static struct snd_pcm_ops soc_pcm_ops = { .open = soc_pcm_open, .close = soc_codec_close, .hw_params = soc_pcm_hw_params, .hw_free = soc_pcm_hw_free, .prepare = soc_pcm_prepare, .trigger = soc_pcm_trigger, .poi
一,虚拟机内部声音导出到本地宿主机内 主要是针对qemu虚拟机下的音频如何使用,首先要查看help命令: qemu-system-x86_64 -audio-help 1. 这个命令能告诉我们audio的一些基本的信息和使用方法,以及Qemu支持的驱动 Audio options: QEMU_AUDIO_DAC_FIXED_SETTINGS: boolean, default = 1 Use fixed settings for host ...
staticstructsnd_pcm_opssoc_pcm_ops={ .open =soc_pcm_open, .close =soc_codec_close, .hw_params =soc_pcm_hw_params, .hw_free =soc_pcm_hw_free, .prepare =soc_pcm_prepare, .trigger =soc_pcm_trigger, .pointer =soc_pcm_pointer, ...
.trigger = soc_pcm_trigger, }; ==> soc_pcm_open cpu_dai->ops->startup // 无 platform->pcm_ops->open // s3c_dma_open 分配DMA空间 codec_dai->ops->startup // uda134x_startup card_dai_link->ops->startup // s3c24xx_uda134x_startup 获取clock时钟源 // cpu_dai单元 struct snd...
pcm->fast_ops = &snd_pcm_hw_fast_ops; static int snd_pcm_hw_mmap_control(snd_pcm_t *pcm) { snd_pcm_hw_t *hw = pcm->private_data; void *ptr; int err; if (hw->sync_ptr == NULL) { // 如果还没有mmap,那么执行mmap映射内核空间驱动使用的声音缓冲区 ...
.open = soc_pcm_open, .close = soc_codec_close, .hw_params = soc_pcm_hw_params, .hw_free = soc_pcm_hw_free, .prepare = soc_pcm_prepare, .trigger = soc_pcm_trigger, }; ==> soc_pcm_open cpu_dai->ops->startup // 无 ...
.open = soc_pcm_open, .close = soc_codec_close, .hw_params = soc_pcm_hw_params, .hw_free = soc_pcm_hw_free, .prepare = soc_pcm_prepare, .trigger = soc_pcm_trigger, }; ==> soc_pcm_open cpu_dai->ops->startup // 无 ...
_snd_pcm_hw_open ==> snd_pcm_hw_open(pcmp, name, card, device, subdevice, stream, mode | (nonblock ? SND_PCM_NONBLOCK : 0), 0, sync_ptr_ioctl); ==> snd_ctl_hw_open filename等于"/dev/snd/controlC0" ==> snd_open_device(filename, fmode); ctl->ops = &snd_ctl_hw_ops;...
标准的snd_soc_ops回调 通常由asoc core在进行PCM操作时调用 startup shutdown hw_params hw_free prepare trigger 降低pop音,由asoc-core调用 digital_mute soc-dai.h文件里定义的下面函数,通常在machine驱动 struct snd_soc_ops接口的hw_params()函数里 被调用,接收struct snd_soc_dai 实例参数。
_snd_pcm_hw_open ==> snd_pcm_hw_open(pcmp, name, card, device, subdevice, stream, mode | (nonblock ? SND_PCM_NONBLOCK : 0), 0, sync_ptr_ioctl); ==> snd_ctl_hw_open filename等于"/dev/snd/controlC0" ==> snd_open_device(filename, fmode); ctl->ops = &snd_ctl_hw_ops;...