snd_pcm_set_appl_ptr(pcm, &hw->mmap_control->appl_ptr, hw->fd, SNDRV_PCM_MMAP_OFFSET_CONTROL); return 0; } snd_pcm_mmap switch (i->type) { case SND_PCM_AREA_MMAP: // 表示为数据区分配驱动内存,在snd_pcm_hw_channel_info中设置了type ptr = mmap(NULL, size, PROT_READ|PROT_WRI...
==> pcm_write(audiobuf, l); ==> writei_func(handle, data, count);就是调用上面的snd_pcm_writei ==> snd_pcm_writei ==> _snd_pcm_writei ==> pcm->fast_ops->writei(pcm->fast_op_arg, buffer, size); ==> snd_pcm_plugin_writei ==> snd_pcm_write_areas(pcm, areas, 0, siz...
Oct 29 20:44:11 raspberrypi snapclient[1516]: snd_pcm_avail_delay failed: Broken pipe, avail: 6000, delay: 6000, retrying. Oct 29 20:44:11 raspberrypi snapclient[1516]: snd_pcm_avail_delay failed again: Broken pipe, avail: 6000, delay: 6000, using snd_pcm_avail and snd_pcm_delay...
period_size = snd_pcm_hw_params_get_period_size(params, &dir);/* write the parameters to device */err = snd_pcm_hw_params(handle, params);if(err <0) {printf("Unable to set hw params for playback: %s\n", snd_strerror(err));returnerr; }return0; } 开发者ID:Jay-Jay-OPL,项目...
示例1: ao_plugin_close ▲点赞 7▼ /* close the audio device */intao_plugin_close(ao_device *device){ ao_alsa_internal *internal;if(device) {if((internal = (ao_alsa_internal *) device->internal)) {if(internal->pcm_handle) {/* this is a PulseAudio ALSA emulation bug workaround;s...
JackShmReadWritePtr::~JackShmReadWritePtr - Init notdonefor-1, skipping unlock JackShmReadWritePtr::~JackShmReadWritePtr - Init notdonefor-1, skipping unlock ALSA lib pcm_oss.c:397:(_snd_pcm_oss_open) Cannot open device /dev/dsp ALSA lib pcm_oss.c:397:(_snd_pcm_oss_open) Cannot...
plugin-write(pcm, areas, offset, frames, slave_areas, slave_offset, &slave_frames);即调用snd_pcm_linear_write_areas函数将areas中的frames频数据拷贝到slave_areas内存区= pcm-fast_ops-mmap_commit(pcm-fast_op_arg, offset, frames);= snd_pcm_dmix_mmap_commit= snd_pcm_dmix_sync_area/* ...
write(STDOUT_FILENO,buffer,bytesRead);// 输出录音数据(示例代码) } // 关闭设备文件 close(fd); return0; } 这个代码使用 Linux 中的ioctl函数来配置录音参数,然后通过循环读取/dev/snd/pcmC0D0c设备文件中的音频数据。你可以在循环内对音频数据进行处理,并根据需要输出或保存录音数据。
_snd_pcm_empty_open和snd_pcm_open_named_slave==>snd_pcm_open_conf(pcmp,name,root,conf,stream,mode);==>open_func=snd_dlobj_cache_lookup(open_name);将获得lib库中_snd_pcm_empty_open函数 所以open_func将等于_snd_pcm_empty_open _snd_pcm_empty_open _snd_pcm_asym_open _snd_pcm_plug_...
==> pcm_write(audiobuf, l); ==> writei_func(handle, data, count);就是调用上面的snd_pcm_writei ==> snd_pcm_writei ==> _snd_pcm_writei ==> pcm->fast_ops->writei(pcm->fast_op_arg, buffer, size); ==> snd_pcm_plugin_writei ==> snd_pcm_write_areas(pcm, areas, 0, siz...