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• Encoding of two full hd streams in Linux + GPU with Intel HD4000 / VA API / FFMPEG / OpenGL

  27 juin 2017, par qknight

  i want to encode/stream two full hd streams in realtime from my laptop to a remote location using linux/xorg on the host.

  VA API

  for this i’ve been playing with the VA API but the performance is pretty bad with 5.59 fps (see paste below).

  FFMPEG

  using ffmpeg with CPU encoding i get about 200 fps but then all cores of my Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz are busy and the fan turns on.

  future plans

  i want GPU support in encoding and later integrate this into a program which streams a virtual xorg ’screen’, see https://lastlog.de/wiki/index.php/Raspberry_PI_virtual_screen for more details on my plans.

  maybe h264 isn’t even what i want ? so if someone advices towards a different implementation, i’d welcome that.

  besides VA API there seems to be QuickSync but i didn’t experiment with that yet as it is not packaged on NixOS just yet.

  note : i need a library to have a smooth integration into the code.

  h264encode -w 1920 -h 1080 —profile MPSource frame is 1920x1080 and will code clip to 1920x1088 with crop
  INPUT:Try to encode H264...
  
  INPUT : Resolution : 1920x1080, 60 frames
  
  INPUT : FrameRate : 30
  
  INPUT : Bitrate : 14929920
  
  INPUT : Slieces : 1
  
  INPUT : IntraPeriod : 30
  
  INPUT : IDRPeriod : 60
  
  INPUT : IpPeriod : 1
  
  INPUT : Initial QP : 26
  
  INPUT : Min QP : 0
  
  INPUT : Source YUV : AUTO generated
  
  INPUT : Coded Clip : /tmp/test.264
  
  INPUT : Rec   Clip : Not save reconstructed frame
  libva info : VA-API version 0.38.1
  
  libva info : va_getDriverName() returns 0
  
  libva info : Trying to open /run/opengl-driver/lib/dri/i965_drv_video.so
  
  libva info : Found init function __vaDriverInit_0_38
  
  libva info : va_openDriver() returns 0
  
  Use profile VAProfileH264Main
  
  Support rate control mode (0x12):CBR CQP 
  
  RateControl mode : CQP
  
  Support VAConfigAttribEncPackedHeaders
  
  Support packed sequence headers
  
  Support packed picture headers
  
  Support packed slice headers
  
  Support packed misc headers
  
  Support 1 RefPicList0 and 1 RefPicList1
  
  Loading data into surface 15.....Complete surface loading
  
        \00000059(054456 bytes coded)
  PERFORMANCE :   Frame Rate : 5.59 fps (60 frames, 10730 ms (178.83 ms per frame))
  
  PERFORMANCE :   Compression ratio : 51:1
  
  PERFORMANCE :     UploadPicture : 10467 ms (174.45, 97.55% percent)
  
  PERFORMANCE :     vaBeginPicture : 0 ms (0.00, 0.00% percent)
  
  PERFORMANCE :     vaRenderHeader : 1 ms (0.02, 0.01% percent)
  
  PERFORMANCE :     vaEndPicture : 42 ms (0.70, 0.39% percent)
  
  PERFORMANCE :     vaSyncSurface : 244 ms (4.07, 2.27% percent)
  
  PERFORMANCE :     SavePicture : 7 ms (0.12, 0.07% percent)
  
  PERFORMANCE :     Others : -31 ms (71582787.75, 40027653.91% percent)
  
  (Multithread enabled, the timing is only for reference)
  

  i’ve seen https://www.reddit.com/r/linux/comments/1qk1yu/is_there_currently_opensource_software_to_encode/ though but i’m not sure what do do with it.

• FFMPEG filtergraph 'warning, too many B-frames in a row' [on hold]

  26 juin 2017, par Leif Andersen

  I am trying to append two videos together with FFmpeg’s filtergraph. One video is sized 1920x1080 at 30fps, and another 1280x720 at 25fps. Both use yuv420p, and have the same pixel densities. I am currently ignoring the audio tracks. The following is my filtergraph :

  [video2]fifo[video3];
  
  [video3]pad=width=1920:height=1080[video9];
  
  [video9]fps=fps=25[video11];
  
  [video11]setpts=expr=PTS-STARTPTS[video17];
  
  
  
  [video6]fifo[video7];
  
  [video7]pad=width=1920:height=1080[video13];
  
  [video13]fps=fps=25[video15];
  
  [video15]setpts=expr=PTS-STARTPTS[video19];
  
  
  
  [video17][video19]concat=v=1:a=0:n=2[video21];
  
  [video21]pad=width=1920:height=1080[video23];
  
  [video23]fps=fps=25[video25];
  
  [video25]format=pix_fmts=yuv420p[video27]

  The first chain tries to convert the first video into a common format, that starts at 0 for the concat filter. The second chain does the same as the first. Finally, the third chain concatenates them videos together, and sets some properties for the resulting playlist.

  Unfortunately, when I run this error, ffmpeg repeatedly outputs :

  [mpeg4 @ 0x7fc16a810600] warning, too many B-frames in a row

  When finished, I see the first video, padded to the correct resolution and frame rate, but instead of the second Video I see black. Additionally, the entire video is several days in length, starting with the first Video and ending in several days of just black.

  I cannot figure out why I am getting this error, as it seems like I am setting the videos to have identical properties. What am I missing ?

  Also, for what its worth, I am using FFmpeg’s C API rather than the command line tool. I am using libavformat/libavcodec/libavutil to do the encoding/decoding and libavfilter for the filtergraph.

• Webcam streaming from Mac using FFmpeg

  13 décembre 2019, par Galaxy

  I want to stream my webcam from Mac using FFmpeg.

  First I checked the supported devices using ffmpeg -f avfoundation -list_devices true -i ""

  Output :

  [AVFoundation input device @ 0x7fdf1bd03000] AVFoundation video devices:
  
  [AVFoundation input device @ 0x7fdf1bd03000] [0] USB 2.0 Camera #2
  
  [AVFoundation input device @ 0x7fdf1bd03000] [1] FaceTime HD Camera
  
  [AVFoundation input device @ 0x7fdf1bd03000] [2] Capture screen 0
  
  [AVFoundation input device @ 0x7fdf1bd03000] [3] Capture screen 1
  
  [AVFoundation input device @ 0x7fdf1bd03000] AVFoundation audio devices:
  
  [AVFoundation input device @ 0x7fdf1bd03000] [0] Built-in Microphone

  The device[0] is the webcam I want to use.

  ---

  Then I tried to capture the webcam using ffmpeg -f avfoundation -i "0" out.mpg

  Output :

  [avfoundation @ 0x7fe7f3810600] Selected framerate (29.970030) is not supported by the device
  
  [avfoundation @ 0x7fe7f3810600] Supported modes:
  
  [avfoundation @ 0x7fe7f3810600]   320x240@[120.101366 120.101366]fps
  
  [avfoundation @ 0x7fe7f3810600]   640x480@[120.101366 120.101366]fps
  
  [avfoundation @ 0x7fe7f3810600]   800x600@[60.000240 60.000240]fps
  
  [avfoundation @ 0x7fe7f3810600]   1024x768@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   1280x720@[60.000240 60.000240]fps
  
  [avfoundation @ 0x7fe7f3810600]   1280x1024@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   1920x1080@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   320x240@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   640x480@[30.000030 30.000030]fps
  
  [avfoundation @ 0x7fe7f3810600]   800x600@[20.000000 20.000000]fps
  
  [avfoundation @ 0x7fe7f3810600]   1024x768@[6.000002 6.000002]fps
  
  0: Input/output error

  ---

  After that, I tried stream this webcam from my Mac using ffmpeg -f avfoundation -framerate 30 -i "0" -f mpeg1video -b 200k -r 30 -vf scale=1920:1080 http://127.0.0.1:8082/

  Output :

  [avfoundation @ 0x7f8515012800] An error occurred: The activeVideoMinFrameDuration passed is not supported by the device.  Use -activeFormat.videoSupportedFrameRateRanges to discover valid ranges.0: Input/output error

  ---

  I cannot capture or stream this webcam. However when I used the Facetime camera instead of this webcam, everything was OK. I’ve been searching for this problem for a few days, but still cannot fix it. Does anyone have experience with webcam and FFmpeg on Mac ?