[mythtv-users] frustrating comments about sample rates (what not to do)

[Donavan Stanley]

On 8/29/05, Larry Symms <lsymms at comcast.net> wrote:
> In mpegrecorder.cpp it states "// only 48kHz works properly." regarding
> audio sample rates which I have tested and proven true.  What happens is
> a discrepancy in displayed time and actual position in the recording.
> This leads to skipping back when trying to skip forward because myth is
> miscalculating the current position based on time elapsed.  The problem
> is that the comments in Recording Profiles in TV Settings in Myth
> frontend say: "Sets the audio sampling rate for your DSP.  Ensure that
> you choose a sampling rate appropriate for your device.  btaudio may
> only allow 32000."  This implys that not only is it ok to change the
> sampling rate from the default but that it is recomended.  This is not
> the case.  Do not be deceived, 48000 is the only acceptable setting for
> mpeg encoders unless you never watch recordings while they're
> recording.  When playing recordings while they are recording the sample
> rate is gathered from the codec settings in the db rather than the mpeg
> header.  If any of this is incorrect by all means correct me but I'm 99%
> sure this is the case based on the code I've gone through and the tests
> I've conducted.


The big thing you appear to be missing is the btaudio and mpegrecorder
have nothing to do with each other.  If you have a card which uses
btaudio you're going to be using nupplevideoencoder.