From 5c9077eabc9a0ffbd4c8b0724ddcd69ef2b1a7ed Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Fri, 29 Jan 2016 07:00:08 -0200 Subject: [media] v4l2-mc.h: Split audio from baseband output Analog TV tuners have a separate output pad for the audio IF or audio sampled data. This pad is connected to a different chipset. Add an extra pad for it and improve the documentation. Signed-off-by: Mauro Carvalho Chehab --- include/media/v4l2-mc.h | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) (limited to 'include/media/v4l2-mc.h') diff --git a/include/media/v4l2-mc.h b/include/media/v4l2-mc.h index f6fcd70f3548..c174e5b4f188 100644 --- a/include/media/v4l2-mc.h +++ b/include/media/v4l2-mc.h @@ -19,20 +19,26 @@ * * @TUNER_PAD_RF_INPUT: Radiofrequency (RF) sink pad, usually linked to a * RF connector entity. - * @TUNER_PAD_OUTPUT: Tuner output pad. This is actually more complex than - * a single pad output, as, in addition to luminance and - * chrominance IF a tuner may have internally an - * audio decoder (like xc3028) or it may produce an audio - * IF that will be used by an audio decoder like msp34xx. - * It may also have an IF-PLL demodulator on it, like - * tuners with tda9887. Yet, currently, we don't need to - * represent all the dirty details, as this is transparent - * for the V4L2 API usage. So, let's represent all kinds - * of different outputs as a single source pad. + * @TUNER_PAD_OUTPUT: Tuner video output source pad. Contains the video + * chrominance and luminance or the hole bandwidth + * of the signal converted to an Intermediate Frequency + * (IF) or to baseband (on zero-IF tuners). + * @TUNER_PAD_AUD_OUT: Tuner audio output source pad. Tuners used to decode + * analog TV signals have an extra pad for audio output. + * Old tuners use an analog stage with a saw filter for + * the audio IF frequency. The output of the pad is, in + * this case, the audio IF, with should be decoded either + * by the bridge chipset (that's the case of cx2388x + * chipsets) or may require an external IF sound + * processor, like msp34xx. On modern silicon tuners, + * the audio IF decoder is usually incorporated at the + * tuner. On such case, the output of this pad is an + * audio sampled data. * @TUNER_NUM_PADS: Number of pads of the tuner. */ enum tuner_pad_index { TUNER_PAD_RF_INPUT, TUNER_PAD_OUTPUT, + TUNER_PAD_AUD_OUT, TUNER_NUM_PADS -}; \ No newline at end of file +}; -- cgit v1.2.3