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• ffmpeg opus rtp mpegts streaming has huge delay

  3 avril 2017, par Marcelo Emmerich

  I can’t seem to stream anything without huge delay/latency (> 5 secs). Here is my command :

  ffmpeg.exe -f dshow -i audio="Mikrofonarray Logitech (HD570)" 
  
   -acodec opus -f rtp_mpegts rtp://127.0.0.1:5004

  I receive with :

  ffplay.exe rtp://127.0.0.1:5004

  It works, but the receiver (even on same machine) gets the audio 7 seconds later. I tried changing the codec (AAC), the bitrate, the sample rate, nothing seems to have an effect on this. What am I missing ?

  Thanks

• FFMpeg/video4linux2,v4l2 : The v4l2 frame is 46448 bytes, but 153600 bytes are expected (Webcam capture not fast enough ?)

  30 août 2013, par user763410

  I am trying to capture webcam output in linux/ubuntu. I have a chicony webcam (lenovo laptop). I am running inside a VMWARE virtual machine. The capture is not proceeding beyond 10 seconds. can you please help.

  The command I used is :

  $ ffmpeg -y  -f video4linux2 -r 20 -s 160x120 -i /dev/video0 -acodec libfaac -ab 128k  /tmp/web.avi

  The most important message I am getting is :

  [video4linux2,v4l2 @ 0x9e43fa0] The v4l2 frame is 46448 bytes, but 153600 bytes are expected

  Complete message from ffmpeg :

  ffmpeg version N-55159-gf118b41 Copyright (c) 2000-2013 the FFmpeg developers
  
    built on Aug 18 2013 09:09:13 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
  
    configuration: --enable-libass --prefix=/opt/ffmpeg --enable-debug --enable-libfreetype
  
    libavutil      52. 40.100 / 52. 40.100
  
    libavcodec     55. 19.100 / 55. 19.100
  
    libavformat    55. 12.102 / 55. 12.102
  
    libavdevice    55.  3.100 / 55.  3.100
  
    libavfilter     3. 82.100 /  3. 82.100
  
    libswscale      2.  4.100 /  2.  4.100
  
    libswresample   0. 17.103 /  0. 17.103
  
  [video4linux2,v4l2 @ 0x9e43fa0] The V4L2 driver changed the video from 160x120 to 320x240
  
  [video4linux2,v4l2 @ 0x9e43fa0] The driver changed the time per frame from 1/20 to 1/15
  
  Input #0, video4linux2,v4l2, from '/dev/video0':
  
    Duration: N/A, start: 6424.338678, bitrate: 18432 kb/s
  
      Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 320x240, 18432 kb/s, 15 fps, 15 tbr, 1000k tbn, 1000k tbc
  
  Codec AVOption ab (set bitrate (in bits/s)) specified for output file #0 (/tmp/web.avi) has not been used for any stream. The most likely reason is either wrong type (e.g. a video option with no video streams) or that it is a private option of some encoder which was not actually used for any stream.
  
  Output #0, avi, to '/tmp/web.avi':
  
    Metadata:
  
      ISFT            : Lavf55.12.102
  
      Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 320x240, q=2-31, 200 kb/s, 20 tbn, 20 tbc
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (rawvideo -> mpeg4)
  
  Press [q] to stop, [?] for help
  
  [video4linux2,v4l2 @ 0x9e43fa0] The v4l2 frame is 46448 bytes, but 153600 bytes are expected
  
  /dev/video0: Invalid data found when processing input
  
  frame=   29 fps= 14 q=3.5 Lsize=      87kB time=00:00:01.45 bitrate= 490.0kbits/s    
  
  video:80kB audio:0kB subtitle:0 global headers:0kB muxing overhead 7.760075%
  
  [video4linux2,v4l2 @ 0x9e43fa0] Some buffers are still owned by the caller on close.

• Realtime http ogg stream with ffmpeg latency

  4 septembre 2013, par MastErAldo

  I'm using the Kinect as an infrared camera and through a named pipe i send each captured frame to FFMPEG which encodes them in an ogg/theora stream that is sent to an http server.
  The server than broadcasts the video to every connected user. The users use the Cortado applet to play the video.

  The video plays fine, but the latency keeps on increasing continuously. So if at the beginning the latency is about 100ms, in a minute it reaches up to 10 seconds.

  However the playback is smooth, the bandwidth is enough and the encoding machine and the server CPU is not overloaded, so I don't understand what can make the latency increase.

  This is the ffmpeg command line that we use :

  ffmpeg.exe -f segment -f rawvideo -pix_fmt rgb565 -s 640x480 -i \\.\pipe\CAH_STREAM_PIPE -fflags nobuffer -r 60 -b:v 128k -bufsize 1024k -s 240x160 -codec:v libtheora -qscale:v 1 -f ogg http://localhost/video_stream.ogg

  Am I missing some parameters or setting some of them to wrong values ? Or the problem is elsewhere ?

  BTW : I'm not sure about using nobuffer and bufsize at the same time

  Thanks