testcases/kernel/device-drivers/v4l/user_space/doc/spec/r12342.htm - platform/external/ltp - Gitiles

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 ><H1
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 ></A
 >ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</H1
 ><DIV
 CLASS="REFNAMEDIV"
 ><A
 NAME="AEN12346"
 ></A
 ><H2
 >Name</H2
 >VIDIOC_G_TUNER, VIDIOC_S_TUNER&nbsp;--&nbsp;Get or set tuner attributes</DIV
 ><DIV
 CLASS="REFSYNOPSISDIV"
 ><A
 NAME="AEN12350"
 ></A
 ><H2
 >Synopsis</H2
 ><DIV
 CLASS="FUNCSYNOPSIS"
 ><P
 ></P
 ><A
 NAME="AEN12351"
 ></A
 ><P
 ><CODE
 ><CODE
 CLASS="FUNCDEF"
 >int ioctl</CODE
 >(int fd, int request, struct v4l2_tuner
 *argp);</CODE
 ></P
 ><P
 ></P
 ></DIV
 ><DIV
 CLASS="FUNCSYNOPSIS"
 ><P
 ></P
 ><A
 NAME="AEN12361"
 ></A
 ><P
 ><CODE
 ><CODE
 CLASS="FUNCDEF"
 >int ioctl</CODE
 >(int fd, int request, const struct v4l2_tuner
 *argp);</CODE
 ></P
 ><P
 ></P
 ></DIV
 ></DIV
 ><DIV
 CLASS="REFSECT1"
 ><A
 NAME="AEN12371"
 ></A
 ><H2
 >Arguments</H2
 ><P
 ></P
 ><DIV
 CLASS="VARIABLELIST"
 ><DL
 ><DT
 ><CODE
 CLASS="PARAMETER"
 >fd</CODE
 ></DT
 ><DD
 ><P
 >File descriptor returned by <A
 HREF="r14090.htm"
 ><CODE
 CLASS="FUNCTION"
 >open()</CODE
 ></A
 >.</P
 ></DD
 ><DT
 ><CODE
 CLASS="PARAMETER"
 >request</CODE
 ></DT
 ><DD
 ><P
 >VIDIOC_G_TUNER, VIDIOC_S_TUNER</P
 ></DD
 ><DT
 ><CODE
 CLASS="PARAMETER"
 >argp</CODE
 ></DT
 ><DD
 ><P
 ></P
 ></DD
 ></DL
 ></DIV
 ></DIV
 ><DIV
 CLASS="REFSECT1"
 ><A
 NAME="AEN12391"
 ></A
 ><H2
 >Description</H2
 ><P
 >To query the attributes of a tuner applications initialize the
 <CODE
 CLASS="STRUCTFIELD"
 >index</CODE
 > field and zero out the
 <CODE
 CLASS="STRUCTFIELD"
 >reserved</CODE
 > array of a struct&nbsp;<A
 HREF="r12342.htm#V4L2-TUNER"
 >v4l2_tuner</A
 > and call the
 <CODE
 CLASS="CONSTANT"
 >VIDIOC_G_TUNER</CODE
 > ioctl with a pointer to this
 structure. Drivers fill the rest of the structure or return an
 <SPAN
 CLASS="ERRORCODE"
 >EINVAL</SPAN
 > error code when the index is out of bounds. To enumerate all tuners
 applications shall begin at index zero, incrementing by one until the
 driver returns <SPAN
 CLASS="ERRORCODE"
 >EINVAL</SPAN
 >.</P
 ><P
 >Tuners have two writable properties, the audio mode and
 the radio frequency. To change the audio mode, applications initialize
 the <CODE
 CLASS="STRUCTFIELD"
 >index</CODE
 >,
 <CODE
 CLASS="STRUCTFIELD"
 >audmode</CODE
 > and
 <CODE
 CLASS="STRUCTFIELD"
 >reserved</CODE
 > fields and call the
 <CODE
 CLASS="CONSTANT"
 >VIDIOC_S_TUNER</CODE
 > ioctl. This will
 <SPAN
 CLASS="emphasis"
 ><I
 CLASS="EMPHASIS"
 >not</I
 ></SPAN
 > change the current tuner, which is determined
 by the current video input. Drivers may choose a different audio mode
 if the requested mode is invalid or unsupported. Since this is a
 write-only ioctl, it does not return the actually
 selected audio mode.</P
 ><P
 >To change the radio frequency the <A
 HREF="r11094.htm"
 ><CODE
 CLASS="CONSTANT"
 >VIDIOC_S_FREQUENCY</CODE
 ></A
 > ioctl
 is available.</P
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="V4L2-TUNER"
 ></A
 ><P
 ><B
 >Table 1. struct <CODE
 CLASS="STRUCTNAME"
 >v4l2_tuner</CODE
 ></B
 ></P
 ><TABLE
 BORDER="0"
 FRAME="void"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="25%"
 TITLE="C1"><COL
 WIDTH="25%"
 TITLE="C2"><COL
 WIDTH="25%"
 TITLE="C3"><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >index</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >Identifies the tuner, set by the
 application.</TD
 ></TR
 ><TR
 ><TD
 >__u8</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >name</CODE
 >[32]</TD
 ><TD
 COLSPAN="2"
 ><P
 >Name of the tuner, a
 NUL-terminated ASCII string. This information is intended for the
 user.</P
 ></TD
 ></TR
 ><TR
 ><TD
 >enum&nbsp;<A
 HREF="r12342.htm#V4L2-TUNER-TYPE"
 >v4l2_tuner_type</A
 ></TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >type</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >Type of the tuner, see <A
 HREF="r12342.htm#V4L2-TUNER-TYPE"
 >Table 2</A
 >.</TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >capability</CODE
 ></TD
 ><TD
 COLSPAN="2"
 ><P
 >Tuner capability flags, see
 <A
 HREF="r12342.htm#TUNER-CAPABILITY"
 >Table 3</A
 >. Audio flags indicate the ability
 to decode audio subprograms. They will <SPAN
 CLASS="emphasis"
 ><I
 CLASS="EMPHASIS"
 >not</I
 ></SPAN
 >
 change, for example with the current video standard.</P
 ><P
 >When
 the structure refers to a radio tuner only the
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LOW</CODE
 > and
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_STEREO</CODE
 > flags can be
 set.</P
 ></TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >rangelow</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >The lowest tunable frequency in
 units of 62.5 kHz, or if the <CODE
 CLASS="STRUCTFIELD"
 >capability</CODE
 >
 flag <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LOW</CODE
 > is set, in units of 62.5
 Hz.</TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >rangehigh</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >The highest tunable frequency in
 units of 62.5 kHz, or if the <CODE
 CLASS="STRUCTFIELD"
 >capability</CODE
 >
 flag <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LOW</CODE
 > is set, in units of 62.5
 Hz.</TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >rxsubchans</CODE
 ></TD
 ><TD
 COLSPAN="2"
 ><P
 >Some tuners or audio
 decoders can determine the received audio subprograms by analyzing
 audio carriers, pilot tones or other indicators. To pass this
 information drivers set flags defined in <A
 HREF="r12342.htm#TUNER-RXSUBCHANS"
 >Table 4</A
 > in this field. For
 example:</P
 ></TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_MONO</CODE
 ></TD
 ><TD
 >receiving mono audio</TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >STEREO | SAP</CODE
 ></TD
 ><TD
 >receiving stereo audio and a secondary audio
 program</TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >MONO | STEREO</CODE
 ></TD
 ><TD
 >receiving mono or stereo audio, the hardware cannot
 distinguish</TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >LANG1 | LANG2</CODE
 ></TD
 ><TD
 >receiving bilingual audio</TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >MONO | STEREO | LANG1 | LANG2</CODE
 ></TD
 ><TD
 >receiving mono, stereo or bilingual
 audio</TD
 ></TR
 ><TR
 ><TD
 >&nbsp;</TD
 ><TD
 >&nbsp;</TD
 ><TD
 COLSPAN="2"
 ><P
 >When the
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_STEREO</CODE
 >,
 <CODE
 CLASS="CONSTANT"
 >_LANG1</CODE
 >, <CODE
 CLASS="CONSTANT"
 >_LANG2</CODE
 > or
 <CODE
 CLASS="CONSTANT"
 >_SAP</CODE
 > flag is cleared in the
 <CODE
 CLASS="STRUCTFIELD"
 >capability</CODE
 > field, the corresponding
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_</CODE
 > flag must not be set
 here.</P
 ><P
 >This field is valid only if this is the tuner of the
 current video input, or when the structure refers to a radio
 tuner.</P
 ></TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >audmode</CODE
 ></TD
 ><TD
 COLSPAN="2"
 ><P
 >The selected audio mode, see
 <A
 HREF="r12342.htm#TUNER-AUDMODE"
 >Table 5</A
 > for valid values. The audio mode does
 not affect audio subprogram detection, and like a <A
 HREF="x542.htm"
 >control</A
 > it does not automatically change
 unless the requested mode is invalid or unsupported. See <A
 HREF="r12342.htm#TUNER-MATRIX"
 >Table 6</A
 > for possible results when
 the selected and received audio programs do not
 match.</P
 ><P
 >Currently this is the only field of struct
 <CODE
 CLASS="STRUCTNAME"
 >v4l2_tuner</CODE
 > applications can
 change.</P
 ></TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >signal</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >The signal strength if known, ranging
 from 0 to 65535. Higher values indicate a better signal.</TD
 ></TR
 ><TR
 ><TD
 >__s32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >afc</CODE
 ></TD
 ><TD
 COLSPAN="2"
 >Automatic frequency control: When the
 <CODE
 CLASS="STRUCTFIELD"
 >afc</CODE
 > value is negative, the frequency is too
 low, when positive too high.</TD
 ></TR
 ><TR
 ><TD
 >__u32</TD
 ><TD
 ><CODE
 CLASS="STRUCTFIELD"
 >reserved</CODE
 >[4]</TD
 ><TD
 COLSPAN="2"
 >Reserved for future extensions. Drivers and
 applications must set the array to zero.</TD
 ></TR
 ></TBODY
 ></TABLE
 ></DIV
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="V4L2-TUNER-TYPE"
 ></A
 ><P
 ><B
 >Table 2. enum v4l2_tuner_type</B
 ></P
 ><TABLE
 BORDER="0"
 FRAME="void"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="38%"
 TITLE="C1"><COL
 WIDTH="12%"
 TITLE="C2"><COL
 WIDTH="50%"
 TITLE="C3"><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_RADIO</CODE
 ></TD
 ><TD
 >1</TD
 ><TD
 >&nbsp;</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 ></TD
 ><TD
 >2</TD
 ><TD
 >&nbsp;</TD
 ></TR
 ></TBODY
 ></TABLE
 ></DIV
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="TUNER-CAPABILITY"
 ></A
 ><P
 ><B
 >Table 3. Tuner and Modulator Capability Flags</B
 ></P
 ><TABLE
 BORDER="0"
 FRAME="void"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="38%"
 TITLE="C1"><COL
 WIDTH="12%"
 TITLE="C2"><COL
 WIDTH="50%"
 TITLE="C3"><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LOW</CODE
 ></TD
 ><TD
 >0x0001</TD
 ><TD
 >When set, tuning frequencies are expressed in units of
 62.5&nbsp;Hz, otherwise in units of 62.5&nbsp;kHz.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_NORM</CODE
 ></TD
 ><TD
 >0x0002</TD
 ><TD
 >This is a multi-standard tuner; the video standard
 can or must be switched. (B/G PAL tuners for example are typically not
       considered multi-standard because the video standard is automatically
       determined from the frequency band.) The set of supported video
       standards is available from the struct&nbsp;<A
 HREF="r8936.htm#V4L2-INPUT"
 >v4l2_input</A
 > pointing to this tuner,
       see the description of ioctl <A
 HREF="r8936.htm"
 ><CODE
 CLASS="CONSTANT"
 >VIDIOC_ENUMINPUT</CODE
 ></A
 > for details. Only
       <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners can have this capability.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_STEREO</CODE
 ></TD
 ><TD
 >0x0010</TD
 ><TD
 >Stereo audio reception is supported.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LANG1</CODE
 ></TD
 ><TD
 >0x0040</TD
 ><TD
 >Reception of the primary language of a bilingual
 audio program is supported. Bilingual audio is a feature of
 two-channel systems, transmitting the primary language monaural on the
 main audio carrier and a secondary language monaural on a second
 carrier. Only
       <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners can have this capability.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LANG2</CODE
 ></TD
 ><TD
 >0x0020</TD
 ><TD
 >Reception of the secondary language of a bilingual
 audio program is supported. Only
       <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners can have this capability.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_SAP</CODE
 ></TD
 ><TD
 >0x0020</TD
 ><TD
 ><P
 >Reception of a secondary audio program is
 supported. This is a feature of the BTSC system which accompanies the
 NTSC video standard. Two audio carriers are available for mono or
 stereo transmissions of a primary language, and an independent third
 carrier for a monaural secondary language. Only
       <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners can have this capability.</P
 ><P
 >Note the
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_LANG2</CODE
 > and
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_SAP</CODE
 > flags are synonyms.
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_CAP_SAP</CODE
 > applies when the tuner
 supports the <CODE
 CLASS="CONSTANT"
 >V4L2_STD_NTSC_M</CODE
 > video
 standard.</P
 ></TD
 ></TR
 ></TBODY
 ></TABLE
 ></DIV
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="TUNER-RXSUBCHANS"
 ></A
 ><P
 ><B
 >Table 4. Tuner Audio Reception Flags</B
 ></P
 ><TABLE
 BORDER="0"
 FRAME="void"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="38%"
 TITLE="C1"><COL
 WIDTH="12%"
 TITLE="C2"><COL
 WIDTH="50%"
 TITLE="C3"><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_MONO</CODE
 ></TD
 ><TD
 >0x0001</TD
 ><TD
 >The tuner receives a mono audio signal.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_STEREO</CODE
 ></TD
 ><TD
 >0x0002</TD
 ><TD
 >The tuner receives a stereo audio signal.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_LANG1</CODE
 ></TD
 ><TD
 >0x0008</TD
 ><TD
 >The tuner receives the primary language of a
 bilingual audio signal. Drivers must clear this flag when the current
 video standard is <CODE
 CLASS="CONSTANT"
 >V4L2_STD_NTSC_M</CODE
 >.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_LANG2</CODE
 ></TD
 ><TD
 >0x0004</TD
 ><TD
 >The tuner receives the secondary language of a
 bilingual audio signal (or a second audio program).</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_SAP</CODE
 ></TD
 ><TD
 >0x0004</TD
 ><TD
 >The tuner receives a Second Audio Program. Note the
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_LANG2</CODE
 > and
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_SAP</CODE
 > flags are synonyms. The
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_SAP</CODE
 > flag applies when the
 current video standard is <CODE
 CLASS="CONSTANT"
 >V4L2_STD_NTSC_M</CODE
 >.</TD
 ></TR
 ></TBODY
 ></TABLE
 ></DIV
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="TUNER-AUDMODE"
 ></A
 ><P
 ><B
 >Table 5. Tuner Audio Modes</B
 ></P
 ><TABLE
 BORDER="0"
 FRAME="void"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="38%"
 TITLE="C1"><COL
 WIDTH="12%"
 TITLE="C2"><COL
 WIDTH="50%"
 TITLE="C3"><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_MONO</CODE
 ></TD
 ><TD
 >0</TD
 ><TD
 >Play mono audio. When the tuner receives a stereo
 signal this a down-mix of the left and right channel. When the tuner
 receives a bilingual or SAP signal this mode selects the primary
 language.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_STEREO</CODE
 ></TD
 ><TD
 >1</TD
 ><TD
 ><P
 >Play stereo audio. When the tuner receives
 bilingual audio it may play different languages on the left and right
 channel or the primary language on both channels. behave as in mono
 mode.</P
 ><P
 >Playing different languages in this mode is
 deprecated. New drivers should do this only in
 <CODE
 CLASS="CONSTANT"
 >MODE_LANG1_LANG2</CODE
 >.</P
 ><P
 >When the tuner
 receives no stereo signal or does not support stereo reception the
 driver shall fall back to <CODE
 CLASS="CONSTANT"
 >MODE_MONO</CODE
 >.</P
 ></TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_LANG1</CODE
 ></TD
 ><TD
 >3</TD
 ><TD
 >Play the primary language, mono or stereo. Only
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners support this
 mode.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_LANG2</CODE
 ></TD
 ><TD
 >2</TD
 ><TD
 >Play the secondary language, mono. When the tuner
 receives no bilingual audio or SAP, or their reception is not
 supported the driver shall fall back to mono or stereo mode. Only
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners support this
 mode.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_SAP</CODE
 ></TD
 ><TD
 >2</TD
 ><TD
 >Play the Second Audio Program. When the tuner
 receives no bilingual audio or SAP, or their reception is not
 supported the driver shall fall back to mono or stereo mode. Only
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners support this mode.
 Note the <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_LANG2</CODE
 > and
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_SAP</CODE
 > are synonyms.</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_LANG1_LANG2</CODE
 ></TD
 ><TD
 >4</TD
 ><TD
 >Play the primary language on the left channel, the
 secondary language on the right channel. When the tuner receives no
 bilingual audio or SAP, it shall fall back to
 <CODE
 CLASS="CONSTANT"
 >MODE_LANG1</CODE
 > or <CODE
 CLASS="CONSTANT"
 >MODE_MONO</CODE
 >.
 Only <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_ANALOG_TV</CODE
 > tuners support this
 mode.</TD
 ></TR
 ></TBODY
 ></TABLE
 ></DIV
 ><DIV
 CLASS="TABLE"
 ><A
 NAME="TUNER-MATRIX"
 ></A
 ><P
 ><B
 >Table 6. Tuner Audio Matrix</B
 ></P
 ><TABLE
 BORDER="1"
 FRAME="border"
 WIDTH="100%"
 CLASS="CALSTABLE"
 ><COL
 WIDTH="20%"
 ALIGN="LEFT"><COL
 WIDTH="20%"
 TITLE="C2"><COL
 WIDTH="20%"><COL
 WIDTH="20%"><COL><COL
 WIDTH="20%"
 TITLE="C6"><THEAD
 ><TR
 ><TH
 >&nbsp;</TH
 ><TH
 COLSPAN="5"
 ALIGN="CENTER"
 >Selected
 <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_MODE_</CODE
 ></TH
 ></TR
 ><TR
 ><TH
 >Received <CODE
 CLASS="CONSTANT"
 >V4L2_TUNER_SUB_</CODE
 ></TH
 ><TH
 ><CODE
 CLASS="CONSTANT"
 >MONO</CODE
 ></TH
 ><TH
 ><CODE
 CLASS="CONSTANT"
 >STEREO</CODE
 ></TH
 ><TH
 ><CODE
 CLASS="CONSTANT"
 >LANG1</CODE
 ></TH
 ><TH
 ><CODE
 CLASS="CONSTANT"
 >LANG2 = SAP</CODE
 ></TH
 ><TH
 ><CODE
 CLASS="CONSTANT"
 >LANG1_LANG2</CODE
 ><A
 NAME="AEN12723"
 HREF="r12342.htm#FTN.AEN12723"
 ><SPAN
 CLASS="footnote"
 >[a]</SPAN
 ></A
 ></TH
 ></TR
 ></THEAD
 ><TBODY
 VALIGN="TOP"
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >MONO</CODE
 ></TD
 ><TD
 >Mono</TD
 ><TD
 >Mono/Mono</TD
 ><TD
 >Mono</TD
 ><TD
 >Mono</TD
 ><TD
 >Mono/Mono</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >MONO | SAP</CODE
 ></TD
 ><TD
 >Mono</TD
 ><TD
 >Mono/Mono</TD
 ><TD
 >Mono</TD
 ><TD
 >SAP</TD
 ><TD
 >Mono/SAP (preferred) or Mono/Mono</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >STEREO</CODE
 ></TD
 ><TD
 >L+R</TD
 ><TD
 >L/R</TD
 ><TD
 >Stereo L/R (preferred) or Mono L+R</TD
 ><TD
 >Stereo L/R (preferred) or Mono L+R</TD
 ><TD
 >L/R (preferred) or L+R/L+R</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >STEREO | SAP</CODE
 ></TD
 ><TD
 >L+R</TD
 ><TD
 >L/R</TD
 ><TD
 >Stereo L/R (preferred) or Mono L+R</TD
 ><TD
 >SAP</TD
 ><TD
 >L+R/SAP (preferred) or L/R or L+R/L+R</TD
 ></TR
 ><TR
 ><TD
 ><CODE
 CLASS="CONSTANT"
 >LANG1 | LANG2</CODE
 ></TD
 ><TD
 >Language&nbsp;1</TD
 ><TD
 >Lang1/Lang2 (deprecated<A
 NAME="AEN12763"
 HREF="r12342.htm#FTN.AEN12763"
 ><SPAN
 CLASS="footnote"
 >[b]</SPAN
 ></A
 >) or
 Lang1/Lang1</TD
 ><TD
 >Language&nbsp;1</TD
 ><TD
 >Language&nbsp;2</TD
 ><TD
 >Lang1/Lang2 (preferred) or Lang1/Lang1</TD
 ></TR
 ></TBODY
 ><TR
 ><TD
 COLSPAN="6"
 >Notes:<BR><A
 NAME="FTN.AEN12723"
 >a. </A
 >This
 mode has been added in Linux 2.6.17 and may not be supported by older
 drivers.<BR><A
 NAME="FTN.AEN12763"
 >b. </A
 >Playback of
 both languages in <CODE
 CLASS="CONSTANT"
 >MODE_STEREO</CODE
 > is deprecated. In
 the future drivers should produce only the primary language in this
 mode. Applications should request
 <CODE
 CLASS="CONSTANT"
 >MODE_LANG1_LANG2</CODE
 > to record both languages or a
 stereo signal.<BR></TD
 ></TR
 ></TABLE
 ></DIV
 ></DIV
 ><DIV
 CLASS="REFSECT1"
 ><A
 NAME="AEN12770"
 ></A
 ><H2
 >Return Value</H2
 ><P
 >On success <SPAN
 CLASS="RETURNVALUE"
 >0</SPAN
 > is returned, on error <SPAN
 CLASS="RETURNVALUE"
 >-1</SPAN
 > and the <CODE
 CLASS="VARNAME"
 >errno</CODE
 > variable is set appropriately:</P
 ><P
 ></P
 ><DIV
 CLASS="VARIABLELIST"
 ><DL
 ><DT
 ><SPAN
 CLASS="ERRORCODE"
 >EINVAL</SPAN
 ></DT
 ><DD
 ><P
 >The struct&nbsp;<A
 HREF="r12342.htm#V4L2-TUNER"
 >v4l2_tuner</A
 > <CODE
 CLASS="STRUCTFIELD"
 >index</CODE
 > is
 out of bounds.</P
 ></DD
 ></DL
 ></DIV
 ></DIV
 ><DIV
 CLASS="NAVFOOTER"
 ><HR
 ALIGN="LEFT"
 WIDTH="100%"><TABLE
 SUMMARY="Footer navigation table"
 WIDTH="100%"
 BORDER="0"
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 WIDTH="33%"
 ALIGN="left"
 VALIGN="top"
 ><A
 HREF="r12265.htm"
 ACCESSKEY="P"
 >Prev</A
 ></TD
 ><TD
 WIDTH="34%"
 ALIGN="center"
 VALIGN="top"
 ><A
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 ><TD
 WIDTH="33%"
 ALIGN="right"
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 ACCESSKEY="N"
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 ></TR
 ><TR
 ><TD
 WIDTH="33%"
 ALIGN="left"
 VALIGN="top"
 >ioctl VIDIOC_G_STD, VIDIOC_S_STD</TD
 ><TD
 WIDTH="34%"
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 ><A
 HREF="r7624.htm"
 ACCESSKEY="U"
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	<HTML
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	><H1
	><A
	NAME="VIDIOC-G-TUNER"
	></A
	>ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</H1
	><DIV
	CLASS="REFNAMEDIV"
	><A
	NAME="AEN12346"
	></A
	><H2
	>Name</H2
	>VIDIOC_G_TUNER, VIDIOC_S_TUNER -- Get or set tuner attributes</DIV
	><DIV
	CLASS="REFSYNOPSISDIV"
	><A
	NAME="AEN12350"
	></A
	><H2
	>Synopsis</H2
	><DIV
	CLASS="FUNCSYNOPSIS"
	><P
	></P
	><A
	NAME="AEN12351"
	></A
	><P
	><CODE
	><CODE
	CLASS="FUNCDEF"
	>int ioctl</CODE
	>(int fd, int request, struct v4l2_tuner
	*argp);</CODE
	></P
	><P
	></P
	></DIV
	><DIV
	CLASS="FUNCSYNOPSIS"
	><P
	></P
	><A
	NAME="AEN12361"
	></A
	><P
	><CODE
	><CODE
	CLASS="FUNCDEF"
	>int ioctl</CODE
	>(int fd, int request, const struct v4l2_tuner
	*argp);</CODE
	></P
	><P
	></P
	></DIV
	></DIV
	><DIV
	CLASS="REFSECT1"
	><A
	NAME="AEN12371"
	></A
	><H2
	>Arguments</H2
	><P
	></P
	><DIV
	CLASS="VARIABLELIST"
	><DL
	><DT
	><CODE
	CLASS="PARAMETER"
	>fd</CODE
	></DT
	><DD
	><P
	>File descriptor returned by <A
	HREF="r14090.htm"
	><CODE
	CLASS="FUNCTION"
	>open()</CODE
	></A
	>.</P
	></DD
	><DT
	><CODE
	CLASS="PARAMETER"
	>request</CODE
	></DT
	><DD
	><P
	>VIDIOC_G_TUNER, VIDIOC_S_TUNER</P
	></DD
	><DT
	><CODE
	CLASS="PARAMETER"
	>argp</CODE
	></DT
	><DD
	><P
	></P
	></DD
	></DL
	></DIV
	></DIV
	><DIV
	CLASS="REFSECT1"
	><A
	NAME="AEN12391"
	></A
	><H2
	>Description</H2
	><P
	>To query the attributes of a tuner applications initialize the
	<CODE
	CLASS="STRUCTFIELD"
	>index</CODE
	> field and zero out the
	<CODE
	CLASS="STRUCTFIELD"
	>reserved</CODE
	> array of a struct <A
	HREF="r12342.htm#V4L2-TUNER"
	>v4l2_tuner</A
	> and call the
	<CODE
	CLASS="CONSTANT"
	>VIDIOC_G_TUNER</CODE
	> ioctl with a pointer to this
	structure. Drivers fill the rest of the structure or return an
	<SPAN
	CLASS="ERRORCODE"
	>EINVAL</SPAN
	> error code when the index is out of bounds. To enumerate all tuners
	applications shall begin at index zero, incrementing by one until the
	driver returns <SPAN
	CLASS="ERRORCODE"
	>EINVAL</SPAN
	>.</P
	><P
	>Tuners have two writable properties, the audio mode and
	the radio frequency. To change the audio mode, applications initialize
	the <CODE
	CLASS="STRUCTFIELD"
	>index</CODE
	>,
	<CODE
	CLASS="STRUCTFIELD"
	>audmode</CODE
	> and
	<CODE
	CLASS="STRUCTFIELD"
	>reserved</CODE
	> fields and call the
	<CODE
	CLASS="CONSTANT"
	>VIDIOC_S_TUNER</CODE
	> ioctl. This will
	<SPAN
	CLASS="emphasis"
	><I
	CLASS="EMPHASIS"
	>not</I
	></SPAN
	> change the current tuner, which is determined
	by the current video input. Drivers may choose a different audio mode
	if the requested mode is invalid or unsupported. Since this is a
	write-only ioctl, it does not return the actually
	selected audio mode.</P
	><P
	>To change the radio frequency the <A
	HREF="r11094.htm"
	><CODE
	CLASS="CONSTANT"
	>VIDIOC_S_FREQUENCY</CODE
	></A
	> ioctl
	is available.</P
	><DIV
	CLASS="TABLE"
	><A
	NAME="V4L2-TUNER"
	></A
	><P
	><B
	>Table 1. struct <CODE
	CLASS="STRUCTNAME"
	>v4l2_tuner</CODE
	></B
	></P
	><TABLE
	BORDER="0"
	FRAME="void"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="25%"
	TITLE="C1"><COL
	WIDTH="25%"
	TITLE="C2"><COL
	WIDTH="25%"
	TITLE="C3"><TBODY
	VALIGN="TOP"
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>index</CODE
	></TD
	><TD
	COLSPAN="2"
	>Identifies the tuner, set by the
	application.</TD
	></TR
	><TR
	><TD
	>__u8</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>name</CODE
	>[32]</TD
	><TD
	COLSPAN="2"
	><P
	>Name of the tuner, a
	NUL-terminated ASCII string. This information is intended for the
	user.</P
	></TD
	></TR
	><TR
	><TD
	>enum <A
	HREF="r12342.htm#V4L2-TUNER-TYPE"
	>v4l2_tuner_type</A
	></TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>type</CODE
	></TD
	><TD
	COLSPAN="2"
	>Type of the tuner, see <A
	HREF="r12342.htm#V4L2-TUNER-TYPE"
	>Table 2</A
	>.</TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>capability</CODE
	></TD
	><TD
	COLSPAN="2"
	><P
	>Tuner capability flags, see
	<A
	HREF="r12342.htm#TUNER-CAPABILITY"
	>Table 3</A
	>. Audio flags indicate the ability
	to decode audio subprograms. They will <SPAN
	CLASS="emphasis"
	><I
	CLASS="EMPHASIS"
	>not</I
	></SPAN
	>
	change, for example with the current video standard.</P
	><P
	>When
	the structure refers to a radio tuner only the
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LOW</CODE
	> and
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_STEREO</CODE
	> flags can be
	set.</P
	></TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>rangelow</CODE
	></TD
	><TD
	COLSPAN="2"
	>The lowest tunable frequency in
	units of 62.5 kHz, or if the <CODE
	CLASS="STRUCTFIELD"
	>capability</CODE
	>
	flag <CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LOW</CODE
	> is set, in units of 62.5
	Hz.</TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>rangehigh</CODE
	></TD
	><TD
	COLSPAN="2"
	>The highest tunable frequency in
	units of 62.5 kHz, or if the <CODE
	CLASS="STRUCTFIELD"
	>capability</CODE
	>
	flag <CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LOW</CODE
	> is set, in units of 62.5
	Hz.</TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>rxsubchans</CODE
	></TD
	><TD
	COLSPAN="2"
	><P
	>Some tuners or audio
	decoders can determine the received audio subprograms by analyzing
	audio carriers, pilot tones or other indicators. To pass this
	information drivers set flags defined in <A
	HREF="r12342.htm#TUNER-RXSUBCHANS"
	>Table 4</A
	> in this field. For
	example:</P
	></TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_MONO</CODE
	></TD
	><TD
	>receiving mono audio</TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	><CODE
	CLASS="CONSTANT"
	>STEREO \| SAP</CODE
	></TD
	><TD
	>receiving stereo audio and a secondary audio
	program</TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	><CODE
	CLASS="CONSTANT"
	>MONO \| STEREO</CODE
	></TD
	><TD
	>receiving mono or stereo audio, the hardware cannot
	distinguish</TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	><CODE
	CLASS="CONSTANT"
	>LANG1 \| LANG2</CODE
	></TD
	><TD
	>receiving bilingual audio</TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	><CODE
	CLASS="CONSTANT"
	>MONO \| STEREO \| LANG1 \| LANG2</CODE
	></TD
	><TD
	>receiving mono, stereo or bilingual
	audio</TD
	></TR
	><TR
	><TD
	> </TD
	><TD
	> </TD
	><TD
	COLSPAN="2"
	><P
	>When the
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_STEREO</CODE
	>,
	<CODE
	CLASS="CONSTANT"
	>_LANG1</CODE
	>, <CODE
	CLASS="CONSTANT"
	>_LANG2</CODE
	> or
	<CODE
	CLASS="CONSTANT"
	>_SAP</CODE
	> flag is cleared in the
	<CODE
	CLASS="STRUCTFIELD"
	>capability</CODE
	> field, the corresponding
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_</CODE
	> flag must not be set
	here.</P
	><P
	>This field is valid only if this is the tuner of the
	current video input, or when the structure refers to a radio
	tuner.</P
	></TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>audmode</CODE
	></TD
	><TD
	COLSPAN="2"
	><P
	>The selected audio mode, see
	<A
	HREF="r12342.htm#TUNER-AUDMODE"
	>Table 5</A
	> for valid values. The audio mode does
	not affect audio subprogram detection, and like a <A
	HREF="x542.htm"
	>control</A
	> it does not automatically change
	unless the requested mode is invalid or unsupported. See <A
	HREF="r12342.htm#TUNER-MATRIX"
	>Table 6</A
	> for possible results when
	the selected and received audio programs do not
	match.</P
	><P
	>Currently this is the only field of struct
	<CODE
	CLASS="STRUCTNAME"
	>v4l2_tuner</CODE
	> applications can
	change.</P
	></TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>signal</CODE
	></TD
	><TD
	COLSPAN="2"
	>The signal strength if known, ranging
	from 0 to 65535. Higher values indicate a better signal.</TD
	></TR
	><TR
	><TD
	>__s32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>afc</CODE
	></TD
	><TD
	COLSPAN="2"
	>Automatic frequency control: When the
	<CODE
	CLASS="STRUCTFIELD"
	>afc</CODE
	> value is negative, the frequency is too
	low, when positive too high.</TD
	></TR
	><TR
	><TD
	>__u32</TD
	><TD
	><CODE
	CLASS="STRUCTFIELD"
	>reserved</CODE
	>[4]</TD
	><TD
	COLSPAN="2"
	>Reserved for future extensions. Drivers and
	applications must set the array to zero.</TD
	></TR
	></TBODY
	></TABLE
	></DIV
	><DIV
	CLASS="TABLE"
	><A
	NAME="V4L2-TUNER-TYPE"
	></A
	><P
	><B
	>Table 2. enum v4l2_tuner_type</B
	></P
	><TABLE
	BORDER="0"
	FRAME="void"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="38%"
	TITLE="C1"><COL
	WIDTH="12%"
	TITLE="C2"><COL
	WIDTH="50%"
	TITLE="C3"><TBODY
	VALIGN="TOP"
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_RADIO</CODE
	></TD
	><TD
	>1</TD
	><TD
	> </TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	></TD
	><TD
	>2</TD
	><TD
	> </TD
	></TR
	></TBODY
	></TABLE
	></DIV
	><DIV
	CLASS="TABLE"
	><A
	NAME="TUNER-CAPABILITY"
	></A
	><P
	><B
	>Table 3. Tuner and Modulator Capability Flags</B
	></P
	><TABLE
	BORDER="0"
	FRAME="void"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="38%"
	TITLE="C1"><COL
	WIDTH="12%"
	TITLE="C2"><COL
	WIDTH="50%"
	TITLE="C3"><TBODY
	VALIGN="TOP"
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LOW</CODE
	></TD
	><TD
	>0x0001</TD
	><TD
	>When set, tuning frequencies are expressed in units of
	62.5 Hz, otherwise in units of 62.5 kHz.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_NORM</CODE
	></TD
	><TD
	>0x0002</TD
	><TD
	>This is a multi-standard tuner; the video standard
	can or must be switched. (B/G PAL tuners for example are typically not
	considered multi-standard because the video standard is automatically
	determined from the frequency band.) The set of supported video
	standards is available from the struct <A
	HREF="r8936.htm#V4L2-INPUT"
	>v4l2_input</A
	> pointing to this tuner,
	see the description of ioctl <A
	HREF="r8936.htm"
	><CODE
	CLASS="CONSTANT"
	>VIDIOC_ENUMINPUT</CODE
	></A
	> for details. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners can have this capability.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_STEREO</CODE
	></TD
	><TD
	>0x0010</TD
	><TD
	>Stereo audio reception is supported.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LANG1</CODE
	></TD
	><TD
	>0x0040</TD
	><TD
	>Reception of the primary language of a bilingual
	audio program is supported. Bilingual audio is a feature of
	two-channel systems, transmitting the primary language monaural on the
	main audio carrier and a secondary language monaural on a second
	carrier. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners can have this capability.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LANG2</CODE
	></TD
	><TD
	>0x0020</TD
	><TD
	>Reception of the secondary language of a bilingual
	audio program is supported. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners can have this capability.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_SAP</CODE
	></TD
	><TD
	>0x0020</TD
	><TD
	><P
	>Reception of a secondary audio program is
	supported. This is a feature of the BTSC system which accompanies the
	NTSC video standard. Two audio carriers are available for mono or
	stereo transmissions of a primary language, and an independent third
	carrier for a monaural secondary language. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners can have this capability.</P
	><P
	>Note the
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_LANG2</CODE
	> and
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_SAP</CODE
	> flags are synonyms.
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_CAP_SAP</CODE
	> applies when the tuner
	supports the <CODE
	CLASS="CONSTANT"
	>V4L2_STD_NTSC_M</CODE
	> video
	standard.</P
	></TD
	></TR
	></TBODY
	></TABLE
	></DIV
	><DIV
	CLASS="TABLE"
	><A
	NAME="TUNER-RXSUBCHANS"
	></A
	><P
	><B
	>Table 4. Tuner Audio Reception Flags</B
	></P
	><TABLE
	BORDER="0"
	FRAME="void"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="38%"
	TITLE="C1"><COL
	WIDTH="12%"
	TITLE="C2"><COL
	WIDTH="50%"
	TITLE="C3"><TBODY
	VALIGN="TOP"
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_MONO</CODE
	></TD
	><TD
	>0x0001</TD
	><TD
	>The tuner receives a mono audio signal.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_STEREO</CODE
	></TD
	><TD
	>0x0002</TD
	><TD
	>The tuner receives a stereo audio signal.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_LANG1</CODE
	></TD
	><TD
	>0x0008</TD
	><TD
	>The tuner receives the primary language of a
	bilingual audio signal. Drivers must clear this flag when the current
	video standard is <CODE
	CLASS="CONSTANT"
	>V4L2_STD_NTSC_M</CODE
	>.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_LANG2</CODE
	></TD
	><TD
	>0x0004</TD
	><TD
	>The tuner receives the secondary language of a
	bilingual audio signal (or a second audio program).</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_SAP</CODE
	></TD
	><TD
	>0x0004</TD
	><TD
	>The tuner receives a Second Audio Program. Note the
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_LANG2</CODE
	> and
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_SAP</CODE
	> flags are synonyms. The
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_SAP</CODE
	> flag applies when the
	current video standard is <CODE
	CLASS="CONSTANT"
	>V4L2_STD_NTSC_M</CODE
	>.</TD
	></TR
	></TBODY
	></TABLE
	></DIV
	><DIV
	CLASS="TABLE"
	><A
	NAME="TUNER-AUDMODE"
	></A
	><P
	><B
	>Table 5. Tuner Audio Modes</B
	></P
	><TABLE
	BORDER="0"
	FRAME="void"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="38%"
	TITLE="C1"><COL
	WIDTH="12%"
	TITLE="C2"><COL
	WIDTH="50%"
	TITLE="C3"><TBODY
	VALIGN="TOP"
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_MONO</CODE
	></TD
	><TD
	>0</TD
	><TD
	>Play mono audio. When the tuner receives a stereo
	signal this a down-mix of the left and right channel. When the tuner
	receives a bilingual or SAP signal this mode selects the primary
	language.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_STEREO</CODE
	></TD
	><TD
	>1</TD
	><TD
	><P
	>Play stereo audio. When the tuner receives
	bilingual audio it may play different languages on the left and right
	channel or the primary language on both channels. behave as in mono
	mode.</P
	><P
	>Playing different languages in this mode is
	deprecated. New drivers should do this only in
	<CODE
	CLASS="CONSTANT"
	>MODE_LANG1_LANG2</CODE
	>.</P
	><P
	>When the tuner
	receives no stereo signal or does not support stereo reception the
	driver shall fall back to <CODE
	CLASS="CONSTANT"
	>MODE_MONO</CODE
	>.</P
	></TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_LANG1</CODE
	></TD
	><TD
	>3</TD
	><TD
	>Play the primary language, mono or stereo. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners support this
	mode.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_LANG2</CODE
	></TD
	><TD
	>2</TD
	><TD
	>Play the secondary language, mono. When the tuner
	receives no bilingual audio or SAP, or their reception is not
	supported the driver shall fall back to mono or stereo mode. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners support this
	mode.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_SAP</CODE
	></TD
	><TD
	>2</TD
	><TD
	>Play the Second Audio Program. When the tuner
	receives no bilingual audio or SAP, or their reception is not
	supported the driver shall fall back to mono or stereo mode. Only
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners support this mode.
	Note the <CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_LANG2</CODE
	> and
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_SAP</CODE
	> are synonyms.</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_LANG1_LANG2</CODE
	></TD
	><TD
	>4</TD
	><TD
	>Play the primary language on the left channel, the
	secondary language on the right channel. When the tuner receives no
	bilingual audio or SAP, it shall fall back to
	<CODE
	CLASS="CONSTANT"
	>MODE_LANG1</CODE
	> or <CODE
	CLASS="CONSTANT"
	>MODE_MONO</CODE
	>.
	Only <CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_ANALOG_TV</CODE
	> tuners support this
	mode.</TD
	></TR
	></TBODY
	></TABLE
	></DIV
	><DIV
	CLASS="TABLE"
	><A
	NAME="TUNER-MATRIX"
	></A
	><P
	><B
	>Table 6. Tuner Audio Matrix</B
	></P
	><TABLE
	BORDER="1"
	FRAME="border"
	WIDTH="100%"
	CLASS="CALSTABLE"
	><COL
	WIDTH="20%"
	ALIGN="LEFT"><COL
	WIDTH="20%"
	TITLE="C2"><COL
	WIDTH="20%"><COL
	WIDTH="20%"><COL><COL
	WIDTH="20%"
	TITLE="C6"><THEAD
	><TR
	><TH
	> </TH
	><TH
	COLSPAN="5"
	ALIGN="CENTER"
	>Selected
	<CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_MODE_</CODE
	></TH
	></TR
	><TR
	><TH
	>Received <CODE
	CLASS="CONSTANT"
	>V4L2_TUNER_SUB_</CODE
	></TH
	><TH
	><CODE
	CLASS="CONSTANT"
	>MONO</CODE
	></TH
	><TH
	><CODE
	CLASS="CONSTANT"
	>STEREO</CODE
	></TH
	><TH
	><CODE
	CLASS="CONSTANT"
	>LANG1</CODE
	></TH
	><TH
	><CODE
	CLASS="CONSTANT"
	>LANG2 = SAP</CODE
	></TH
	><TH
	><CODE
	CLASS="CONSTANT"
	>LANG1_LANG2</CODE
	><A
	NAME="AEN12723"
	HREF="r12342.htm#FTN.AEN12723"
	><SPAN
	CLASS="footnote"
	>[a]</SPAN
	></A
	></TH
	></TR
	></THEAD
	><TBODY
	VALIGN="TOP"
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>MONO</CODE
	></TD
	><TD
	>Mono</TD
	><TD
	>Mono/Mono</TD
	><TD
	>Mono</TD
	><TD
	>Mono</TD
	><TD
	>Mono/Mono</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>MONO \| SAP</CODE
	></TD
	><TD
	>Mono</TD
	><TD
	>Mono/Mono</TD
	><TD
	>Mono</TD
	><TD
	>SAP</TD
	><TD
	>Mono/SAP (preferred) or Mono/Mono</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>STEREO</CODE
	></TD
	><TD
	>L+R</TD
	><TD
	>L/R</TD
	><TD
	>Stereo L/R (preferred) or Mono L+R</TD
	><TD
	>Stereo L/R (preferred) or Mono L+R</TD
	><TD
	>L/R (preferred) or L+R/L+R</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>STEREO \| SAP</CODE
	></TD
	><TD
	>L+R</TD
	><TD
	>L/R</TD
	><TD
	>Stereo L/R (preferred) or Mono L+R</TD
	><TD
	>SAP</TD
	><TD
	>L+R/SAP (preferred) or L/R or L+R/L+R</TD
	></TR
	><TR
	><TD
	><CODE
	CLASS="CONSTANT"
	>LANG1 \| LANG2</CODE
	></TD
	><TD
	>Language 1</TD
	><TD
	>Lang1/Lang2 (deprecated<A
	NAME="AEN12763"
	HREF="r12342.htm#FTN.AEN12763"
	><SPAN
	CLASS="footnote"
	>[b]</SPAN
	></A
	>) or
	Lang1/Lang1</TD
	><TD
	>Language 1</TD
	><TD
	>Language 2</TD
	><TD
	>Lang1/Lang2 (preferred) or Lang1/Lang1</TD
	></TR
	></TBODY
	><TR
	><TD
	COLSPAN="6"
	>Notes:<BR><A
	NAME="FTN.AEN12723"
	>a. </A
	>This
	mode has been added in Linux 2.6.17 and may not be supported by older
	drivers.<BR><A
	NAME="FTN.AEN12763"
	>b. </A
	>Playback of
	both languages in <CODE
	CLASS="CONSTANT"
	>MODE_STEREO</CODE
	> is deprecated. In
	the future drivers should produce only the primary language in this
	mode. Applications should request
	<CODE
	CLASS="CONSTANT"
	>MODE_LANG1_LANG2</CODE
	> to record both languages or a
	stereo signal.<BR></TD
	></TR
	></TABLE
	></DIV
	></DIV
	><DIV
	CLASS="REFSECT1"
	><A
	NAME="AEN12770"
	></A
	><H2
	>Return Value</H2
	><P
	>On success <SPAN
	CLASS="RETURNVALUE"
	>0</SPAN
	> is returned, on error <SPAN
	CLASS="RETURNVALUE"
	>-1</SPAN
	> and the <CODE
	CLASS="VARNAME"
	>errno</CODE
	> variable is set appropriately:</P
	><P
	></P
	><DIV
	CLASS="VARIABLELIST"
	><DL
	><DT
	><SPAN
	CLASS="ERRORCODE"
	>EINVAL</SPAN
	></DT
	><DD
	><P
	>The struct <A
	HREF="r12342.htm#V4L2-TUNER"
	>v4l2_tuner</A
	> <CODE
	CLASS="STRUCTFIELD"
	>index</CODE
	> is
	out of bounds.</P
	></DD
	></DL
	></DIV
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