Black Hole
May contain traces of nut
OK, same deal - anybody with something to add, post it up and I'll add it in.
Encyclopedic Glossary of Terms
Readers please note: while much of the following is general information, where relevant it is specific to the Humax HDR-FOX T2 and (to a lesser extent) the HD-FOX T2.
BYTs
AD
AR
Booting
CF, CFW
Channel
CMYK
Colour Space
Container Format
CRID, P-CRID, S-CRID
CRT
DHCP
DLNA
Dolby
DRM
DSO
DTCP
DTT
DVB
Encryption
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Encyclopedic Glossary of Terms
Readers please note: while much of the following is general information, where relevant it is specific to the Humax HDR-FOX T2 and (to a lesser extent) the HD-FOX T2.
BYTs
Bright Young Things - Fittingly at the top of the list (even though I've thought of something to explain starting with "A"), BYTs is the term I've coined for the fantastic bunch with the youth and energy to figure out the hacks that comprise the CF (see CF) for the HD/HDR-FOX T2. Wind the clock back 20 or 30 years and it could have been me, but the brain now struggles to keep up. Don't worry, the rest of this glossary is serious (but not necessarily without tongue-in-cheek)!
Credit where credit is due: af123 is the driving force behind the creation of a customised firmware update (which provides the way in), and much of the code that subsequently gets installed to the hard drive as packages. raydon started the ball rolling by coming up with the Foxy process in the first place. Other contributors I count as BYTs are xyz321, Drutt, Tawny, Sam Widges, Ian Jukes, ChrisDaniels, philhdr, njm, prpr, /df (anyone feeling left out: not intentional, ping me a PM and I'll add you in). A more extensive list of credits and attributions can be found HERE (click).
I don't count myself as a BYT, I follow in their footsteps as groupie and self-appointed archivist.
AD
Audio Description - A service which provides commentary describing the inaudible aspects of a TV programme for the blind/partially sighted. Some users have been perplexed to find this turned on apparently randomly: there is a setting for it in the menus, and also the speaker button on the handset (to the right of "OPT+") cycles through the various modes - which might have been pressed accidentally.
AR
Accurate Recording - See EPG.
Booting
Booting is the jargon for the process of electronics hardware sorting itself out after it has been turned on, prior to being able to do something useful. The term comes from the phrase "pulled up by his own boot straps" - meaning making something of yourself from nothing - and was originally referred to as boot-strapping and then abbreviated to booting. Computer hardware doesn't know what to do until it has a program loaded into memory, so dedicated mechanisms are required to get the first (simple) program into memory which can then take over and load a more complex program... and so on. Dedicated hardware (which commonly has its program readily available and doesn't need loading) often needs to set up operating parameters under program instruction, and this is also considered part of the boot process. See also Firmware v. Software.
With regard to the Humax HD- or HDR-FOX T2, there are various ways they can be booted, with varying effects and consequences. To aid clear communication I encourage the use of standardised terms to describe them, as follows:
Cold Start / Cold Restart - We use "cold" to describe a state where no power is arriving at the unit at all. Thus a cold start is when the unit is booted by turning the power on. In the case of the HDR-FOX T2, there is a mains switch on the back. In the case of the HD-FOX T2, there is no switch so a cold start is when the unit is plugged in at the wall and the wall switch (if there is one) turned on. A cold restart is when the unit was powered, but power is removed and then restored.
Warm Start / Warm Restart - Converse to "cold", "warm" describes a state where the unit was powered but in stand-by, so a warm start is when the unit was turned on using the stand-by button or the remote control. I have noticed there is sometimes a difference between a button warm start and a remote control warm start (on the HD-FOX T2). A warm restart is when the unit is put into stand-by and then turned on again, but note that a proper warm restart does not happen unless some time is allowed between the off and the on for the shut-down processes to complete (approx 30 secs).
Hard Reset - The HD-FOX T2 is blessed with a reset button (located behind the front flap). Pressing this (while the unit is powered) performs a hard reset.
Soft Reset - Also known as a software reset, this is where software executes a restart command (as can be done from the custom firmware Web Interface when required after a remote recording schedule change). Same effect as a warm restart.
CF, CFW
Custom (or Customised) Firmware. In very brief summary: a few small additions to the standard firmware in the Humax allow additional program code to be installed on the hard drive and executed as part of the day-to-day operational environment, creating a rich set of additional facilities (for example: web browser access to the files and EPG; ability to download StDef and HiDef recordings in the clear; external drives in NTFS format... etc). The additions to the standard firmware are applied by installing a customised firmware update file from a USB drive or stick, and removing them again is as simple as re-updating with the original Humax firmware. With the firmware additions in place, a minimal web interface becomes available and the full suite of software additions can be downloaded and installed from there, and after that the user can choose to install a selection of optional "packages". Thus the "CF" is actually mostly software rather than firmware. See Firmware v Software.
Note that another common meaning of CF is "Compact Flash" (a type of memory card, particularly used in cameras), but this is unlikely to cause confusion in the context of the HDR-FOX T2.
Channel
See LCN.
CMYK
See Colour Space.
Colour Space
There is a wide variety of methods for specifying the colour and brightness of a pixel, and which is best depends on the specific application. In the case of displays which generate their own light (rather than reflect light like a painting), the emitters which contribute to the appearance of each pixel are red, green, and blue - hence RGB. Typically each "colour channel" is given a brightness value between 0 and 255 (ie one byte of data), three bytes providing the data for one pixel where "0,0,0" represents black, and "255,255,255" represents white (the same amount of each of red, green, and blue produces neutral grey tones). The higher the colour channel values, the brighter the pixel will be.
This is in contrast to printing on paper, where instead of being "additive", the inks are "subtractive". Light falling on the page is reflected by the white paper, and the pigments in the ink absorb some of the spectrum. The inks used for full-colour printing are CMYK: cyan, magenta, yellow, and "K" for black (not "B" which could be confused with blue) - black is used in addition to CMY because it would take an awful lot of CMY pigments to make a dot properly black. Cyan, magenta, and yellow are the "complimentary" colours to red, green, and blue. In this case, the higher the colour channel values, the darker the pixel will be.
Before the digital era, video signals were sent as analogue waveforms which represented each row (then called a "line"). Methods were invented to encode the colour and brightness in the video signal which suited each particular transmission medium, hence we have Composite and Component video. Component video is an extension to monochrome video - where a single channel carries a luminance signal (ie just the brightnesses along a black&white line in the raster). Two "side" channels are added which carry colour difference signals, and combined with the luminance are used to calculate the RGB signals. The advantage (at the time) was that the luminance signal could still be used on its own by ignoring the colour difference signals. Component signals are variously called YCbCr, Y'CbCr, YPbPr, YUV ("Y" representing luminance) - the differences being in the precise way that the components are calculated from RGB or vice versa.
Composite takes the component signals and combines them into a single analogue waveform by modulating the colour diffence signals onto a high-frequency carrier wave. The cleverness of this is that a monochrome receiver will not have been designed to detect the colour carrier, so will only see the luminance component. The manner in which the colour difference signals are modulated is the difference between the European PAL (Phase Alternating Line) system and the American NTSC (National Television System Committee) system (PAL was designed to correct the problems that NTSC had when using wireless broadcast transmission - it became known as "Never Twice the Same Colour").
No colour system can represent every possible hue, intensity, and brightness. Apart from the granularity of the digital representation (eg 24-bit RGB has "only" 16 million different values), there are colours which cannot be reproduced just by adding elements of red, green, and blue light (in the case of RGB). The method of encoding the colour information is called the "colour space", and the range of colours that can be represented within it is the "gamut". In fact, the colour spaces in use are designed to be a close match to the human visual system - so although in theory not every colour can be reproduced, it is of little practical disadvantage (unless you are experimenting with colour perception in animals - including humans).
The signal connections for analogue video depend on which colour system is in use. RGB requires three channels (typically a triple screened cable with RCA/phono connectors). Add stereo audio to that and there are five channels. Component similarly, three video and two audio. Composite plus stereo audio is the typical three-wire connection, with the video signal on the yellow connector and the stereo audio on red and white. SCART includes connections for composite and stereo audio, plus three channels that can be used as RGB or component according to the equipment (sometimes there is a selectable option in a settings menu - if given the choice use RGB).
Container Format
In order to combine video, audio, subtitles, audio description, alternative audio (eg foreign language dub) etc into a single file or stream, there needs to be a method for multiplexing them together. You can't, for example, just deliver the video and then the audio, because all the video would have to be stored up until the audio became available so that they could then be played together in sync. It might be possible to define a combined video and audio format, but then what about everything else which needs to be delivered? The solution is a container format.
MP4, for example, is not a video file format but a container format. Within the MP4, there are (typically) .AVC video and .AAC audio streams, but the actual streams could be almost anything (not all codecs are supported in any particular container format). The container format provides the method for splitting each of the streams within it into small chunks, and multiplexing them together with some more information to label each chunk so that they can be split out and reassembled when played. MKV is another container format. TS is the container format for UK digital TV, see also TS.
CRID, P-CRID, S-CRID
Content Reference IDentifier - The EPG provides unique reference codes to the programmes which are useful for machines to track the programmes (and potentially to retrieve additional information via the Internet). The Programme CRID (P-CRID - unofficial) identifies the programme individually and allows the Humax to ensure that repeats don't get recorded, the Series CRID (S-CRID - unofficial) allows it to identify programmes to be recorded by series link. The CRID codes can be seen on the Humax programme information screen (via the "i" button) by turning them on in the hidden service menu.
(The use of abbreviations PRID and SRID is now deprecated.)
CRT
Cathode-Ray Tube - the part which displays the picture in the old-fashioned bulky TVs, ie not plasma, LCD, or LED (or any other flat-panel technology).
DHCP
Dynamic Host Configuration Protocol - For your devices to co-exist on your home network, they each need a unique "address" so that data meant for a particular device gets there and not somewhere else. This is the IP (Internet Protocol) Address, and typically for a home network the addresses will be 192.168.0.x or 192.168.1.x (where x is 0-255). It is possible to allocate these addresses manually, but it is a chore and you have to make sure you choose a valid address and don't allocate the same address to more than one device. DHCP is an automatic system which lets the device request an address from a manager device - often the router in your broadband connection - but it is dynamic which can result in problems with the allocated IP address changing (particularly if the router reboots). If you need to be sure what IP address is allocated to the Humax, use DHCP initially and then fix it by changing to manual in the settings (but this can lead to its own problems), or configure the router to always hand out the same address by DHCP, or do both: fix the address at the router (which prevents it being handed to any other device) and set the Humax manually (which avoids problems with HomePlugs being slow to wake up).
DLNA
Digital Living Network Alliance - a set of standards which allow compatible devices to locate each other on the local Ethernet network, and access each other's content for streamed playback, without the user having to understand network configuration settings. If you want to use the Humax's media streaming capability to show its content elsewhere (firmware update 1.02.20 onwards), you will need a DLNA client - possibly a program running on a PC, or another Humax box - although it is possible to use non-DLNA media players if you can work out the correct network reference. The advantage of using another Humax is that it can access the HiDef content too (most other solutions will only access StDef recordings - see DTCP). You can also use a DLNA server to provide content to the Humax, again either running on a PC or using a NAS box with built-in DLNA capability (many do these days).
By setting Content Share = ON in the HDR-FOX menus, you are enabling it as a DLNA service on your home network (not available on HD-FOX). By selecting Network from the Media >> Storage menu (HDR-FOX or HD-FOX), you are accessing the DLNA services available on your home network (not including itself). Note that HiDef recordings are not made available by DLNA to non-DTCP compliant clients.
See also UPnP, DTCP.
Dolby
Dolby Laboratories invented and patented a number of processes for deriving multichannel audio (surround sound) over the years. The original Dolby encoder used the relative phasing of signals in the stereo channels (essentially a difference signal) to create a rear channel - this only works properly if the left and right stereo channels are recorded deliberately with this in mind, and the technique for achieving this is the essence of the Dolby patents. Dolby Pro Logic is an updated surround-from-stereo decoder. Cinema film used Dolby sound tracks, but then added more sound tracks (particularly 70mm film) to achieve full multi-track surround sound without Dolby encoding (and licence fees). Dolby Labs then patented a way to re-organise the multiple sound tracks to use them more effectively, and so the arms race went on. Now we have digital audio streams with enough bandwidth to carry a full high-quality stereo signal in a lossless format or surround in an encoded format, Dolby TrueHD is a codec for transmitting up to 14-channel surround sound in a (reportedly) lossless format. See also Surround Sound. Founder Ray Dolby, who started out by developing filters to reduce the background hiss in recordings (and hence improve the perceived quality dramatically), died in September 2013 aged 80.
DRM
Digital Rights Management - the means by which copyright holders attempt to protect their material by limiting its use, in particular securing it by means of encryption or other measures so that (for example) it can't be copied or it is only playable on a particular licenced device. The encryption of the recordings on the HD/HDR-FOX is a form of DRM, see also DTCP.
DSO
Digital Switch-Over - The process of the UK converting from fully-analogue TV to fully-digital. The first main phase introduced digital transmissions alongside the analogue, region by region, but the digital channels have/had to be at reduced power to avoid interference. The second main phase involves turning off the analogue transmissions completely and boosting the digital power to achieve the required geographic coverage. There are various sub-phases where the transmission frequencies are juggled around. The London area will be almost the last to complete, the mandarins having decided to experiment on the rest of us first.
DTCP
Digital Transmission Content Protection - a means of securing rights-restricted material transferred by any digital channel (in our case Ethernet). As a media server, the Humax protects HiDef recordings by DTCP, thus restricting your choice of clients to those which have paid the relevant licence fees (not unlike HDCP). Note that (by running the CF) DTCP can be effectively switched off. See also HDCP.
DTT
Digital Terrestrial Television - See DVB.
DVB
Digital Video Broadcasting - This is the replacement for the analogue method of TV transmission, the advantage being that a digital data stream occupying the same bandwidth in the frequency spectrum as one analogue service (and using modern data-compression techniques) can carry sufficient information for 4 HiDef video services or many StDef video plus music and text services. "DVB" encompasses DVB-T/DVB-S (terrestrial and satellite) and DVB-T2/DVB-S2 (second generation terrestrial and satellite) and many other standards. In particular: DVB-T2 uses an improved (more efficient) video compression technique that is used in the UK for HiDef TV services, while the StDef services are transmitted using DVB-T (if you are buying a TV tuner card or dongle for your PC and you want it to receive HiDef, make sure it is T2 capable).
Note that the entire digital traffic carried on any particular broadcast channel (of many services, ie a "mux" or multiplex) is either DVB-T or DVB-T2. Thus any other services (such as StDef TV or radio) carried on a DVB-T2 mux alongside HiDef services must also be T2 encoded, and require a T2-capable receiver. Because the T2 scheme is more efficient in bandwidth, there are plans to switch the entire network to T2, at which point first-generation DVB-T receivers (TVs, set-top boxes, PVRs, tuner dongles, etc) will become redundant. (This is, in particular, to reduce the overall bandwidth requirement for UK broadcast TV and make way to accommodate 5G mobile communications.)
See also LCN.
Encryption
Both HDR- and HD-FOX encrypt their recordings using keys unique to each individual machine and are undecypherable on any other machine. We have suspicions about the encryption method, but the keys are buried inside the hardware and unobtainable. As standard, the HDR-FOX decrypts StDef recordings when played to TV (obviously), copied to a USB drive, or streamed to a DLNA client. HiDef is not decrypted when copied, and is sent as a protected stream to DLNA. The HD-FOX only decrypts when playing back to TV.
The CF was born out of the desire to eliminate these restrictions (but has since become much more). First we were gifted Foxy, which can be used to unlock HiDef recordings for decryption when copied to USB. Now we can unlock HiDef automatically in the background so that it can also be streamed unprotected, and then by a bit of trickery stream StDef or HiDef to a file capture on the same device, and thus replace an encrypted recording with a decrypted one - all without user intervention.
Things are not so rosy for the HD-FOX, which lacks the DLNA server functionality used for auto-decryption on the HDR-FOX. However, it is now known how to decrypt by software.
See also .ts, Foxy.
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