AUdIoCoUrSeS
Joined: 31 Oct 2002
Posts: 2014
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| Week 10 - Transmission of digital audio in broadcast product |
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Transmission of digital audio in broadcast production<br>
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<p>The following concepts are to be researched this week:</p>
<p>• <a href="http://www.google.com/custom?hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BLH%3A50%3BLW%3A300%3BGL%3A1%3BBGC%3AFFFFFF%3BT%3A%23000000%3BLC%3A%23000000%3BVLC%3A%23000000%3BALC%3A%23000000%3BGALT%3A%23000000%3BGFNT%3A%23999999%3BGIMP%3A%23999999%3BDIV%3A%23FF8400%3BLBGC%3AFF8400%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.audiocourses.com%3B&domains=audiocourses.com&q=digital%2Baudio%2BWire&btnG=Search&sitesearch=">Wire</a>
</p>
<p>• <a href="http://www.google.com/custom?hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BLH%3A50%3BLW%3A300%3BGL%3A1%3BBGC%3AFFFFFF%3BT%3A%23000000%3BLC%3A%23000000%3BVLC%3A%23000000%3BALC%3A%23000000%3BGALT%3A%23000000%3BGFNT%3A%23999999%3BGIMP%3A%23999999%3BDIV%3A%23FF8400%3BLBGC%3AFF8400%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.audiocourses.com%3B&domains=audiocourses.com&q=digital%2Baudio%2Btelephony&btnG=Search&sitesearch=" target="_blank">Digital
telephony</a> </p>
<p>• <a href="http://www.google.com/custom?hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BLH%3A50%3BLW%3A300%3BGL%3A1%3BBGC%3AFFFFFF%3BT%3A%23000000%3BLC%3A%23000000%3BVLC%3A%23000000%3BALC%3A%23000000%3BGALT%3A%23000000%3BGFNT%3A%23999999%3BGIMP%3A%23999999%3BDIV%3A%23FF8400%3BLBGC%3AFF8400%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.audiocourses.com%3B&domains=audiocourses.com&q=digital%2Baudio%2BMicrowave%2Band%2Bradio%2Blinks&btnG=Search&sitesearch=" target="_blank">Microwave
and radio links</a> </p>
<p>• <a href="http://www.google.com/custom?hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BLH%3A50%3BLW%3A300%3BGL%3A1%3BBGC%3AFFFFFF%3BT%3A%23000000%3BLC%3A%230000CC%3BVLC%3A%230000CC%3BALC%3A%230000CC%3BGALT%3A%23008000%3BGFNT%3A%23000000%3BGIMP%3A%23000000%3BDIV%3A%230000CC%3BLBGC%3AFFFFFF%3B&q=digital%2Baudio%2BSatellite&btnG=Search" target="_blank">Satellite</a></p>
<ul>
<li><a href="http://www.google.com/custom?q=Audio%2BProduction%2BFor%2BThe%2BInternet&btnG=Search&hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1;L%3Ahttp%3A//www.audiocourses.com/images/logo2.gif;LH%3A50;LW%3A300;GL%3A1;BGC%3AFFFFFF;T%3A#000000;LC%3A#000000;VLC%3A#000000;ALC%3A#000000;GALT%3A#000000;GFNT%3A#999999;GIMP%3A#999999;DIV%3A#FF8400;LBGC%3AFF8400;AH%3Acenter;S%3Ahttp%3A//www.audiocourses.com;&domains=audiocourses.com" target="_blank">Audio
Production For The Internet</a></li>
</ul>
<p>General Links:</p>
<p><a href="http://www.google.com/custom?domains=audiocourses.com&q=Transmission%2Bof%2Bdigital%2Baudio%2Bin%2Bbroadcast%2Bproduction&sitesearch=audiocourses.com&sa=Search&client=pub-8263957883925270&forid=1&channel=6163154558&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23000000%3BGL%3A1%3BDIV%3A%23FF8400%3BVLC%3A000000%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3AFF8400%3BALC%3A000000%3BLC%3A000000%3BT%3A000000%3BGFNT%3A999999%3BGIMP%3A999999%3BLH%3A50%3BLW%3A300%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BS%3Ahttp%3A%2F%2Fwww.audiocourses.com%3BFORID%3A1%3B&hl=en" target="_blank">Audiocourses.com
search</a></p>
<p><a href="http://www.google.com/custom?hl=en&lr=&ie=ISO-8859-1&oe=ISO-8859-1&c2coff=1&client=pub-8263957883925270&cof=FORID%3A1%3BL%3Ahttp%3A%2F%2Fwww.audiocourses.com%2Fimages%2Flogo2.gif%3BLH%3A50%3BLW%3A300%3BGL%3A1%3BBGC%3AFFFFFF%3BT%3A%23000000%3BLC%3A%23000000%3BVLC%3A%23000000%3BALC%3A%23000000%3BGALT%3A%23000000%3BGFNT%3A%23999999%3BGIMP%3A%23999999%3BDIV%3A%23FF8400%3BLBGC%3AFF8400%3BAH%3Acenter%3BS%3Ahttp%3A%2F%2Fwww.audiocourses.com%3B&domains=audiocourses.com&q=Transmission%2Bof%2Bdigital%2Baudio%2Bin%2Bbroadcast%2Bproduction&btnG=Search&sitesearch=" target="_blank">Google
Search</a></p>
<p> ;;</p>
<p>Questions:</p>
<p>1. Explain the basic difference between downloading text & graphics files
as compared to the streaming of a sound file over the internet.</p>
<p>2. Describe the process of creating a DVD master</p>
<p>3. Explain the authoring process in creating a DVD for full production film.</p>
<p>4. Describe,. with particular regard to the method of billing, the DIVX system.</p>
<p>5. Discus briefly the problems of Data Streaming on the Internet.</p>
<p>6. What is Eureka 147?</p>
<p>7. Describe the current state of DAB in the UK</p>
<p>8. What is SDARS?</p>
<p>9. Explain the term repeater.</p>
<p>10. Explain Lossy data compression.</p>
<p>11. What is meant by the The psychoacoustic model?</p>
<p>12. What is ASIASTAR?</p>
<p>13. Describe how IP Telephony works. (<a href="http://www.intel.com/network/csp/resources/white_papers/4070web.htm" target="_blank">link</a>)
_________________
It's all in the ears. - Learn the concepts not the software.
Audio Courses is a way into the music business for you
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Mon May 09, 2005 7:47 am |
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Rico1210
Joined: 03 Aug 2004
Posts: 39
Location: Newcastle, UK |
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Hi,
answers for this week. My pc went crazy on Sunday, had to restart it. But it wouldn't switch back on, think it was too hot. It's working now tho, and i'm archiving my work, thought i'd lost it all for a moment.
1. Explain the basic difference between downloading text & graphics files as compared to the streaming of a sound file over the internet.
The basic difference between downloading text & graphics files compared to streaming audio over the internet is that a file being streamed does not have to be downloaded completely before it can be played. When a file is streamed over the internet, it is heard as it is being downloaded. Data is sent in real time, rather than wait until it is completed downloaded. The file is buffered until the minimal amount of packets are received to start streaming. This works because a stub file is used in place of the real file, which contains the url of the actual file. The navigator downloads the stub file and passes it to the player, which parses the stubfile, and downloads (and plays) the actual file.
2. Describe the process of creating a DVD master
The process of creating a DVD master, or DVD authoring is as follows: The first step is to plan how the various elements of the project are going to work together. The source materials to be used are then gathered, these may include video or stereo/multichannel audio plus menus. The source material is then encoded into a format that is compliant with DVD, and navigational instructions are added for end-user control. The encoded material and navigational instructions are then multiplexed into a DVD-compliant stream, which is then burned to a DVD video or DVD Audio master.
3. Explain the authoring process in creating a DVD for full production film.
A DVD almost always contains more than just the film. A DVD may also contain documentaries, alternative scenes, interviews, a number of alternative language soundtracks and graphics in addition to the visual material. The visual material may also vary throughout the film from slow simple scenes to fast complex scenes that need large data bandwidth. Authoring involves initially allocating sections of the available data rate to the different strands of the completed film, therefore ensuring that the maximum data rate is not exceeded. Data compression is then undertaken and reviewed carefully before the completed master is created.
4. Describe, with particular regard to the method of billing, the DIVX system.
The DIVX system is based on that of a DVD system. DIVX players are fitted with a modem to communicate with a central billing office. A DIVX disc can be bought at a relatively low price to allow one viewing, with any subsequent viewing being charged to your account. An unlimited view disc is also available at a far greater charge.
5. Discus briefly the problems of Data Streaming on the Internet.
Normal internet operation requires the entire file to be downloaded complete with error checking, before being able to be played back. Streaming is the instantaneous transfer of data in virtually real time. The major problems with streaming is that it requires large data bandwidth and a buffer in order to smooth out any seams due to error correction or re-transmission.
6. What is Eureka 147?
Eureka 147 is a digital audio broadcasting system(DAB), designed specifically for robust reception by mobile, portable, and fixed receivers, using simple non-directional antennas. The Eureka 147 Digital Audio Broadcasting system is the most significant advance in radio technology since the introduction of FM stereo. The three main elements of the Eureka 147 system are: MUSICAM audio coding, Transmission coding and multiplexing, and COFDM modulation. Masking Pattern Universal Sub-band Integrated Coding And Multiplexing(MUSICAM) uses psychoacoustical coding to code only audio signal components that the ear will hear, and discard any audio information that, according to the psychoacoustical model, the ear will not perceive. The benefits of such coding systems are a reduced bit-rate and improved representation of the audio data. Transmission coding and multiplexing combines all of the data into a single data stream ready for transmission. Coded Orthogonal Frequency Division Multiplexing modulation(COFDM) is a modulation scheme that uses multiple digitally modulated carriers instead of one single digitally modulated carrier. Using such a scheme improves efficiency.
7. Describe the current state of DAB in the UK
In the United Kingdom, the BBC is pioneering the introduction of digital radio services by establishing a national transmission network for Digital Audio Broadcast(DAB), and exploring the potential of DAB to deliver new programming that would have previously been impossible using existing analogue AM/FM radio systems. In the United Kingdom, 12.5 MHz of Band III spectrum from 217.5 - 230 MHz has been allocated to DAB. This will accommodate seven multiplexes. The BBC has been allocated one of these channels for its national DAB multiplex to operate on a single frequency network of transmitters throughout the UK. The remaining six multiplexes are to be regulated by the Radio Authority and will be licensed to commercial broadcasters for national, regional and local independent radio services. The BBC's local & regional services will also accommodated within these multiplexes. Channels currently available in the UK include BBC Radios 1, 2, 3, 4, 5 and 5 Live, BBC Radio 5 Live Sports Extra, BBC Radio 6, BBC 1Xtra (Contemporary black music channel), BBC7 (speech,drama,comedy and childrens), Classic FM, Virgin Radio, Core (Fresh hits), PrimeTime Radio (Easy listening) TalkSport, Planet Rock, Life (Adult contemporary) Oneword (Speech), BBC Asian Network and BBC World Service.
8. What is SDARS?
Satellite Digital Audio Radio Service(SDARS), also known as Digital Audio Radio Satellite(DARS) are terms used to describe satellite radio. Satellite radio operates in the 2.3-GHz S band, from 2320 to 2345 MHz. SDARS employs a dual-transmitter broadcast format in which signals are sent from both satellite-based and terrestrial transmitters. The satellite transmission will cover most areas, but are complemented by terrestrial transmitters when satellite coverage is blocked by tall buildings or other urban obstacles. Examples of the SDARS include XM Satellite radio and SIRIUS Satellite Radio in the United States, which provide customers with as many as 100 channels of MP3-quality digital radio.
9. Explain the term repeater.
A repeater is type of radio transmitter that receives a signal then re-transmits it to enable the signal to be reached from further away.
10. Explain Lossy data compression.
Lossy data compression is when a file or signal is compressed into a lower format ie. 32-bit compressed to 16-bit, or 320kb/s down to 192kb/s The file or signal will lose data in the compression process, but will still be accurately presented to the human ear.
11. What is meant by the The psychoacoustic model?
The psychoacoustic model contains the properties and limits of the human auditory system; in particular, the spectral and temporal masking effects of the inner ear. It is used in coding techniques to code only audio signal components that the ear will hear, and discard any audio information that, according to the psychoacoustical model, the ear will not perceive. The benefits of such coding systems are a reduced bit-rate and improved representation of the audio data.
12. What is ASIASTAR?
ASIASTAR is one of two satellites launched and controlled by Worldspace, the worlds first digital satellite radio network. Worldspace have partners that include BBC, CNN, Virgin Radio, Fox News and Bloomberg. ASIASTAR serves most of South Asia and overlaps in the Middle East. AFRISTAR is worldspace's other satellite that serves Africa, Europe, and the Middle East. Worldstar is also licensed to serve Central and South America and were scheduled to launch their third satellite AMERISTAR, but this has not happened because of the frequencies used by the American Airforce.
13. Describe how IP Telephony works.
IP telephony uses the Internet to send audio between two or more computer users in real time. The first IP telephony software product surfaced in early 1995. It allows a user to sit at their pc and use a microphone and speakers to talk to another user. IP telephony works by identifying a user's Internet Protocol (IP) address. IP telephone gateways allow PC's to connect to any telephone in the world. On one side, the gateway connects to a telephone, on the other side, the gateway connects to the internet. The gateway digitizes, compresses and packetizes the signal using IP and routes it to it's destinationover the internet. The gateway then reverses the operation for packets coming in from the network and going ou tto the phone. As both operations take place together at the same time, the outcome is a duplex conversation.
http://web.archive.org/web/20040401020811/http%3A//www.bbc.co.uk/rd/pubs/papers/paper_21/paper_21.html
http://en.wikipedia.org/wiki/AsiaStar |
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Mon May 16, 2005 3:31 am |
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All times are GMT. The time now is Fri May 16, 2008 4:41 pm
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