我对ALSA录音和播音的理解,当我们通过麦克风讲话的声音搜集到声卡里之后,内存从声卡里读取声音数据的过程就是录音过程,即snd_pcm_readi()函数的执行,把内存中的声音数据写入到声卡的过程就是播音过程,即snd_pcm_writei()函数的执行。 分类: 视音频处理 好文要顶 关注我 收藏该文 微信分享 苍月代表我 粉丝-...
DM8168使用ALSA在A8采集音频,每次使用sysfs动态切换HDMI输出制式,snd_pcm_readi耗时特别大(阻塞模式),声音卡顿,平台为DVR_RDK2.8,想问一下,下面的代码执行怎么影响ALSA的采集? VDIS_CMD_ARG2(gBuff, VDIS_TIMINGS_SETVENC, 0, 3) VDIS_CMD_ARG2(gBuff, VDIS_TIMINGS_SETVENC, 0, 0) V...
snd_pcm_readi 是ALSA(Advanced Linux Sound Architecture)库中的一个函数,用于从 PCM(Pulse Code Modulation)设备中读取音频数据。当你遇到 snd_pcm_readi 返回-5 时,这通常表示函数执行失败,并返回一个错误代码。在 ALSA 中,错误代码通常以负值表示。 1. 确认 snd_pcm_readi 函数返回 -5 的含义...
1,sizeof(buf), fp))) {switch(snd_pcm_writei(pcm, buf, l / framesize)) {case-EBADF:return-1;case-EPIPE:#ifndefNDEBUGsnd_pcm_recover(pcm, -EPIPE,0);#else
prefer_subdevice = kctl->prefer_pcm_subdevice; if (prefer_subdevice != -1) break; } } up_read(&card->controls_rwsem); It would seem ctl_files is supposed to be protected by controls_rwsem, however turns out all routines manipulating it take ctl_files_rwlock spinlock instead. ...
pcm_tablegen.h pcx.c pcxenc.c pgssubdec.c pictordec.c png.c png.h pngdec.c pngenc.c pnm.c pnm.h pnm_parser.c pnmdec.c pnmenc.c psymodel.c psymodel.h pthread.c ptx.c put_bits.h qcelpdata.h qcelpdec.c qdm2.c qdm2_tablegen.c qdm2_tablegen.h qdm2data.h qdrw.c ...
Item: PCM [dB gain: 0.00, -0.40] with a single bar <100>PCM<100> for playback, and nothing else... I'm at a bit of a loss to know what is going wrong (or perhaps what I'm doing wrong) or what I should do next Any thoughts would be appreciated n patch_cs8409.h.rej.txt...
tests/channel_test tests/long_read_write_test tests/stdin_test tests/stdout_test \ tests/dither_test tests/fix_this tests/largefile_test tests/benchmark tests/ogg_opus_test BUILT_SOURCES += \ tests/write_read_test.c \ tests/pcm_test.c \ tests/header_test.c \ tests/utils.c \...
mutex_lock(&stream->device->lock);if(stream->runtime->state != SNDRV_PCM_STATE_SETUP && stream->runtime->state != SNDRV_PCM_STATE_RUNNING) { mutex_unlock(&stream->device->lock);return-EBADFD; } avail = snd_compr_get_avail(stream); ...
它设置了I2C的地址宽度为8位,寄存器宽度为16位,I2C通信方式,如果根据这些参数继续追踪io_types[i].read,则会发现它最终调用了I2C的标准读函数: staticunsignedintdo_i2c_read(structsnd_soc_codec *codec,void*reg,intreglen,void*data,intdatalen)