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Digital TV Channel Inquiry - The 19.38 MBit/S Capacity Standard - Page 2

post #31 of 37

Think we're talking apples and oranges. Your situation is where distribution to cable cos is H264 but distribution to subscribers is still MPEG2. However AIUI some CableCos are now sending H264 directly to subscribers for them to decode. Not widespread - but it has popped up in HTPC threads (as some GPUs are struggling with them)

My point was that a consumer set top box decoding H264 content that it receives will not transcode H264 to MPEG2, it will decode it to baseband video.
post #32 of 37
Quote:
Originally Posted by olyteddy View Post

A lot of it can be done through FirmWare upgrades. Just like installing a new codec in Windows.

Most consumer set top boxes use hardware SoCs with integrated video decoding implemented in hardware not software. The CPUs in most SoCs are quite low power - as they don't have to handle video processing.

If the SoC supports H264 in hardware and only the software/firmware doesn't enable it then a firmware/software upgrade could add H264 compatibility. However older SoCs are likely to only have MPEG2 hardware decoding integrated into them - so a software/firmware update won't be able to enable H264 as there is no hardware to enable.

Set top boxes are quite different from PCs in the way they handle video decoding.
post #33 of 37
Quote:
Originally Posted by BCF68 View Post

Well maybe but my cable company still hands out STBs that are nearly a decade old. Some don't even have HDMI.

I had a cable guy tell me that they had so many older STB"s..that were still capitalized and the bean counters would not allow them to dispose or upgrade yet as they still had "life" in them...
post #34 of 37
Quote:
Originally Posted by ybsane View Post

By the end of 2012 into 2013 it will be, almost every set top box sold to MSO's are H.264 equipped. Not sure where your information is from but it is not very up to date. The H.264 to MPEG-2 conversion is way out in left field.

Maybe every box sold by then will be capable of H.264 but the bulk of cable boxes in the wild will still not be H.264 capable. Many cable companies that are using H.264 for some of their content are only using it for specific channels or tiers. So they can limit the number of boxes they have to replace. It would cost too much to replace all of the old boxes in a short period of time. Eventually over many years they will be replaced, but not anytime soon.
post #35 of 37
Quote:
Originally Posted by aaronwt View Post

Maybe every box sold by then will be capable of H.264 but the bulk of cable boxes in the wild will still not be H.264 capable. Many cable companies that are using H.264 for some of their content are only using it for specific channels or tiers. So they can limit the number of boxes they have to replace. It would cost too much to replace all of the old boxes in a short period of time. Eventually over many years they will be replaced, but not anytime soon.

Yep - makes sense for premium and specific tiers to switch first, and basic channels to switch last.
post #36 of 37
Re. Your original question re OTA in US.
H.264 (ATSC Spec A/72) has been adopted for use with Mobile DTV (ATSC A/153 spec) enhancement to current ATSC:
http://en.wikipedia.org/wiki/Advanced_Television_Systems_Committee_standards
http://en.wikipedia.org/wiki/ATSC-M/H

ATSC was chosen for use in the US after extensive testing against the European candidate (COFDM) for four primary
reasons: 1) more robust for the same received SNR, 2) much higher resistance to impulse noise, 3) lower transmitter
power for the same reception quality and 4) Patents were owned by Zenith, a US Company,...USA, USA, USA!!!!
[Soon afterwards, Zenith sold Patent Rights to Korea for a healthy profit.....]

The current DVB-T and newer DVB-T2 systems may have reduced these differences with improved decoder chips, but
then ATSC decoder chips have undergone dramatic improvement over the past several years as well. I have NOT seen
any side-by-side comparisons of ALL of the current systems ATSC, ATSC-M/H, DVB-T, DVB-T2, DVB-H, Japan's ISDB-T
and China's ADTB-T, although there are some old tests of ATSC vs DVB-T vs ISDB-T....using antique decoder chips.
The wiki article reports that DVB-T may have better multipath handling capability than ATSC....but I have NOT seen any
tests using modern decoder chips with dramatically improved multipath performance, so take it with a grain of salt.

Work continues on ATSC 2.0, the proposed Next Generation ATSC improvement in broadcast capability:
http://www.atsc.org/cms/pdf/bootcamp/ATSC_2.pdf
It will include delivery of NRT (Non-Real Time) data and video programs, per ATSC spec A/103:
http://www.atsc.org/cms/index.php/standards/published-standards/296-a1032012-non-real-time-content-delivery
[Includes MPEG2 and H.264 (MPEG4), but none of the NEW proposed video codecs.]

Check out the fol. studies, esp the Planning Team 2 Report on Next Generation Broadcast TV:
http://www.atsc.org/cms/index.php/standards/other-technical-documents/262-planning-team-reports
After a Candidate Standard(s) is released to industry for comment, changes voted on and then incorporated, we won't
really know what is REAL and what won't make the cut. So we are still waiting to see an almost final ATSC 2.0 spec,
which is promised some time later THIS YEAR. [Maybe they'll even permit reception of ATSC and DVB-T/T2....maybe]
Edited by holl_ands - 8/20/12 at 12:19pm
post #37 of 37
Obviously, the data rate that can be carried in a given bandwidth increases linearly with the permitted bandwidth.
Hence 8 MHz in Europe has the inherent capability to carry 33.3% higher data rate than 6 MHz in US. [BTW: Italy is 7 MHz.]

After that, there is a trade-off of robustness vs data rate capability. ATSC-M/H uses transmission redundancy to provide
very robust performance (needed for tiny hand-held negative Gain antennas at ground level) at the expense of data rate.
DBT-T/T2 has a much wider selection of waveforms and resultant data rates, so the broadcaster can tailor the
transmission to the perceived situation. Urban areas might be better served with reduced range but higher data rates,
whereas in the US, most broadcasters are trying to expand their coverage areas. On the other hand, Cable systems
don't have to provide protection against signal fading and hence can use waveforms with less error correction and higher
data rates (e.g. 38 Mbps in each 6 MHz channel using QAM-256 instead of 8VSB or 16VSB cable-only mode).
Edited by holl_ands - 8/20/12 at 12:31pm
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