1 .. SPDX-License-Identifier: GFDL-1.1-no-invari 1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2 .. c:namespace:: V4L 2 .. c:namespace:: V4L
3 3
4 .. _VIDIOC_ENUMSTD: 4 .. _VIDIOC_ENUMSTD:
5 5
6 ******************************************* 6 *******************************************
7 ioctl VIDIOC_ENUMSTD, VIDIOC_SUBDEV_ENUMSTD 7 ioctl VIDIOC_ENUMSTD, VIDIOC_SUBDEV_ENUMSTD
8 ******************************************* 8 *******************************************
9 9
10 Name 10 Name
11 ==== 11 ====
12 12
13 VIDIOC_ENUMSTD - VIDIOC_SUBDEV_ENUMSTD - Enume 13 VIDIOC_ENUMSTD - VIDIOC_SUBDEV_ENUMSTD - Enumerate supported video standards
14 14
15 Synopsis 15 Synopsis
16 ======== 16 ========
17 17
18 .. c:macro:: VIDIOC_ENUMSTD 18 .. c:macro:: VIDIOC_ENUMSTD
19 19
20 ``int ioctl(int fd, VIDIOC_ENUMSTD, struct v4l 20 ``int ioctl(int fd, VIDIOC_ENUMSTD, struct v4l2_standard *argp)``
21 21
22 .. c:macro:: VIDIOC_SUBDEV_ENUMSTD 22 .. c:macro:: VIDIOC_SUBDEV_ENUMSTD
23 23
24 ``int ioctl(int fd, VIDIOC_SUBDEV_ENUMSTD, str 24 ``int ioctl(int fd, VIDIOC_SUBDEV_ENUMSTD, struct v4l2_standard *argp)``
25 25
26 Arguments 26 Arguments
27 ========= 27 =========
28 28
29 ``fd`` 29 ``fd``
30 File descriptor returned by :c:func:`open( 30 File descriptor returned by :c:func:`open()`.
31 31
32 ``argp`` 32 ``argp``
33 Pointer to struct :c:type:`v4l2_standard`. 33 Pointer to struct :c:type:`v4l2_standard`.
34 34
35 Description 35 Description
36 =========== 36 ===========
37 37
38 To query the attributes of a video standard, e 38 To query the attributes of a video standard, especially a custom (driver
39 defined) one, applications initialize the ``in 39 defined) one, applications initialize the ``index`` field of struct
40 :c:type:`v4l2_standard` and call the :ref:`VID 40 :c:type:`v4l2_standard` and call the :ref:`VIDIOC_ENUMSTD`
41 ioctl with a pointer to this structure. Driver 41 ioctl with a pointer to this structure. Drivers fill the rest of the
42 structure or return an ``EINVAL`` error code w 42 structure or return an ``EINVAL`` error code when the index is out of
43 bounds. To enumerate all standards application 43 bounds. To enumerate all standards applications shall begin at index
44 zero, incrementing by one until the driver ret 44 zero, incrementing by one until the driver returns ``EINVAL``. Drivers may
45 enumerate a different set of standards after s 45 enumerate a different set of standards after switching the video input
46 or output. [#f1]_ 46 or output. [#f1]_
47 47
48 .. c:type:: v4l2_standard 48 .. c:type:: v4l2_standard
49 49
50 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm 50 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
51 51
52 .. flat-table:: struct v4l2_standard 52 .. flat-table:: struct v4l2_standard
53 :header-rows: 0 53 :header-rows: 0
54 :stub-columns: 0 54 :stub-columns: 0
55 :widths: 1 1 2 55 :widths: 1 1 2
56 56
57 * - __u32 57 * - __u32
58 - ``index`` 58 - ``index``
59 - Number of the video standard, set by t 59 - Number of the video standard, set by the application.
60 * - :ref:`v4l2_std_id <v4l2-std-id>` 60 * - :ref:`v4l2_std_id <v4l2-std-id>`
61 - ``id`` 61 - ``id``
62 - The bits in this field identify the st 62 - The bits in this field identify the standard as one of the common
63 standards listed in :ref:`v4l2-std-id` 63 standards listed in :ref:`v4l2-std-id`, or if bits 32 to 63 are
64 set as custom standards. Multiple bits 64 set as custom standards. Multiple bits can be set if the hardware
65 does not distinguish between these sta 65 does not distinguish between these standards, however separate
66 indices do not indicate the opposite. 66 indices do not indicate the opposite. The ``id`` must be unique.
67 No other enumerated struct :c:type:`v4 67 No other enumerated struct :c:type:`v4l2_standard` structure,
68 for this input or output anyway, can c 68 for this input or output anyway, can contain the same set of bits.
69 * - __u8 69 * - __u8
70 - ``name``\ [24] 70 - ``name``\ [24]
71 - Name of the standard, a NUL-terminated 71 - Name of the standard, a NUL-terminated ASCII string, for example:
72 "PAL-B/G", "NTSC Japan". This informat 72 "PAL-B/G", "NTSC Japan". This information is intended for the
73 user. 73 user.
74 * - struct :c:type:`v4l2_fract` 74 * - struct :c:type:`v4l2_fract`
75 - ``frameperiod`` 75 - ``frameperiod``
76 - The frame period (not field period) is 76 - The frame period (not field period) is numerator / denominator.
77 For example M/NTSC has a frame period 77 For example M/NTSC has a frame period of 1001 / 30000 seconds.
78 * - __u32 78 * - __u32
79 - ``framelines`` 79 - ``framelines``
80 - Total lines per frame including blanki 80 - Total lines per frame including blanking, e. g. 625 for B/PAL.
81 * - __u32 81 * - __u32
82 - ``reserved``\ [4] 82 - ``reserved``\ [4]
83 - Reserved for future extensions. Driver 83 - Reserved for future extensions. Drivers must set the array to
84 zero. 84 zero.
85 85
86 86
87 .. c:type:: v4l2_fract 87 .. c:type:: v4l2_fract
88 88
89 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm 89 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
90 90
91 .. flat-table:: struct v4l2_fract 91 .. flat-table:: struct v4l2_fract
92 :header-rows: 0 92 :header-rows: 0
93 :stub-columns: 0 93 :stub-columns: 0
94 :widths: 1 1 2 94 :widths: 1 1 2
95 95
96 * - __u32 96 * - __u32
97 - ``numerator`` 97 - ``numerator``
98 - 98 -
99 * - __u32 99 * - __u32
100 - ``denominator`` 100 - ``denominator``
101 - 101 -
102 102
103 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm 103 .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.5cm}|
104 104
105 .. _v4l2-std-id: 105 .. _v4l2-std-id:
106 106
107 .. flat-table:: typedef v4l2_std_id 107 .. flat-table:: typedef v4l2_std_id
108 :header-rows: 0 108 :header-rows: 0
109 :stub-columns: 0 109 :stub-columns: 0
110 :widths: 1 1 2 110 :widths: 1 1 2
111 111
112 * - __u64 112 * - __u64
113 - ``v4l2_std_id`` 113 - ``v4l2_std_id``
114 - This type is a set, each bit represent 114 - This type is a set, each bit representing another video standard
115 as listed below and in :ref:`video-sta 115 as listed below and in :ref:`video-standards`. The 32 most
116 significant bits are reserved for cust 116 significant bits are reserved for custom (driver defined) video
117 standards. 117 standards.
118 118
119 119
120 .. code-block:: c 120 .. code-block:: c
121 121
122 #define V4L2_STD_PAL_B ((v4l2_std 122 #define V4L2_STD_PAL_B ((v4l2_std_id)0x00000001)
123 #define V4L2_STD_PAL_B1 ((v4l2_std 123 #define V4L2_STD_PAL_B1 ((v4l2_std_id)0x00000002)
124 #define V4L2_STD_PAL_G ((v4l2_std 124 #define V4L2_STD_PAL_G ((v4l2_std_id)0x00000004)
125 #define V4L2_STD_PAL_H ((v4l2_std 125 #define V4L2_STD_PAL_H ((v4l2_std_id)0x00000008)
126 #define V4L2_STD_PAL_I ((v4l2_std 126 #define V4L2_STD_PAL_I ((v4l2_std_id)0x00000010)
127 #define V4L2_STD_PAL_D ((v4l2_std 127 #define V4L2_STD_PAL_D ((v4l2_std_id)0x00000020)
128 #define V4L2_STD_PAL_D1 ((v4l2_std 128 #define V4L2_STD_PAL_D1 ((v4l2_std_id)0x00000040)
129 #define V4L2_STD_PAL_K ((v4l2_std 129 #define V4L2_STD_PAL_K ((v4l2_std_id)0x00000080)
130 130
131 #define V4L2_STD_PAL_M ((v4l2_std 131 #define V4L2_STD_PAL_M ((v4l2_std_id)0x00000100)
132 #define V4L2_STD_PAL_N ((v4l2_std 132 #define V4L2_STD_PAL_N ((v4l2_std_id)0x00000200)
133 #define V4L2_STD_PAL_Nc ((v4l2_std 133 #define V4L2_STD_PAL_Nc ((v4l2_std_id)0x00000400)
134 #define V4L2_STD_PAL_60 ((v4l2_std 134 #define V4L2_STD_PAL_60 ((v4l2_std_id)0x00000800)
135 135
136 ``V4L2_STD_PAL_60`` is a hybrid standard with 136 ``V4L2_STD_PAL_60`` is a hybrid standard with 525 lines, 60 Hz refresh
137 rate, and PAL color modulation with a 4.43 MHz 137 rate, and PAL color modulation with a 4.43 MHz color subcarrier. Some
138 PAL video recorders can play back NTSC tapes i 138 PAL video recorders can play back NTSC tapes in this mode for display on
139 a 50/60 Hz agnostic PAL TV. 139 a 50/60 Hz agnostic PAL TV.
140 140
141 .. code-block:: c 141 .. code-block:: c
142 142
143 #define V4L2_STD_NTSC_M ((v4l2_std 143 #define V4L2_STD_NTSC_M ((v4l2_std_id)0x00001000)
144 #define V4L2_STD_NTSC_M_JP ((v4l2_std 144 #define V4L2_STD_NTSC_M_JP ((v4l2_std_id)0x00002000)
145 #define V4L2_STD_NTSC_443 ((v4l2_std 145 #define V4L2_STD_NTSC_443 ((v4l2_std_id)0x00004000)
146 146
147 ``V4L2_STD_NTSC_443`` is a hybrid standard wit 147 ``V4L2_STD_NTSC_443`` is a hybrid standard with 525 lines, 60 Hz refresh
148 rate, and NTSC color modulation with a 4.43 MH 148 rate, and NTSC color modulation with a 4.43 MHz color subcarrier.
149 149
150 .. code-block:: c 150 .. code-block:: c
151 151
152 #define V4L2_STD_NTSC_M_KR ((v4l2_std 152 #define V4L2_STD_NTSC_M_KR ((v4l2_std_id)0x00008000)
153 153
154 #define V4L2_STD_SECAM_B ((v4l2_std 154 #define V4L2_STD_SECAM_B ((v4l2_std_id)0x00010000)
155 #define V4L2_STD_SECAM_D ((v4l2_std 155 #define V4L2_STD_SECAM_D ((v4l2_std_id)0x00020000)
156 #define V4L2_STD_SECAM_G ((v4l2_std 156 #define V4L2_STD_SECAM_G ((v4l2_std_id)0x00040000)
157 #define V4L2_STD_SECAM_H ((v4l2_std 157 #define V4L2_STD_SECAM_H ((v4l2_std_id)0x00080000)
158 #define V4L2_STD_SECAM_K ((v4l2_std 158 #define V4L2_STD_SECAM_K ((v4l2_std_id)0x00100000)
159 #define V4L2_STD_SECAM_K1 ((v4l2_std 159 #define V4L2_STD_SECAM_K1 ((v4l2_std_id)0x00200000)
160 #define V4L2_STD_SECAM_L ((v4l2_std 160 #define V4L2_STD_SECAM_L ((v4l2_std_id)0x00400000)
161 #define V4L2_STD_SECAM_LC ((v4l2_std 161 #define V4L2_STD_SECAM_LC ((v4l2_std_id)0x00800000)
162 162
163 /* ATSC/HDTV */ 163 /* ATSC/HDTV */
164 #define V4L2_STD_ATSC_8_VSB ((v4l2_std 164 #define V4L2_STD_ATSC_8_VSB ((v4l2_std_id)0x01000000)
165 #define V4L2_STD_ATSC_16_VSB ((v4l2_std 165 #define V4L2_STD_ATSC_16_VSB ((v4l2_std_id)0x02000000)
166 166
167 ``V4L2_STD_ATSC_8_VSB`` and ``V4L2_STD_ATSC_16 167 ``V4L2_STD_ATSC_8_VSB`` and ``V4L2_STD_ATSC_16_VSB`` are U.S.
168 terrestrial digital TV standards. Presently th 168 terrestrial digital TV standards. Presently the V4L2 API does not
169 support digital TV. See also the Linux DVB API 169 support digital TV. See also the Linux DVB API at
170 `https://linuxtv.org <https://linuxtv.org>`__. 170 `https://linuxtv.org <https://linuxtv.org>`__.
171 171
172 .. code-block:: c 172 .. code-block:: c
173 173
174 #define V4L2_STD_PAL_BG (V4L2_STD_ 174 #define V4L2_STD_PAL_BG (V4L2_STD_PAL_B |
175 V4L2_STD_PAL_B1 | 175 V4L2_STD_PAL_B1 |
176 V4L2_STD_PAL_G) 176 V4L2_STD_PAL_G)
177 #define V4L2_STD_B (V4L2_STD_ 177 #define V4L2_STD_B (V4L2_STD_PAL_B |
178 V4L2_STD_PAL_B1 | 178 V4L2_STD_PAL_B1 |
179 V4L2_STD_SECAM_B) 179 V4L2_STD_SECAM_B)
180 #define V4L2_STD_GH (V4L2_STD_ 180 #define V4L2_STD_GH (V4L2_STD_PAL_G |
181 V4L2_STD_PAL_H | 181 V4L2_STD_PAL_H |
182 V4L2_STD_SECAM_G | 182 V4L2_STD_SECAM_G |
183 V4L2_STD_SECAM_H) 183 V4L2_STD_SECAM_H)
184 #define V4L2_STD_PAL_DK (V4L2_STD_ 184 #define V4L2_STD_PAL_DK (V4L2_STD_PAL_D |
185 V4L2_STD_PAL_D1 | 185 V4L2_STD_PAL_D1 |
186 V4L2_STD_PAL_K) 186 V4L2_STD_PAL_K)
187 #define V4L2_STD_PAL (V4L2_STD_ 187 #define V4L2_STD_PAL (V4L2_STD_PAL_BG |
188 V4L2_STD_PAL_DK | 188 V4L2_STD_PAL_DK |
189 V4L2_STD_PAL_H | 189 V4L2_STD_PAL_H |
190 V4L2_STD_PAL_I) 190 V4L2_STD_PAL_I)
191 #define V4L2_STD_NTSC (V4L2_STD_ 191 #define V4L2_STD_NTSC (V4L2_STD_NTSC_M |
192 V4L2_STD_NTSC_M_JP | 192 V4L2_STD_NTSC_M_JP |
193 V4L2_STD_NTSC_M_KR) 193 V4L2_STD_NTSC_M_KR)
194 #define V4L2_STD_MN (V4L2_STD_ 194 #define V4L2_STD_MN (V4L2_STD_PAL_M |
195 V4L2_STD_PAL_N | 195 V4L2_STD_PAL_N |
196 V4L2_STD_PAL_Nc | 196 V4L2_STD_PAL_Nc |
197 V4L2_STD_NTSC) 197 V4L2_STD_NTSC)
198 #define V4L2_STD_SECAM_DK (V4L2_STD_ 198 #define V4L2_STD_SECAM_DK (V4L2_STD_SECAM_D |
199 V4L2_STD_SECAM_K | 199 V4L2_STD_SECAM_K |
200 V4L2_STD_SECAM_K1) 200 V4L2_STD_SECAM_K1)
201 #define V4L2_STD_DK (V4L2_STD_ 201 #define V4L2_STD_DK (V4L2_STD_PAL_DK |
202 V4L2_STD_SECAM_DK) 202 V4L2_STD_SECAM_DK)
203 203
204 #define V4L2_STD_SECAM (V4L2_STD_ 204 #define V4L2_STD_SECAM (V4L2_STD_SECAM_B |
205 V4L2_STD_SECAM_G | 205 V4L2_STD_SECAM_G |
206 V4L2_STD_SECAM_H | 206 V4L2_STD_SECAM_H |
207 V4L2_STD_SECAM_DK | 207 V4L2_STD_SECAM_DK |
208 V4L2_STD_SECAM_L | 208 V4L2_STD_SECAM_L |
209 V4L2_STD_SECAM_LC) 209 V4L2_STD_SECAM_LC)
210 210
211 #define V4L2_STD_525_60 (V4L2_STD_ 211 #define V4L2_STD_525_60 (V4L2_STD_PAL_M |
212 V4L2_STD_PAL_60 | 212 V4L2_STD_PAL_60 |
213 V4L2_STD_NTSC | 213 V4L2_STD_NTSC |
214 V4L2_STD_NTSC_443) 214 V4L2_STD_NTSC_443)
215 #define V4L2_STD_625_50 (V4L2_STD_ 215 #define V4L2_STD_625_50 (V4L2_STD_PAL |
216 V4L2_STD_PAL_N | 216 V4L2_STD_PAL_N |
217 V4L2_STD_PAL_Nc | 217 V4L2_STD_PAL_Nc |
218 V4L2_STD_SECAM) 218 V4L2_STD_SECAM)
219 219
220 #define V4L2_STD_UNKNOWN 0 220 #define V4L2_STD_UNKNOWN 0
221 #define V4L2_STD_ALL (V4L2_STD_ 221 #define V4L2_STD_ALL (V4L2_STD_525_60 |
222 V4L2_STD_625_50) 222 V4L2_STD_625_50)
223 223
224 .. raw:: latex 224 .. raw:: latex
225 225
226 \begingroup 226 \begingroup
227 \tiny 227 \tiny
228 \setlength{\tabcolsep}{2pt} 228 \setlength{\tabcolsep}{2pt}
229 229
230 .. NTSC/M PAL/M 230 .. NTSC/M PAL/M /N /B /D /H /I SECAM/B /D /K1 /L
231 .. tabularcolumns:: |p{1.43cm}|p{1.38cm}|p{1.5 231 .. tabularcolumns:: |p{1.43cm}|p{1.38cm}|p{1.59cm}|p{1.7cm}|p{1.7cm}|p{1.17cm}|p{0.64cm}|p{1.71cm}|p{1.6cm}|p{1.07cm}|p{1.07cm}|p{1.07cm}|
232 232
233 .. _video-standards: 233 .. _video-standards:
234 234
235 .. flat-table:: Video Standards (based on :ref 235 .. flat-table:: Video Standards (based on :ref:`itu470`)
236 :header-rows: 1 236 :header-rows: 1
237 :stub-columns: 0 237 :stub-columns: 0
238 238
239 * - Characteristics 239 * - Characteristics
240 - M/NTSC [#f2]_ 240 - M/NTSC [#f2]_
241 - M/PAL 241 - M/PAL
242 - N/PAL [#f3]_ 242 - N/PAL [#f3]_
243 - B, B1, G/PAL 243 - B, B1, G/PAL
244 - D, D1, K/PAL 244 - D, D1, K/PAL
245 - H/PAL 245 - H/PAL
246 - I/PAL 246 - I/PAL
247 - B, G/SECAM 247 - B, G/SECAM
248 - D, K/SECAM 248 - D, K/SECAM
249 - K1/SECAM 249 - K1/SECAM
250 - L/SECAM 250 - L/SECAM
251 * - Frame lines 251 * - Frame lines
252 - :cspan:`1` 525 252 - :cspan:`1` 525
253 - :cspan:`8` 625 253 - :cspan:`8` 625
254 * - Frame period (s) 254 * - Frame period (s)
255 - :cspan:`1` 1001/30000 255 - :cspan:`1` 1001/30000
256 - :cspan:`8` 1/25 256 - :cspan:`8` 1/25
257 * - Chrominance sub-carrier frequency (Hz) 257 * - Chrominance sub-carrier frequency (Hz)
258 - 3579545 ± 10 258 - 3579545 ± 10
259 - 3579611.49 ± 10 259 - 3579611.49 ± 10
260 - 4433618.75 ± 5 260 - 4433618.75 ± 5
261 261
262 (3582056.25 ± 5) 262 (3582056.25 ± 5)
263 - :cspan:`3` 4433618.75 ± 5 263 - :cspan:`3` 4433618.75 ± 5
264 - 4433618.75 ± 1 264 - 4433618.75 ± 1
265 - :cspan:`2` f\ :sub:`OR` = 4406250 ± 2 265 - :cspan:`2` f\ :sub:`OR` = 4406250 ± 2000,
266 266
267 f\ :sub:`OB` = 4250000 ± 2000 267 f\ :sub:`OB` = 4250000 ± 2000
268 * - Nominal radio-frequency channel bandwi 268 * - Nominal radio-frequency channel bandwidth (MHz)
269 - 6 269 - 6
270 - 6 270 - 6
271 - 6 271 - 6
272 - B: 7; B1, G: 8 272 - B: 7; B1, G: 8
273 - 8 273 - 8
274 - 8 274 - 8
275 - 8 275 - 8
276 - 8 276 - 8
277 - 8 277 - 8
278 - 8 278 - 8
279 - 8 279 - 8
280 * - Sound carrier relative to vision carri 280 * - Sound carrier relative to vision carrier (MHz)
281 - 4.5 281 - 4.5
282 - 4.5 282 - 4.5
283 - 4.5 283 - 4.5
284 - 5.5 ± 0.001 [#f4]_ [#f5]_ [#f6]_ 284 - 5.5 ± 0.001 [#f4]_ [#f5]_ [#f6]_ [#f7]_
285 - 6.5 ± 0.001 285 - 6.5 ± 0.001
286 - 5.5 286 - 5.5
287 - 5.9996 ± 0.0005 287 - 5.9996 ± 0.0005
288 - 5.5 ± 0.001 288 - 5.5 ± 0.001
289 - 6.5 ± 0.001 289 - 6.5 ± 0.001
290 - 6.5 290 - 6.5
291 - 6.5 [#f8]_ 291 - 6.5 [#f8]_
292 292
293 .. raw:: latex 293 .. raw:: latex
294 294
295 \endgroup 295 \endgroup
296 296
297 297
298 Return Value 298 Return Value
299 ============ 299 ============
300 300
301 On success 0 is returned, on error -1 and the 301 On success 0 is returned, on error -1 and the ``errno`` variable is set
302 appropriately. The generic error codes are des 302 appropriately. The generic error codes are described at the
303 :ref:`Generic Error Codes <gen-errors>` chapte 303 :ref:`Generic Error Codes <gen-errors>` chapter.
304 304
305 EINVAL 305 EINVAL
306 The struct :c:type:`v4l2_standard` ``index 306 The struct :c:type:`v4l2_standard` ``index`` is out
307 of bounds. 307 of bounds.
308 308
309 ENODATA 309 ENODATA
310 Standard video timings are not supported f 310 Standard video timings are not supported for this input or output.
311 311
312 .. [#f1] 312 .. [#f1]
313 The supported standards may overlap and we 313 The supported standards may overlap and we need an unambiguous set to
314 find the current standard returned by :ref: 314 find the current standard returned by :ref:`VIDIOC_G_STD <VIDIOC_G_STD>`.
315 315
316 .. [#f2] 316 .. [#f2]
317 Japan uses a standard similar to M/NTSC (V4 317 Japan uses a standard similar to M/NTSC (V4L2_STD_NTSC_M_JP).
318 318
319 .. [#f3] 319 .. [#f3]
320 The values in brackets apply to the combina 320 The values in brackets apply to the combination N/PAL a.k.a.
321 N\ :sub:`C` used in Argentina (V4L2_STD_PAL 321 N\ :sub:`C` used in Argentina (V4L2_STD_PAL_Nc).
322 322
323 .. [#f4] 323 .. [#f4]
324 In the Federal Republic of Germany, Austria 324 In the Federal Republic of Germany, Austria, Italy, the Netherlands,
325 Slovakia and Switzerland a system of two so 325 Slovakia and Switzerland a system of two sound carriers is used, the
326 frequency of the second carrier being 242.1 326 frequency of the second carrier being 242.1875 kHz above the
327 frequency of the first sound carrier. For s 327 frequency of the first sound carrier. For stereophonic sound
328 transmissions a similar system is used in A 328 transmissions a similar system is used in Australia.
329 329
330 .. [#f5] 330 .. [#f5]
331 New Zealand uses a sound carrier displaced 331 New Zealand uses a sound carrier displaced 5.4996 ± 0.0005 MHz from
332 the vision carrier. 332 the vision carrier.
333 333
334 .. [#f6] 334 .. [#f6]
335 In Denmark, Finland, New Zealand, Sweden an 335 In Denmark, Finland, New Zealand, Sweden and Spain a system of two
336 sound carriers is used. In Iceland, Norway 336 sound carriers is used. In Iceland, Norway and Poland the same system
337 is being introduced. The second carrier is 337 is being introduced. The second carrier is 5.85 MHz above the vision
338 carrier and is DQPSK modulated with 728 kbi 338 carrier and is DQPSK modulated with 728 kbit/s sound and data
339 multiplex. (NICAM system) 339 multiplex. (NICAM system)
340 340
341 .. [#f7] 341 .. [#f7]
342 In the United Kingdom, a system of two soun 342 In the United Kingdom, a system of two sound carriers is used. The
343 second sound carrier is 6.552 MHz above the 343 second sound carrier is 6.552 MHz above the vision carrier and is
344 DQPSK modulated with a 728 kbit/s sound and 344 DQPSK modulated with a 728 kbit/s sound and data multiplex able to
345 carry two sound channels. (NICAM system) 345 carry two sound channels. (NICAM system)
346 346
347 .. [#f8] 347 .. [#f8]
348 In France, a digital carrier 5.85 MHz away 348 In France, a digital carrier 5.85 MHz away from the vision carrier
349 may be used in addition to the main sound c 349 may be used in addition to the main sound carrier. It is modulated in
350 differentially encoded QPSK with a 728 kbit 350 differentially encoded QPSK with a 728 kbit/s sound and data
351 multiplexer capable of carrying two sound c 351 multiplexer capable of carrying two sound channels. (NICAM system)
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