客戶要求實現錄音功能，所以采用Pyaudio進行聲音流采集
安裝和示例請訪問:
http://people.csail.mit.edu/hubert/pyaudio/
遇到顯示警告問題:
ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround40 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround41 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround50 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround51 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround71 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958 ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.hdmi ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm.c:2450:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline ALSA lib ../../../alsa-lib-1.1.2/src/pcm/pcm_dmix.c:1041:(snd_pcm_dmix_open) unable to open slave Cannot connect to server socket err = No such file or directory Cannot connect to server request channel jack server is not running or cannot be started JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
上面一些不影響錄音的警報,ALSA部分是沒有找到聲卡,下面是沒有找打jack server。聲音采集是OK了不過客戶對報警不滿意，所以尋找辦法清除報警信息。
消除ALSA 報警（博客地址忘了）
/usr/share/alsa/alsa.conf(可能位置有變化)，中配置了聲卡信息，那么可以根據上面的報錯刪除對應的聲卡就可以了。
這樣就只剩下jack server的信息了。因為Pyaudio 在實例對象時，直接開啟了聲音采集和播放的功能，所以一直沒有辦法關掉jack server 的信息。
使用 sys模塊去除警報
在代碼中使用 os.close(sys.stderr.fileno()) # (記得導入模塊) 參考：https://stackoverflow.com/questions/36956083/how-can-the-terminal-output-of-executables-run-by-python-functions-be-silenced-i 這樣可以不展示系統的err消息，所以ALSA 和jack server 的消息都不會被展示。
具體的原理和代碼示例參照 https://eli.thegreenplace.net/2015/redirecting-all-kinds-of-stdout-in-python/
使用sounddevice 據說也可以解決這個問題(沒試過)