Home |
Search |
Today's Posts |
|
#1
|
|||
|
|||
What is the point of digital voice?
In rec.radio.amateur.equipment Jerry Stuckle wrote:
On 2/26/2015 3:28 PM, rickman wrote: On 2/26/2015 10:09 AM, Jerry Stuckle wrote: On 2/26/2015 3:58 AM, AndyW wrote: On 25/02/2015 13:55, Jerry Stuckle wrote: Not really true, at least in the United States. All TV's here use the same (proprietary) chipsets to decompress the digital signal. However, it makes a huge difference on the resolution being used, i.e. 720P, 1080P, 1080I, UHD... The difference is in what happens after the signal is decompressed. I am unsure of US TV. In the UK terrestrial TV is all digital. Analog(ue) was switched off a few years ago. I am referring to the whole box from antenna to screen, most of our TVs come with built-in 'Freeview'. I have a digital set about 6 years old that struggles to handle complex images but my new toy handles it perfectly. My newer TV uses a newer chipset and more efficient decoding algorithm that is made possible because of the higher power chipset. The older chipsets are still in production and still being sold, presumably the TV manufacturers can buy them cheaply, stick them in the TV and rely on marketing buzz over technical demonstration to sell then for a larger markup. Most people I know buy on screen size anyway. My understanding - which may be incorrect - is that the TV has a fixed time based upon the framerate in which to decode the image and display it before it has to start on the next frame. Better quality TVs are capable of fully decompressing the image and displaying it between frames but the cheaper and older ones cannot handle a new image every frame and so, when it runs out of time decoding the image it just gets sent to the screen, tesselations and all. Standing ready to be corrected. Andy Andy, I don't know what the Europeans use, so I can't speak for you guys. But here in the United States, everything is digital also, and has been for years (here come the trolls). Yes, the TV only has a certain amount of time to decode the signal. But in the U.S., the method used is proprietary to one company. The chipsets required to decode the signal are all produced by this company, so all TV's have similar decoding. I think you are confusing all chip makers using the same algorithm with all TV makers buying their chips from the same chip maker. http://www.toshiba.com/taec/componen...GProdBrief.pdf http://www.broadcom.com/products/Cab...utions/BCM3560 http://www.fujitsu.com/cn/fsp/home-e...t/MB86H01.html Are you suggesting that all of these chip makers are reselling one company's products? If you would bother to understand what you referenced, NONE of these chipsets are hi-def (1080). And yes, H.264 is a proprietary algorithm, with only one company providing the chipsets. http://en.wikipedia.org/wiki/H.264/MPEG-4_AVC begin quote A hardware H.264 encoder can be an ASIC or an FPGA. ASIC encoders with H.264 encoder functionality are available from many different semiconductor companies, but the core design used in the ASIC is typically licensed from one of a few companies such as Chips&Media, Allegro DVT, On2 (formerly Hantro, acquired by Google), Imagination Technologies, NGCodec. Some companies have both FPGA and ASIC product offerings.[56] Texas Instruments manufactures a line of ARM + DSP cores that perform DSP H.264 BP encoding 1080p at 30fps.[57] This permits flexibility with respect to codecs (which are implemented as highly optimized DSP code) while being more efficient than software on a generic CPU. end quote See also: http://en.wikipedia.org/wiki/H.264/M...mplementations http://en.wikipedia.org/wiki/MPEG_LA -- Jim Pennino |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|