打开PCM设备 设置硬件参数 读/写数据 PCM播放示例代码 PCM录音示例代码 使用异步方法 snd_async_add_pcm_handler()函数 snd_pcm_avail_update()函数 PCM异步播放示例 PCM异步录音示例 使用poll()函数 使用poll I/O多路复用实现读写 PCM播放示例 PCM录音示例 PCM设备状态 PCM播放——加入状态控制 snd_pcm_readi/...
snd_pcm_open_conf 调用snd_dlobj_cache_get在动态库中libasound_module_pcm_hw.so获取函数指针_snd_pcm_hw_open_snd_pcm_hw_open通过调用snd_pcm_hw_open来创建hw_pcm设备。snd_pcm_hw_open函数原型如下int snd_pcm_hw_open(snd_pcm_t **pcmp, const char *name, int card, int device, int subdevic...
This adds a virtio based sound card device that provides output and input PCM streams to a virtual guest. In order to build the virtio-snd device the VIRTIO_SND configuration option should be enabled in the hw/audio/Kconfig file. The device can be provided to a guest using the following ...
PCM的访问类型,暂时主要关注SND_PCM_ACCESS_RW_INTERLEAVED交错排列和SND_PCM_ACCESS_RW_NONINTERLEAVED非交错排列: /** PCM access type */typedefenum_snd_pcm_access{/** mmap access with simple interleaved channels */SND_PCM_ACCESS_MMAP_INTERLEAVED=0,/** mmap access with simple non interleaved channe...
snd_pcm_writei通过调用_snd_pcm_writei写入PCM数据流,_snd_pcm_writei函数原型如下 static inline snd_pcm_sframes_t _snd_pcm_writei(snd_pcm_t *pcm, const void *buffer, snd_pcm_uframes_t size) { /* lock handled in the callback */ if (!pcm->fast_ops->writei) return -ENOSYS; ret...