Question

i have build a small test app in Flash Pro 5.5 overlayed with the AIR 3 sdk.
is has just 2 buttons to record and playback audio from the microphone.

when i test this on my iPhone 3g – i record myself saying “1-2-3-4-5”. but when i playback a half a second or so is missing from the beginning : “3-4-5-“.

when i test this on the desktop all is fine

is this a result of the iPhone 3g’s cpu power or is it a bug or is it my code?

thanks
Saar

if anyone could try this code and see if he/she reproduces this, i would appreciate it

this is the app:

all i have on stage is 2 rectangled movie clips named “recorded” and “player”
all the code is in this document class:

package  {

          import flash.display.MovieClip;
          import flash.media.Microphone;
          import flash.media.SoundMixer;
          import flash.events.MouseEvent;
          import flash.utils.ByteArray;
          import flash.media.Sound;
          import flash.media.SoundChannel;
          import flash.events.SampleDataEvent;
          import flash.media.AudioPlaybackMode;


          public class RecTest extends MovieClip {
                    var mic:Microphone;
                    var nowRecording:Boolean = false;
                    var nowPlaying:Boolean = false;
                    var recordedBytes:ByteArray = new ByteArray();
                    var s:Sound = new Sound();
                    var sc:SoundChannel;

                    public function RecTest() {
                              mic = Microphone.getMicrophone(-1);
                              SoundMixer.useSpeakerphoneForVoice = true;
                              SoundMixer.audioPlaybackMode = AudioPlaybackMode.MEDIA;
                              mic.gain = 100;
                              mic.setSilenceLevel(0);
                              mic.rate = 44;

                              recorder.addEventListener(MouseEvent.CLICK, onRec);
                              player.addEventListener(MouseEvent.CLICK, onPlay);
                    }

                    function onRec(e:MouseEvent) {
                              if (nowRecording) {
                                        trace("stopped");
                                        mic.removeEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
                                        nowRecording = false;
                              } else {
                                        trace("recording");
                                        recordedBytes.position = 0;
                                        recordedBytes.length = 0;
                                        mic.addEventListener(SampleDataEvent.SAMPLE_DATA, getMicAudio);
                                        nowRecording = true;
                              }
                    }

                    function onPlay(e:MouseEvent) {
                              if (nowPlaying) {
                                        trace("stopped");
                                        sc.stop();
                                        s.removeEventListener(SampleDataEvent.SAMPLE_DATA, playAudio);
                                        nowPlaying = false;
                              } else {
                                        trace("playing");
                                        recordedBytes.position = 0;
                                        s.addEventListener(SampleDataEvent.SAMPLE_DATA, playAudio);
                                        sc = s.play();
                                                sc.addEventListener(Event.SOUND_COMPLETE, onComplete,false,0,true);
                                        nowPlaying = true;
                              }
                    }

                        function onComplete(e:Event) {
                                              trace("stopped");
                                              s.removeEventListener(SampleDataEvent.SAMPLE_DATA, playAudio);
                                              nowPlaying = false;
                    }


                    function getMicAudio(e:SampleDataEvent) {
                              recordedBytes.writeBytes(e.data);
                    }

                    function playAudio(e:SampleDataEvent) {
                              for (var i:int = 0; i < 8092 && recordedBytes.bytesAvailable > 0; i++) {
                                        e.data.writeBytes(recordedBytes);
                                        e.data.writeBytes(recordedBytes);
                              }
                    }
          }

}

Answer 1

ok, this seems to be a lag in the iOS recording. so i use a workaround: constant recording to a buffer and using the buttons to record the in and out positions of the ByteArray for playback