OpenSL 不是文件格式和访问的框架。如果您想要原始 PCM 文件,只需打开它进行写入并将 OpenSL 回调中的所有缓冲区放入文件中。但是,如果您想要编码音频,则需要您自己的编解码器和格式处理程序。你可以使用 ffmpeg 库,或者内置的 stagefright。
更新将播放缓冲区写入本地原始 PCM 文件
我们从 native-audio-jni.c 开始
#include <stdio.h>
FILE* rawFile = NULL;
int bClosing = 0;
...
void bqPlayerCallback(SLAndroidSimpleBufferQueueItf bq, void *context)
{
assert(bq == bqPlayerBufferQueue);
assert(NULL == context);
// for streaming playback, replace this test by logic to find and fill the next buffer
if (--nextCount > 0 && NULL != nextBuffer && 0 != nextSize) {
SLresult result;
// enqueue another buffer
result = (*bqPlayerBufferQueue)->Enqueue(bqPlayerBufferQueue, nextBuffer, nextSize);
// the most likely other result is SL_RESULT_BUFFER_INSUFFICIENT,
// which for this code example would indicate a programming error
assert(SL_RESULT_SUCCESS == result);
(void)result;
// AlexC: here we write:
if (rawFile) {
fwrite(nextBuffer, nextSize, 1, rawFile);
}
}
if (bClosing) { // it is important to do this in a callback, to be on the correct thread
fclose(rawFile);
rawFile = NULL;
}
// AlexC: end of changes
}
...
void Java_com_example_nativeaudio_NativeAudio_startRecording(JNIEnv* env, jclass clazz)
{
bClosing = 0;
rawFile = fopen("/sdcard/rawFile.pcm", "wb");
...
void Java_com_example_nativeaudio_NativeAudio_shutdown(JNIEnv* env, jclass clazz)
{
bClosing = 1;
...