Commit Graph

92 Commits

Author SHA1 Message Date
Mauro Carvalho Chehab
7f95751519 media: vidtv: cleanup PAT write function
Avoid initializing the structs multiple times and pass the
PAT struct as a pointer, instead of a var.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
c570fb9ffc media: vidtv: cleanup PSI table header function
- Pass struct header_write_args as a pointer, instead of
  passing as a var;

- Initialize the psi_args struct only once.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
974ea17692 media: vidtv: cleanup PSI descriptor write function
This function initializes the psi_args twice, and receives
a struct, instead of a pointer to a struct.

Clean it up.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
9e0067417b media: vidtv: simplify the crc writing logic
Cleanup the table_section_crc32_write_into() function
by initializing struct psi_write_args only once and by
passing the args as a pointer.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
5edbd330e3 media: vidtv: simplify PSI write function
The function vidtv_psi_ts_psi_write_into() initializes the
ts_header fields several times, and receives a struct
as argument, instead of using a pointer to struct.

Cleanup the function, in order to reduce its stack usage
and to avoid initializing the ts_header multiple times.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
160028542b media: vidtv: add date to the current event
The current event is using an undefined date. Instead, it
should be the timestamp when the EIT table was generated.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:24 +01:00
Mauro Carvalho Chehab
bfa4aaebe8 media: vidtv: fix service_id at SDT table
The service_id there should be equal to the one used
on other tables, otherwise, EIT entries won't be valid.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
11f4933f7b media: vidtv: fix service type
As the service currently broadcasts just audio, change the
service type to reflect that.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
039b7caed1 media: vidtv: add a PID entry for the NIT table
On normal TS streams, the NIT table has its own entry at PAT,
but not at PMT.

While here, properly handle alloc problems when creating
PMT entries.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
91a8a240e2 media: vidtv: properly fill EIT service_id
The EIT header ID field should not contain the network ID, but,
instead, the service_id of the program described at EIT.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
1d2b2a6d8c media: vidtv: fix the network ID range
As defined at ETSI TS 101 162, original network IDs up to 0xfebf
are reserved for registration at dvb.org.

Let's use, instead, an original network ID at the range
0xff00-0xffff, as this is for private temporary usage.

As the same value is also used for the network ID,
the range 0xff01-0xffff also fits better, as values
lower than that depend if the network is used for
satellite, terrestrial, cable of CI.

While here, move the TS ID to the bridge code, where it
is used, and change its value, as it was identical to
the value previously used by network ID. While we could
keep the same value, let's change it, just to make easier
to check for the new code while reading it with DVB tools
like dvbinspector.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
b9e09e06e3 media: vidtv: improve EIT data
Place some text at EIT data, and use ISO 8859-15 encoding for
the German letter "ü" (u mit umlat) letter.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
ec3eda53f4 media: vidtv: cleanup null packet initialization logic
Initialize the destination buffer/size and the initial
offset when creating the local var.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
c857b065ab media: vidtv: pre-initialize mux arrays
Instead of first zeroing all fields at the mux structs and
then filling, do some initialization for the const data
when they're created.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
330d135679 media: vidtv: remove some unused functions
Right now, there's no need to access the length of some
tables. So, drop the unused functions.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
a8bd461ca3 media: vidtv: do some cleanups at the driver
Do some cleanups at the coding style of the driver:
- remove "inline" declarations;
- use reverse xmas-tree for local var declarations;
- Adjust some indent to avoid breaking 80-cols;
- Cleanup some comments.

No functional changes.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 08:05:23 +01:00
Mauro Carvalho Chehab
163d72a2d3 media: vidtv: avoid copying data for PES structs
Minimize the number of data copies and initialization at
the code, passing them as pointers instead of duplicating
the data.

The only case where we're keeping the data copy is at
vidtv_pes_write_h(), as it needs a copy of the passed
arguments. On such case, we're being more explicit.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:47:34 +01:00
Mauro Carvalho Chehab
0a33ab1682 media: vidtv: avoid data copy when initializing the multiplexer
Initialize the fields of the arguments directly when
declaring it, and pass the args as a pointer, instead of
copying them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:45:20 +01:00
Mauro Carvalho Chehab
0d271a79c7 media: vidtv: fix some notes at the tone generator
The sheet music used to generate the tones had a few
polyphonic notes. Due to that, its conversion to a
tones sequence had a few errors.

Also, due to a bug at the tone generator, it was missing
the pause at the initial compass.

Fix them.

While here, reduce the compass to 100bpm.

The music was converted from a Music XML file using
this small script:

<snip>
my $count = 0;
my $silent = 0;
my $note;
my $octave;
print "\t";
while (<>) {
	$note = $1 if (m,\<step\>(.*)\</step\>,);
	$octave = "_$1" if (m,\<octave\>(.*)\</octave\>,);
	if (m,\<alter\>1\</alter\>,) {
		$note .= "S";
		$sharp = 1;
	}
	if (m,\<rest/\>,) {
		$note = "SILENT";
		$silent = 1;
	}
	if (m,\<duration\>(.*)\</duration\>,) {
		printf "{ NOTE_${note}${octave}, %d},", $1 * 128 / 480;
		$count++;
		if ($silent || $count >= 3) {
			print "\n\t";
			$count = 0;
			$silent = 0;
		} else {
			print " ";
			print " " if (!$sharp);
		}
		$sharp = 0;
		$note = "";
		$octave = "";
	};
};
print "\n";
</snip>

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:44:58 +01:00
Mauro Carvalho Chehab
ab6bad0a4d media: vidtv: fix the tone generator logic
The tone generator logic were repeating the song after the
first silent. There's also a wrong logic at the note
offset calculus, which may create some noise.

Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:44:38 +01:00
Mauro Carvalho Chehab
af66e03edd media: vidtv: fix the name of the program
While the original plan was to use the first movement of
the 5th Symphony, it was opted to use the Für Elise song,
instead.

Fix it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:44:19 +01:00
Mauro Carvalho Chehab
31e82355a1 media: vidtv: don't use recursive functions
The Linux stack is too short. So, using recursive functions
is a very bad idea. Convert those into non-recursive ones.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:43:58 +01:00
Mauro Carvalho Chehab
3be8037960 media: vidtv: add error checks
Currently, there are not checks if something gets bad during
memory allocation: it will simply use NULL pointers and
crash.

Add error path at the logic which allocates memory for the
MPEG-TS generator code, propagating the errors up to the
vidtv_bridge. Now, if something wents bad, start_streaming
will return an error that userspace can detect:

	ERROR    DMX_SET_PES_FILTER failed (PID = 0x2000): 12 Cannot allocate memory

and the driver doesn't crash.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:43:40 +01:00
Mauro Carvalho Chehab
8922e3931d media: vidtv: reorganize includes
- Place the includes on alphabetical order;
- get rid of asm/byteorder.h;
- add bug.h at vidtv_s302m.c, as it is needed by
  inux/fixp-arith.h

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:41:03 +01:00
Daniel W. S. Almeida
c2b6ca661a media: vidtv: psi: fix missing assignments in while loops
Some variables were only assigned once but were used in while
loops as if they had been updated at every iteration. Fix this.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:40:36 +01:00
Daniel W. S. Almeida
99b99d135e media: vidtv: Move s302m specific fields into encoder context
A few fields used only by the tone generator in the s302m encoder
are stored in struct vidtv_encoder. Move them into
struct vidtv_s302m_ctx instead. While we are at it: fix a
checkpatch warning for long lines.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:40:16 +01:00
Daniel W. S. Almeida
84306c96b1 media: vidtv: psi: extract descriptor chaining code into a helper
The code to append a descriptor to the end of a chain is repeated
throughout the psi generator code. Extract it into its own helper
function to avoid cluttering.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:39:54 +01:00
Daniel W. S. Almeida
7a7899f6f5 media: vidtv: psi: Implement an Event Information Table (EIT)
Implement an Event Information Table (EIT) as per EN 300 468
5.2.4.

The EIT provides information in chronological order regarding
the events contained within each service.

For now only present event information is supported.

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:39:31 +01:00
Daniel W. S. Almeida
c2f78f0cb2 media: vidtv: psi: add a Network Information Table (NIT)
Add a Network Information Table (NIT) as specified in ETSI EN 300 468.

This table conveys information relating to the physical organization of
the multiplexes carried via a given network and the characteristics of
the network itself.

It is conveyed in the output of vidtv as packets with TS PID of 0x0010

[mchehab+huawei@kernel.org: removed an extra blank line]
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:37:59 +01:00
Daniel W. S. Almeida
dd6dbe8d7e media: vidtv: extract the initial CRC value to into a #define
The same constant (0xffffffff) is used in three different functions.

Extract it into a #define to avoid repetition.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-11-26 07:35:49 +01:00
Mauro Carvalho Chehab
bfea1d81b5 media: vidtv: fix decoding with gstreamer and Vlc
Neither Vlc nor Gstreamer likes the PES_scrambling_control bits.

In the case of GST, this can be seen with:

	$ GST_DEBUG=2 LANG=C gst-play-1.0 pcm_audio.ts
	...
	0:00:00.097973439 12308 0x55f7ddd155e0 WARN               pesparser pesparse.c:411:mpegts_parse_pes_header: Wrong '0x10' marker before PES_scrambling_control (0x40)
	0:00:00.097987026 12308 0x55f7ddd155e0 WARN                 tsdemux tsdemux.c:2314:gst_ts_demux_parse_pes_header: Error parsing PES header. pid: 0x111 stream_type: 0x6
	...

So, change, it. After such change, the stream now plays
fine with Vlc, Gstreamer, ffmpeg - and with programs
that use such libraries, like Kaffeine.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:24:54 +02:00
Mauro Carvalho Chehab
a61d7d19a3 media: vidtv: rewrite the adaption field logic
When compared with a stream generated via ffmpeg, it can be
noticed that the PES doesn't contain any PCR info. That could
cause problems with userspace decoding. So, rewrite the
logic that fills the adaptation info, in order to allow it
to add PCR frames without breaking frame alignment.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:24:33 +02:00
Mauro Carvalho Chehab
09196d86e3 media: vidtv: simplify parameters for vidtv_pes_write_stuffing()
Instead of passing struct pes_ts_header_write_args fields as
function parameters, just pass a pointer to the struct.

That would allow adding more args without needing to change
the function prototype.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:22:00 +02:00
Mauro Carvalho Chehab
d6a36eda73 media: vidtv: fix a typo
optinal -> optional

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:21:37 +02:00
Mauro Carvalho Chehab
2f21772961 media: vidtv: cleanup SDT string identifiers
In order to better test userspace applications, add an encoding
for the strings. The original channel string is also too big.
As we're just playing the first compasses of the 5th Beethoven
Symphony, change the service name to just "Beethoven". Also,
add a provider's name. For such purpose, let's point it to
the Linux media community website.

With such changes, the SDT table now looks more like one got
from a real digital TV channel:

SDT
| table_id         0x42
| section_length      44
| one                 2
| zero                1
| syntax              1
| transport_stream_id 1860
| current_next        1
| version             0
| one2                3
| section_number      0
| last_section_number 0
| network_id          65281
| reserved            255
|\
|- service 0x0880
|   EIT schedule          0
|   EIT present following 0
|   free CA mode          0
|   running status        4
|   descriptor length     27
|        0x48: service_descriptor
|           service type  1
|           provider      'LinuxTV.org'
|           name          'Beethoven'
|_  1 services

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:21:17 +02:00
Mauro Carvalho Chehab
fc4405a5f1 media: vidtv: cleanup PSI version numbers
There's no reason to use static vars to store PSI version
numbers.

Also, currently, version numbers are starting with 0x01,
because there's a code being called that increases it to
1 for all table initializer code, as the code may support
dynamic changes at the PS tables on some future.

So, let's just initialize them to 0x1f, in order for the
versions to be reported as starting from 0.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:20:56 +02:00
Mauro Carvalho Chehab
56ce9eff94 media: vidtv: fix initialization of the network_id field at SDT
This field should point to the network ID, and has different
ranges for cable, terrestrial or satellite. It also has
an special range for temporary private usage.

For now, let's use the temporary private one. Once the
Network Information Table (NIT) gets added, this should be
reviewed.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:20:35 +02:00
Mauro Carvalho Chehab
02578bdf31 media: vidtv: remove more ENDIAN_BITFIELD nonsense
Changeset 870e350d4e ("media: vidtv: get rid of ENDIAN_BITFIELD nonsense")
was incomplete. There are still some wrong endannes logic at
the driver. Get rid of them.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:20:09 +02:00
Mauro Carvalho Chehab
880a8fc077 media: vidtv: simplify PCR logic to get jiffies
There's no need to have a check when setting timing.past_jiffies,
as we can simply do the initialization earlier at vidtv_mux_init().

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-10-01 09:19:48 +02:00
Dafna Hirschfeld
2f49146349 media: vivid: Add support to the CSC API
The CSC API (Colorspace conversion) allows userspace to try
to configure the colorspace, transfer function, Y'CbCr/HSV encoding
and the quantization for capture devices. This patch adds support
to the CSC API in vivid.
Using the CSC API, userspace is allowed to do the following:

- Set the colorspace.
- Set the xfer_func.
- Set the ycbcr_enc function for YUV formats.
- Set the hsv_enc function for HSV formats
- Set the quantization for YUV and RGB formats.

Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-26 10:21:34 +02:00
Mauro Carvalho Chehab
9e76f2cff7 media: vidtv: remove an impossible condition
As warned by smatch:

	drivers/media/test-drivers/vidtv/vidtv_psi.c:93 vidtv_psi_update_version_num() warn: impossible condition '(h->version > 32) => (0-31 > 32)'

h_version is declared as:

		u8  version:5;

Meaning that its value ranges from 0 to 31. Incrementing 31 on such
data will overflow to zero, as expected.

So, just drop the uneeded overflow check.

While here, use "foo++" instead of "++foo", as this is a much
more common pattern.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:03:36 +02:00
Mauro Carvalho Chehab
ad458524b3 media: vidtv: cleanup the logic which estimates buffer size
There's no need to use u64 over there. In a matter of fact,
the div is not even needed, as it is multiplying by 1000 and
dividing by 1000.

So, simplify the logic.

While here, constrain the buffer size to a certain range
(between the current value and 10 times it)

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:03:18 +02:00
Daniel W. S. Almeida
37b288f54b media: vidtv: fix build on 32bit architectures
Fix the following error for builds on 32bit architectures:

ERROR: modpost: "__udivdi3"
[drivers/media/test-drivers/vidtv/dvb-vidtv-bridge.ko] undefined!

Which is due to 64bit divisions that did not go through the helpers
in linux/math64.h

As vidtv_mux_check_mux_rate was not operational in its current form,
drop the entire function while it is not fixed properly.

For now, call vidtv_mux_pad_with_nulls with a constant number of packets
to avoid warnings due to unused functions when building this driver.

The 64bit division used in the s302m is not needed, remove them and use
a fixed number of frames and a constant PTS increment instead.

Fixes: f90cf6079b ("media: vidtv: add a bridge driver")
Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:02:58 +02:00
Mauro Carvalho Chehab
c5d83ba23e media: vidtv: Add a music instead of playing a single tone
Keep playing a single tone is not too nice, and prevents
checking some weird things.

So, instead, implement a simple tone generator, changing
the code to play a public domain song (5th Symphony of
Beethoven), using sinusoidal waves.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:02:01 +02:00
Mauro Carvalho Chehab
c2a9baf96f media: vidtv: get rid of its own sinusoidal waveform
Instead, use the code from linux/fixp-arith.h.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:01:40 +02:00
Mauro Carvalho Chehab
82d00a1a2a media: vidtv: add a poor guy's simulation to preBER stats
A typical digital TV stream has errors that are corrected
by Viterbi. While the error rate after Viterbi is usually
zero, with good signals, there are some chances of getting
random errors before that, which are auto-corrected by
the error code algorithm.

Add a poor guy's implementation that would show some
noise at the pre-BER part of the demod.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:01:20 +02:00
Mauro Carvalho Chehab
9ec6f4bb60 media: vidtv: fix DVB-S/S2 tuning logic
Satellite setups are different than terrestrial and cable ones,
as there is a device coupled at the antenna, called LNBf, which
converts the frequency from a GHz range at C-Band or Ku-Band
into an intermediate frequency at S-Band (ranging up to ~2GHz).

There are several different models of LNBf, with different
IF conversions, but the most common nowadays is called
Universal LNBf. Those got their frequency ranges extended in the
past, when Astra 19.2E sattellite was launched.

The universal LNBf has two local oscilators:

	- 9.75 GHz
	- 10.6 GHz

The first one is used when the frequency is between 10.7 GHz
up to 11.7 GHz. The second one is for frequencies between
11.7 GHz to 12.75 GHz.

With that, the IF signal will be at 950 MHz to 2,150 MHz range.

Add support for doing the above math, and make clear that
the frequencies expected by the driver should be at Ku-Band
range.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:00:40 +02:00
Mauro Carvalho Chehab
d38829a5e1 media: vidtv: add DiSEqC dummy ops
Those are needed for real applications to work with Satellite
systems.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-17 12:00:19 +02:00
Mauro Carvalho Chehab
741043b02c media: vidtv: don't initialize cnr2qual var
As reported by gcc:

	drivers/media/test-drivers/vidtv/vidtv_demod.c: In function 'vidtv_demod_set_frontend':
	drivers/media/test-drivers/vidtv/vidtv_demod.c:265:42: warning: variable 'cnr2qual' set but not used [-Wunused-but-set-variable]
	  265 |  const struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL;
	      |                                          ^~~~~~~~

It turns that the var is not needed at all. So, just drop it.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-14 16:10:08 +02:00
Mauro Carvalho Chehab
d859a712a3 media: vidtv: adjust signal strength range
On real devices, signal strength is always a negative
number when represented in dBm. A more interesting
range is to use dBmV (which is what Kaffeine does,
for example). The conversion from the two units are
simple:

	dBmV = dBm - 108

Usually, signal strength ranges up to 100dBmV. Adjust the
maximum value to be around 74 dBmV, when there's no
frequency shift, which represents a good signal.

With that, Kaffeine displays it a lot better.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-14 16:02:55 +02:00