[android-developers] Audio Latency big problem on some devices
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
Re: [android-developers] Audio Latency big problem on some devices
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/commonsguy http://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
[android-developers] TouchEvent... A BIG problem
Hi, I'm new to Android, and I love it! I was wondering how many touch are possible at the same time? The user click and drag (move) and while he's dragging he clicks again (Other finger) and drag it too.. mmm, piano (multi touched) app... (with dragging)... is that possible? Thanks -- 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
[android-developers] Not a big problem.
Hi Developers. Now i have a small problem. I want to create a global variable in my program. Please give me the coding of create a global variable. Thanks in advance. Suman. --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
