path: root/Documentation/DocBook/dvb/dvbproperty.xml

<section id="FE_GET_SET_PROPERTY">
<title>FE_GET_PROPERTY/FE_SET_PROPERTY</title>

<programlisting>
/* Reserved fields should be set to 0 */
struct dtv_property {
	__u32 cmd;
	union {
		__u32 data;
		struct {
			__u8 data[32];
			__u32 len;
			__u32 reserved1[3];
			void *reserved2;
		} buffer;
	} u;
	int result;
} __attribute__ ((packed));

/* num of properties cannot exceed DTV_IOCTL_MAX_MSGS per ioctl */
#define DTV_IOCTL_MAX_MSGS 64

struct dtv_properties {
	__u32 num;
	struct dtv_property *props;
};
</programlisting>

<section id="FE_GET_PROPERTY">
<title>FE_GET_PROPERTY</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call returns one or more frontend properties. This call only
 requires read-only access to the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link>,
 dtv_properties &#x22C6;props);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int num</para>
</entry><entry
 align="char">
<para>Equals <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link> for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct dtv_property *props</para>
</entry><entry
 align="char">
<para>Points to the location where the front-end property commands are stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>ERRORS</para>
<informaltable><tgroup cols="2"><tbody><row>
  <entry align="char"><para>EINVAL</para></entry>
  <entry align="char"><para>Invalid parameter(s) received or number of parameters out of the range.</para></entry>
 </row><row>
  <entry align="char"><para>ENOMEM</para></entry>
  <entry align="char"><para>Out of memory.</para></entry>
 </row><row>
  <entry align="char"><para>EFAULT</para></entry>
  <entry align="char"><para>Failure while copying data from/to userspace.</para></entry>
 </row><row>
  <entry align="char"><para>EOPNOTSUPP</para></entry>
  <entry align="char"><para>Property type not supported.</para></entry>
 </row></tbody></tgroup></informaltable>
</section>

<section id="FE_SET_PROPERTY">
<title>FE_SET_PROPERTY</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>This ioctl call sets one or more frontend properties. This call only
 requires read-only access to the device.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
 align="char">
<para>int ioctl(int fd, int request = <link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link>,
 dtv_properties &#x22C6;props);</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry align="char">
<para>int fd</para>
</entry><entry
 align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
 </row><row><entry
 align="char">
<para>int num</para>
</entry><entry
 align="char">
<para>Equals <link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link> for this command.</para>
</entry>
 </row><row><entry
 align="char">
<para>struct dtv_property *props</para>
</entry><entry
 align="char">
<para>Points to the location where the front-end property commands are stored.</para>
</entry>
 </row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row>
  <entry align="char"><para>EINVAL</para></entry>
  <entry align="char"><para>Invalid parameter(s) received or number of parameters out of the range.</para></entry>
 </row><row>
  <entry align="char"><para>ENOMEM</para></entry>
  <entry align="char"><para>Out of memory.</para></entry>
 </row><row>
  <entry align="char"><para>EFAULT</para></entry>
  <entry align="char"><para>Failure while copying data from/to userspace.</para></entry>
 </row><row>
  <entry align="char"><para>EOPNOTSUPP</para></entry>
  <entry align="char"><para>Property type not supported.</para></entry>
 </row></tbody></tgroup></informaltable>
</section>

<section>
	<title>Property types</title>
<para>
On <link linkend="FE_GET_PROPERTY">FE_GET_PROPERTY</link>/<link linkend="FE_SET_PROPERTY">FE_SET_PROPERTY</link>,
the actual action is determined by the dtv_property cmd/data pairs. With one single ioctl, is possible to
get/set up to 64 properties. The actual meaning of each property is described on the next sections.
</para>

<para>The available frontend property types are:</para>
<programlisting>
#define DTV_UNDEFINED		0
#define DTV_TUNE		1
#define DTV_CLEAR		2
#define DTV_FREQUENCY		3
#define DTV_MODULATION		4
#define DTV_BANDWIDTH_HZ	5
#define DTV_INVERSION		6
#define DTV_DISEQC_MASTER	7
#define DTV_SYMBOL_RATE		8
#define DTV_INNER_FEC		9
#define DTV_VOLTAGE		10
#define DTV_TONE		11
#define DTV_PILOT		12
#define DTV_ROLLOFF		13
#define DTV_DISEQC_SLAVE_REPLY	14
#define DTV_FE_CAPABILITY_COUNT	15
#define DTV_FE_CAPABILITY	16
#define DTV_DELIVERY_SYSTEM	17
#define DTV_ISDBT_PARTIAL_RECEPTION	18
#define DTV_ISDBT_SOUND_BROADCASTING	19
#define DTV_ISDBT_SB_SUBCHANNEL_ID	20
#define DTV_ISDBT_SB_SEGMENT_IDX	21
#define DTV_ISDBT_SB_SEGMENT_COUNT	22
#define DTV_ISDBT_LAYERA_FEC			23
#define DTV_ISDBT_LAYERA_MODULATION		24
#define DTV_ISDBT_LAYERA_SEGMENT_COUNT		25
#define DTV_ISDBT_LAYERA_TIME_INTERLEAVING	26
#define DTV_ISDBT_LAYERB_FEC			27
#define DTV_ISDBT_LAYERB_MODULATION		28
#define DTV_ISDBT_LAYERB_SEGMENT_COUNT		29
#define DTV_ISDBT_LAYERB_TIME_INTERLEAVING	30
#define DTV_ISDBT_LAYERC_FEC			31
#define DTV_ISDBT_LAYERC_MODULATION		32
#define DTV_ISDBT_LAYERC_SEGMENT_COUNT		33
#define DTV_ISDBT_LAYERC_TIME_INTERLEAVING	34
#define DTV_API_VERSION		35
#define DTV_CODE_RATE_HP	36
#define DTV_CODE_RATE_LP	37
#define DTV_GUARD_INTERVAL	38
#define DTV_TRANSMISSION_MODE	39
#define DTV_HIERARCHY		40
#define DTV_ISDBT_LAYER_ENABLED	41
#define DTV_ISDBS_TS_ID		42
</programlisting>
</section>

<section id="fe_property_common">
	<title>Parameters that are common to all Digital TV standards</title>
	<section id="DTV_FREQUENCY">
		<title><constant>DTV_FREQUENCY</constant></title>

		<para>Central frequency of the channel, in HZ.</para>

		<para>Notes:</para>
		<para>1)For ISDB-T, the channels are usually 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.</para>

		<para>2)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.</para>
	</section>

	<section id="DTV_BANDWIDTH_HZ">
		<title><constant>DTV_BANDWIDTH_HZ</constant></title>

		<para>Bandwidth for the channel, in HZ.</para>

		<para>Possible values:
			<constant>1712000</constant>,
			<constant>5000000</constant>,
			<constant>6000000</constant>,
			<constant>7000000</constant>,
			<constant>8000000</constant>,
			<constant>10000000</constant>.
		</para>

		<para>Notes:</para>

		<para>1) For ISDB-T it should be always 6000000Hz (6MHz)</para>
		<para>2) For ISDB-Tsb it can vary depending on the number of connected segments</para>
		<para>3) Bandwidth doesn't apply for DVB-C transmissions, as the bandwidth
			 for DVB-C depends on the symbol rate</para>
		<para>4) 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).</para>
		<para>5) DVB-T supports 6, 7 and 8MHz.</para>
		<para>6) In addition, DVB-T2 supports 1.172, 5 and 10MHz.</para>
	</section>

	<section id="DTV_DELIVERY_SYSTEM">
		<title><constant>DTV_DELIVERY_SYSTEM</constant></title>

		<para>Specifies the type of Delivery system</para>

		<para>Possible values: </para>
<programlisting>
typedef enum fe_delivery_system {
	SYS_UNDEFINED,
	SYS_DVBC_ANNEX_AC,
	SYS_DVBC_ANNEX_B,
	SYS_DVBT,
	SYS_DSS,
	SYS_DVBS,
	SYS_DVBS2,
	SYS_DVBH,
	SYS_ISDBT,
	SYS_ISDBS,
	SYS_ISDBC,
	SYS_ATSC,
	SYS_ATSCMH,
	SYS_DMBTH,
	SYS_CMMB,
	SYS_DAB,
	SYS_DVBT2,
} fe_delivery_system_t;
</programlisting>

	</section>

	<section id="DTV_TRANSMISSION_MODE">
		<title><constant>DTV_TRANSMISSION_MODE</constant></title>

		<para>Specifies the number of carriers used by the standard</para>

		<para>Possible values are:</para>
<programlisting>
typedef enum fe_transmit_mode {
	TRANSMISSION_MODE_2K,
	TRANSMISSION_MODE_8K,
	TRANSMISSION_MODE_AUTO,
	TRANSMISSION_MODE_4K,
	TRANSMISSION_MODE_1K,
	TRANSMISSION_MODE_16K,
	TRANSMISSION_MODE_32K,
} fe_transmit_mode_t;
</programlisting>

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