Re: how to turn my computer into a TV
On Fri, Jun 22, 2012 at 10:13 AM, Dieter BSD wrote: >>> The cx88wiki URL above describes the cx88 software (in ports). >>> For tuners without a hardware encoder, raw video/audio is the only >>> thing you can get from the tuner when receiving NTSC. >> >> Nope. > > Prove me wrong. Post the command line to have cx88 (in ports) output > encoded (mpeg or similar) video with a pcHDTV HD3000 tuner card > receiving a NTSC input. Please see my comment following the bit you quoted. Cheers ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
Re: how to turn my computer into a TV
On Fri, Jun 22, 2012 at 8:27 AM, Dieter BSD wrote: >> Yes, technically there are still some that exist, for now. However, >> their death certificate is signed and they're so few that it's not >> worth mentioning. > > If you don't think NTSC is worth mentioning, why do you keep posting > the same incorrect statements over and over again? Your disagree that NTSC is out, soon including the very few exceptions that remain? You disagree that NTSC is not worth mentioning at this point? Well, to be fair, one of those is fact but the other is opinion, which everyone is welcome to -- differing or not. > NTSC is not a stream of bits. NTSC is analog. The tuner converts > the NTSC analog waveform into a raw stream of bits. This raw > stream of bits is too large to conviently store on disk, so it > needs to be compressed/encoded into mpeg or similar. Some > tuners include a hardware encoder, but many do not. Nope. > The cx88wiki URL above describes the cx88 software (in ports). > For tuners without a hardware encoder, raw video/audio is the only > thing you can get from the tuner when receiving NTSC. Nope. It seems you want to talk about things more along the lines of what's technically in the realm of possibility while I prefer sticking to real world scenario & application. Which, leaves us at an impasseI guess. Cheers ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
Re: (no subject)
On Thu, Jun 21, 2012 at 1:29 PM, Dieter BSD wrote: >> With very very very few exceptions, all analog NTSC broadcasts have >> been switched to digital, by the FCC mandated deadline of June 12, >> 2009. > > As long as there remain some NTSC broadcasts, there might be some > that you wish to watch. That's why I wrote: Yes, technically there are still some that exist, for now. However, their death certificate is signed and they're so few that it's not worth mentioning. >> You absolutely do NOT have to reencode a stream > > I did not say anything about RE-encoding anything. Only about > encoding/compressing the high bandwidth datastream the tuner > generates from NTSC. And to be clear, this only applies to > NTSC, not to ATSC. NTSC streams are not broadcast raw. What do you call encoding data that's already encoded if you don't think it's reencoding? Also, doing so causes degredation so unless there's a need for the user to do so, he's better off not wasting his time. >> Tuners do NOT provide raw audio/video to the system in any case. > > http://corona.homeunix.net/cx88wiki/Overview/RawVideo While that's technically possible in _some_ cases, and assuming it's fully implemented and functional, I'm unaware of any software that actually provides raw data to the user. I suppose I should have worded my point differently. ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
Re: how to turn my computer into a TV
On Mon, Jun 18, 2012 at 11:56 PM, Wojciech Puchar wrote: >> >> An old Pentium 4 3ghz can decode HD with plenty of cpu resources to >> spare so unless a person using something older than that, they've >> certainly got "modern" cpu power. > > actually even intel atom D525 is OK if decoder can be multithreaded. I have a few Atom systems but they all use vdpau for decoding and I never bothered to see how just the Atom holds up on it's own for decoding. :) ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
Re: how to turn my computer into a TV
On Mon, Jun 18, 2012 at 10:21 AM, Dieter BSD wrote: > user.vdr writes: >> Recording doesn't require any compression unless you are transcoding >> in real-time. There's no difference between recording ATSC, NTSC, PAL, >> etc, and it's actually irrelevant what the stream is. > > This is incorrect. ATSC is compressed before broadcast, so > you receive the data already compresed. NTSC and PAL are > broadcast in analog. The tuner performs A-to-D which gives > an uncompressed data stream. Have fun trying to store that. > As a practical matter, you have to compress the data in real time. > Some, not all, tuners include hardware compression. All consumer digital broadcasts are compressed typically with mpeg2 or mpeg4. With very very very few exceptions, all analog NTSC broadcasts have been switched to digital, by the FCC mandated deadline of June 12, 2009. Tuners perform demodulation, not decompression. There are a few "premium" or "full-featured" devices which have an on-board decoder such as a Hauppauge Nexus-s or the TechnoTrend S2-6400. You absolutely do NOT have to reencode a stream unless you want to alter the resolution, bitrate, or compression method. Tuners do NOT provide raw audio/video to the system in any case. >> Lastly, it's possible to save a single channel or the entire stream >> which usually contains several channels. Even when saving the full >> stream, it likely uses far less bandwidth than your media offers so >> there's no problem there. > > This appariently refers to ATSC. Yes, modern disks have plenty > of bandwidth to store the entire ATSC stream. The main reason > to filter PIDs is to save disk *space*. Also, some software > can't select which program to decode. It refers to ANY multiplex. Again, the standard used for broadcast is irrelevant. Also, any program that can tune a channel has the ability to filter the pids, otherwise it would be impossible to tune a channel. > Wojciech writes: >> most people vastly underestimate power of modern CPUs. > > Many people overestimate the "moderness" of most people's CPUs. An old Pentium 4 3ghz can decode HD with plenty of cpu resources to spare so unless a person using something older than that, they've certainly got "modern" cpu power. ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
Re: how to turn my computer into a TV
On Sun, Jun 17, 2012 at 6:31 PM, Dieter BSD wrote:
> [ Added multimedia@ as that is a more appropriate list than hackers ]
>
>> I just moved into a very cramped apartment
>> we are using a broadcast signal only [current US {NYC} standards]
>
> Recording ATSC takes very little CPU. Recording NTSC takes either
> a lot of CPU or hardware compression. Decoding either takes a lot of CPU
> (or hardware decoding which AFAIK FreeBSD doesn't have). You can use
> at(1) for automated recordings. A full ATSC channel is 19.3 Mbps.
> Some tuners allow filtering by PID, which saves disk space.
Recording doesn't require any compression unless you are transcoding
in real-time. There's no difference between recording ATSC, NTSC, PAL,
etc, and it's actually irrelevant what the stream is. The broadcast
streams are digital so when you "record" them, you are actually just
saving the stream to some type of media (usually a harddrive). It's
like saving a file where the file contents is audio/video, and it
takes however long your show/timer/etc is. The only impact on the cpu
is the same impact you have when you save any big file -- very little
on any modern cpu.
Lastly, it's possible to save a single channel or the entire stream
which usually contains several channels. Even when saving the full
stream, it likely uses far less bandwidth than your media offers so
there's no problem there.
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