From patchwork Mon Jul 27 15:12:06 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Valentin X-Patchwork-Id: 37552 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n6RFNae0017123 for ; Mon, 27 Jul 2009 15:23:37 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752429AbZG0PXf (ORCPT ); Mon, 27 Jul 2009 11:23:35 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752403AbZG0PXf (ORCPT ); Mon, 27 Jul 2009 11:23:35 -0400 Received: from smtp.nokia.com ([192.100.122.233]:36440 "EHLO mgw-mx06.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752122AbZG0PXb (ORCPT ); Mon, 27 Jul 2009 11:23:31 -0400 Received: from vaebh105.NOE.Nokia.com (vaebh105.europe.nokia.com [10.160.244.31]) by mgw-mx06.nokia.com (Switch-3.3.3/Switch-3.3.3) with ESMTP id n6RFN3Ut006903; Mon, 27 Jul 2009 18:23:08 +0300 Received: from esebh102.NOE.Nokia.com ([172.21.138.183]) by vaebh105.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 27 Jul 2009 18:23:12 +0300 Received: from vaebe101.NOE.Nokia.com ([10.160.244.11]) by esebh102.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 27 Jul 2009 18:23:12 +0300 Received: from localhost.localdomain ([172.21.41.99]) by vaebe101.NOE.Nokia.com with Microsoft SMTPSVC(6.0.3790.3959); Mon, 27 Jul 2009 18:23:12 +0300 From: Eduardo Valentin To: "ext Hans Verkuil" , "ext Mauro Carvalho Chehab" Cc: "ext Douglas Schilling Landgraf" , "Nurkkala Eero.An (EXT-Offcode/Oulu)" , "Aaltonen Matti.J (Nokia-D/Tampere)" , Linux-Media , Eduardo Valentin Subject: [PATCHv14 4/8] v4l2-spec: Add documentation description for FM TX extended control class Date: Mon, 27 Jul 2009 18:12:06 +0300 Message-Id: <1248707530-4068-5-git-send-email-eduardo.valentin@nokia.com> X-Mailer: git-send-email 1.6.2.GIT In-Reply-To: <1248707530-4068-4-git-send-email-eduardo.valentin@nokia.com> References: <1248707530-4068-1-git-send-email-eduardo.valentin@nokia.com> <1248707530-4068-2-git-send-email-eduardo.valentin@nokia.com> <1248707530-4068-3-git-send-email-eduardo.valentin@nokia.com> <1248707530-4068-4-git-send-email-eduardo.valentin@nokia.com> X-OriginalArrivalTime: 27 Jul 2009 15:23:12.0192 (UTC) FILETIME=[277B3C00:01CA0ECE] X-Nokia-AV: Clean Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This single patch adds documentation description for FM Modulator (FM TX) Extended Control Class and its Control IDs. The text was added under "Extended Controls" section. Signed-off-by: Eduardo Valentin --- v4l2-spec/Makefile | 1 + v4l2-spec/controls.sgml | 215 +++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 216 insertions(+), 0 deletions(-) diff --git a/v4l2-spec/Makefile b/v4l2-spec/Makefile index 4f11745..7a8d161 100644 --- a/v4l2-spec/Makefile +++ b/v4l2-spec/Makefile @@ -243,6 +243,7 @@ ENUMS = \ v4l2_power_line_frequency \ v4l2_priority \ v4l2_tuner_type \ + v4l2_preemphasis \ STRUCTS = \ v4l2_audio \ diff --git a/v4l2-spec/controls.sgml b/v4l2-spec/controls.sgml index 8e0e024..502f84d 100644 --- a/v4l2-spec/controls.sgml +++ b/v4l2-spec/controls.sgml @@ -458,6 +458,12 @@ video is actually encoded into that format. Unfortunately, the original control API lacked some features needed for these new uses and so it was extended into the (not terribly originally named) extended control API. + + Even though the MPEG encoding API was the first effort +to use the Extended Control API, nowadays there are also other classes +of Extended Controls, such as Camera Controls and FM Transmitter Controls. +The Extended Controls API as well as all Extended Controls classes are +described in the following text.
@@ -1815,6 +1821,215 @@ control must support read access and may support write access.
+ +
+ FM Transmitter Control Reference + + The FM Transmitter (FM_TX) class includes controls for common features of +FM transmissions capable devices. Currently this class includes parameters for audio +compression, pilot tone generation, audio deviation limiter, RDS transmission and +tuning power features. + + + FM_TX Control IDs + + + + + + + + + + + ID + Type + Description + + + + + + V4L2_CID_FM_TX_CLASS  + class + The FM_TX class +descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a +description of this control class. + + + V4L2_CID_RDS_TX_PI  + integer + + Sets the RDS Programme Identification field +for transmission. + + + V4L2_CID_RDS_TX_PTY  + integer + + Sets the RDS Programme Type field for transmission. +This encodes up to 31 pre-defined programme types. + + + V4L2_CID_RDS_TX_DEVIATION  + integer + + Configures RDS signal frequency deviation level in Hz. +The range and step are driver-specific. + + + V4L2_CID_RDS_TX_PS_NAME  + string + + Sets the Programme Service name (PS_NAME) for transmission. +It is intended for static display on a receiver. It is the primary aid to listeners in programme service +identification and selection. In Annex E of , the RDS specification, +there is a full description of the correct character encoding for Programme Service name strings. +Also from RDS specification, PS is usually a single eight character text. However, it is also possible +to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured +with steps of 8 characters. The result is it must always contain a string with size multiple of 8. + + + V4L2_CID_RDS_TX_RADIO_TEXT  + string + + Sets the Radio Text info for transmission. It is a textual description of +what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names, +programme-related information or any other text. In these cases, RadioText should be used in addition to +V4L2_CID_RDS_TX_PS_NAME. The encoding for Radio Text strings is also fully described +in Annex E of . The length of Radio Text strings depends on which RDS Block is being +used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible +to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured +with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. + + + V4L2_CID_AUDIO_LIMITER_ENABLED  + boolean + + Enables or disables the audio deviation limiter feature. +The limiter is useful when trying to maximize the audio volume, minimize receiver-generated +distortion and prevent overmodulation. + + + + V4L2_CID_AUDIO_LIMITER_RELEASE_TIME  + integer + + Sets the audio deviation limiter feature release time. +Unit is in useconds. Step and range are driver-specific. + + + V4L2_CID_AUDIO_LIMITER_DEVIATION  + integer + + Configures audio frequency deviation level in Hz. +The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_ENABLED  + boolean + + Enables or disables the audio compression feature. +This feature amplifies signals below the threshold by a fixed gain and compresses audio +signals above the threshold by the ratio of Threshold/(Gain + Threshold). + + + V4L2_CID_AUDIO_COMPRESSION_GAIN  + integer + + Sets the gain for audio compression feature. It is +a dB value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_THRESHOLD  + integer + + Sets the threshold level for audio compression freature. +It is a dB value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME  + integer + + Sets the attack time for audio compression feature. +It is a useconds value. The range and step are driver-specific. + + + V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME  + integer + + Sets the release time for audio compression feature. +It is a useconds value. The range and step are driver-specific. + + + V4L2_CID_PILOT_TONE_ENABLED  + boolean + + Enables or disables the pilot tone generation feature. + + + V4L2_CID_PILOT_TONE_DEVIATION  + integer + + Configures pilot tone frequency deviation level. Unit is +in Hz. The range and step are driver-specific. + + + V4L2_CID_PILOT_TONE_FREQUENCY  + integer + + Configures pilot tone frequency value. Unit is +in Hz. The range and step are driver-specific. + + + V4L2_CID_FM_TX_PREEMPHASIS  + integer + + Configures the pre-emphasis value for broadcasting. +A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies. +Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_preemphasis +defines possible values for pre-emphasis. Here they are: + + + + + V4L2_PREEMPHASIS_DISABLED  + No pre-emphasis is applied. + + + V4L2_PREEMPHASIS_50_uS  + A pre-emphasis of 50 uS is used. + + + V4L2_PREEMPHASIS_75_uS  + A pre-emphasis of 75 uS is used. + + + + + + + V4L2_CID_TUNE_POWER_LEVEL  + integer + + Sets the output power level for signal transmission. +Unit is in dBuV. Range and step are driver-specific. + + + V4L2_CID_TUNE_ANTENNA_CAPACITOR  + integer + + This selects the value of antenna tuning capacitor +manually or automatically if set to zero. Unit, range and step are driver-specific. + + + + +
+ +For more details about RDS specification, refer to + document, from CENELEC. +