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• How to get full name of default microphone ?

  9 août 2019, par Jiapeng Li

  Been trying to get full name of microphone as a variable on Python for usage of ffmpeg. I have already tried

  p = pyaudio.PyAudio()
  
  default_device = p.get_default_input_device_info()
  
  print(default_device['name'])

  and here was the output :

  Microphone (Conexant SmartAudio         #it was truncated to 31 characters length

  Obviously,that was truncated and not what i wanted.
  Tried sounddevice too :

  import sounddevice as sd
  
  s = sd.query_devices()
  
  print(s)

  Output :

     0 Microsoft Sound Mapper - Input, MME (2 in, 0 out)
  
  >  1 Microphone (Conexant SmartAudio, MME (2 in, 0 out)           #still truncated
  
     2 Microsoft Sound Mapper - Output, MME (0 in, 2 out)
  
  <  3 Speakers (Conexant SmartAudio H, MME (0 in, 2 out)
  
     4 Primary Sound Capture Driver, Windows DirectSound (2 in, 0 out)
  
     5 Microphone (Conexant SmartAudio HD), Windows DirectSound (2 in, 0 out)    #now got normal,but why?
  
     6 Primary Sound Driver, Windows DirectSound (0 in, 2 out)
  
     7 Speakers (Conexant SmartAudio HD), Windows DirectSound (0 in, 2 out)
  
     8 Speakers (Conexant SmartAudio HD), Windows WASAPI (0 in, 2 out)
  
     9 Microphone (Conexant SmartAudio HD), Windows WASAPI (2 in, 0 out)
  
    10 Stereo Mix (Conexant HD Stereo Mix), Windows WDM-KS (2 in, 0 out)
  
    11 Microphone (Conexant HD Audio capture), Windows WDM-KS (2 in, 0 out)
  
    12 Speakers (Conexant HD Audio output), Windows WDM-KS (0 in, 2 out)

  It can be seen that device number 1 was my default one and if that was full name it would be perfect but unfortunately that was not.

  Then the only thing i could have thought of was to capture full name from list that ffmpeg provided :

  'ffmpeg -list_devices true -f dshow -i dummy':
  
  [dshow @ 000001cc4f298d00] DirectShow video devices (some may be both video and audio devices)
  
  [dshow @ 000001cc4f298d00]  "USB2.0 VGA UVC WebCam"
  
  [dshow @ 000001cc4f298d00]     Alternative name "@device_pnp_\\?\usb#vid_13d3&pid_5a07&mi_00#6&2f27e633&0&0000#{65e8773d-8f56-11d0-a3b9-00a0c9223196}\global"
  
  [dshow @ 000001cc4f298d00]  "screen-capture-recorder"
  
  [dshow @ 000001cc4f298d00]     Alternative name "@device_sw_{860BB310-5D01-11D0-BD3B-00A0C911CE86}\{4EA69364-2C8A-4AE6-A561-56E4B5044439}"
  
  [dshow @ 000001cc4f298d00] DirectShow audio devices
  
  [dshow @ 000001cc4f298d00]  "Microphone (Conexant SmartAudio HD)"
  
  [dshow @ 000001cc4f298d00]     Alternative name "@device_cm_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\wave_{AFE404CD-A721-49BE-8AC5-669DA725185F}"
  
  [dshow @ 000001cc4f298d00]  "virtual-audio-capturer"
  
  [dshow @ 000001cc4f298d00]     Alternative name "@device_sw_{33D9A762-90C8-11D0-BD43-00A0C911CE86}\{8E146464-DB61-4309-AFA1-3578E927E935}"

  I used

  popen = subprocess.Popen('ffmpeg -list_devices true -f dshow -i dummy', stdout=subprocess.PIPE)
  
  popen.wait()
  
  
  
  lines = popen.stdout.readlines()
  
  print(lines)

  After that i got totally confused because the output was an empty list. Now i am lost in desert and know nowhere to go. Really appreciate it if you could help.

• FFMPEG compression - Piping vs File [on hold]

  27 avril 2014, par raaj

  Good Day,

  I have written an application that uses the V4L2 driver to capture H264 Raw frames from a C920. The bytes are output into stdout, and can be piped to a file or any program

  What I am trying to do is this :

  ./capture | ffmpeg -f h264 -i - -b 500000 -vcodec copy out.mp4

  The idea is to capture a raw video and convert it to an mp4 file on the fly. It works perfectly, however, the bit rate compression is never applied. It ends up with a file the same size as the raw file (since the camera outputs a compressed h264 file but in raw frames already)

  However, if I was to do this instead

  ./cature > input.raw

  ffmpeg -i out.mp4 -b 500000 output.mp4

  Now, it compresses the file down to a reasonable size. Is there a reason for this ? My only current solution right now is to use an alternative like gstreamer (which has issues with h264) or to figure out the ffmpeg API and see if I can add some code to make it do compression on the frames on the fly.

• I can't use HW encoder of QSV by ffmpeg

  6 novembre 2017, par Ubunkun

  I would like to use to encode by Intel H/W encode QSV.

  Intel(R) Core(TM) i7-5650U CPU @ 2.20GHz

  lspci -nn -s 0:02.0
  00:02.0 VGA compatible controller [0300] : Intel Corporation Broadwell-U Integrated Graphics [8086:1626] (rev 09)

  I could install MediaServerStudioEssentials2017R2 and ffpemg.

  # vainfo | grep -v 'unknown'
  
  error: can't connect to X server!
  
  libva info: VA-API version 0.99.0
  
  libva info: va_getDriverName() returns 0
  
  libva info: User requested driver 'iHD'
  
  libva info: Trying to open /opt/intel/mediasdk/lib64/iHD_drv_video.so
  
  libva info: Found init function __vaDriverInit_0_32
  
  libva info: va_openDriver() returns 0
  
  vainfo: VA-API version: 0.99 (libva 1.67.0.pre1)
  
  vainfo: Driver version: 16.5.1.59511-ubit
  
  vainfo: Supported profile and entrypoints
  
        VAProfileH264ConstrainedBaseline: VAEntrypointVLD
  
        VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
  
        VAProfileH264Main               : VAEntrypointVLD
  
        VAProfileH264Main               : VAEntrypointEncSlice
  
        VAProfileH264High               : VAEntrypointVLD
  
        VAProfileH264High               : VAEntrypointEncSlice
  
        VAProfileMPEG2Simple            : VAEntrypointEncSlice
  
        VAProfileMPEG2Simple            : VAEntrypointVLD
  
        VAProfileMPEG2Main              : VAEntrypointEncSlice
  
        VAProfileMPEG2Main              : VAEntrypointVLD
  
        VAProfileVC1Advanced            : VAEntrypointVLD
  
        VAProfileVC1Main                : VAEntrypointVLD
  
        VAProfileVC1Simple              : VAEntrypointVLD
  
        VAProfileJPEGBaseline           : VAEntrypointVLD
  
        VAProfileJPEGBaseline           : VAEntrypointEncPicture
  
        VAProfileVP8Version0_3          : VAEntrypointEncSlice
  
        VAProfileVP8Version0_3          : VAEntrypointVLD
  
        VAProfileNone                   : VAEntrypointVideoProc

  and

  # ffmpeg -codecs | grep qsv
  
  ffmpeg version N-86584-g4976a34 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-11)
  
    configuration: --enable-libmfx
  
    libavutil      55. 66.100 / 55. 66.100
  
    libavcodec     57. 99.100 / 57. 99.100
  
    libavformat    57. 73.100 / 57. 73.100
  
    libavdevice    57.  7.100 / 57.  7.100
  
    libavfilter     6. 94.100 /  6. 94.100
  
    libswscale      4.  7.101 /  4.  7.101
  
    libswresample   2.  8.100 /  2.  8.100
  
   DEV.LS h264                 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 (decoders: h264 h264_qsv h264_cuvid ) (encoders: h264_nvenc h264_qsv h264_vaapi nvenc nvenc_h264 )
  
   DEV.L. hevc                 H.265 / HEVC (High Efficiency Video Coding) (decoders: hevc hevc_qsv hevc_cuvid ) (encoders: nvenc_hevc hevc_nvenc hevc_qsv hevc_vaapi )
  
   DEV.L. mpeg2video           MPEG-2 video (decoders: mpeg2video mpegvideo mpeg2_qsv mpeg2_cuvid ) (encoders: mpeg2video mpeg2_qsv mpeg2_vaapi )
  
   D.V.L. vc1                  SMPTE VC-1 (decoders: vc1 vc1_qsv vc1_cuvid )
  
   DEV.L. vp8                  On2 VP8 (decoders: vp8 vp8_cuvid vp8_qsv ) (encoders: vp8_vaapi )

  But, I tried to encode as below.

  # ffmpeg -i test.avi -c:v h264_qsv -b:v 2000k -r 30 -s 720x480 -acodec copy -look_ahead 0 qsv.mp4
  
  ・・・
  
  [h264_qsv @ 0x3139f40] No device available for encoder (device type qsv for codec h264_qsv).
  
  [h264_qsv @ 0x3139f40] Encoder will work with partial HW acceleration
  
  [h264_qsv @ 0x3139f40] Warning in encoder initialization: partial acceleration (4)
  
  ・・・

  It seems like that the encoding is using by software. It’s slow.
  How can I do by H/W encode ? If you know it, let me know it.

  Bests,