Hi Ricard, On Wed, 14 Nov 2018 at 16:07, Ricard Wanderlof <ricard.wanderlof@xxxxxxxx> wrote: > > > On Wed, 14 Nov 2018, Clément Péron wrote: > > > From: Adrien Charruel <adrien.charruel@xxxxxxxxxxxx> > > > > The AK4118A is a digital audio transceiver supporting 8 input channels > > at 192kHz and with 24bits resolution. > > It converts the S/PDIF signal to I2S format and is configurable over I2C. > > > > This driver introduce a minimal support of the AK4118, like selecting the > > input channel, reading input frequency and detecting some errors. > > I'm curious, from what it seems, there is no checking that the input > sample rate actually matches the configured sample rate? It's perfectly > understandable for a driver which has 'minimal support', but it's > something a user must be aware of; for instance if someone does > > arecord -r 48000 output.wav > > when the input data actually has a rate of 44100 Hz then the file will be > written with a header specifying 44100 Hz but the data will actually be > 48000 Hz. > > It's not an objection on my part, just an observation. I don't know how > ALSA could enforce this in any way; ideally (barring automatic sample rate > conversion) one would want an error message that the sample rate specified > when opening the stream does not match the sample rate of the S/PDIF input > data. I'm quite new with linux audio driver but adding in ak4118_hw_params a check like if params_rate(params) == ak4118_rate should do the job no ? Regards, Clement > > /Ricard > -- > Ricard Wolf Wanderlof ricardw(at)axis.com > Axis Communications AB, Lund, Sweden www.axis.com > Phone +46 46 272 2016 Fax +46 46 13 61 30
