HDMI from 1.0 to 2.1: how has the interface evolved?
We are not going to comment on the story of HDMI since its inception, but a basic summary of the specification as such is always useful, but, above all, how it has evolved over the years.
HDMI or High-Definition Multimedia Interface was designed in late 2002 (1.0 with 3.96 Gbit / s) and was marketed well into the year 2003 through its 1.0 specification, which could support a resolution of 1280 × 720 And till 60 Hz through 1.45 Gbit / s, or failing that 1920 × 1080 until 60 hz with 3.20 Gbit / s.
As we can see, the limitations were evident, even considering that it had the current 19 pins, but it was a standard that had just been born and needed time. Version 1.1 contained the same features, but added support for DVD Audio.
HDMI 1.2 (3.96 Gbits / s maximum) arrived in August 2005 and brought with it the audio of up to 8 channels, where in addition in terms of resolution and Hz they rose by 1280 × 720 to 120 Hz and support was given for 1440p at 30 Hz with a bandwidth of 2.78 Gbits / s, where curiously less width was needed than in FHD at 60 Hz (3.20 Gbit / s).
For his part HDMI 1.2a just added the spec CEC (Electronic Consumer Control) respecting everything said in its previous version.
HDMI 1.3 was a cable change and the introduction of 4K
In summer 2006 the version arrived HDMI 1.3 (8.16 Gbit / s maximum) which was a new advance in terms of resolution and hertz for gaming, but also had limitations in certain modes. A) Yes, 720p could bear up 120 Hz and FHD rose to the 144 Hz natively, where for the first time we saw the support to the 240 Hz under this resolution.
This support included RGB compression to reduce the bandwidth of the cable, since it reached 14 Gbits / s. On 2560x1440p support was given until 144 Hz Also, but as in 1080p they included RGB compression, where it reached 14.08 Gbit / s.
The 120 Hz they also suffered from such compression despite only getting 11.59 Gbit / s bandwidth. For the first time a cable as standard supported the resolution 4K, and it did so natively at 30 Hz without restrictions and at 60 and 75 Hz with color compression.
We cannot forget the support to 5K with color compression due to the 10.94 Gbit / s it needed.
The pretensions of the standard did not change while they were releasing versions and it remained in terms of resolution and hertz exactly the same until 1.4b, also included. This does not mean that there were no improvements to each version, since between 1.3 and 1.4b was added, for example, DTS-HD or Dolby TrueHD, an audio return channel, or support for Ethernet.
HDMI 2.and 2.0b
With version 2 of HDMI (14.4 Gbit / s maximum) that arrived at the end of 2013, another quite important leap in performance was made, since 720p remained native until 120 Hz, 1080p did the same until 240 Hz and 1440p achieved that the 144 Hz did not need color compression with its consequent loss of quality.
Unfortunately, the 1440p at 240 Hz they still needed them (24.62 Gbit / s). For its part, 4K was supported for the first time up to 75 and 120 Hz, both with RGB compression, but we were able to use the 60 Hz no loss.
The resolution 5K (2880p) it finally had native 30 Hz lossless and even reached 60 Hz with compression, showing that it could be scaled one step further in terms of pixels. And so it was, since we were able to enjoy the 8K (24.48 Gbit / s) at 30 Hz with RGB compression.
Other relevant details were the implementation of audio up to 1536 kHz (7.1 to 192 KHz), support for 21: 9 aspect ratio, or dynamic synchronization of streaming video and audio.
HDMI 2.0a was released in 2015 and only added support for HDR, while version 2.0b came out a year later providing the only novelty HLG (Hybrid Log-Gamma),
The latest version of the standard (HDMI 2.1) arrived in January 2017 with new improvements in resolution and hertz, where by standard it is stated that a cable is needed HDMI 4K as such, although many advise on certified cable due to the brutal increase in bandwidth that was achieved.
And it is that we went from the 14.4 Gbps of the version 2.0b at 42.6 Gbps of this version 2.1. This assumes that in 720p we will have 30, 60 and 120 Hz, in 1080p up to 30.60, 120, 144 and 240 Hz, in 1440p support up to 30, 60.75, 120, 144 and 240 Hz, all without color compression.
Going to 4K, we will have 30, 60, 75, 120 and 144 Hz natively and without restrictions, but the 240 Hz (54.84 Gbps) will need compression, although in this case we already opted to DSC and not RGB as such.
5K or 2880p will house 30 Hz, 60 Hz and 120 Hz, having this last compression DSC by needing 45.66 Gbps. Finally, 8K will only have natively 30 Hz, since, although now the 60 Hz and 120 Hz both of these refresh rates will require DSC.