[android-developers] Re: Mic audio capture is of poor quality
Problem solved. We didn't know about the android AudioRecord API which can record raw PCM up to 44khz. We ended up using 16-bit 11khz PCM encoded to WAV with the java speech api (we used the Tritonus library). On Jun 3, 4:22 pm, Robert Peterson robby.peter...@gmail.com wrote: As a first step toward a speech recognition project, we wrote a simple voice recording application based on the information in this thread:http://groups.google.com/group/android-developers/browse_thread/threa... It is working; however, the audio is extremely poor -- too staticy for our needs. As a comparison, we did a similar audio file captured with audacity on a PC and it was much better. Has anyone been able to record high quality audio with the android dev phone? According to the documentation of MediaRecorder, there is only one audio encoder AMR (Narrowband) audio codec and three output formats--3gpp, mpeg, and raw AMR:http://developer.android.com/reference/android/media/MediaRecorder.html According to wikipedia, AMR encoding is only 8hz. Is there a better option available.. perhaps a lower-level API compared to MediaRecorder? We are testing on Windows XP, with a Logitec USB microphone, eclipse ganymede, and we are using all the defaults for an android 1.5 app (no emulator command-line options.. we defined the sdcard in the avd manager). --~--~-~--~~~---~--~~ 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] Recording mic audio during a call
We need to record the mic audio while a user is on a call. Note that we are not trying to record the voice of all the participants on the call (which is dubious for legal reasons), only the voice of the user holding the handset. We wrote an app that uses the AudioRecord API to record the user's voice which works well and produces high quality audio. When activated during a call, the app does record the user's voice; however, the other callers cannot hear the user while the recording is in progress. There are no errors in logcat. So, it seems when the AudioRecord API is active, it takes full control of the mic and the mic input is never routed back through to the call so other parties can hear the audio. This is possible on other platforms like Nokia. Does anyone know of a workaround? Perhaps there is a setting in the AudioRecord API that we missed? --~--~-~--~~~---~--~~ 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] AMR encoding uses 8hz sampling rate?
According to wikipedia, the AMR encoding which is the only option we see for the MediaRecorder API uses a Sampling frequency of 8 kHz/13- bit We are writing a voice recognition application. We have an equivalent app on the iphone which we have found performs best with a sampling rate of 22hz or better. At 8hz the voice recognition is not usable as the word error rate goes up by about 15%. Is there an equivalent API for android to change the sampling rate? --~--~-~--~~~---~--~~ 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] Microphone audio capture with emulator is of very poor quality
As a first step toward a speech recognition project, we wrote a simple voice recording application based on the information in this thread: http://groups.google.com/group/android-developers/browse_thread/thread/860b5f346c59f2ca/b94fa1131077321f?lnk=gstq=microphone+emulator#b94fa1131077321f It is working; however, the audio is extremely poor -- too staticy for our needs: http://juzzam.org:9090/myAudioFile.3gpp http://juzzam.org:9090/myAudioFile.mpeg http://juzzam.org:9090/myAudioFile.amr As a comparison, here is a similar audio file captured with audacity on a PC: http://juzzam.org:9090/myAudioFile_onPC.mp3 Has anyone been able to record high quality audio with the emulator? If not, is it any better on the android dev phone? According to the documentation of MediaRecorder, there is only one audio encoder AMR (Narrowband) audio codec and three output formats--3gpp, mpeg, and raw AMR: http://developer.android.com/reference/android/media/MediaRecorder.html Here is the Activity source: http://juzzam.org:9090/RecordMicrophone.java.txt We are testing on Windows XP, with a Logitec USB microphone, eclipse ganymede, and we are using all the defaults for an android 1.5 app (no emulator command-line options.. we defined the sdcard in the avd manager). --~--~-~--~~~---~--~~ 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] Microphone audio capture with emulator is of very poor quality
As a first step toward a speech recognition project, we wrote a simple voice recording application based on the information in this thread: groups.google.com/group/android-developers/browse_thread/thread/ 860b5f346c59f2ca/b94fa1131077321f?lnk=gstq=microphone +emulator#b94fa1131077321f It is working; however, the audio is extremely poor -- too staticy for our needs. When we do a similar recording with audacity on a pc, the quality is very clear. Has anyone been able to record high quality audio with the emulator? If not, is it any better on the android dev phone? According to the documentation of MediaRecorder, there is only one audio encoder AMR (Narrowband) audio codec and three output formats--3gpp, mpeg, and raw AMR: http://developer.android.com/reference/android/media/MediaRecorder.html It seems as though the only open is AMR NB which is always 8hz? Is there an API to record with something like 24hz? We are testing on Windows XP, with a Logitec USB microphone, eclipse ganymede, and we are using all the defaults for an android 1.5 app (no emulator command-line options.. we defined the sdcard in the avd manager). --~--~-~--~~~---~--~~ 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 -~--~~~~--~~--~--~---
