As your source of information, I have read the HDMI spec since version 1.2. It is not the most entertaining thing to read, but it is the thing you must do if you are involved in HDMI transmitters and receivers. So let's talk about cables. The main difference is speed that the cable needs to support. The main trouble with HDMI cables is if their impedance do not match the 50 Ohm. If impedances are not matched, reflections occur and can disturb the bit stream sent. The higher the bit rate, the more difficult it is to achieve a case that is close to ideal. Prior to 1.3, DeepColor did not exist, so only 24bit video could be transferred in 4:4:4 format (or 36bit in 4:2:2 mode). This means that the max throughput is at 1080p, so the cable needs to support a bitrate of 1425MHz per channel. Now, for 1.3 (the a version is mostly a change in the compliance test) and DeepColor (that is optional!), cables need to support 48bit video, meaning twice the bitrate, 2850MHz per channel. As you can see, cables catalogued for version 1.3 supporting DeepColor need to be better built for the same distance. What do those numbers mean to you? Nothing, as DeepColor is something you should not be worried about. As far as I know, most LCD screens support either 15bit or 24bit pixel representation (6bit or 8bit per channel), meaning that is the weakest link in your viewing experience. DVDs and BluRays only support 24bit colors, so you can only really get more colors at the source if you have some sort of processing. But, generally speaking, TVs usually have a 30bit or 36bit processing chain. Why then do they need such level of precision if they are going to represent those in a 24bit format? That is because of the accumulated error due to arithmetic operations. Typical operations that you might need to be aware of are YPbPr to RGB conversion, and brightness and contrast correction. Let's say that if you have a +/-1 error at 10bit during those operations, when you truncate it to 8bit, you will not notice. If you have the same error at 8bit, a TV with a 24bit panel should be able to reproduce it. Having more data at the input can usually mean a better pixel representation. Still, I would bet on the fact that most people do not care of a deviation of 1 in the pixel representation. If you have an HDMI 1.3 with DeepColor TV, you could try to turn it on and off from the DVD or BluRay player (sorry, PS3 folks, that is something that you can not select on a PS3). If you can see the difference, tell me, because then I need to go to the optician again.
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As your source of information, I have read the HDMI spec since version 1.2. It is not the most entertaining thing to read, but it is the thing you must do if you are involved in HDMI transmitters and receivers.
So let's talk about cables. The main difference is speed that the cable needs to support. The main trouble with HDMI cables is if their impedance do not match the 50 Ohm. If impedances are not matched, reflections occur and can disturb the bit stream sent. The higher the bit rate, the more difficult it is to achieve a case that is close to ideal.
Prior to 1.3, DeepColor did not exist, so only 24bit video could be transferred in 4:4:4 format (or 36bit in 4:2:2 mode). This means that the max throughput is at 1080p, so the cable needs to support a bitrate of 1425MHz per channel.
Now, for 1.3 (the a version is mostly a change in the compliance test) and DeepColor (that is optional!), cables need to support 48bit video, meaning twice the bitrate, 2850MHz per channel. As you can see, cables catalogued for version 1.3 supporting DeepColor need to be better built for the same distance.
What do those numbers mean to you? Nothing, as DeepColor is something you should not be worried about. As far as I know, most LCD screens support either 15bit or 24bit pixel representation (6bit or 8bit per channel), meaning that is the weakest link in your viewing experience. DVDs and BluRays only support 24bit colors, so you can only really get more colors at the source if you have some sort of processing.
But, generally speaking, TVs usually have a 30bit or 36bit processing chain. Why then do they need such level of precision if they are going to represent those in a 24bit format? That is because of the accumulated error due to arithmetic operations. Typical operations that you might need to be aware of are YPbPr to RGB conversion, and brightness and contrast correction. Let's say that if you have a +/-1 error at 10bit during those operations, when you truncate it to 8bit, you will not notice. If you have the same error at 8bit, a TV with a 24bit panel should be able to reproduce it. Having more data at the input can usually mean a better pixel representation. Still, I would bet on the fact that most people do not care of a deviation of 1 in the pixel representation.
If you have an HDMI 1.3 with DeepColor TV, you could try to turn it on and off from the DVD or BluRay player (sorry, PS3 folks, that is something that you can not select on a PS3). If you can see the difference, tell me, because then I need to go to the optician again.