoying feature of using the speaker/phones volume control to also adjust the line out level. This is useful if the PC has no input level control, but if it has, use the PC's input level control to adjust levels, and set the deck's output level to maximum. --Redrose64 (talk) 17:24, 12 November 2014 (UTC)

(edit conflict) Steve, start at line level. Keep in mind that for this situation, you do not require that the nominal impedance exactly matches (in other words, you don't require maximum power transfer).

You probably want to connect the headphone-out on the tape deck into the "Line In" on the PC. (You probably do not want to use the "microphone in," which would be suitable for a very weak signal, like a completely un-amplified microphone).

Nimur (talk) 17:27, 12 November 2014 (UTC)

Just a thought. Have tried googling the make and model of your deck. Someone may have been thoughtful enough to take the guess work out. Also what are you plugging it into...? Meaning that the jack of your computer maybe expecting a 'mic' with a much higher impedance than headphones. See Nimur's post above on line voltage. Bear with me, I typing this on a MAC not a PC and a quick look on Preferences > Sound shows I can choose a 'Audio Line-In port' option. I'll see if I can get the chance to crank my PC into life and look a Linux flavour or two for similar options. Might save a lot of hassle.--Aspro (talk) 18:08, 12 November 2014 (UTC)

Yep. All my sound cards have 'line in' sockets and Ubuntu has an input option for sounds. Are we answering your question or going off on a tangent?--Aspro (talk) 18:22, 12 November 2014 (UTC)

Or when all else fails: Follow these instructions for ripping from cassettes using Ubuntu Linux & Audacity. [1] Modern electronics will (should) compensate for any remaining miss-match and the input volume level control will adjust for line level voltage; even on a vintage deck. Final thought. To refresh my memory, just had a look at the back of my desktop towers. Does your desktop support a separate sound-card or does it just have the standard sockets? Without a separate sound card you will be connecting straight to the mother board (double check by looking inside). The sound quality will not be as good as a dedicated sound-card. Remember, computers are sold on price and so many (most) perform at the lowest common denominator acceptable to John Doe. For family archival recordings that may be handed down to future generations, this little detail may be worth checking. Final finally: Clean the heads !!! [2]--Aspro (talk) 18:37, 12 November 2014 (UTC)

For family stuff, record onto a good archival CD. Say... [3] Then put a CD/DVD machine in a sealed plastic bag with a silica-gel pack (and all the technical data) so that your descendants can more easily transfer the recordings to whatever the middle 21st Century storage medium is – without them (your descendants) depending on a serendipitous discover at a Goodwill Store for a vintage CD/DVD machine . As for all your Andy Williams and Barry Manilow greatest hits however, I suggest -just letting them fade away ;-)--Aspro (talk) 21:25, 12 November 2014 (UTC)

Yeah...trouble with that is that it's probably exactly what my 'ascendants' thought when they sealed the audio cassettes away. Turning the audio into numbers is obviously a good step because analog recordings fade and digital ones don't. Then it's just a matter of ensuring that the files are still there and still readable. I can use a "raw" audio file (just the sample bytes) and I'm pretty sure they can figure out the right replay speed from either the filename or by listening to some of the music in the recording. So with such a simple format, all I need to do is to store it in enough places to ensure that the files will still be there. Using a single archival medium seems to be the problem - but copying all the files that I care about from one medium to the next and the next after that means that I never have to care about getting stuck with an obsolete format that nobody can read. I still have files from floppy disks on my Atari ST on the harddrive of my desktop PC - backed up onto my cloud servers' account. Documentation for the 16 color image formats we used back then is easy to find online...so a while back, I converted them to GIF's - and now they are PNG's. The old MIDI-file music still plays just fine! SteveBaker (talk) 21:59, 12 November 2014 (UTC)

Of course digital media degrades over time, typical life span for a home-burnt consumer grade DVD is only ~5-10 years [4]! You might want to contact an archivist if you want professional advice on this and related matters. If you really want longevity without yearly data hygiene, your best bet would be to press a metallic analog record. Likewise, if you want to preserve photos for your descendents (again, assuming no regular maintenance/transfer/backup/migration), then your best bet is to print on acid free paper. Now, you are probably willing to migrate the binary files to various formats and media over the years, but the idea that digital information does not degrade is a very popular misconception. SemanticMantis (talk) 17:19, 13 November 2014 (UTC)

So the consensus is LINE-OUT to LINE-IN, volume on the tape deck to the max, clean the heads and make sure the PC knows to use LINE levels on that sound port. Well, that's what I guessed first and I got nothing out - so I'm betting I have a bad wire or a wonky tape deck or something. Thanks! SteveBaker (talk) 21:59, 12 November 2014 (UTC)

You have good audio from the deck via headphones -yes. So that's probably OK. Use something else (other than the deck) to pump audio into the desktop. If that is OK then its probably.... Second thoughts... Your neighbors may be cursed blessed with having to drag up the odd 10 to 14 year old child. They have loads of odd cables and things hidden in their bedrooms and will be able to sort this sort of problem out in a jiffy. They may probably be able to download all the software and sort out the dependencies in order that it all works whilst they are still doing their school homework. Ask them. What have you got to loose (other than your pride and appearing in their eyes as an old fogy ;-) !! Letting them have 'hands on' to the problem is easier for them, than you trying to describe it over the ether and making sense of our ramblings based on your ramblings. Hopefully, the cloud will elevate the need to keep transferring stuff onto new media. But I guess that is what the Sumerian's claimed with their clay tablets. But what did the Egyptians do - yes you guessed it - they invented papyrus.--Aspro (talk) 23:10, 12 November 2014 (UTC)

I have been told by some in the industry that an old tape player will have the heads magnetized and can damage the tape if you don't degauss it first. Plenty of guides out there for that. --  Gadget850 ^talk 22:25, 12 November 2014 (UTC)