Talk:Videos/A Digital Media Primer For Geeks - Revision history

Gmaxwell: moved Talk:A Digital Media Primer For Geeks/Episode 01 to Talk:Videos/A Digital Media Primer For Geeks

2013-02-25T23:59:48Z

moved Talk:A Digital Media Primer For Geeks/Episode 01 to Talk:Videos/A Digital Media Primer For Geeks

← Older revision		Revision as of 23:59, 25 February 2013
(No difference)

Xiphmont: /* 32 bit IEEE754 float */

2012-03-09T01:20:56Z

32 bit IEEE754 float

← Older revision		Revision as of 01:20, 9 March 2012
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	The video says that 32 bit floats have 24 bits of resolution and a 7 bit exponent.		The video says that 32 bit floats have 24 bits of resolution and a 7 bit exponent.
	This is incorrect. The exponent is eight bits. The mantissa does have a resolution of 24 bits, but only 23 bits are explicit. The encoding has one implicit bit that is always '1'. A 32 bit float can store all possible 24 bit integers exactly.		This is incorrect. The exponent is eight bits. The mantissa does have a resolution of 24 bits, but only 23 bits are explicit. The encoding has one implicit bit that is always '1'. A 32 bit float can store all possible 24 bit integers exactly. [[User:Xiphmont\|Xiphmont]] 17:20, 8 March 2012 (PST)

Xiphmont: /* 32 bit IEEE754 float */ one more to get it completely right

2012-03-09T01:18:35Z

32 bit IEEE754 float: one more to get it completely right

← Older revision		Revision as of 01:18, 9 March 2012
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	== 32 bit IEEE754 float ==		== 32 bit IEEE754 float ==

	The video says that floats have 24 bits of resolution and a 7 bit exponent.		The video says that 32 bit floats have 24 bits of resolution and a 7 bit exponent.
			This is incorrect. The exponent is eight bits. The mantissa does have a resolution of 24 bits, but only 23 bits are explicit. The encoding has one implicit bit that is always '1'. A 32 bit float can store all possible 24 bit integers exactly.
	This is incorrect. ~~They~~ have 23 bits ~~of resolution and an 8~~ bit ~~exponent~~.

Rmmh: /* 32 bit IEEE754 float */ new section

2012-03-07T07:19:50Z

32 bit IEEE754 float: new section

← Older revision		Revision as of 07:19, 7 March 2012
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	:Note that the PCM audio signal, once modulated to NTSC or PAL, can be recorded on any video recorder, not just U-matic. The most common tape format for PCM audio was Sony Betamax. Sony sold Betamax decks bundled with external PCM A/D converter units for the pro audio market. The PCM-F1 was designed to be used with Betacam VCRs. -- Dryo		:Note that the PCM audio signal, once modulated to NTSC or PAL, can be recorded on any video recorder, not just U-matic. The most common tape format for PCM audio was Sony Betamax. Sony sold Betamax decks bundled with external PCM A/D converter units for the pro audio market. The PCM-F1 was designed to be used with Betacam VCRs. -- Dryo

			== 32 bit IEEE754 float ==

			The video says that floats have 24 bits of resolution and a 7 bit exponent.

			This is incorrect. They have 23 bits of resolution and an 8 bit exponent.

Lee Carré: moved Talk:A Digital Media Primer For Geeks (episode 1) to Talk:A Digital Media Primer For Geeks/Episode 01: Establishing a hierarchical structure, especially in anticipation of future episodes. This allows for meta pages, such as giving a su...

2011-09-16T21:57:22Z

moved Talk:A Digital Media Primer For Geeks (episode 1) to Talk:A Digital Media Primer For Geeks/Episode 01: Establishing a hierarchical structure, especially in anticipation of future episodes. This allows for meta pages, such as giving a su...

← Older revision		Revision as of 21:57, 16 September 2011
(No difference)

StFS: /* General discussion */

2011-06-15T00:20:42Z

General discussion

← Older revision		Revision as of 00:20, 15 June 2011
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	The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)		The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)
	:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]		:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]

	When do you plan to create and/or release the next episode in this series? --[[User:Minerva\|Minerva]] 05:52, 16 November 2010 (UTC)		When do you plan to create and/or release the next episode in this series? --[[User:Minerva\|Minerva]] 05:52, 16 November 2010 (UTC)

			Mad props to you for taking the time and spending the effort to make this video. I've been waiting for episode 2 since this first came out, any chance of that being produced soon? --[[User:StFS\|StFS]] 17:20, 14 June 2011 (PDT)

	=== Atom/RSS feed ===		=== Atom/RSS feed ===

Minerva: /* General discussion */

2010-11-16T05:52:04Z

General discussion

← Older revision		Revision as of 05:52, 16 November 2010
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	The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)		The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)
	:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]		:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]
			When do you plan to create and/or release the next episode in this series? --[[User:Minerva\|Minerva]] 05:52, 16 November 2010 (UTC)

	=== Atom/RSS feed ===		=== Atom/RSS feed ===

Richardash1981: /* Video vegetables (they're good for you!) */ I think there is a slight glitch with 4:2:0 vs 4:1:1 but I'm not sure

2010-10-20T21:31:17Z

Video vegetables (they're good for you!): I think there is a slight glitch with 4:2:0 vs 4:1:1 but I'm not sure

← Older revision		Revision as of 21:31, 20 October 2010
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	:::Imagine a small 2x2 image, with the top two pixels blue, and the bottom two pixels red. Luminance will be sampled at each pixel, but (for 4:2:0), only one sample of Cr will be taken for this 2x2 set, so you'll have to decide where. If you place the sample on the middle horizontally, but aligned with every even or odd line, you'll get a sample from either blue, or red. If you place the sample horizontally and vertically, you'll get a sample from pink. Similarly for each other possible placement algorithm. [[User:Ogg.k.ogg.k\|Ogg.k.ogg.k]] 10:24, 25 September 2010 (UTC)		:::Imagine a small 2x2 image, with the top two pixels blue, and the bottom two pixels red. Luminance will be sampled at each pixel, but (for 4:2:0), only one sample of Cr will be taken for this 2x2 set, so you'll have to decide where. If you place the sample on the middle horizontally, but aligned with every even or odd line, you'll get a sample from either blue, or red. If you place the sample horizontally and vertically, you'll get a sample from pink. Similarly for each other possible placement algorithm. [[User:Ogg.k.ogg.k\|Ogg.k.ogg.k]] 10:24, 25 September 2010 (UTC)

			=== color and colorspace ===
			I'm not 100% sure of this, but when I was messing with analogue and digitised-analogue video at University, I thought the key difference between 4:1:1 YUV and 4:2:0 YUV is that the former has the same color sub-sampling on every field (dealing with interlaced content), each at one-quarter of full rate, where as 4:2:0 YUV has only Y and U in the first field, then only Y and V in the second.

			Effectively the "4:2:0" signal is successively 4:2:0 and 4:0:2, which is why the V component doesn't go away altogether as the name implies. The reason for such a strange encoding standard and it's use for PAL-format DV encoding is that the analogue PAL signal already does the throwing away of half the colour information from each field in the analogue composite signal used to get video around production facilities, so there would only be reduced temporal resolution U and V input to be digitised. It obviously makes a lot less sense for progressive-scan content without the interlace (it would look pretty poor to reduce the colour frame rate to 12.5 fps). There is an argument that the conversion of 4:2:0 interlaced content into progressive data for computer display converts it into 4:1:1 material when the color planes of the two fields are married up?

			The only important thing to come out of this is that the diagram on the whiteboard looks a lot more like 4:1:1 video, and I would expect that to be the correct choice for progressive-scan content (which I take your images to be, it being simpler). The narration of the next scene also uses 4:1:1 rather than 4:2:0, which tends to emphasise the same point.

	==Containers==		==Containers==

Iluvcapra: /* Raw (digital audio) meat */

2010-09-26T18:41:53Z

Raw (digital audio) meat

← Older revision		Revision as of 18:41, 26 September 2010
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	:I normally suggest to people looking for increased to look into acoustic holography techniques like higher-order ambisonics and wavefield synthesis.		:I normally suggest to people looking for increased to look into acoustic holography techniques like higher-order ambisonics and wavefield synthesis.
	:The beyond 48kHz sampling subject subject has been [http://www.google.com/custom?domains=hydrogenaudio.org&q=96khz&sa=Google+Search&sitesearch=hydrogenaudio.org&client=pub-4544327213918729&forid=1&channel=7051718642&ie=ISO-8859-1&oe=ISO-8859-1&flav=0000&sig=6_g3ghDcS6bRpfcd&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3AFFFFFF%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BLH%3A50%3BLW%3A262%3BL%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%2Fforums%2Flogo50.png%3BS%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%3BFORID%3A1&hl=en discussed a number of times on hydrogen audio], I recommend reading the thread there. They are quite informative. Most audio groups out there online and off are not very scientifically oriented (e.g. evidence based)— HA is special because it is one of the few that are.--[[User:Gmaxwell\|Gmaxwell]] 06:00, 24 September 2010 (UTC)		:The beyond 48kHz sampling subject subject has been [http://www.google.com/custom?domains=hydrogenaudio.org&q=96khz&sa=Google+Search&sitesearch=hydrogenaudio.org&client=pub-4544327213918729&forid=1&channel=7051718642&ie=ISO-8859-1&oe=ISO-8859-1&flav=0000&sig=6_g3ghDcS6bRpfcd&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3AFFFFFF%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BLH%3A50%3BLW%3A262%3BL%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%2Fforums%2Flogo50.png%3BS%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%3BFORID%3A1&hl=en discussed a number of times on hydrogen audio], I recommend reading the thread there. They are quite informative. Most audio groups out there online and off are not very scientifically oriented (e.g. evidence based)— HA is special because it is one of the few that are.--[[User:Gmaxwell\|Gmaxwell]] 06:00, 24 September 2010 (UTC)
	::I don't think higher Fs's than 48000 Hz are justified for psychoacoustic reasons, but we definitely use them in production for sound effects and music mastering, because it significantly improves the quality of pitch shifting and time stretching. On features we record all sound effects at 96 kHz (at least) so we have the liberty to pitch it down an octave. We shoot at 96k or 192k, and I archive to FLAC and use Apple Lossless .m4a's for online use, since they're better supported by our DAWs. [[User:Iluvcapra\|Iluvcapra]] 18:39, 26 September 2010 (UTC)		::I don't think higher Fs's than 48000 Hz are justified for psychoacoustic reasons, but we definitely use them in production for sound effects and music mastering, because it significantly improves the quality of pitch shifting and time stretching. On features we record all sound effects at 96 kHz (at least) so we have the liberty to pitch it down an octave. We shoot at 96k or 192k, and I archive to FLAC and use Apple Lossless .m4a's for online use, since they're better supported by our DAWs. As a distribution format though a base rate of 48kHz is definitely all you need for the home listening environment. [[User:Iluvcapra\|Iluvcapra]] 18:39, 26 September 2010 (UTC)

	==Video vegetables (they're good for you!)==		==Video vegetables (they're good for you!)==

Iluvcapra: /* Raw (digital audio) meat */

2010-09-26T18:40:12Z

Raw (digital audio) meat

← Older revision		Revision as of 18:40, 26 September 2010
Line 15:		Line 15:
	:I normally suggest to people looking for increased to look into acoustic holography techniques like higher-order ambisonics and wavefield synthesis.		:I normally suggest to people looking for increased to look into acoustic holography techniques like higher-order ambisonics and wavefield synthesis.
	:The beyond 48kHz sampling subject subject has been [http://www.google.com/custom?domains=hydrogenaudio.org&q=96khz&sa=Google+Search&sitesearch=hydrogenaudio.org&client=pub-4544327213918729&forid=1&channel=7051718642&ie=ISO-8859-1&oe=ISO-8859-1&flav=0000&sig=6_g3ghDcS6bRpfcd&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3AFFFFFF%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BLH%3A50%3BLW%3A262%3BL%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%2Fforums%2Flogo50.png%3BS%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%3BFORID%3A1&hl=en discussed a number of times on hydrogen audio], I recommend reading the thread there. They are quite informative. Most audio groups out there online and off are not very scientifically oriented (e.g. evidence based)— HA is special because it is one of the few that are.--[[User:Gmaxwell\|Gmaxwell]] 06:00, 24 September 2010 (UTC)		:The beyond 48kHz sampling subject subject has been [http://www.google.com/custom?domains=hydrogenaudio.org&q=96khz&sa=Google+Search&sitesearch=hydrogenaudio.org&client=pub-4544327213918729&forid=1&channel=7051718642&ie=ISO-8859-1&oe=ISO-8859-1&flav=0000&sig=6_g3ghDcS6bRpfcd&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3AFFFFFF%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BLH%3A50%3BLW%3A262%3BL%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%2Fforums%2Flogo50.png%3BS%3Ahttp%3A%2F%2Fwww.hydrogenaudio.org%3BFORID%3A1&hl=en discussed a number of times on hydrogen audio], I recommend reading the thread there. They are quite informative. Most audio groups out there online and off are not very scientifically oriented (e.g. evidence based)— HA is special because it is one of the few that are.--[[User:Gmaxwell\|Gmaxwell]] 06:00, 24 September 2010 (UTC)
	:I don't think higher Fs's than 48000 Hz are justified for psychoacoustic reasons, but we definitely use them in production for sound effects and music mastering, because it significantly improves the quality of pitch shifting and time stretching. On features we record all sound effects at 96 kHz (at least) so we have the liberty to pitch it down an octave. We shoot at 96k or 192k, and I archive to FLAC and use Apple Lossless .m4a's for online use, since they're better supported by our DAWs. [[User:Iluvcapra\|Iluvcapra]] 18:39, 26 September 2010 (UTC)		::I don't think higher Fs's than 48000 Hz are justified for psychoacoustic reasons, but we definitely use them in production for sound effects and music mastering, because it significantly improves the quality of pitch shifting and time stretching. On features we record all sound effects at 96 kHz (at least) so we have the liberty to pitch it down an octave. We shoot at 96k or 192k, and I archive to FLAC and use Apple Lossless .m4a's for online use, since they're better supported by our DAWs. [[User:Iluvcapra\|Iluvcapra]] 18:39, 26 September 2010 (UTC)

	==Video vegetables (they're good for you!)==		==Video vegetables (they're good for you!)==

← Older revision		Revision as of 00:20, 15 June 2011
Line 51:		Line 51:
	The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)		The video hasn't yet been formally released but we have all the sites up early in order to get everything debugged... Feedback on site functionality prior to the official release would be very helpful. --[[User:Gmaxwell\|Gmaxwell]] 15:15, 22 September 2010 (UTC)
	:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]		:Released now, but still tell us about bugs :-) --[[User:Xiphmont\|Monty]]

	When do you plan to create and/or release the next episode in this series? --[[User:Minerva\|Minerva]] 05:52, 16 November 2010 (UTC)		When do you plan to create and/or release the next episode in this series? --[[User:Minerva\|Minerva]] 05:52, 16 November 2010 (UTC)

			Mad props to you for taking the time and spending the effort to make this video. I've been waiting for episode 2 since this first came out, any chance of that being produced soon? --[[User:StFS\|StFS]] 17:20, 14 June 2011 (PDT)

	=== Atom/RSS feed ===		=== Atom/RSS feed ===