4 ms·

Am I seeing the past in a nostalgic light or were DVD 480p considerably better than YouTube 480p? I feel like streaming services compress their streams so hard

Am I seeing the past in a nostalgic light or were DVD 480p considerably better than YouTube 480p? I feel like streaming services compress their streams so hard that the resolution indicators become meaningless.

jiggawatts 3y ago
I watch 4320p (8K) streams when possible because it noticeably improves the quality on my 4K screens — and this is with my worsening eyesight! That shouldn’t be noticeable if the 4K stream was encoded properly.
- koromak 3y ago
  Similarly, 4K video looks much better on a 1080p screen than a 1080p video. A youtuber posted a comparison, its easy to see even in a still image. Its all in their encoding algorithm.
- edvinbesic 3y ago
  I believe this is to some degree due to chroma key subsampling, where in a 4k stream you will only have 1080p worth of light intensity encoded (cluster of 4px). So if you play an 8k stream and downscale to 4k you actually have full chroma (1:1). There could of course be other factors involved as well but this is definitely a pretty big contributor.
  - olaulaja 3y ago
    You have chroma and luma the wrong way around, chroma is color and luma is light intensity. Chroma is still the thing being subsampled. I've never really noticed effects from chroma subsampling so my guess would be the bitrate just being better with the higher resolution. Also "full res->compress->downsample" might be more efficient than "full res->downsample->compress" since downsampling is a (really bad) form of lossy compression as well.
- kevincox 3y ago
  > That shouldn’t be noticeable if the 4K stream was encoded properly. I don't think this is true. At some point there are diminishing returns. At some point if the 4k video has twice the bitrate it is going to have more information available. Some will be lost in the down sampling but it isn't "improper" to end up with more data on the screen. It is true that YouTube bitrates are pretty "conservative" for the resolution but I don't think that is "improper" it is just a tradeoff based on common device an internet speeds. They could be more bandwidth efficient if they did a custom transcode for each user's screen size and bandwidth but that is infeasible. So it is fine that some users will not be able to stream the 4k transcode on their 4k screen and will need to use the 2k stream and some users will have extra bandwidth on their 1080p screen so will stream the 2k version for better quality. The goal isn't to be perfect for each device but to be good on average.
oersted 3y ago
It's interesting to see how tiny Netflix mobile download files are. 200MB - 300MB for full-length movies, ~150MB for series episodes. This is on "Standard quality", but still. After some quick Googling (grain of salt) I see that a standard DVD of 4.7GB tends go have (usual encoding) up to 135 min of 480p video. That's a big difference! Even when considering that modern encoding might be more efficient. It is lossy compression, and the lossyness seems to be cranked way up.
- botanical 3y ago
  DVD's definitely didn't use up the entire 4.7GB. A movie was anything from 700MB to 1GB
  - wodenokoto 3y ago
    I remember old dvd players had a noticeable pause in the movie when it changed layers.
    - Sohcahtoa82 3y ago
      Yup. The movie producers would try to hide it by placing the layer change in a scene change, but I often still noticed it.
  - phonon 3y ago
    I think you're confusing them with MPEG-4 rips that are burned on DVD-R.
    - antiloper 3y ago
      Yes, DVDs use the MPEG-2 codec which has a horrible compression ratio compared to H.264 (and CD audio is completely uncompressed).
  - SirMaster 3y ago
    Commercial DVD movies were bigger than this. They used dual-layer DVDs and the main movie was often 6-7GB.
defrost 3y ago
In days of yore before upscaling was computationally practical a better standard was PAL region DVD's that were encoded from master (be that hires digital tape or direct from film). In PAL regions, the PAL signal uses 625 signal lines, of which 576 (known as 576i signal) appear as visible lines on the television set, whereas NTSC formatted signal uses 525 lines, of which 480 appear visibly (480i). In PAL video, every second line has the phase of the color signal reversed, which leads to the signals flattening out the frequency between the lines. Effectively what this means is that damage to the signal appears as errors in saturation (level of color) rather than hue (shade of color) as it would appear in NTSC video, leading to a higher-fidelity picture of the original studio version.
Macha 3y ago
The difference is bitrate. DVDs were 10 mbit of MPEG-2 while YouTube 480p is 2.5mbit of h264 (or transcodes thereof). These are different encodings so it's not a 1 to 1 comparison of bitrates as h264 is more efficient, but this article indicates that you'd need 4mbit of h264 (which is closer to that YouTube allocates to 720p video) to match the perceived quality of 10mbit of MPEG-2: https://streaminglearningcenter.com/articles/h264-vs-mpeg-2-quality.html https://streaminglearningcenter.com/articles/h264-vs-mpeg-2-...
- ksec 3y ago
  I am not sure where you get the 2.5Mbps and 4 Mbps number from because those are very high numbers for streaming ( or even for torrent downloading ) for those resolution and Youtube dont use any where near those number. A quick check shows Youtube only uses around 600Kbps on 720P video. And anywhere between 1.5 to 1.8Mbps for 1080P content. I am guessing their relatively low quality compared to their bitrate is because their encoding process optimise for encoding time rather than quality per bit simply because of the volume they have per day.
  - Macha 3y ago
    2.5mbps are youtube's own recommendations: https://support.google.com/youtube/answer/1722171?hl=en#zippy=%2Cbitrate https://support.google.com/youtube/answer/1722171?hl=en#zipp... They will then transcode it to h265, or webm which uses even less bandwidth, but I'm giving them the benefit of the doubt here and assuming they target their transcoding setup to preserve as much quality as they recommend providing them. And of course this is VBR not CBR, so some scenes will use less. 4mbps is the linked article description of where h264 matches DVD quality. Yes, 4mbps is more than most streaming sites will give for 480p. This does mean that most streaming sites are inferior to DVDs at 480p. The fact that most streaming sites use less bitrate than a DVD-equivalent quality is therefore not surprising, giving that people have noticed that exact fact. Streaming sites do not pick their bitrate to maximise quality given a fixed maximum filesize, so it's not surprising that they choose a lower bitrate (and therefore lower quality) than DVDs. They're instead optimizing for things like their server costs, time to playback start, or the ability to perform uninterrupted playback over the internet connection of users resorting to these lower resolution settings.
Saris 3y ago
Yep, streaming sites use so much compression to save on costs that everything looks much worse then it should.
- SirMaster 3y ago
  Eh, this isn't really my experience these days. Here is Disney+ stream vs a Disc 1:1 copy: https://nicko88.com/misc/compare/Ant%20Man%20Quantumania/ https://nicko88.com/misc/compare/Ant%20Man%20Quantumania/ https://nicko88.com/misc/compare/Avatar%20The%20Way%20of%20Water/ https://nicko88.com/misc/compare/Avatar%20The%20Way%20of%20W... Streaming looks only slightly marginally worse IMO.

jiggawatts 3y ago

I watch 4320p (8K) streams when possible because it noticeably improves the quality on my 4K screens — and this is with my worsening eyesight! That shouldn’t be noticeable if the 4K stream was encoded properly.

koromak 3y ago
Similarly, 4K video looks much better on a 1080p screen than a 1080p video. A youtuber posted a comparison, its easy to see even in a still image. Its all in their encoding algorithm.
edvinbesic 3y ago
I believe this is to some degree due to chroma key subsampling, where in a 4k stream you will only have 1080p worth of light intensity encoded (cluster of 4px). So if you play an 8k stream and downscale to 4k you actually have full chroma (1:1). There could of course be other factors involved as well but this is definitely a pretty big contributor.
- olaulaja 3y ago
  You have chroma and luma the wrong way around, chroma is color and luma is light intensity. Chroma is still the thing being subsampled. I've never really noticed effects from chroma subsampling so my guess would be the bitrate just being better with the higher resolution. Also "full res->compress->downsample" might be more efficient than "full res->downsample->compress" since downsampling is a (really bad) form of lossy compression as well.
kevincox 3y ago
> That shouldn’t be noticeable if the 4K stream was encoded properly. I don't think this is true. At some point there are diminishing returns. At some point if the 4k video has twice the bitrate it is going to have more information available. Some will be lost in the down sampling but it isn't "improper" to end up with more data on the screen. It is true that YouTube bitrates are pretty "conservative" for the resolution but I don't think that is "improper" it is just a tradeoff based on common device an internet speeds. They could be more bandwidth efficient if they did a custom transcode for each user's screen size and bandwidth but that is infeasible. So it is fine that some users will not be able to stream the 4k transcode on their 4k screen and will need to use the 2k stream and some users will have extra bandwidth on their 1080p screen so will stream the 2k version for better quality. The goal isn't to be perfect for each device but to be good on average.

oersted 3y ago

It's interesting to see how tiny Netflix mobile download files are. 200MB - 300MB for full-length movies, ~150MB for series episodes. This is on "Standard quality", but still. After some quick Googling (grain of salt) I see that a standard DVD of 4.7GB tends go have (usual encoding) up to 135 min of 480p video. That's a big difference! Even when considering that modern encoding might be more efficient. It is lossy compression, and the lossyness seems to be cranked way up.

botanical 3y ago
DVD's definitely didn't use up the entire 4.7GB. A movie was anything from 700MB to 1GB
- wodenokoto 3y ago
  I remember old dvd players had a noticeable pause in the movie when it changed layers.
  - Sohcahtoa82 3y ago
    Yup. The movie producers would try to hide it by placing the layer change in a scene change, but I often still noticed it.
- phonon 3y ago
  I think you're confusing them with MPEG-4 rips that are burned on DVD-R.
  - antiloper 3y ago
    Yes, DVDs use the MPEG-2 codec which has a horrible compression ratio compared to H.264 (and CD audio is completely uncompressed).
- SirMaster 3y ago
  Commercial DVD movies were bigger than this. They used dual-layer DVDs and the main movie was often 6-7GB.

defrost 3y ago

In days of yore before upscaling was computationally practical a better standard was PAL region DVD's that were encoded from master (be that hires digital tape or direct from film). In PAL regions, the PAL signal uses 625 signal lines, of which 576 (known as 576i signal) appear as visible lines on the television set, whereas NTSC formatted signal uses 525 lines, of which 480 appear visibly (480i). In PAL video, every second line has the phase of the color signal reversed, which leads to the signals flattening out the frequency between the lines. Effectively what this means is that damage to the signal appears as errors in saturation (level of color) rather than hue (shade of color) as it would appear in NTSC video, leading to a higher-fidelity picture of the original studio version.

Macha 3y ago

The difference is bitrate. DVDs were 10 mbit of MPEG-2 while YouTube 480p is 2.5mbit of h264 (or transcodes thereof). These are different encodings so it's not a 1 to 1 comparison of bitrates as h264 is more efficient, but this article indicates that you'd need 4mbit of h264 (which is closer to that YouTube allocates to 720p video) to match the perceived quality of 10mbit of MPEG-2: https://streaminglearningcenter.com/articles/h264-vs-mpeg-2-quality.html https://streaminglearningcenter.com/articles/h264-vs-mpeg-2-...

ksec 3y ago
I am not sure where you get the 2.5Mbps and 4 Mbps number from because those are very high numbers for streaming ( or even for torrent downloading ) for those resolution and Youtube dont use any where near those number. A quick check shows Youtube only uses around 600Kbps on 720P video. And anywhere between 1.5 to 1.8Mbps for 1080P content. I am guessing their relatively low quality compared to their bitrate is because their encoding process optimise for encoding time rather than quality per bit simply because of the volume they have per day.
- Macha 3y ago
  2.5mbps are youtube's own recommendations: https://support.google.com/youtube/answer/1722171?hl=en#zippy=%2Cbitrate https://support.google.com/youtube/answer/1722171?hl=en#zipp... They will then transcode it to h265, or webm which uses even less bandwidth, but I'm giving them the benefit of the doubt here and assuming they target their transcoding setup to preserve as much quality as they recommend providing them. And of course this is VBR not CBR, so some scenes will use less. 4mbps is the linked article description of where h264 matches DVD quality. Yes, 4mbps is more than most streaming sites will give for 480p. This does mean that most streaming sites are inferior to DVDs at 480p. The fact that most streaming sites use less bitrate than a DVD-equivalent quality is therefore not surprising, giving that people have noticed that exact fact. Streaming sites do not pick their bitrate to maximise quality given a fixed maximum filesize, so it's not surprising that they choose a lower bitrate (and therefore lower quality) than DVDs. They're instead optimizing for things like their server costs, time to playback start, or the ability to perform uninterrupted playback over the internet connection of users resorting to these lower resolution settings.

Saris 3y ago

Yep, streaming sites use so much compression to save on costs that everything looks much worse then it should.

SirMaster 3y ago
Eh, this isn't really my experience these days. Here is Disney+ stream vs a Disc 1:1 copy: https://nicko88.com/misc/compare/Ant%20Man%20Quantumania/ https://nicko88.com/misc/compare/Ant%20Man%20Quantumania/ https://nicko88.com/misc/compare/Avatar%20The%20Way%20of%20Water/ https://nicko88.com/misc/compare/Avatar%20The%20Way%20of%20W... Streaming looks only slightly marginally worse IMO.