RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Patrick Boettcher]

Hi all,

I'd like to request some comments about the extension of the DVB-API 5 
to support ISDB-T and ISDB-Tsb. Some stubs in frontend.h and friends have 
been there since the beginning and now it's time to have real user-space 
support for that standard.

I hope that we can finish the discussion of this RFC before the merge 
window of 2.6.32, so that it can be included then.

The current version of the patches can be found here:

http://linuxtv.org/hg/~pb/v4l-dvb/rev/eabb8cfcf32a

Changelog:
This patch increments the DVB-API to version 5.1 in order to reflect the 
addition of ISDB-T and ISDB-Tsb on Linux' DVB-API.

Changes in detail:
- added a small document to describe how to use the API to tune to an ISDB-T or ISDB-Tsb channel
- added necessary fields to dtv_frontend_cache
- added a smarter clear-cache function which resets all fields of the dtv_frontend_cache
- added a TRANSMISSION_MODE_4K to fe_transmit_mode_t

I also added a document trying to descibe in short all the needed 
parameters (DTV_CMDs) for ISDB-T(sb) and how to use them. I'm inlining 
this document, as it is the base for the RFC as well:

(Disclaimer: ISDB-T and ISDB-Tsb is relative complex from the parameters 
point of view compared to DVB-T and for me the standard-document was not 
making things very easy for me as a software-writer. Please don't blame me 
for so many additions)

-----------------
This document describes shortly what are the possible parameters in
the Linux DVB-API called "S2API" in order to tune an ISDB-T/ISDB-Tsb
demodulator:

This ISDB-T/ISDB-Tsb API extension should reflect all information
needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible
that some very sophisticated devices won't need certain parameters to
tune.

The information given here should help application writers to know how
to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.

The details given here about ISDB-T and ISDB-Tsb are just enough to basically
show the dependencies between the needed parameter values, but surely some
information is left out. For more detailed information see the standard document:
ARIB STD-B31 - "Transmission System for Digital Terrestrial Television
Broadcasting".

In order to read this document one has to know about the channel
structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to the
reader that an ISDB-T channel consists of 13 segments, that it can
have up to 3 layer sharing those segments, and so on.

Parameters used by ISDB-T and ISDB-Tsb.

Existing parameters
===================

a) DTV_BANDCOUNT_HZ

Help the front-end, for example, to set up base-band-filters.

Possible values:

For ISDB-T it should be always 6000000Hz (6MHz)
For ISDB-Tsb it can vary depending on the number of connected segments

b) DTV_DELIVERY_SYSTEM

Possible values: SYS_ISDBT

c) DTV_TRANSMISSION_MODE

ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K

Possible values: TRANSMISSION_MODE_2K, TRANSMISSION_MODE_8K,
 	 TRANSMISSION_MODE_AUTO, TRANSMISSION_MODE_4K

If DTV_TRANSMISSION_MODE is set the TRANSMISSION_MODE_AUTO the
hardware will try to find the correct FFT-size (if capable) and use
the TMCC to fill in the missing parameters.

TRANSMISSION_MODE_4K is added at the same time as the other new parameters.

d) DTV_GUARD_INTERVAL

Possible values: GUARD_INTERVAL_1_32, GUARD_INTERVAL_1_16, GUARD_INTERVAL_1_8,
 	 GUARD_INTERVAL_1_4, GUARD_INTERVAL_AUTO

If DTV_GUARD_INTERVAL is set the GUARD_INTERVAL_AUTO the hardware will
try to find the correct guard interval (if capable) and use the TMCC to fill
in the missing parameters.

New parameters
==============

1. DTV_ISDBT_PARTIAL_RECEPTION (1b)

If DTV_ISDBT_SOUND_BROADCASTING is '0' this bit-field represents whether
the channel is in partial reception mode or not.

If '1' DTV_ISDBT_LAYERA_* values are assigned to the center segment and
DTV_ISDBT_LAYERA_SEGMENT_COUNT has to be '1'.

If in addition DTV_ISDBT_SOUND_BROADCASTING is '1'
DTV_ISDBT_PARTIAL_RECEPTION represents whether this ISDB-Tsb channel
is consisting of one segment and layer or three segments and two layers.

Possible values: 0, 1, -1 (AUTO)

2. DTV_ISDBT_SOUND_BROADCASTING (1b)

This field represents whether the other DTV_ISDBT_*-parameters are
referring to an ISDB-T and an ISDB-Tsb channel. (See also
DTV_ISDBT_PARTIAL_RECEPTION).

Possible values: 0, 1, -1 (AUTO)

3. DTV_ISDBT_SB_SUBCHANNEL_ID

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

(Note of the author: This might not be the correct description of the
  SUBCHANNEL-ID in all details, but it is my understanding of the technical
  background needed to program a device)

An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
set of connected ISDB-Tsb channels. In this set of channels every
channel can be received independently. The number of connected
ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum
bandwidth available.

Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
broadcaster has several possibilities to put those channels in the
air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8
segments from position 1-8 to 5-13 or anything in between.

The underlying layer of segments are subchannels: each segment is
consisting of several subchannels with a predefined IDs. A sub-channel
is used to help the demodulator to synchronize on the channel.

An ISDB-T channel is always centered over all sub-channels. As for
the example above, in ISDB-Tsb it is no longer as simple as that.

The DTV_ISDBT_SB_SUBCHANNEL_ID parameter is used to give the
sub-channel ID of the segment to be demodulated.

Possible values: 0 .. 41, -1 (AUTO)

4. DTV_ISDBT_SB_SEGMENT_IDX

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_IDX gives the index of the segment to be
demodulated for an ISDB-Tsb channel where several of them are
transmitted in the connected manner.

Possible values: 0 .. DTV_ISDBT_SB_SEGMENT_COUNT-1

Note: This value cannot be determined by an automatic channel search.

5. DTV_ISDBT_SB_SEGMENT_COUNT

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_COUNT gives the total count of connected ISDB-Tsb
channels.

Possible values: 1 .. 13

Note: This value cannot be determined by an automatic channel search.

6. Hierarchical layers

ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
ISDB-T hierarchical layers can be decoded simultaneously. For that
reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.

ISDB-T has 3 hierarchical layers which each can use a part of the
available segments. The total number of segments over all layers has
to 13 in ISDB-T.

6.1 DTV_ISDBT_LAYER_ENABLED (3b)

Hierarchical reception in ISDB-T is achieved by enabling or disabling
layers in the decoding process. Setting all bits of
DTV_ISDBT_LAYER_ENABLED to '1' forces all layers (if applicable) to be
demodulated. This is the default.

If the channel is in the partial reception mode
(DTV_ISDBT_PARTIAL_RECEPTION=1) the central segment can be decoded
independently of the other 12 segments. In that mode layer A has to
have a SEGMENT_COUNT of 1.

In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb
according to DTV_ISDBT_PARTIAL_RECEPTION. SEGMENT_COUNT must be filled
accordingly.

Possible values: 0x1, 0x2, 0x4 (|-able)

DTV_ISDBT_LAYER_ENABLED[0:0] - layer A
DTV_ISDBT_LAYER_ENABLED[1:1] - layer B
DTV_ISDBT_LAYER_ENABLED[2:2] - layer C
DTV_ISDBT_LAYER_ENABLED[31:3] unused

6.2 DTV_ISDBT_LAYER*_FEC

Possible values: FEC_AUTO, FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8,

6.3 DTV_ISDBT_LAYER*_MODULATION

Possible values: QAM_AUTO, DQPSK, QAM_16, QAM_64, DQPSK

Note: If layer C is DQPSK layer B has to be DQPSK. If layer B is DQPSK
and DTV_ISDBT_PARTIAL_RECEPTION=0 layer has to be DQPSK.

6.4 DTV_ISDBT_LAYER*_SEGMENT_COUNT

Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)

Note: Truth table for DTV_ISDBT_SOUND_BROADCASTING and
DTV_ISDBT_PARTIAL_RECEPTION and LAYER*_SEGMENT_COUNT

  PR | SB || layer A width | layer B width | layer C width | total
----+----++---------------+---------------+---------------+-------
   0 |  0 || 1 .. 13       | 1 .. 13       | 1..13         | 13
   1 |  0 || 1             | 1 .. 13       | 1..13         | 13
   0 |  1 || 1             | 0             | 0             | 1
   1 |  1 || 1             | 2             | 0             | 3


6.5 DTV_ISDBT_LAYER*_TIME_INTERLEAVING

Possible values: 0, 1, 2, 3, -1 (AUTO)

Note: The real inter-leaver depth-names depend on the mode (fft-size); the values
here are referring to what can be found in the TMCC-structure -
independent of the mode.

-----------------


thanks for the feedback in advance,
Patrick.

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Patrick Boettcher]

Hi again,

I updated some things in the document, please use the following for your 
comments:

Version 1.2 - 2009-08-04
========================

Changelog
=========

v1.2 - 2009-08-04
- removed DTV_BANDWIDTH from being a necessary parameter - now optional

v1.1 - 2009-08-04
- added DTV_FREQUENCY as a necessary parameter

v1.0 - 2009-08-03
- initial draft

Proposal
========

This document describes shortly what are the possible parameters in the Linux
DVB-API called "S2API" and now DVB API 5 in order to tune an ISDB-T/ISDB-Tsb
demodulator:

This ISDB-T/ISDB-Tsb API extension should reflect all information
needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible
that some very sophisticated devices won't need certain parameters to
tune.

The information given here should help application writers to know how
to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.

The details given here about ISDB-T and ISDB-Tsb are just enough to basically
show the dependencies between the needed parameter values, but surely some
information is left out. For more detailed information see the standard document:
ARIB STD-B31 - "Transmission System for Digital Terrestrial Television
Broadcasting".

In order to read this document one has to know about the channel
structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to the
reader that an ISDB-T channel consists of 13 segments, that it can
have up to 3 layer sharing those segments, and so on.

Parameters used by ISDB-T and ISDB-Tsb.

Existing parameters
===================

a) DTV_FREQUENCY

Central frequency of the channel.

For ISDB-T the channels are usally transmitted with an offset of 143kHz. E.g. a
valid frequncy could be 474143 kHz. The stepping is bound to the bandwidth of
the channel which is 6MHz.

As in ISDB-Tsb the channel consists of only one or three segments the
frequency step is 429kHz, 3*429 respectively. As for ISDB-T the
central frequency of the channel is expected.

b) DTV_BANDWIDTH_HZ (optional)

Possible values:

For ISDB-T it should be always 6000000Hz (6MHz)
For ISDB-Tsb it can vary depending on the number of connected segments

Note: Hardware specific values might be given here, but standard
applications should not bother to set a value to this field as
standard demods are ignoring it anyway.

Bandwidth in ISDB-T is fixed (6MHz) or can be easily derived from
other parameters (DTV_ISDBT_SB_SEGMENT_IDX,
DTV_ISDBT_SB_SEGMENT_COUNT).

c) DTV_DELIVERY_SYSTEM

Possible values: SYS_ISDBT

d) DTV_TRANSMISSION_MODE

ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K

Possible values: TRANSMISSION_MODE_2K, TRANSMISSION_MODE_8K,
 	 TRANSMISSION_MODE_AUTO, TRANSMISSION_MODE_4K

If DTV_TRANSMISSION_MODE is set the TRANSMISSION_MODE_AUTO the
hardware will try to find the correct FFT-size (if capable) and will
use TMCC to fill in the missing parameters.

TRANSMISSION_MODE_4K is added at the same time as the other new parameters.

e) DTV_GUARD_INTERVAL

Possible values: GUARD_INTERVAL_1_32, GUARD_INTERVAL_1_16, GUARD_INTERVAL_1_8,
 	 GUARD_INTERVAL_1_4, GUARD_INTERVAL_AUTO

If DTV_GUARD_INTERVAL is set the GUARD_INTERVAL_AUTO the hardware will
try to find the correct guard interval (if capable) and will use TMCC to fill
in the missing parameters.

New parameters
==============

1. DTV_ISDBT_PARTIAL_RECEPTION (1b)

If DTV_ISDBT_SOUND_BROADCASTING is '0' this bit-field represents whether
the channel is in partial reception mode or not.

If '1' DTV_ISDBT_LAYERA_* values are assigned to the center segment and
DTV_ISDBT_LAYERA_SEGMENT_COUNT has to be '1'.

If in addition DTV_ISDBT_SOUND_BROADCASTING is '1'
DTV_ISDBT_PARTIAL_RECEPTION represents whether this ISDB-Tsb channel
is consisting of one segment and layer or three segments and two layers.

Possible values: 0, 1, -1 (AUTO)

2. DTV_ISDBT_SOUND_BROADCASTING (1b)

This field represents whether the other DTV_ISDBT_*-parameters are
referring to an ISDB-T and an ISDB-Tsb channel. (See also
DTV_ISDBT_PARTIAL_RECEPTION).

Possible values: 0, 1, -1 (AUTO)

3. DTV_ISDBT_SB_SUBCHANNEL_ID

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

(Note of the author: This might not be the correct description of the
  SUBCHANNEL-ID in all details, but it is my understanding of the technical
  background needed to program a device)

An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
set of connected ISDB-Tsb channels. In this set of channels every
channel can be received independently. The number of connected
ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum
bandwidth available.

Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
broadcaster has several possibilities to put those channels in the
air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8
segments from position 1-8 to 5-13 or anything in between.

The underlying layer of segments are subchannels: each segment is
consisting of several subchannels with a predefined IDs. A sub-channel
is used to help the demodulator to synchronize on the channel.

An ISDB-T channel is always centered over all sub-channels. As for
the example above, in ISDB-Tsb it is no longer as simple as that.

The DTV_ISDBT_SB_SUBCHANNEL_ID parameter is used to give the
sub-channel ID of the segment to be demodulated.

Possible values: 0 .. 41, -1 (AUTO)

4. DTV_ISDBT_SB_SEGMENT_IDX

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_IDX gives the index of the segment to be
demodulated for an ISDB-Tsb channel where several of them are
transmitted in the connected manner.

Possible values: 0 .. DTV_ISDBT_SB_SEGMENT_COUNT-1

Note: This value cannot be determined by an automatic channel search.

5. DTV_ISDBT_SB_SEGMENT_COUNT

This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.

DTV_ISDBT_SB_SEGMENT_COUNT gives the total count of connected ISDB-Tsb
channels.

Possible values: 1 .. 13

Note: This value cannot be determined by an automatic channel search.

6. Hierarchical layers

ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
ISDB-T hierarchical layers can be decoded simultaneously. For that
reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.

ISDB-T has 3 hierarchical layers which each can use a part of the
available segments. The total number of segments over all layers has
to 13 in ISDB-T.

6.1 DTV_ISDBT_LAYER_ENABLED (3b)

Hierarchical reception in ISDB-T is achieved by enabling or disabling
layers in the decoding process. Setting all bits of
DTV_ISDBT_LAYER_ENABLED to '1' forces all layers (if applicable) to be
demodulated. This is the default.

If the channel is in the partial reception mode
(DTV_ISDBT_PARTIAL_RECEPTION=1) the central segment can be decoded
independently of the other 12 segments. In that mode layer A has to
have a SEGMENT_COUNT of 1.

In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb
according to DTV_ISDBT_PARTIAL_RECEPTION. SEGMENT_COUNT must be filled
accordingly.

Possible values: 0x1, 0x2, 0x4 (|-able)

DTV_ISDBT_LAYER_ENABLED[0:0] - layer A
DTV_ISDBT_LAYER_ENABLED[1:1] - layer B
DTV_ISDBT_LAYER_ENABLED[2:2] - layer C
DTV_ISDBT_LAYER_ENABLED[31:3] unused

6.2 DTV_ISDBT_LAYER*_FEC

Possible values: FEC_AUTO, FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8,

6.3 DTV_ISDBT_LAYER*_MODULATION

Possible values: QAM_AUTO, QPSK, QAM_16, QAM_64, DQPSK

Note: If layer C is DQPSK layer B has to be DQPSK. If layer B is DQPSK
and DTV_ISDBT_PARTIAL_RECEPTION=0 layer has to be DQPSK.

6.4 DTV_ISDBT_LAYER*_SEGMENT_COUNT

Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)

Note: Truth table for DTV_ISDBT_SOUND_BROADCASTING and
DTV_ISDBT_PARTIAL_RECEPTION and LAYER*_SEGMENT_COUNT

  PR | SB || layer A width | layer B width | layer C width | total
----+----++---------------+---------------+---------------+-------
   0 |  0 || 1 .. 13       | 1 .. 13       | 1..13         | 13
   1 |  0 || 1             | 1 .. 13       | 1..13         | 13
   0 |  1 || 1             | 0             | 0             | 1
   1 |  1 || 1             | 2             | 0             | 3


6.5 DTV_ISDBT_LAYER*_TIME_INTERLEAVING

Possible values: 0, 1, 2, 3, -1 (AUTO)

Note: The real inter-leaver depth-names depend on the mode (fft-size); the values
here are referring to what can be found in the TMCC-structure -
independent of the mode.


On Mon, 3 Aug 2009, Patrick Boettcher wrote:

> Hi all,
>
> I'd like to request some comments about the extension of the DVB-API 5 to 
> support ISDB-T and ISDB-Tsb. Some stubs in frontend.h and friends have been 
> there since the beginning and now it's time to have real user-space support 
> for that standard.
>
> I hope that we can finish the discussion of this RFC before the merge window 
> of 2.6.32, so that it can be included then.
>
> The current version of the patches can be found here:
>
> http://linuxtv.org/hg/~pb/v4l-dvb/rev/eabb8cfcf32a
>
> Changelog:
> This patch increments the DVB-API to version 5.1 in order to reflect the 
> addition of ISDB-T and ISDB-Tsb on Linux' DVB-API.
>
> Changes in detail:
> - added a small document to describe how to use the API to tune to an ISDB-T 
> or ISDB-Tsb channel
> - added necessary fields to dtv_frontend_cache
> - added a smarter clear-cache function which resets all fields of the 
> dtv_frontend_cache
> - added a TRANSMISSION_MODE_4K to fe_transmit_mode_t
>
> I also added a document trying to descibe in short all the needed parameters 
> (DTV_CMDs) for ISDB-T(sb) and how to use them. I'm inlining this document, as 
> it is the base for the RFC as well:
>
> [..]

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Akihiro TSUKADA]

Hi Patrick,

Thank you for your effort to add support for ISDB-T/S.
I've skimmed through the ARIB standard before,
but it is too complicated for me to understand well enough.
So this is not a comment for the API extension itself,
but for the document part.

Some of the parameters are currently (and probably will stay)
fixed or not used  according to the "operational guidelines".
For example, DQPSK is not used at all (if I read correctly).
These guidelines are defined in ARIB TR-B14 for ISDB-T and
in ARIB TR-B15 for ISDB-S respectively.

So, including these two TRs (in additino to ARIB STD-B31)
as a reference in the document may help readers.
---------
Akihiro TSUKADA
--------------------------------------
Power up the Internet with Yahoo! Toolbar.
http://pr.mail.yahoo.co.jp/toolbar/

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Patrick Boettcher]

Hi Akihiro,

thanks for commenting.

On Wed, 5 Aug 2009, Akihiro TSUKADA wrote:

> Hi Patrick,
>
> Thank you for your effort to add support for ISDB-T/S.
> I've skimmed through the ARIB standard before,
> but it is too complicated for me to understand well enough.
> So this is not a comment for the API extension itself,
> but for the document part.
>
> Some of the parameters are currently (and probably will stay)
> fixed or not used  according to the "operational guidelines".

Yeah, that's usually the case with complex standards. For DVB-T in theory 
1500 parameter-combinations are possible, but only 5-10 different are used 
in the world. (For ISDB-T the number of possible combinations are more 
than 100000, iirc).

> For example, DQPSK is not used at all (if I read correctly).
> These guidelines are defined in ARIB TR-B14 for ISDB-T and
> in ARIB TR-B15 for ISDB-S respectively.

Hmm, I'm actually not working on ISDB-S (Satelite), but on ISDB-Tsb 
(sound-broadcasting or also known as 1seg) which is based on ISDB-T's 
modulation principles (COFDM, segment etc).

> So, including these two TRs (in additino to ARIB STD-B31)
> as a reference in the document may help readers.

I'll at TR-B14 only.

thanks for the comments,
--

Patrick Boettcher - Kernel Labs
http://www.kernellabs.com/

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Patrick Boettcher]

On Wed, 5 Aug 2009, Patrick Boettcher wrote:
>> For example, DQPSK is not used at all (if I read correctly).
>> These guidelines are defined in ARIB TR-B14 for ISDB-T and
>> in ARIB TR-B15 for ISDB-S respectively.
>
> Hmm, I'm actually not working on ISDB-S (Satelite), but on ISDB-Tsb 
> (sound-broadcasting or also known as 1seg) which is based on ISDB-T's

Here I have to correct myself: 1seg is not the (commercial) name for 
ISDB-Tsb, but for the ISDB-T central segment, which can be received 
independently (Partial reception).

--

Patrick Boettcher - Kernel Labs
http://www.kernellabs.com/

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Michael Krufky]

On Mon, Aug 3, 2009 at 1:53 PM, Patrick
Boettcher<patrick.boettcher@desy.de> wrote:
> Hi all,
>
> I'd like to request some comments about the extension of the DVB-API 5 to
> support ISDB-T and ISDB-Tsb. Some stubs in frontend.h and friends have been
> there since the beginning and now it's time to have real user-space support
> for that standard.
>
> I hope that we can finish the discussion of this RFC before the merge window
> of 2.6.32, so that it can be included then.
>
> The current version of the patches can be found here:
>
> http://linuxtv.org/hg/~pb/v4l-dvb/rev/eabb8cfcf32a
>
> Changelog:
> This patch increments the DVB-API to version 5.1 in order to reflect the
> addition of ISDB-T and ISDB-Tsb on Linux' DVB-API.
>
> Changes in detail:
> - added a small document to describe how to use the API to tune to an ISDB-T
> or ISDB-Tsb channel
> - added necessary fields to dtv_frontend_cache
> - added a smarter clear-cache function which resets all fields of the
> dtv_frontend_cache
> - added a TRANSMISSION_MODE_4K to fe_transmit_mode_t
>
> I also added a document trying to descibe in short all the needed parameters
> (DTV_CMDs) for ISDB-T(sb) and how to use them. I'm inlining this document,
> as it is the base for the RFC as well:
>
> (Disclaimer: ISDB-T and ISDB-Tsb is relative complex from the parameters
> point of view compared to DVB-T and for me the standard-document was not
> making things very easy for me as a software-writer. Please don't blame me
> for so many additions)
>
> -----------------
> This document describes shortly what are the possible parameters in
> the Linux DVB-API called "S2API" in order to tune an ISDB-T/ISDB-Tsb
> demodulator:
>
> This ISDB-T/ISDB-Tsb API extension should reflect all information
> needed to tune any ISDB-T/ISDB-Tsb hardware. Of course it is possible
> that some very sophisticated devices won't need certain parameters to
> tune.
>
> The information given here should help application writers to know how
> to handle ISDB-T and ISDB-Tsb hardware using the Linux DVB-API.
>
> The details given here about ISDB-T and ISDB-Tsb are just enough to
> basically
> show the dependencies between the needed parameter values, but surely some
> information is left out. For more detailed information see the standard
> document:
> ARIB STD-B31 - "Transmission System for Digital Terrestrial Television
> Broadcasting".
>
> In order to read this document one has to know about the channel
> structure in ISDB-T and ISDB-Tsb. I.e. it has to be known to the
> reader that an ISDB-T channel consists of 13 segments, that it can
> have up to 3 layer sharing those segments, and so on.
>
> Parameters used by ISDB-T and ISDB-Tsb.
>
> Existing parameters
> ===================
>
> a) DTV_BANDCOUNT_HZ
>
> Help the front-end, for example, to set up base-band-filters.
>
> Possible values:
>
> For ISDB-T it should be always 6000000Hz (6MHz)
> For ISDB-Tsb it can vary depending on the number of connected segments
>
> b) DTV_DELIVERY_SYSTEM
>
> Possible values: SYS_ISDBT
>
> c) DTV_TRANSMISSION_MODE
>
> ISDB-T supports three carrier/symbol-size: 8K, 4K, 2K. It is called
> 'mode' in the standard: Mode 1 is 2K, mode 2 is 4K, mode 3 is 8K
>
> Possible values: TRANSMISSION_MODE_2K, TRANSMISSION_MODE_8K,
>         TRANSMISSION_MODE_AUTO, TRANSMISSION_MODE_4K
>
> If DTV_TRANSMISSION_MODE is set the TRANSMISSION_MODE_AUTO the
> hardware will try to find the correct FFT-size (if capable) and use
> the TMCC to fill in the missing parameters.
>
> TRANSMISSION_MODE_4K is added at the same time as the other new parameters.
>
> d) DTV_GUARD_INTERVAL
>
> Possible values: GUARD_INTERVAL_1_32, GUARD_INTERVAL_1_16,
> GUARD_INTERVAL_1_8,
>         GUARD_INTERVAL_1_4, GUARD_INTERVAL_AUTO
>
> If DTV_GUARD_INTERVAL is set the GUARD_INTERVAL_AUTO the hardware will
> try to find the correct guard interval (if capable) and use the TMCC to fill
> in the missing parameters.
>
> New parameters
> ==============
>
> 1. DTV_ISDBT_PARTIAL_RECEPTION (1b)
>
> If DTV_ISDBT_SOUND_BROADCASTING is '0' this bit-field represents whether
> the channel is in partial reception mode or not.
>
> If '1' DTV_ISDBT_LAYERA_* values are assigned to the center segment and
> DTV_ISDBT_LAYERA_SEGMENT_COUNT has to be '1'.
>
> If in addition DTV_ISDBT_SOUND_BROADCASTING is '1'
> DTV_ISDBT_PARTIAL_RECEPTION represents whether this ISDB-Tsb channel
> is consisting of one segment and layer or three segments and two layers.
>
> Possible values: 0, 1, -1 (AUTO)
>
> 2. DTV_ISDBT_SOUND_BROADCASTING (1b)
>
> This field represents whether the other DTV_ISDBT_*-parameters are
> referring to an ISDB-T and an ISDB-Tsb channel. (See also
> DTV_ISDBT_PARTIAL_RECEPTION).
>
> Possible values: 0, 1, -1 (AUTO)
>
> 3. DTV_ISDBT_SB_SUBCHANNEL_ID
>
> This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.
>
> (Note of the author: This might not be the correct description of the
>  SUBCHANNEL-ID in all details, but it is my understanding of the technical
>  background needed to program a device)
>
> An ISDB-Tsb channel (1 or 3 segments) can be broadcasted alone or in a
> set of connected ISDB-Tsb channels. In this set of channels every
> channel can be received independently. The number of connected
> ISDB-Tsb segment can vary, e.g. depending on the frequency spectrum
> bandwidth available.
>
> Example: Assume 8 ISDB-Tsb connected segments are broadcasted. The
> broadcaster has several possibilities to put those channels in the
> air: Assuming a normal 13-segment ISDB-T spectrum he can align the 8
> segments from position 1-8 to 5-13 or anything in between.
>
> The underlying layer of segments are subchannels: each segment is
> consisting of several subchannels with a predefined IDs. A sub-channel
> is used to help the demodulator to synchronize on the channel.
>
> An ISDB-T channel is always centered over all sub-channels. As for
> the example above, in ISDB-Tsb it is no longer as simple as that.
>
> The DTV_ISDBT_SB_SUBCHANNEL_ID parameter is used to give the
> sub-channel ID of the segment to be demodulated.
>
> Possible values: 0 .. 41, -1 (AUTO)
>
> 4. DTV_ISDBT_SB_SEGMENT_IDX
>
> This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.
>
> DTV_ISDBT_SB_SEGMENT_IDX gives the index of the segment to be
> demodulated for an ISDB-Tsb channel where several of them are
> transmitted in the connected manner.
>
> Possible values: 0 .. DTV_ISDBT_SB_SEGMENT_COUNT-1
>
> Note: This value cannot be determined by an automatic channel search.
>
> 5. DTV_ISDBT_SB_SEGMENT_COUNT
>
> This field only applies if DTV_ISDBT_SOUND_BROADCASTING is '1'.
>
> DTV_ISDBT_SB_SEGMENT_COUNT gives the total count of connected ISDB-Tsb
> channels.
>
> Possible values: 1 .. 13
>
> Note: This value cannot be determined by an automatic channel search.
>
> 6. Hierarchical layers
>
> ISDB-T channels can be coded hierarchically. As opposed to DVB-T in
> ISDB-T hierarchical layers can be decoded simultaneously. For that
> reason a ISDB-T demodulator has 3 viterbi and 3 reed-solomon-decoders.
>
> ISDB-T has 3 hierarchical layers which each can use a part of the
> available segments. The total number of segments over all layers has
> to 13 in ISDB-T.
>
> 6.1 DTV_ISDBT_LAYER_ENABLED (3b)
>
> Hierarchical reception in ISDB-T is achieved by enabling or disabling
> layers in the decoding process. Setting all bits of
> DTV_ISDBT_LAYER_ENABLED to '1' forces all layers (if applicable) to be
> demodulated. This is the default.
>
> If the channel is in the partial reception mode
> (DTV_ISDBT_PARTIAL_RECEPTION=1) the central segment can be decoded
> independently of the other 12 segments. In that mode layer A has to
> have a SEGMENT_COUNT of 1.
>
> In ISDB-Tsb only layer A is used, it can be 1 or 3 in ISDB-Tsb
> according to DTV_ISDBT_PARTIAL_RECEPTION. SEGMENT_COUNT must be filled
> accordingly.
>
> Possible values: 0x1, 0x2, 0x4 (|-able)
>
> DTV_ISDBT_LAYER_ENABLED[0:0] - layer A
> DTV_ISDBT_LAYER_ENABLED[1:1] - layer B
> DTV_ISDBT_LAYER_ENABLED[2:2] - layer C
> DTV_ISDBT_LAYER_ENABLED[31:3] unused
>
> 6.2 DTV_ISDBT_LAYER*_FEC
>
> Possible values: FEC_AUTO, FEC_1_2, FEC_2_3, FEC_3_4, FEC_5_6, FEC_7_8,
>
> 6.3 DTV_ISDBT_LAYER*_MODULATION
>
> Possible values: QAM_AUTO, DQPSK, QAM_16, QAM_64, DQPSK
>
> Note: If layer C is DQPSK layer B has to be DQPSK. If layer B is DQPSK
> and DTV_ISDBT_PARTIAL_RECEPTION=0 layer has to be DQPSK.
>
> 6.4 DTV_ISDBT_LAYER*_SEGMENT_COUNT
>
> Possible values: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -1 (AUTO)
>
> Note: Truth table for DTV_ISDBT_SOUND_BROADCASTING and
> DTV_ISDBT_PARTIAL_RECEPTION and LAYER*_SEGMENT_COUNT
>
>  PR | SB || layer A width | layer B width | layer C width | total
> ----+----++---------------+---------------+---------------+-------
>  0 |  0 || 1 .. 13       | 1 .. 13       | 1..13         | 13
>  1 |  0 || 1             | 1 .. 13       | 1..13         | 13
>  0 |  1 || 1             | 0             | 0             | 1
>  1 |  1 || 1             | 2             | 0             | 3
>
>
> 6.5 DTV_ISDBT_LAYER*_TIME_INTERLEAVING
>
> Possible values: 0, 1, 2, 3, -1 (AUTO)
>
> Note: The real inter-leaver depth-names depend on the mode (fft-size); the
> values
> here are referring to what can be found in the TMCC-structure -
> independent of the mode.
>
> -----------------
>
>
> thanks for the feedback in advance,
> Patrick.

Patrick,

It's extremely exciting to finally see this surfacing to the mailing
lists -- It will be a great addition to linux-dvb to have support for
the ISDB digital standards.

One thing that I see missing right now is userspace utilities.  Do you
have any plans to add ISDB scanning support to dvb-apps, and tuning
support to the *zap utility?  This would be the best way to get the
application developers started on incorporating ISDB support into the
apps shipping today.

Regards,

Mike

Re: RFC: adding ISDB-T/ISDB-Tsb to DVB-API 5

[Patrick Boettcher]

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1360 bytes --]

Hi Michael,

thanks for your response.

On Wed, 5 Aug 2009, Michael Krufky wrote:
> It's extremely exciting to finally see this surfacing to the mailing
> lists -- It will be a great addition to linux-dvb to have support for
> the ISDB digital standards.

Thanks, but I have to say it again, as I said it to Akihiro already. Those 
patches are not adding ISDB-S nor ISDB-C to the API. I'm not sure how 
different ISDB-S and ISDB-C are compared to their corresponding DVB 
pendants; however my patches are just adding support for ISDB-T and 
ISDB-Tsb.

> One thing that I see missing right now is userspace utilities.  Do you
> have any plans to add ISDB scanning support to dvb-apps, and tuning
> support to the *zap utility?  This would be the best way to get the
> application developers started on incorporating ISDB support into the
> apps shipping today.

Yeah this is in preparation. The scan works rather simply, as the section 
tables are partially identical to the ones in DVB (there is an SDT for 
service-names, there is a NIT, for network name) - so as a first shot it 
should be sufficient to add ISDB-T initial tuning data parsing to scan; 
this will also show how to tuning an ISDB-T channel.

See attached for a first draft of the initial tuning data file for Tokyo.

best regards,
--

Patrick Boettcher - Kernel Labs
http://www.kernellabs.com/

[-- Attachment #2: Type: TEXT/PLAIN, Size: 3188 bytes --]

# list of ISDB-T frequencies used in Tokyo, Japan (2009-08-06)
# identifier (IT/ISB)
#  central-frequency
#  |          transmission-mode
#  |          |  guard-interval
#  |          |  |    partial-reception-bit
#  |          |  |    | c-rate (A)
#  |          |  |    | |       modulation (A)
#  |          |  |    | |       |     segment-count (A)
#  |          |  |    | |       |     |  interleaving (A)
#  |          |  |    | |       |     |  | c-rate (B)
#  |          |  |    | |       |     |  | |        modulation (B)
#  |          |  |    | |       |     |  | |        |     segment-count (B)
#  |          |  |    | |       |     |  | |        |     |  interleaving (B)
#  |          |  |    | |       |     |  | |        |     |  | c-rate (C)
#  |          |  |    | |       |     |  | |        |     |  | |        modulation (C)
#  |          |  |    | |       |     |  | |        |     |  | |        |    segment-count (C)
#  |          |  |    | |       |     |  | |        |     |  | |        |    | interleaving (C)
IT 515143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # Tokyo Metroplitan TV
IT 521143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # Fuji TV
IT 527143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # TBS TV
IT 533143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # TV Tokyo
IT 539143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # TV Asahi
IT 545143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # Nihon TV
IT 551143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # NHK Education
IT 557143000  8K 1/8  1 FEC_2_3 QPSK  1  3 FEC_3_4  QAM64 12 2 FEC_NONE AUTO 0 0  # NHK Sogo
IT 563143000  8K 1/4  0 FEC_3_4 QAM64 13 2 FEC_NONE AUTO  0  0 FEC_NONE AUTO 0 0  # Broadcasting University

#  example for ISDB-Tsb
#
#  identifier (IT/ISB)
#    central-frequency
#    |         transmission-mode
#    |         |  guard-interval
#    |         |  |    partial-reception-bit
#    |         |  |    | segment-idx
#    |         |  |    | | segment-total-count
#    |         |  |    | | | subchannel_id
#    |         |  |    | | | |  c-rate (A)
#    |         |  |    | | | |  |       modulation (A)
#    |         |  |    | | | |  |       |    segment-count (A)
#    |         |  |    | | | |  |       |    | interleaving (A)
#    |         |  |    | | | |  |       |    | | c-rate (B)
#    |         |  |    | | | |  |       |    | | |       modulation (B)
#    |         |  |    | | | |  |       |    | | |       |     segment-count (B)
#    |         |  |    | | | |  |       |    | | |       |     | interleaving (B)
#ISB 170000000 8K 1/32 0 1 8 2  FEC_1_2 QPSK 1 0 FEC_NONE AUTO 0 0
#ISB 170429000 8K 1/32 0 2 8 6  FEC_1_2 QPSK 1 0 FEC_NONE AUTO 0 0
#ISB 170868000 8K 1/32 0 3 8 10 FEC_1_2 QPSK 1 0 FEC_NONE AUTO 0 0
#ISB 171726000 8K 1/32 0 5 8 18 FEC_1_2 QPSK 1 0 FEC_NONE AUTO 0 0
#ISB 172584000 8K 1/32 0 7 8 26 FEC_1_2 QPSK 1 0 FEC_1_2  QPSK 2 0
#ISB 173013000 8K 1/32 0 8 8 30 FEC_1_2 QPSK 1 0 FEC_NONE AUTO 0 0