Thanks for that link! It says there in section 6.3 that: Using the above definitions, device implementations SHOULD exhibit each of these properties: • cold output latency of 100 milliseconds or less • warm output latency of 10 milliseconds or less • continuous output latency of 45 milliseconds or less • cold input latency of 100 milliseconds or less • continuous input latency of 50 milliseconds or less
which would be fine for me (continuous input latency). So I guess my no-name Chinese tablet is non-conforming, having a latency of around 360 msec.! On Feb 4, 11:25 am, Mark Murphy <mmur...@commonsware.com> wrote: > For devices that legitimately have the Android Market, audio latency > has had requirements in the CDD since Android 2.2: > > http://source.android.com/compatibility/downloads.html > > I am not expert enough on the topic to know whether the requirements > specified in the CDD meet your needs or not. > > You will have two potential problems with "a no-name Chinese tablet": > > 1. It might not have the Market at all > > 2. It might have a pirated copy of the Market > > In either case, they did not necessarily meet the CDD for their > specific version of Android, and all bets are off. > > > > > > > > > > On Sat, Feb 4, 2012 at 11:16 AM, RLScott <fixthatpi...@yahoo.com> wrote: > > You wouldn't think 1024 samples at 22050 samples per second was > > especially low latency. And on most devices, using the AudioRecord > > class I have no trouble in getting individual buffers of 1024 samples > > (about 20 buffers per second) evenly spaced in time. But on at least > > one device, the timing seems to be very irregular. My application is > > a musical instrument tuner, and it is important to get small buffers > > in a timely manner. So I tested the timing by logging the time > > between reads. Here is the timing in milliseconds using an original > > Motorola Droid: > > > 37 36 62 46 42 31 62 47 41 31 > > > Nice! But here is the same info from a no-name Chinese tablet running > > 2.3.1: > > > 359 0 0 0 0 1 0 0 366 0 0 ... > > > It is apparent that the no-name tablet is batching the audio data into > > blocks of 8192 samples. So I get 8 buffers in rapid succession and > > then have to wait another 360 milliseconds for the next buffer. > > > Most devices behave more like the Droid, with latency low enough to > > deliver evenly-spaced buffers of 1024 samples. But I sure hope there > > aren't too many devices like that no-name tablet. Anyone have any > > updated insight into the problem of audio latency? > > > -- > > You received this message because you are subscribed to the Google > > Groups "Android Developers" group. > > To post to this group, send email to android-developers@googlegroups.com > > To unsubscribe from this group, send email to > > android-developers+unsubscr...@googlegroups.com > > For more options, visit this group at > >http://groups.google.com/group/android-developers?hl=en > > -- > Mark Murphy (a Commons > Guy)http://commonsware.com|http://github.com/commonsguyhttp://commonsware.com/blog|http://twitter.com/commonsguy > > Android Training in NYC:http://marakana.com/training/android/ -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
