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Originally Posted by PaulHarald
I have learned that NICAM is 'digital', but as it is decoded at the user end, it is broadcast in analogue format, not digital - it only becomes 'digital' after it has been decoded by my TV and/or DVD recorder (thanks to Inabsentia at Dime).
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I don't understand that sentence - NICAM is a digital broadcast method. The audio starts as analogue (maybe) in the TV studio, gets converted to NICAM (a digital format), the NICAM bitstream is transmitted with the analogue TV broadcast, and then finally your TV or VCR will convert the NICAM digital bitstream back to analogue audio.
More information that you probably want on NICAM can be found here:
http://tallyho.bc.nu/~steve/nicam.html
Basically, the NICAM process starts by sampling the audio at 14-bit/32KHz, and this is "companded" (a lossy data-reduction process) to 10-bit/32KHz for transmission.
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So if we compare this to TV-land: Is a DIGITAL TV stream (audio) usually 256kbps? Or is it better? And for the non-digital TV with Nicam stereo: May the NICAM stereo signal be less compressed? In that case, the freq analysis of my LPCM audio capture would look better. Why would standalone recorders have the options of 384kbps AC3 and the best ones even LPCM - the user manual says "for recording uncompressed high quality audio..."
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Most digital TV stations use 256kbps MP2 compression. Some use 192kbps or even as low as 128kbps, but I've never seen any TV (or radio) stations broadcasting MP2 audio greater than 256kbps.
Some TV stations have (sometimes in addition to MP2), a higher bitrate (e.g. 448kbps) AC-3 stream.
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