Messages in this thread | | | Date | Tue, 19 Sep 2023 11:53:30 +0000 | From | Sakari Ailus <> | Subject | Re: [RFC PATCH v3 6/9] media: v4l2: Add audio capture and output support |
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Hi Shengjiu,
On Tue, Sep 19, 2023 at 06:31:09PM +0800, Shengjiu Wang wrote:
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> > > +************************* > > > +V4L2_AUDIO_FMT_LPCM ('LPCM') > > > +*************************
Something to fix here, too...?
> > > + > > > +Linear Pulse-Code Modulation (LPCM) > > > + > > > + > > > +Description > > > +=========== > > > + > > > +This describes audio format used by the audio memory to memory driver. > > > + > > > +It contains the following fields: > > > + > > > +.. flat-table:: > > > + :widths: 1 4 > > > + :header-rows: 1 > > > + :stub-columns: 0 > > > + > > > + * - Field > > > + - Description > > > + * - u32 samplerate; > > > + - which is the number of times per second that samples are taken. > > > + * - u32 sampleformat; > > > + - which determines the number of possible digital values that can be used to represent each sample > > > > 80 characters (or less) per line, please. > > Ok, will change it. > > > > > Which values could this field have and what do they signify? > > The values are SNDRV_PCM_FORMAT_S8, SNDRV_PCM_FORMAT_U8... > which are the PCM format, defined in ALSA.
I suppose this is documented in ALSA documentation. Could you refer to that?
> > > > > > + * - u32 channels; > > > + - channel number for each sample. > > > > I suppose the rest of the buffer would be samples? This should be > > documented. I think there are also different ways the data could be > > arrangeed and this needs to be documented, too. > > All data in the buffer are the samples, the 'samplerate', 'sampleformat' > 'channels' I list here is try to describe the samples. > I was confused how to write this document, so I list the characters.
The layout of this data in memory needs to be documented. I think a reference to ALSA documentation would be the best.
-- Regards,
Sakari Ailus
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