/**
* make sine wave humble MediaAudio.
*
* @return
*/
private MediaAudio beepSamples() {
int sampleRate = 44100; // 44.1KHz
int sampleNum = 44100; // 44100 samples(1sec)
int channel = 2; // 2channel(stereo)
int tone = 440; // 440Hz tone.
int bit = 16; // 16bit
ByteBuffer buffer = ByteBuffer.allocate((int) sampleNum * bit * channel / 8);
double rad = tone * 2 * Math.PI / sampleRate; // radian for each sample.
double max = (1 << (bit - 2)) - 1; // ampletude
buffer.order(ByteOrder.LITTLE_ENDIAN);
for (int i = 0; i < sampleNum; i++) {
short data = (short) (Math.sin(rad * i) * max);
for (int j = 0; j < channel; j++) {
buffer.putShort(data);
}
}
buffer.flip();
logger.info("data size for 1sec buffer.:" + buffer.remaining());
MediaAudio samples =
MediaAudio.make(
sampleNum, sampleRate, channel, Layout.CH_LAYOUT_STEREO, Type.SAMPLE_FMT_S16);
samples.getData(0).put(buffer.array(), 0, 0, buffer.remaining());
logger.info(
"{}",
samples.getDataPlaneSize(0)); // why this size is little bit bigger than original buffer?
samples.setComplete(true);
samples.setTimeBase(Rational.make(1, 44100));
samples.setTimeStamp(0);
samples.setNumSamples(sampleNum);
return samples;
}
private void processConvert(Muxer muxer, Encoder encoder) throws Exception {
muxer.open(null, null);
MediaPacket packet = MediaPacket.make();
MediaAudio samples = beepSamples();
logger.info(samples.toString());
if (samples.getSampleRate() != encoder.getSampleRate()
|| samples.getFormat() != encoder.getSampleFormat()
|| samples.getChannelLayout() != encoder.getChannelLayout()) {
final MediaAudioResampler resampler =
MediaAudioResampler.make(
encoder.getChannelLayout(),
encoder.getSampleRate(),
encoder.getSampleFormat(),
samples.getChannelLayout(),
samples.getSampleRate(),
samples.getFormat());
resampler.open();
MediaAudio spl =
MediaAudio.make(
samples.getNumSamples(),
encoder.getSampleRate(),
encoder.getChannels(),
encoder.getChannelLayout(),
encoder.getSampleFormat());
resampler.resample(spl, samples);
logger.info(spl.toString());
logger.info("{}", spl.getNumSamples());
Assert.assertEquals(spl.getNumSamples(), samples.getNumSamples());
samples = spl;
}
logger.info(samples.toString());
// we only have one set of samples.
encoder.encodeAudio(packet, samples);
logger.info("{}", packet);
if (packet.isComplete()) muxer.write(packet, false);
// Flush the encoders
do {
encoder.encodeAudio(packet, null);
logger.info("{}", packet);
if (packet.isComplete()) {
muxer.write(packet, false);
}
} while (packet.isComplete());
muxer.close();
}