Mailing List Archive

On Mon, Sep 27, 2021 at 11:29 AM Klaas de Waal <klaas.de.waal@gmail.com>
wrote:

> Hi,
>
> I have been experimenting a bit with the ExternalRecorder of MythTV
> together with the mythhdhrrecorder "MythTV External Recorder for the
> SiliconDust HDHR tuners" of Gary Buhrmaster. This combination makes it
> possible to record from the HDHomeRun using the HTTP interface.
> The HTTP interface is what is recommended to use by SiliconDust and it is
> the only interface with which ATSC-3.0 channels can be received.
> For DVB I have now fixed the channel scan; this means that mythtv-setup
> can, via the mythhdhrrecorder, import the channel list of the HDHomeRun.
> Which is far more convenient than manually entering the HDHomeRun channel
> list with mythtv-setup.
> It would be great if this would work not only for DVB but also for ATSC.
> However, I do expect that the channel list for ATSC does have a different
> format than the channel list for DVB.
>
> So the question is: can somebody with an ATSC HDHomeRun please capture the
> lineup (the result of http:<ip_address>/lineup.json) and post that here?
>
> Thanks,
> Klaas.
>

Hi Klaas,

I am attaching the requested data.

I recently acquired a SiliconDust Flex which allows me to pull in ATSC 3.0.
I only have one set of stations broadcasting in HEVC and they are currently
just doing 1080p and stereo. I am hopeful they will start broadcasting some
4k content as well as atmos surround sound soon.

Gary has written a tool which allows the channel table to be populated from
SchedulesDirect data instead of doing a channel scan, but this is only
viable if the user is using SchedulesDirect. I assume you are not, but you
still might find these tools interesting:
https://github.com/garybuhrmaster/MythUtil

John

On 9/27/21 1:28 PM, Klaas de Waal wrote:
> I have been experimenting a bit with the ExternalRecorder of MythTV
> together with the mythhdhrrecorder "MythTV External Recorder for the
> SiliconDust HDHR tuners" of Gary Buhrmaster. This combination makes it
> possible to record from the HDHomeRun using the HTTP interface.
> The HTTP interface is what is recommended to use by SiliconDust and it
> is the only interface with which ATSC-3.0 channels can be received.

As I understand it, mythhdhrrecorder does not currently support
multirec. However, you should be able to get the entire (non ATSC 3)
stream with
https://info.hdhomerun.com/info/http_api#channel_frequency_instead_of_vchannel
<https://info.hdhomerun.com/info/http_api#channel_frequency_instead_of_vchannel>

Although it doesn’t mention it there, I think you can also use /ch<N>
e.g. /ch13 for RF channel 13, assuming the channelmap is set.

> For DVB I have now fixed the channel scan; this means that
> mythtv-setup can, via the mythhdhrrecorder, import the channel list of
> the HDHomeRun. Which is far more convenient than manually entering the
> HDHomeRun channel list with mythtv-setup.
> It would be great if this would work not only for DVB but also for
> ATSC. However, I do expect that the channel list for ATSC does have a
> different format than the channel list for DVB.
>
> So the question is: can somebody with an ATSC HDHomeRun please capture
> the lineup (the result of http:<ip_address>/lineup.json) and post that
> here?

See attached (HDHR4-2US).

I was thinking about changing the HDHomeRun code so you don’t have to
duplicate a capture card per tuner, but I’m working on other things
first so I haven't investigated it yet.

On Mon, 2021-09-27 at 11:40 -0600, John P Poet wrote:
> On Mon, Sep 27, 2021 at 11:29 AM Klaas de Waal
> <klaas.de.waal@gmail.com> wrote:
> > Hi,
> >
> > I have been experimenting a bit with the ExternalRecorder of MythTV
> > together with the mythhdhrrecorder "MythTV External Recorder for
> > the SiliconDust HDHR tuners" of Gary Buhrmaster. This combination
> > makes it possible to record from the HDHomeRun using the HTTP
> > interface.
> > The HTTP interface is what is recommended to use by SiliconDust and
> > it is the only interface with which ATSC-3.0 channels can be
> > received.
> > For DVB I have now fixed the channel scan; this means that mythtv-
> > setup can, via the mythhdhrrecorder, import the channel list of the
> > HDHomeRun. Which is far more convenient than manually entering the
> > HDHomeRun channel list with mythtv-setup.
> > It would be great if this would work not only for DVB but also for
> > ATSC. However, I do expect that the channel list for ATSC does have
> > a different format than the channel list for DVB.
> >
> > So the question is: can somebody with an ATSC HDHomeRun please
> > capture the lineup (the result of http:<ip_address>/lineup.json)
> > and post that here?
> >
> > Thanks,
> > Klaas.
> >
>
>
> Hi Klaas,
>
> I am attaching the requested data.
>
> I recently acquired a SiliconDust Flex which allows me to pull in
> ATSC 3.0. I only have one set of stations broadcasting in HEVC and
> they are currently just doing 1080p and stereo. I am hopeful they
> will start broadcasting some 4k content as well as atmos surround
> sound soon.
>
> Gary has written a tool which allows the channel table to be
> populated from SchedulesDirect data instead of doing a channel scan,
> but this is only viable if the user is using SchedulesDirect. I
> assume you are not, but you still might find these tools interesting:
> https://github.com/garybuhrmaster/MythUtil
>
> John

Hi Klaas,

Here's another sample lineup from a HDHR5-4K Connect 4K.

David

On 9/27/21 1:55 PM, Scott T wrote:
> Although it doesn’t mention it there, I think you can also use /ch<N>
> e.g. /ch13 for RF channel 13, assuming the channelmap is set.
Mentioned here:
https://info.hdhomerun.com/info/troubleshooting:creating_a_sample#save_unfiltered_physical_channel1
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On 9/27/2021 10:57 AM, Scott T wrote:
> On 9/27/21 1:55 PM, Scott T wrote:
>> Although it doesn’t mention it there, I think you can also use /ch<N>
>> e.g. /ch13 for RF channel 13, assuming the channelmap is set.
> Mentioned here:
> https://info.hdhomerun.com/info/troubleshooting:creating_a_sample#save_unfiltered_physical_channel1
>
Full mux is useful for obtaining a capture on one tuner however
generally shouldn't be used for an end user application like mythtv
where all tuners may be used at once and bandwidth could be much higher
than 8VSB. For CableCARD and ATSC 3.0 full mux isn't an option as the
HDHomeRun has to be involved in the tuning/filtering process.

Happy to help with any protocol questions.

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Please don't break the Connect DUO devices (2 tuners for standard ATSC)
when duplicating capture cards. I like your idea just be sure it works
with these older tuners. I don't think the have the HTTP interface. I
can test "Connect DUO" for you on version 31 if needed. I run gentoo and
maintain the mythtv ebuild.

By the way, does anyone know when version 32 will be released? I use
mythtv many hours a day and am reluctant to change the database schema
to version 32 until it is stable.

On 9/27/21 12:55 PM, Scott T wrote:
> I was thinking about changing the HDHomeRun code so you don’t have to
> duplicate a capture card per tuner, but I’m working on other things
> first so I haven't investigated it yet.

On Mon, 2021-09-27 at 14:15 -0500, The Bit Pit wrote:
>  Please don't break the Connect DUO devices (2 tuners for standard
> ATSC) when duplicating capture cards. I like your idea just be sure
> it
> works with these older tuners. I don't think the have the HTTP
> interface. I can test "Connect DUO" for you on version 31 if needed.
> I
> run gentoo and maintain the mythtv ebuild.
>  
>  By the way, does anyone know when version 32 will be released? I use
> mythtv many hours a day and am reluctant to change the database
> schema to version 32 until it is stable.

Next February? Definitely in time for the next LTS build of Ubuntu in
April, since that's basically our release schedule.

David


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On 9/27/21 3:15 PM, The Bit Pit wrote:
> Please don't break the Connect DUO devices (2 tuners for standard
> ATSC) when duplicating capture cards. I like your idea just be sure it
> works with these older tuners.
I have an HDHR4-2US with Firmware Version: 20161117, so I don't want to
break them either.
> I don't think they have the HTTP interface.
They do, I just checked using VLC.

To clarify a little about what I was thinking:

Create a new tuner type using the hdhomerun HTTP API
using the libhdhomerun api:
In setup this tuner should query the network and display a list of
devices if found greater than 1.
For the selected device:
get /sys/hwmodel
HDHR4-2US
get /sys/features
channelmap: us-bcast us-cable us-hrc us-irc kr-bcast kr-cable
modulation: 8vsb qam256 qam64
auto-modulation: auto auto6t auto6c qam

features should be able to be inferred from hwmodel, as should tuner count.
My main idea was to add a max tuners variable to the capture card with a
range of [1, tuner count], so instead of duplicating the same settings
for multiple MythTV capture cards, you only have to configure once with
one capture card.

That new behavior should be orthogonal to using the HTTP API, but it
might as well be added at the same time.

Support for the ATSC 3.0 tuners requires some additional thought.
However, by checking for hwmodel == “HDHR5-4K”, it should be possible
(as a first pass) to have the mixed tuners (0 and 1) on one capture card
and ATSC 1 only tuners (2 and 3) on a separate capture card. Ideally, it
would only be one capture card, but that requires more investigation. 
(You don't want to use tuner 0 or 1 for ATSC 1 if there are other ATSC 1
tuners available when using those tuners would conflict with getting an
ATSC 3.0 recording.)

I’ll add some more comments on ATSC 3 support on the forum.

Regards,
Scott

Another data point. I have 3 hdhr tuners:
The original HDHR-US, an HDHR3-US , and an HDHR4-2US.

FWIW, Silicondust released firmware for the HDHR-US and the HDHR3-US on
Feb 25 2020 and you can still find those firmwares on their web site. So
they're getting some support from Silicondust. I'm not using the 1st gen
tuner at the moment because it's not behaving very well with OTA 8VSB,
but I think it was working well with clear QAM cable before I moved and
cut the cord this summer. But both 3rd and 4th gen tuners are working
well with OTA 8VSB. So another vote to support the old tuners.

On 9/27/2021 4:11 PM, Scott T wrote:
> On 9/27/21 3:15 PM, The Bit Pit wrote:
>> Please don't break the Connect DUO devices (2 tuners for standard
>> ATSC) when duplicating capture cards. I like your idea just be sure
>> it works with these older tuners.
> I have an HDHR4-2US with Firmware Version: 20161117, so I don't want
> to break them either.
>> I don't think they have the HTTP interface.
> They do, I just checked using VLC.
>
> To clarify a little about what I was thinking:
>
> Create a new tuner type using the hdhomerun HTTP API
> using the libhdhomerun api:
> In setup this tuner should query the network and display a list of
> devices if found greater than 1.
> For the selected device:
> get /sys/hwmodel
> HDHR4-2US
> get /sys/features
> channelmap: us-bcast us-cable us-hrc us-irc kr-bcast kr-cable
> modulation: 8vsb qam256 qam64
> auto-modulation: auto auto6t auto6c qam
>
> features should be able to be inferred from hwmodel, as should tuner
> count.
> My main idea was to add a max tuners variable to the capture card with
> a range of [1, tuner count], so instead of duplicating the same
> settings for multiple MythTV capture cards, you only have to configure
> once with one capture card.
>
> That new behavior should be orthogonal to using the HTTP API, but it
> might as well be added at the same time.
>
> Support for the ATSC 3.0 tuners requires some additional thought.
> However, by checking for hwmodel == “HDHR5-4K”, it should be possible
> (as a first pass) to have the mixed tuners (0 and 1) on one capture
> card and ATSC 1 only tuners (2 and 3) on a separate capture card.
> Ideally, it would only be one capture card, but that requires more
> investigation.  (You don't want to use tuner 0 or 1 for ATSC 1 if
> there are other ATSC 1 tuners available when using those tuners would
> conflict with getting an ATSC 3.0 recording.)
>
> I’ll add some more comments on ATSC 3 support on the forum.
>
> Regards,
> Scott
>
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev@mythtv.org
> http://lists.mythtv.org/mailman/listinfo/mythtv-dev
> http://wiki.mythtv.org/Mailing_List_etiquette
> MythTV Forums: https://forum.mythtv.org

On 9/27/21 2:07 PM, Nick Kelsey wrote:
> Full mux is useful for obtaining a capture on one tuner however
> generally shouldn't be used for an end user application like mythtv
> where all tuners may be used at once and bandwidth could be much
> higher than 8VSB. For CableCARD and ATSC 3.0 full mux isn't an option
> as the HDHomeRun has to be involved in the tuning/filtering process.
>
> Happy to help with any protocol questions.

Could you clarify what devices, if not all, support the HTTP API?

When using the HTTP API, if there are multiple digital subchannels on
one RF channel, would tuning to two different subchannels use one
tuner?  e.g.

/auto/v26.1
/auto/v26.2

Or would you have to specify the tuner (for the second or both)? I know
this may require two tuners for some ATSC 3.0 broadcasts.

I know the full mux is not possible when:

* decrypting with a CableCARD (only one stream can be decrypted per tuner)
* using the hardware transcoder of the "Extend" models (can only
process one stream per tuner)
* ATSC 3.0 (because the differing modulations of the Physical Layer
Pipes are not necessarily all mutually compatible simultaneously on
one tuner)

The total data rate is not of concern for ATSC 1 (8VSB) broadcasts
(19.39 × 4 < 100), but may be for other quad tuners (RF channels wider
than the US's 6 MHz, other modulation types) or ATSC 3.0 (theoretically
a max 6 MHz channel capacity of 57 Mbps, but it remains to be seen what
broadcasters actually use).

Thanks,

Scott