如何通过上层代码修改dump音频数据流

我们在分析杂音等问题的时候, 只抓adb log是不够的, dump audio的数据能直观快速的判断是哪一块出了问题, 这里只针对高通平台

1. 如何在Frameworks层音频数据dump

1. //代码路径：frameworks/av/services/audioflinger/Tracks.cpp#getNextBuffer

2. status_t AudioFlinger::PlaybackThread::Track::getNextBuffer(

3. AudioBufferProvider::Buffer* buffer){

4. ServerProxy::Buffer buf;

5. size_t desiredFrames = buffer->frameCount;

6. buf.mFrameCount = desiredFrames;

7. status_t status = mServerProxy->obtainBuffer(&buf);

8. buffer->frameCount = buf.mFrameCount;

9. buffer->raw = buf.mRaw;

10. if (buf.mFrameCount == 0) {

11. mAudioTrackServerProxy->tallyUnderrunFrames(desiredFrames);

12. } else {

13. mAudioTrackServerProxy->tallyUnderrunFrames(0);

14. }

15. int tmpFd = ::open("/data/misc/audio/dumpTrack.pcm", O_CREAT | O_WRONLY | O_APPEND, 0777);

16. if ( tmpFd < 0 ) {

17. ALOGE("Tracks.cpp Fail to open dumpTrack file");

18. } else {

19. ::write(tmpFd, buffer->raw, buffer->frameCount * TrackBase::mChannelCount * 2);

20. ::close(tmpFd);

21. }

22. return status;

23. }

2. 如何在HAL层音频数据dump

1. //hardware/qcom/audio/hal/audio_hw.c#out_write

2. static ssize_t out_write(struct audio_stream_out *stream, const void *buffer,size_t bytes){

3. struct stream_out *out = (struct stream_out *)stream;

4. struct audio_device *adev = out->dev;

5. ssize_t ret = 0;

6. ......

7. } else {

8. if (out->pcm) {

9. if (out->muted)

10. memset((void *)buffer, 0, bytes);

11. ALOGVV("%s: writing buffer (%d bytes) to pcm device", __func__, bytes);

12. int tmpFd = open("/data/misc/audio/dumpTrack_hal.pcm", O_CREAT | O_WRONLY | O_APPEND, 0777);

13.  

14. if ( tmpFd < 0 ) {

15. ALOGE("Fail to open dumpTrack_hal file");

16. } else {

17. write(tmpFd, buffer, bytes);

18. close(tmpFd);

19. }

20. if (adev->adm_request_focus)

21. adev->adm_request_focus(adev->adm_data, out->handle);

22. if (out->usecase == USECASE_AUDIO_PLAYBACK_AFE_PROXY) {

23. ret = pcm_mmap_write(out->pcm, (void *)buffer, bytes);

24. }

25. else

26. ret = pcm_write(out->pcm, (void *)buffer, bytes);

27. if (ret == 0)

28. out->written += bytes / (out->config.channels * sizeof(short));

29. if (adev->adm_abandon_focus)

30. adev->adm_abandon_focus(adev->adm_data, out->handle);

31. }

32. }

33. exit:

34. pthread_mutex_unlock(&out->lock);

35. if (ret != 0) {

36. if (out->pcm)

37. ALOGE("%s: error %zu - %s", __func__, ret, pcm_get_error(out->pcm));

38. out_standby(&out->stream.common);

39. usleep(bytes * 1000000 / audio_stream_out_frame_size(stream) /

40. out_get_sample_rate(&out->stream.common));

41. }

42. return bytes;

43. }