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View Full Version : Thinking of the future: Better compression for HDTV H.264


jnet
06-20-2006, 11:57 AM
I searched the forums and found that this has not been a highly discussed topic, probably because the developments concerning it are fairly recent.

When will BeyondTV consider moving from transport stream mpeg2 for HD to the newer H.264 encoding? I saw one thread in the forum about it posted a year ago, and back then the current hardware couldn't support it.

However, dual core processors are here, and if you can decode H264 realtime (just try to play an Apple Quicktime HD trailer) then it can be encoded realtime.

There are several encoders available that the BeyondTV developers could implement, either through paying or using the open source x264 implementation. Please see the wikipedia for more info: http://en.wikipedia.org/wiki/H264#Software_implementations

I just want to get this topic in the air, as currently 10GB for an hour of HDTV is becoming nonsense, when a whole movie in H264 could be recorded taking up only 4-8gb.

If there are other ideas already in play, please discuss them here, but otherwise I haven't seen any features in BTV yet that address HD compression.

nanook105
06-20-2006, 12:58 PM
You can convert HD recordings to divx

jnet
06-20-2006, 06:07 PM
You can convert HD recordings to divx

Realtime, in BeyondTV? Or are you saying post-processing with converters. If post-processing, thats not the point here, I could do that with H.264 as well, the point is that it'd be nice to have the source going straight to a newer format such as H264.

nanook105
06-20-2006, 06:11 PM
Realtime, in BeyondTV? Or are you saying post-processing with converters. If post-processing, thats not the point here, I could do that with H.264 as well, the point is that it'd be nice to have the source going straight to a newer format such as H264.

Divx conversion is post processing

Fonceur
06-20-2006, 06:21 PM
Typically you will need much more power to encode real time than for a simple decoding, so asking for a software solution might not be the best idea... So you would most likely want that to be handled in hardware, similar to the plextor capture card that can encode to DViX direclty or such... Or once the satellite providers move to H.264, have some Direct TV, Dish Network and such card save the H.264 part directly, similar to the current transport stream saved for OTA/Firewire...

not_Shorty
06-21-2006, 10:59 PM
BTV isn't encoding anything, it is just making a copy of the data that is being streamed. It doesn't *record* HDTV, it just saves the already-encoded data as it receives it. A straight file copy process. And as others have pointed out, encoding is much more heavy lifting than decoding is. The fact that you can decode H.264 data fast enough to play it back properly doesn't mean you have the horsepower to encode it in real-time.

cmcquistion
06-24-2006, 09:26 AM
For what its worth, BTV now has Streamsnip, which can cut the filesize of an hour long HDTV program down to 2-6 GB, typically. This is already built-in, happens as a fairly quick post-processing job, and doesn't change the encoding or decoding process.

Ninety-9 SE-L
06-25-2006, 02:49 AM
I've been working a bit with H.264 lately, I do love the quality, but I know first hand, the H.264 algorithm is very processor intense. It takes quite a bit of power to decode let alone encode. I encoded an MPEG2 file to H.264 on a 3.2GHz P4. A 34min show took about 28min with no other processes running. My laptop cannot decode H.264 without being choppy, so forget using a cheap media extender for BTV link.

I'm quite curious, though. If you have a DivX or H.264 HARDWARE encoder, would BTV be able to view and record that format in real time? I assume it's a dumb question, but I've never tried it.

not_Shorty
06-25-2006, 04:27 AM
hardware encoders, by definition, use no CPU time. Otherwise it would be a software encoder. So, recording and playback at the same time is a no-brainer.

chinna_n
06-22-2007, 03:13 PM
Well, it may not be possible do realtime encoding on many PCs, but then atleast support post processing and playback in H264/x264 format. Worst is BTV can not even playback x264 encoded files. I was comparing X264 vs Divx encoded at same bit rate, x264 is several times better in qualitywise.

As we all know there are open source x264 encoders/decoders, why can't Snapstream just make a plugin available atleast people interested in doing so can do it.

I wonder if anyone at snapstream see these messages, and if they see do they really care about customer interests!!?

rxnelson
06-26-2007, 08:16 PM
+1 for h264 playback.

Nortafett
06-27-2007, 02:11 PM
Dishnet is moving to MPEG 4 in aug 2007....not sure what effect that would have.

acegolfer
07-05-2007, 06:15 AM
AFAIK, there is no x264 real-time encoder for HD quality video. There is a development for 800 by 600, which is not HD.