My requirement is to play 16 bit, 22KHz linear PCM data to audioout using alsa API. I have added 2 section of code which i have written to configure ALSA and audioout wrapper which writes 2048 frames using write API.
問題を消費しています。フレームは非常に高速
//opening audio handle
if ((err = snd_pcm_open (&rsettings->ppcm_handle, name, SND_PCM_STREAM_PLAYBACK, 0)) < 0)
{
return -1;
}
if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0)
{
return -1;
}
if ((err = snd_pcm_hw_params_any (rsettings->ppcm_handle, hw_params)) < 0)
{
return -1;
}
//setting interleaved mode
if ((err = snd_pcm_hw_params_set_access (rsettings->ppcm_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0)
{
return -1;
}
//setting bit depth to 2 byte
if ((err = snd_pcm_hw_params_set_format (rsettings->ppcm_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0)
{
return -1;
}
//設定サンプルレートヘルツ IF((ERR = snd_pcm_hw_params_set_rate(rsettings-> ppcm_handle、hw_params、22050、0))< 0){ リターン-1 22050に、 IF((ERR = snd_pcm_hw_params_set_channels(rsettings-> ppcm_handle、hw_params、1))< 0){ リターン-1 1
にチャンネルの数を設定 }
//。
snd_pcm_uframes_t frame_size = 1024;
if((err = snd_pcm_hw_params_set_period_size_near(rsettings->ppcm_handle, hw_params, &frame_size, 0)) < 0)
{
printf("\n cannot set size");
return -1;
}
// setting number of period to 1
if ((err = snd_pcm_hw_params_set_periods(rsettings->ppcm_handle, hw_params, 1, 1)) < 0)
{
return -1;
}
frame_size = 2048;
//setting buffer size to 2048
if ((err = snd_pcm_hw_params_set_buffer_size_near(rsettings->ppcm_handle, hw_params, &frame_size)) < 0)
{
return -1;
}
if ((err = snd_pcm_nonblock (rsettings->ppcm_handle, 0)) < 0)
{
return -1;
}
if ((err = snd_pcm_hw_params (rsettings->ppcm_handle, hw_params)) < 0)
{
return -1;
}
snd_pcm_hw_params_free (hw_params);
if ((err = snd_pcm_prepare (rsettings->ppcm_handle)) < 0)
{
return -1;
}
}
は、私は私が間違っているつもりだところ、一部が言うことができるnoOfFrames = 2024
while(noOfFrames > 0)
{
if(0 > (poll(descriptors, pollDescriptorCount, 500)))
{
printf("error polling for data");
}
else
{
printf("\nPoll Unblocked");
if(0 > (retVal = snd_pcm_poll_descriptors_revents(rsettings->ppcm_handle, descriptors, pollDescriptorCount, &pollEvent)))
{
printf("\nError getting poll events, return value : %d", retVal);
break;
}
else
{
frames = snd_pcm_avail_update(rsettings->ppcm_handle);
printf("\nAvailable channel frames = %d",frames);
if(frames < 0)
{
if(frames == -EPIPE)
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
else if(frames == -ESTRPIPE)
{
while (-EAGAIN == snd_pcm_resume(rsettings->ppcm_handle))
usleep(2000);
}
else
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
}
else
{
if(frames >= noOfFrames)
{
if ((framesWritten = snd_pcm_writei(rsettings->ppcm_handle, &pBuffer, noOfFrames)) > 0)
{
printf("\nNo of frames written : %d",framesWritten);
noOfFrames = noOfFrames - framesWritten;
free(descriptors);
}
else if(framesWritten < 0)
{
if(framesWritten == -EPIPE)
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
else if(framesWritten == -ESTRPIPE)
{
while (-EAGAIN == snd_pcm_resume(rsettings->ppcm_handle))
usleep(2000);
}
else
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
}
}
else
{
if ((framesWritten = snd_pcm_writei(rsettings->ppcm_handle, &pBuffer, frames)) > 0)
{
printf("\nNo of frames written : %d",framesWritten);
noOfFrames = noOfFrames - framesWritten;
free(descriptors);
}
else if(framesWritten < 0)
{
if(framesWritten == -EPIPE)
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
else if(framesWritten == -ESTRPIPE)
{
while (-EAGAIN == snd_pcm_resume(rsettings->ppcm_handle))
usleep(2000);
}
else
{
snd_pcm_prepare(rsettings->ppcm_handle);
}
}
}
}
}
}
}
以下のようにポーリングを使用してaudioout APIを持っています。
これらの 'free(descriptors);'呼び出しは疑わしいと思われます。 –
'aplay'は動作しますか? –
はいaplayが動作します – Shrinock