From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- Documentation/DocBook/v4l/vidioc-g-tuner.xml | 535 +++++++++++++++++++++++++++ 1 file changed, 535 insertions(+) create mode 100644 Documentation/DocBook/v4l/vidioc-g-tuner.xml (limited to 'Documentation/DocBook/v4l/vidioc-g-tuner.xml') diff --git a/Documentation/DocBook/v4l/vidioc-g-tuner.xml b/Documentation/DocBook/v4l/vidioc-g-tuner.xml new file mode 100644 index 00000000..bd98c734 --- /dev/null +++ b/Documentation/DocBook/v4l/vidioc-g-tuner.xml @@ -0,0 +1,535 @@ + + + ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER + &manvol; + + + + VIDIOC_G_TUNER + VIDIOC_S_TUNER + Get or set tuner attributes + + + + + + int ioctl + int fd + int request + struct v4l2_tuner +*argp + + + + + int ioctl + int fd + int request + const struct v4l2_tuner +*argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_G_TUNER, VIDIOC_S_TUNER + + + + argp + + + + + + + + + Description + + To query the attributes of a tuner applications initialize the +index field and zero out the +reserved array of a &v4l2-tuner; and call the +VIDIOC_G_TUNER ioctl with a pointer to this +structure. Drivers fill the rest of the structure or return an +&EINVAL; when the index is out of bounds. To enumerate all tuners +applications shall begin at index zero, incrementing by one until the +driver returns EINVAL. + + Tuners have two writable properties, the audio mode and +the radio frequency. To change the audio mode, applications initialize +the index, +audmode and +reserved fields and call the +VIDIOC_S_TUNER ioctl. This will +not 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. + + To change the radio frequency the &VIDIOC-S-FREQUENCY; ioctl +is available. + + + struct <structname>v4l2_tuner</structname> + + + + + + + + + __u32 + index + Identifies the tuner, set by the +application. + + + __u8 + name[32] + Name of the tuner, a +NUL-terminated ASCII string. This information is intended for the +user. + + + &v4l2-tuner-type; + type + Type of the tuner, see . + + + __u32 + capability + Tuner capability flags, see +. Audio flags indicate the ability +to decode audio subprograms. They will not +change, for example with the current video standard.When +the structure refers to a radio tuner only the +V4L2_TUNER_CAP_LOW, +V4L2_TUNER_CAP_STEREO and +V4L2_TUNER_CAP_RDS flags can be set. + + + __u32 + rangelow + The lowest tunable frequency in +units of 62.5 kHz, or if the capability +flag V4L2_TUNER_CAP_LOW is set, in units of 62.5 +Hz. + + + __u32 + rangehigh + The highest tunable frequency in +units of 62.5 kHz, or if the capability +flag V4L2_TUNER_CAP_LOW is set, in units of 62.5 +Hz. + + + __u32 + rxsubchans + 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 in this field. For +example: + + + + + V4L2_TUNER_SUB_MONO + receiving mono audio + + + + + STEREO | SAP + receiving stereo audio and a secondary audio +program + + + + + MONO | STEREO + receiving mono or stereo audio, the hardware cannot +distinguish + + + + + LANG1 | LANG2 + receiving bilingual audio + + + + + MONO | STEREO | LANG1 | LANG2 + receiving mono, stereo or bilingual +audio + + + + + When the +V4L2_TUNER_CAP_STEREO, +_LANG1, _LANG2 or +_SAP flag is cleared in the +capability field, the corresponding +V4L2_TUNER_SUB_ flag must not be set +here.This field is valid only if this is the tuner of the +current video input, or when the structure refers to a radio +tuner. + + + __u32 + audmode + The selected audio mode, see + for valid values. The audio mode does +not affect audio subprogram detection, and like a control it does not automatically change +unless the requested mode is invalid or unsupported. See for possible results when +the selected and received audio programs do not +match.Currently this is the only field of struct +v4l2_tuner applications can +change. + + + __u32 + signal + The signal strength if known, ranging +from 0 to 65535. Higher values indicate a better signal. + + + __s32 + afc + Automatic frequency control: When the +afc value is negative, the frequency is too +low, when positive too high. + + + __u32 + reserved[4] + Reserved for future extensions. Drivers and +applications must set the array to zero. + + + +
+ + + enum v4l2_tuner_type + + &cs-def; + + + V4L2_TUNER_RADIO + 1 + + + + V4L2_TUNER_ANALOG_TV + 2 + + + + +
+ + + Tuner and Modulator Capability Flags + + &cs-def; + + + V4L2_TUNER_CAP_LOW + 0x0001 + When set, tuning frequencies are expressed in units of +62.5 Hz, otherwise in units of 62.5 kHz. + + + V4L2_TUNER_CAP_NORM + 0x0002 + 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 &v4l2-input; pointing to this tuner, + see the description of ioctl &VIDIOC-ENUMINPUT; for details. Only + V4L2_TUNER_ANALOG_TV tuners can have this capability. + + + V4L2_TUNER_CAP_STEREO + 0x0010 + Stereo audio reception is supported. + + + V4L2_TUNER_CAP_LANG1 + 0x0040 + 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 + V4L2_TUNER_ANALOG_TV tuners can have this capability. + + + V4L2_TUNER_CAP_LANG2 + 0x0020 + Reception of the secondary language of a bilingual +audio program is supported. Only + V4L2_TUNER_ANALOG_TV tuners can have this capability. + + + V4L2_TUNER_CAP_SAP + 0x0020 + 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 + V4L2_TUNER_ANALOG_TV tuners can have this capability.Note the +V4L2_TUNER_CAP_LANG2 and +V4L2_TUNER_CAP_SAP flags are synonyms. +V4L2_TUNER_CAP_SAP applies when the tuner +supports the V4L2_STD_NTSC_M video +standard. + + + V4L2_TUNER_CAP_RDS + 0x0080 + RDS capture is supported. This capability is only valid for +radio tuners. + + + +
+ + + Tuner Audio Reception Flags + + &cs-def; + + + V4L2_TUNER_SUB_MONO + 0x0001 + The tuner receives a mono audio signal. + + + V4L2_TUNER_SUB_STEREO + 0x0002 + The tuner receives a stereo audio signal. + + + V4L2_TUNER_SUB_LANG1 + 0x0008 + The tuner receives the primary language of a +bilingual audio signal. Drivers must clear this flag when the current +video standard is V4L2_STD_NTSC_M. + + + V4L2_TUNER_SUB_LANG2 + 0x0004 + The tuner receives the secondary language of a +bilingual audio signal (or a second audio program). + + + V4L2_TUNER_SUB_SAP + 0x0004 + The tuner receives a Second Audio Program. Note the +V4L2_TUNER_SUB_LANG2 and +V4L2_TUNER_SUB_SAP flags are synonyms. The +V4L2_TUNER_SUB_SAP flag applies when the +current video standard is V4L2_STD_NTSC_M. + + + V4L2_TUNER_SUB_RDS + 0x0010 + The tuner receives an RDS channel. + + + +
+ + + Tuner Audio Modes + + &cs-def; + + + V4L2_TUNER_MODE_MONO + 0 + 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. + + + V4L2_TUNER_MODE_STEREO + 1 + Play stereo audio. When the tuner receives +bilingual audio it may play different languages on the left and right +channel or the primary language is played on both channels.Playing +different languages in this mode is +deprecated. New drivers should do this only in +MODE_LANG1_LANG2.When the tuner +receives no stereo signal or does not support stereo reception the +driver shall fall back to MODE_MONO. + + + V4L2_TUNER_MODE_LANG1 + 3 + Play the primary language, mono or stereo. Only +V4L2_TUNER_ANALOG_TV tuners support this +mode. + + + V4L2_TUNER_MODE_LANG2 + 2 + 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 +V4L2_TUNER_ANALOG_TV tuners support this +mode. + + + V4L2_TUNER_MODE_SAP + 2 + 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 +V4L2_TUNER_ANALOG_TV tuners support this mode. +Note the V4L2_TUNER_MODE_LANG2 and +V4L2_TUNER_MODE_SAP are synonyms. + + + V4L2_TUNER_MODE_LANG1_LANG2 + 4 + 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 +MODE_LANG1 or MODE_MONO. +Only V4L2_TUNER_ANALOG_TV tuners support this +mode. + + + +
+ + + Tuner Audio Matrix + + + + + + + + + + + Selected +V4L2_TUNER_MODE_ + + + Received V4L2_TUNER_SUB_ + MONO + STEREO + LANG1 + LANG2 = SAP + LANG1_LANG2This +mode has been added in Linux 2.6.17 and may not be supported by older +drivers. + + + + + MONO + Mono + Mono/Mono + Mono + Mono + Mono/Mono + + + MONO | SAP + Mono + Mono/Mono + Mono + SAP + Mono/SAP (preferred) or Mono/Mono + + + STEREO + L+R + L/R + Stereo L/R (preferred) or Mono L+R + Stereo L/R (preferred) or Mono L+R + L/R (preferred) or L+R/L+R + + + STEREO | SAP + L+R + L/R + Stereo L/R (preferred) or Mono L+R + SAP + L+R/SAP (preferred) or L/R or L+R/L+R + + + LANG1 | LANG2 + Language 1 + Lang1/Lang2 (deprecatedPlayback of +both languages in MODE_STEREO is deprecated. In +the future drivers should produce only the primary language in this +mode. Applications should request +MODE_LANG1_LANG2 to record both languages or a +stereo signal.) or +Lang1/Lang1 + Language 1 + Language 2 + Lang1/Lang2 (preferred) or Lang1/Lang1 + + + +
+ + + + &return-value; + + + + EINVAL + + The &v4l2-tuner; index is +out of bounds. + + + + + + + -- cgit v1.2.3