IllegalStateException when MediaCodec.configure An

问题:

I try create encoder for "audio/3gpp" and my app crash...

I use this code

String mMime = "audio/3gpp";
MediaCodec mMediaCodec = MediaCodec.createEncoderByType(mMime);
MediaFormat mMediaFormat = MediaFormat.createAudioFormat(mMime, RECORDER_SAMPLERATE, 1);
mMediaCodec.configure(mMediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mMediaCodec.start();

Exception
java.lang.IllegalStateException
android.media.MediaCodec.native_configure(Native Method)
at android.media.MediaCodec.configure(MediaCodec.java:256)
at com.agent.mobile.TestAppActivity.initMediaCodec(TestAppActivity.java:234)

回答1:

There are some mandatory values that must be set in the format. If you look at the docs for MediaFormat, it says "all keys not marked optional are mandatory". If you fail to set a mandatory key, MediaCodec throws an error because it has been left in an illegal state.

Add:

mMediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, <bit rate>);
mMediaFormat.setInteger(MediaFormat.KEY_SAMPLE_RATE, <sample rate>);
mMediaFormat.setInteger(MediaFormat.KEY_CHANNEL_COUNT, 1);

KEY_MIME should have been set for you by createEncoderByType().