安卓 pcm 转 mp3 mediacodec
时间: 2023-08-17 10:04:24 浏览: 43
安卓平台上可以使用 MediaCodec 来进行 PCM 转 MP3 的操作。以下是一个简单的示例代码:
```java
public void pcmToMp3(String pcmFilePath, String mp3FilePath) {
try {
FileInputStream inputStream = new FileInputStream(pcmFilePath);
FileOutputStream outputStream = new FileOutputStream(mp3FilePath);
// 创建 MediaFormat
MediaFormat mediaFormat = MediaFormat.createAudioFormat("audio/mpeg", 44100, 2);
mediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, 128000);
// 创建 MediaCodec
MediaCodec mediaCodec = MediaCodec.createEncoderByType("audio/mpeg");
mediaCodec.configure(mediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mediaCodec.start();
// 创建 ByteBuffer
ByteBuffer[] inputBuffers = mediaCodec.getInputBuffers();
ByteBuffer[] outputBuffers = mediaCodec.getOutputBuffers();
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
boolean isInputEnd = false;
boolean isOutputEnd = false;
int inputBufferIndex, outputBufferIndex;
// 循环进行编码
while (!isOutputEnd) {
if (!isInputEnd) {
inputBufferIndex = mediaCodec.dequeueInputBuffer(-1);
if (inputBufferIndex >= 0) {
ByteBuffer inputBuffer = inputBuffers[inputBufferIndex];
inputBuffer.clear();
byte[] buffer = new byte[inputBuffer.capacity()];
int length = inputStream.read(buffer);
if (length == -1) {
mediaCodec.queueInputBuffer(inputBufferIndex, 0, 0, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
isInputEnd = true;
} else {
inputBuffer.put(buffer, 0, length);
mediaCodec.queueInputBuffer(inputBufferIndex, 0, length, System.nanoTime() / 1000, 0);
}
}
}
outputBufferIndex = mediaCodec.dequeueOutputBuffer(bufferInfo, 0);
switch (outputBufferIndex) {
case MediaCodec.INFO_OUTPUT_FORMAT_CHANGED:
break;
case MediaCodec.INFO_TRY_AGAIN_LATER:
break;
case MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED:
outputBuffers = mediaCodec.getOutputBuffers();
break;
default:
ByteBuffer outputBuffer = outputBuffers[outputBufferIndex];
byte[] outData = new byte[bufferInfo.size];
outputBuffer.get(outData);
outputStream.write(outData);
mediaCodec.releaseOutputBuffer(outputBufferIndex, false);
break;
}
if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
isOutputEnd = true;
}
}
// 释放资源
mediaCodec.stop();
mediaCodec.release();
inputStream.close();
outputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
```
该示例代码实现了从 PCM 文件中读取音频数据,并使用 MediaCodec 进行 MP3 编码,并输出到指定文件中。需要注意的是,由于 MediaCodec 中的输入数据和输出数据都是使用 ByteBuffer 进行处理的,因此需要将 PCM 数据转换为 ByteBuffer,在进行编码操作。