[HN Gopher] Video codecs and 4k
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Video codecs and 4k
Author : zdw
Score : 82 points
Date : 2022-06-05 14:31 UTC (1 days ago)
(HTM) web link (scalibq.wordpress.com)
(TXT) w3m dump (scalibq.wordpress.com)
| HidyBush wrote:
| I expected a treatise about how different video codecs perform
| when dealing with 4k video, not a very good title imho
| NonNefarious wrote:
| Nor an entirely accurate article.
| Aardwolf wrote:
| That 320x240 need for speed intro video doesn't look bad at all
| to me, for having to be rendered on a 486 era computer!
|
| The low resolution pixels are visible, but I don't see many
| blocking / MPEG artefacts. I've seen much worse 240p videos.
| ogurechny wrote:
| NFS (on both consoles and PC) didn't have any MPEG-encoded
| videos. See
|
| https://wiki.multimedia.cx/index.php/Cinepak
|
| https://wiki.multimedia.cx/index.php/Electronic_Arts_TGV
|
| for 3DO and PC video formats, respectively. You can get the
| original files (ATTRACT[1-3]) from the first link
| (ffmpeg/mplayer had a decoder for that) or the reencodes
| someone made from the second link.
|
| https://ia803209.us.archive.org/view_archive.php?archive=/29...
|
| https://archive.org/details/nfsse-videos
|
| Oh, and the video itself seems to be from a PlayStation
| version, judging by the graphics in the end. Then the title
| should be "1996", and the hardware decoder for more advanced
| MotionJPEG-like video could be used.
|
| Edit: Sorry, that's NFS1 Special Edition intro (without
| Road&Track co-branding).
|
| Before talking about bus bandwidths and video card types,
| author had to mention that you simply couldn't decode such a
| complex format on consumer devices at that time, their CPUs
| weren't fast enough. Back then people used dedicated players
| with options to trade quality for speed to decode just the MP3
| audio files. For video, developers relied on simple codecs with
| integer math, line/block/area/frame copy/movement/discard
| operations, and reduced bpp data, like Cinepak, Indeo, and many
| custom ones. Their metric wasn't the quality level, but amount
| of frame data that could be updated by decoding CPU in a given
| time. Everything that couldn't fit got dropped. Some of those
| allowed to decode at arbitrary locations on arbitrary canvas
| sizes, and implement screen/region scrolling/updating through
| the same decoder, if needed.
|
| Game designers could cheat by sticking to highly compressible
| images. Shots with limited color palette and static (perfectly
| static) CG backgrounds looked better. For example, all of
| Cyberia FMV sequences only have 15 fps, but most of the time
| you don't notice that.
| aidenn0 wrote:
| The low frame rate is visible to me, as is the occasional color
| banding. The spatial resolution looks at least as good as a VHS
| recording of broadcast TV.
| rasz wrote:
| https://wiki.multimedia.cx/index.php/Electronic_Arts_TGV loss-
| less intra frame compression, and block-based motion and VQ for
| inter frames with ADPCM audio. Pretty neat for something
| running fine on 486DX2/66
| _gabe_ wrote:
| This article was amazing! I struggled through learning to use
| ffmepg as a C++ library, and then I found out how restrictive
| their licensing was and about mpeg patent laws which was a huge
| bummer. I'm building a video editor for mathematical animations,
| it's open source and I wanted to distribute a single executable
| as a paid option if you don't want to compile it yourself.
| Unfortunately this is borderline impossible with ffmpegs
| restrictive licensing.
|
| It looks like AV1 will be a great replacement, and seems like it
| will be widely supported in the future. The BSD-3 license also
| seems way more permissive, which is a huge plus. Does anyone have
| any experience using it as a library? I'll definitely be
| experimenting with it, but I wanted to see if anyone else had a
| good experience with it as opposed to ffmpeg or something :)
|
| Edit: I just wanted to add that my mis-capitalization of ffmpeg
| is completely intentional ;)
| klodolph wrote:
| > If we want to get a bit retro here, convincing video playback
| on a consumer PC more or less started when hardware cards such as
| the Video Blaster arrived on the market.
|
| A bit odd to give QuickTime a snub here, which was released in
| 1991.
| rasz wrote:
| Author confused hardware and assumed barebones single frame
| framegrabber was a video accelerator.
|
| QuickTime Road Pizza https://en.wikipedia.org/wiki/Apple_Video
| was one of the first viable universal video codecs on the
| desktop. Its not a coincidence Premiere started out on Mac
| https://en.wikipedia.org/wiki/Adobe_Premiere#History
| rasz wrote:
| 1. As GL1zdA already pointed out in blog comments 1992 Creative
| Video Blaster CT6000 was a single frame screen grabber and not a
| video encoding/decoding accelerator. YT "Creative Videoblaster
| CT6000 in action" https://www.youtube.com/watch?v=5LrwSGRflPE
| shows what it does.
| http://web.archive.org/web/20000829095056/http://www.ctlsg.c...
| "converts a standard full-motion video image (composite video
| source) into a format for display on a computer graphics monitor"
| emphasis on the _image_. "It can position and scale the video
| image onto the output display and allows the video image to be
| merged with computer graphics for interactive multimedia
| applicaiton." means overlay analog video on VGA monitor.
|
| The first true video decoding accelerator on PC market came out
| of David Sarnoff Research Center owned by RCA, later purchased by
| GE, then finally video tech carved out and sold to Intel. Called
| Digital Video Interactive
| https://en.wikipedia.org/wiki/Digital_Video_Interactive it did in
| fact "real time audio and video decompression, 30 frames per
| second with a resolution of 320x240". Intel repackaged it into
| one chip i750 and called it Indeo. Creative released a product
| based on it in mid 1994 - Video Blaster RT300. PCI bus was
| already mainstream in 1994, as were Pentiums. You most likely
| blurred those two together into one product.
|
| 2. "so the quality could be very high. Streams of 8 to 12 mbit of
| data for a single channel were no exception."
|
| SD video DVD bitrate is 10Mbit, and here we have OTA stations
| pushing 720p/1080i at same or lower bw using same codec (US
| mpeg2). Whole multiplexer in ATSC offers ~20Mbit, and then TV
| stations cram 3-4 signals in there. Lu Goughs "DRW2022 - Pt5:
| Digital TV (DVB-T), Digital Radio (DAB+) & FM Radio Analysis"
| https://goughlui.com/2022/06/05/drw2022-pt5-digital-tv-dvb-t...
| blog post offers good overview of the OTA TV broadcasting
| shitshow as seen from Australian perspective. 3-4Mbit is the
| average. There is nothing "very high quality" about OTA HD TV
| broadcast.
|
| "'gold standard' of 4k 60 fps video, streaming services is where
| you'll find it"
|
| you mean Netflix 4K 24 fps at 15Mbit? :-) That is the reality we
| are living in now. Apple is an outlier doing 25-40Mbit,
| everything else is bad.
|
| 3 "CRT has some afterglow after the ray has scanned a given area,
| the even field was still visible somewhat as the odd field was
| drawn. So the two fields would blend somewhat together"
|
| This is simply not how TV works, there is no somewhat, there is
| no afterglow. CRT goes dark after about 10 lines have been
| scanned in.
|
| "An LCD screen does not have the same 'afterglow' that a CRT has"
|
| LCD does in fact retain whole picture until the next update, aka
| "full afterglow" as you would put it.
|
| "so there's no natural 'deinterlacing' effect that blends the
| screens together."
|
| The natural deinterlacing effect happens in viewers brain, not on
| the Screen. You got this entirely backwards. The whole reason
| interlaced picture doesnt work on LCD is because previous frame
| stays on the screen. I highly recommend "How a TV Works in Slow
| Motion - The Slow Mo Guys"
| https://www.youtube.com/watch?v=3BJU2drrtCM
|
| 4. "HD, another new standard was required, as DVD was limited to
| SD."
|
| Sony used HD as an excuse to push new format with new licensing
| fees. Nothing, other than corporate greed, necessitated new
| storage medium. h.264 was already on the market, as were other
| efficient codecs. There were even failed attempts like Versatile
| Multilayer Disc using standard DVD with VC-1 coding.
|
| 5. 4K "special kind of confusion"
|
| who? This is the first time I hear about people associating 4K
| with new video codecs.
| johnwalkr wrote:
| I was huge into following the latest sound cards and video
| cards in the mid-late 90s, owned multiple soundblaster cards,
| and I didn't even remember a product called video blaster. I
| also checked the archive links, and aside from one model, these
| products were for encoding, not decoding. From my recollection,
| FMV on computers was a novelty reserved for short clips in
| games and encyclopedias like Encarta. You could go to a
| computer store and see a demo of a video playing from a cdrom
| on a 486/windows 3.1/MPEG-certified video card around 1993. But
| video on the PC was consistently even similar quality to VHS
| until Windows 95, MacOS System 7 and hardware from that time
| had decent support. If you had windows 95 and even the slowest
| Pentium, you could watch a good quality MPEG file. Granted, no
| content was available except for "weezer.mpg", a music video
| easter egg on the windows 95 cdrom, and you could download
| short high-quality clips such as clever commercials. For
| streaming an entire TV show, you could only find grainy
| "realvideo" streams by word-of-mouth. A sidenote is that they
| did work better in one sense than streaming today-- I remember
| watching star wars in realtime with IRC friends. The serving
| person had a cable modem and at least some of the viewers had
| 56kbps modems. These days, my phone plan throttles to 100kbps
| when I run out of data, and I can load HN, barely load a google
| search, can't load most news sites without timing out, and
| wouldn't even be able to navigate to any kind of video, let
| alone stream one.
|
| I'm also still disappointed in the quality of streaming
| services of movies. 4K often looks worse than 1080p. I live in
| Japan and broadcast TV 1080p looks so so much better than most
| streaming at any resolution. The Mandalorian is the exception
| that comes to mind. It's annoying that anytime I've checked out
| 4k and 8k TVs in an electronics store, I see the same demo
| videos for the last few years. Great-looking but utterly boring
| content like a man swinging ropes around in a puddle and paint
| bouncing around on some kind of speaker cone or drumhead.
| Really drives home the point that content that actually takes
| advantage of the (amazing) 4k+, HDR screens is lacking.
|
| On the other hand, I appreciate that the floor of quality is
| quite high, and for a person that grew up loving "this old
| house" as a kid, I can open youtube and see incredibly high
| quality/high-image quality content on any subject, whether
| broad or deep. And most of it is created, starring produced,
| and edited by one person. That's a totally different discussion
| though.
| ksec wrote:
| >But even MPEG-1 supports a maximum resolution of 4095x4095, and
| a maximum bandwidth of 100 mbit. So it is technically possible to
| encode 4k (3840x2160) content even in MPEG-1, at decent quality.
|
| The reality is that that despite MPEG-1 and MPEG-2 support those
| resolution, none of the mainstream implementation supports it. (
| Although you could always use Software implementation as MPEG-2
| is now patent free ) Hence when you go 4K, only newer version of
| MPEGs are used.
|
| It is also missing MPEG-5 with EVC. And how not only MPEG-4 has
| different codec, AVC itself introduces many different profiles
| where compression efficiency differs greatly.
| giantrobot wrote:
| MPEG-4 part 2 and h.263 also support multiple profiles. MPEG-4
| part 2 is _based_ off of h.263 but with basically all the
| features turned on with its own additional features available.
|
| Annoying the author doesn't seem to understand that multiple
| standards bodies exist. The h.xxx codecs are specified by the
| ITU. MPEG is a totally different organization. The MPEG-x
| standards are specific video encoding and delivery standards.
| The ITU _also_ has delivery specifications but those are mostly
| about telecommunications delivery.
| malkuth23 wrote:
| True. I work with media server playback stuff for live events
| etc. Back in the day, we only used mpeg2 constant bitrate codec
| because it allowed us to sync the playback across multiple
| systems. The first 4k videos we could play were just a slightly
| hacked version of mpeg2. The software I used adopted the
| extension .mxl and claimed they sort of invented a new thing,
| but truthfully, it was just an mpeg2 encoder/decoder that
| ignored that 4095 rule.
|
| Now we use HAP family (DXT/S3 based) or NotchLC (which is a
| specialized codec for media servers that is fairly encumbered
| with patents).
| rasz wrote:
| >Now we use HAP family (DXT/S3 based)
|
| You mean Apple Road Pizza, right? :)
| https://en.wikipedia.org/wiki/Apple_Video#Four_color_mode
| Melatonic wrote:
| I am assuming thats with huge color compression though - I
| forget the details of MPEG1 - 100mbit can be GREAT or CRAP
| depending on the codec
| tatersolid wrote:
| Sort of a Wikipedia-style overview of video codec history. If you
| were expecting some new info or insight, skip the article.
| [deleted]
| hulitu wrote:
| And just like Wikipedia the content is full of errors.
| dopa42365 wrote:
| On Wikipedia YOU can fix it at least!
| hulitu wrote:
| You cannot fix it. There was a discussion on HN some month
| ago about this issue.
| natly wrote:
| I wish HN had way more technical overviews like this from
| people with experience. It's certanily new to me.
| lostmsu wrote:
| If anyone's interested in the programmatic side, I found the new
| Windows APIs for encoding to be very sufficient for both H.264
| and HEVC: https://docs.microsoft.com/en-
| us/uwp/api/Windows.Media.Trans...
|
| I does not have as many tunable options as ffmpeg, but served me
| better for the purpose of multimonitor screen capture (~ 7k by 3k
| total resolution) precisely because it flings DXGI surfaces
| directly without the need to copy pictures from GPU to RAM and
| back for encoding.
| seanalltogether wrote:
| Video deinterlacing is one of those topics that I always felt
| would be a good way to teach myself deep learning techniques. The
| idea that you have a previous frame and a next frame with
| information to help you fill in the gaps of the current frame is
| really intuitive and easy to visualize. I'm sure this has been
| solved really well by now, but it seems like a good problem to
| learn with.
| brigade wrote:
| It's one of the oldest widespread applications of neural
| networks for video, with NNEDI at least dating to 15 years ago.
|
| That said, I don't think there's been much work incorporating
| new research from the current resurgence of deep learning.
| babypuncher wrote:
| I wish Handbrake would incorporate some of these. Its built-
| in deinterlacing options leave me wanting, particularly with
| older animated content.
| IshKebab wrote:
| Definitely already been done, but yeah it's pretty much ideal
| for ML.
| NonNefarious wrote:
| I wouldn't say it has been solved all that well. The problem is
| the temporal difference between the two fields, so moving
| objects have a "comb" distortion while more static parts of the
| image mostly don't.
|
| Interlacing should never have been a part of a digital-TV
| standard, but broadcasters pushed a bunch of FUD and lies
| during the progressive-vs.-interlaced debate. They whined that
| going progressive "would break their pipeline," when that's
| obviously BS because they'd been playing film-originated
| material for decades. Acquisition should always have taken
| place in a progressive format, even if transmission continued
| to be interlaced for a while.
|
| Now we're stuck with a bunch of historical footage that looks
| like shit.
|
| And then there's the asinine perpetuation of non-integer frame
| rates; those too should have been abolished with digital TV.
| Melatonic wrote:
| Yea seriously - interlacing made sense only for when it was
| actually required by the technology. We should have dropped
| it at the first chance we got
| babypuncher wrote:
| Interlacing should never have been part of any digital video
| standard, in my opinion. All it has done is cause problems.
| Early digital productions shot in 720p look better than their
| 1080i peers.
| rasz wrote:
| The problem is first digital video was sill targeting CRTs.
| babypuncher wrote:
| Interlacing could have been handled by the playback
| hardware. At the end of the day, 60 interlaced fields or
| 30 full frames per second still require the same amount
| of bandwidth.
| Melatonic wrote:
| Thats not necessarily only deinterlacing - lots of modern
| codecs are doing compression (pretty much all of them) based on
| how much change there is frame to frame. But almost nothing is
| interlaced these days. Although of course interlacing itself
| was a simple form of what you are describing above in a way.
| phoboslab wrote:
| > MPEG is not free. A license is required for using MPEG.
|
| For MPEG-1 this is not true anymore. All patents have expired.
| It's also far less computationally expensive and easier to
| implement/integrate than more modern codecs. This makes MPEG-1 a
| "good enough" solution for (e.g.) short video clips in a game.
|
| Disclaimer: I wrote pl_mpeg[1], so my opinion is biased.
|
| [1] https://github.com/phoboslab/pl_mpeg
| corysama wrote:
| Fun fact: The PlayStation2 (and maybe PS1?) had an "MDEC"
| coprocessor that was basically a JPEG decoder chip. So, in one
| game we used low-rez MJPEG streams for the characters' pop-up,
| talking-head, conversational clips. The were small enough to
| keep in the 32MB of main RAM for zero-latency and free to
| decode any frame on the fly as needed.
| pvg wrote:
| _and maybe PS1?_
|
| Yeah it started on the PS1, as you say:
|
| https://news.ycombinator.com/item?id=27699899
| corysama wrote:
| lol. Been a long time since I worked on a PS1 ;)
| Melatonic wrote:
| Motion JPEG was once the bain of my existence - the very
| first DSLR's to get video recorded in mjpeg (it was an
| afterthought tacked on - they had no idea it would
| revolutionise an industry). Many of the free decoders were
| quite crap and did not do a good job when you were trying to
| squeeze every last bit of detail out of a 720P mjpeg stream -
| there was one significantly better one which I am forgetting
| the name of now. It was paid but I got a hold of it
| eventually somehow (as a broke college student) through a
| friend or class. One plus of it however from what I remember
| is that the format would play on even the crappiest hardware
| performance wise
| PaulHoule wrote:
| OTA broadcasters have to upgrade to ATSC 3 to support 4K video.
| You either need to get a new TV set or an ATSC 3 decoder to watch
| tune it in.
|
| In Syracuse (about 50 miles away from me) the three network
| broadcasters collaborate to run one ATSC 3 transmitter with big
| which I can tune in with
|
| https://www.silicondust.com/product/hdhomerun-flex-4k/
|
| The picture on ATSC 3 is high-quality 1080i/720p with an
| aggressive surround soundtrack which sounds great for sports
| events on my home theater upstairs. I wind up watching the ATSC 1
| channels more because: ATSC 1 signals have subchannels like Comet
| (I am a sucker for Quantum Leap, Baby Godzilla, Time Bandits,
| ...), the new audio codec in ATSC 3 doesn't work on every device,
| and the ATSC 3 signal is a little less robust than most of the
| ATSC 1 signals.
|
| I think Sinclair broadcasting (the owner of the transmitter) is
| more interested in embedding sports betting into sports events as
| an interactive application than they are in 4K. I think that will
| wait until they start turning off ATSC 1 transmitters and turning
| on more ATSC 3 transmitters, but that will take a long time.
| ipython wrote:
| I looked into this recently when I moved houses and was without
| cable for a few weeks. I thought about purchasing an ATSC 3 box
| to try it out instead of just using an antenna with my TVs
| internal ATSC 1 decoder.
|
| I will never adopt ATSC 3 because they have built targeted
| advertising and viewer tracking into the spec. See for example
| https://rampedup.us/atsc-3-0-marketing-opportunity/. It's
| really too bad but to me this is the final nail in the coffin
| for ota programming in my opinion.
| cogman10 wrote:
| Yup, ATSC 3 is really unfortunately problematic in the amount
| of garbage that's been put into it. The fact it requires an
| internet connection is atrocious.
|
| Hell, the fact that ATSC supports PAID OTA transmissions is
| likewise garbage. It'll just encourage a race to the bottom
| with OTA bandwidth that will (likely) end up killing it off
| all together. Who is going to pay for 4 channels from a
| broadcaster vs streaming? Yet there will be enough incentive
| that you can almost bet the market for free OTA broadcasts
| will go away.
| Melatonic wrote:
| Well that is extremely disappointing.
|
| Sinclair as a media company is also shady as fuck so I am not
| surprised they are the ones going in on this.
|
| Maybe this will create a black market for ATSC 3 boxes that
| have been hacked to remove / block all tracking features -
| sounds like a fun project for someone here :-D
| PaulHoule wrote:
| ATSC 3 supports an application model based on a single page
| application that gets notified of events coming down the
| radio channel by websockets
|
| https://muygs2x2vhb2pjk6g160f1s8-wpengine.netdna-
| ssl.com/wp-...
|
| there is a radio back channel
|
| https://muygs2x2vhb2pjk6g160f1s8-wpengine.netdna-
| ssl.com/wp-...
|
| but the TV is expected to have a real internet connection
| as well as the radio link. Such a system is capable of
| anything a web application is, including tracking.
|
| It would be interesting to see if targeting meant that I
| occasionally get to see an ad for something I could buy
| with my own money as opposed to the injection of the month
| (used to be pill of the month but now it seems to be all
| biologicals) or something seniors can get for free with
| medicare.
| Melatonic wrote:
| So just do not hook the tuner up to the internet then?
| Interesting. Unless of course they do something shady
| like throw a 4G chip inside the box
| cjensen wrote:
| If your TV set can't talk to the internet, you can't be
| tracked. All you lose is the silly 'interactive' features
| that no one uses.
| password4321 wrote:
| What antenna do you recommend?
| PaulHoule wrote:
| Depends on your case. You should look up your location here:
|
| https://tvfool.com/
|
| If you have many stations close by (you live in L.A.) a set
| of rabbit ears can tune in almost as many channels as cable.
| If you live 40 miles away from the transmitter you want an
| outdoor directional antenna. The further away you are from
| the transmitter and the weaker the transmitter, the bigger an
| antenna you need.
|
| There are two cities about 150 degrees apart that have
| transmitters near me, I am thinking of putting up a second
| antenna that points at the secondary city, maybe that way
| I'll be able to get ABC reliably.
| Melatonic wrote:
| I like that OTA is still even a thing but I cannot help but
| think that this is going to fail - who the hell is even using
| OTA let alone tech saavy enough to be UPGRADING their boxes for
| 4k?
|
| I'm still using one of the last Plasma TV's ever made (bought
| it used for cheap) which does have a built in tuner but is
| obviously 1080P only. At my last apartment I was line of site
| and only a few miles from where everything is transmitted from
| so I had great reception. Now it is the opposite and I would
| need to run a cable up the side of my apartment building to get
| an antenna working.
|
| Is ATSC 3 really not backwards compatible? It seems like it
| would be crazy to upgrade to a system that then will not work
| on all older TV's considering that most new TV's sold these
| days do not have a tuner built in at all!
| bluedino wrote:
| > who the hell is even using OTA
|
| It's pretty common with cord cutters.
| saltminer wrote:
| OTA is underrated IMO. I really only watch the local PBS
| affiliate, Chromecast takes care of everything else. And best
| of all, I can watch it on my PC with my Hauppauge tuner
| (though it doesn't do ATSC 3, I don't have any 3 stations in
| my area).
| robonerd wrote:
| > _You either need to get a new TV set or an ATSC 3 decoder to
| watch tune it in._ [...] _until they start turning off ATSC 1
| transmitters_
|
| How did things get this bad? In the 90s and early 00s, you
| could watch virtually any OTA television channel with a
| television made half a lifetime earlier in the 1950s. New
| technology like color television was introduced, but remained
| compatible with old TVs.
|
| In the 50s through 90s virtually nobody gave a damn about
| e-waste. Today everybody plays lip service to the idea, yet
| we're obsoleting recently purchased technology faster than ever
| before, and for what? So you can see individual pores on some
| ball-kicker's nose?
| giantrobot wrote:
| Stations wanting to do ATSC 3.0 broadcast are required to
| broadcast the same content (within bounds of the technology)
| as ATSC 1.0 in that market. There's no required sunset for
| ATSC 1.0 broadcast like there was for NTSC.
|
| ATSC 3.0 isn't backwards compatible because it's signaling is
| different than ATSC 1.0. It ends up being more efficient
| getting a higher data rate in the 6MHz channel. The video
| codec is _also_ more efficient (h.265 vs h.262) allowing more
| program streams per RF channel.
|
| It will be quite a while before ATSC 1.0 is mandated to roll
| over to an updated ATSC standard. Even then there's no reason
| you can't just buy a tuner for the new standard instead of a
| new TV.
| PaulHoule wrote:
| There was a try at an ATSC 2 that kept the same transport but
| added interactive features. They gave up on it and went to
| ATSC 3.
|
| The greatest tragegy in modern television is cable boxes. To
| this day a cable box takes 80W to do what a phone does in
| 0.8W and you are always waiting for it to do it.
|
| There was this
|
| https://en.wikipedia.org/wiki/CableCARD
|
| but a standardized digital signal early on would have gone a
| long way. As it was cable companies struggled mightily with
| proprietary systems until Comcast developed a decent system
| circa 2015.
| [deleted]
| nsgi wrote:
| Isn't the vast majority of 4k content delivered online anyway?
| PaulHoule wrote:
| Probably. You can get 4k Blu Rays but I don't know how big
| that market is compared to streaming.
| tzs wrote:
| I wish they had made audio more robust in ATSC, even if it
| would mean making video less robust. For probably most programs
| a video dropout without an audio dropout is much less
| disruptive than an audio dropout without a video dropout.
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(page generated 2022-06-06 23:01 UTC)