7. period size 这个数值指的是一个周期包含多少帧。 如果设置为 32,那么用户每次读写都是 32帧数据,或者0帧数据。 参考:https://larsimmisch.github.io/pyalsaaudio/terminology.html
Period size:周期,每次硬件中断处理音频数据的Frame个数,对于音频设备的数据读写,单位是Frame。 Buffer size:数据缓冲区大小,这里特指runtime的buffer size,而不是snd_pcm_hardware定义的buffer_bytes_max。一般来说Buffer size =period_size * period_count,period_count相当于处理完一个buffer数据所需的硬件中断次数。
FramesPeriods - AlsaProject 1帧 2声道 48kHz 16bit的pcm 大小是4字节 一个period是每一个中断需要处理的一系列帧 buffer 是一个ring buffer,buffer size 比period_size要大,一般是2倍的period_size,有些是8倍 现在 硬件设置为48k,2 period_count ,perio_size 480帧,所以buffer size 是960帧, 现在想想这个...
[Alsa-devel] problem with "snd_pcm_hw_params_set_period_size_near" James Courtier-Dutton Mon, 29 Sep 2003 14:53:55 -0700 if the buffer size has already been set to 16384, and the period_size is trying to be set to 8196, why do I get the following results: -period_size=8196 d...
> Subject: Re: [Alsa-devel] buffer_size and period_size > > > >Paul, > > So with -p 64 -n 2 settings, what number of bytes of audio data is > >transferred across the PCI bus between each interrupt? > > the period size is always (as with almost all ALSA metrics) in units ...
period_size =snd_pcm_lib_period_bytes(substream); alsa_dsp_send_buffer(prtd, prtd->out_tail, period_size); prtd->out_tail ^=1; ++copy_count; prtd->period++;if(unlikely(prtd->period >= runtime->periods)) prtd->period =0;
I tried to replace it with bluealsa-aplay but the buffer is bigger and I feel latency between video and sound. Would it be possible to add option like --buffer-time / --buffer-size / --period-time / --period-size to bluealsa-aplay ?
runtime->period_size; period_elapsed =1; } snd_pcm_stream_unlock(substream);if(period_elapsed)snd_pcm_period_elapsed(substream); } 开发者ID:168519,项目名称:linux,代码行数:76,代码来源:ivtv-alsa-pcm.c 示例8: snd_msnd_eval_dsp_msg ...
In a suite of lab experiments,Rozenet al.(2008)used small containers with either fresh or old mouse carcasses, introduced mated female beetles and then manipulated beetle brood size. This manipulation allowed observation of parental behavior in terms of choice to breed and larval behavior associated...
I've tried to port some aplication from old ALSA-0.5.x to the new alsa library interface. I'm not an expert in the sound programming and available documentation seems to be rather poor in term of explaining the main concept. I would like to fully understand the exact meaning of buffer_...