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• 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

• mencoder generate mp4 h.264 from jpg playback stops in html videotag chrome

  10 septembre 2013, par jedimorten

  So I have some images from which I create a video with mencoder.

  mencoder -idx -nosound -noskip -of lavf -lavfopts format=mp4 -ovc x264 -x264encopts pass=1:bitrate=2000:crf=24 -o output.mp4 -mf fps=15 'mf://@files.txt'

  (where files.txt is a list of all the files sorted in the right order)

  The videos is created without problems, it plays fine in desktop-player like vlc, but in chrome (on mac) and chromium (ubuntu) some of the videoes has "breakpoints" in which the video just stops.

  Take a look at this fiddle.

  I made an ugly hack (see fiddle) to force a continued play even if the video is damaged, but this does not look very nice when the video has a lot of them "breakpoints".

  For several reasons I need to be using html, so flash would only be a last last resort.
  Any views on what may be causing these breakpoints ? Or a nicer ugly hack to force contiuned playback ?

• ffmpeg created video from images does not play in jwplayer

  10 septembre 2013, par user2281222

  I have created a video from images with ffmpeg. Created video plays fine in my local machine with vlc. But it does not play in jwplayer/any web player.

  Commands used :

  ffmpeg -f image2 -r 1/4 -i image_%d.png -c:v libx264 -pix_fmt yuv420p -vf fps=fps=30 int_video.mp4
  
  
  
  ffmpeg -i int_video.mp4 -c:v libx264 -b:v 500k -pix_fmt yuv420p final.mp4"

  Information about the create video is as below :

          General
  
          Complete name                    : /home/oodles/git/picdeo/web-app/uservideos/admin/z4/username_admin__s3vidname_z4.mp4
  
          Format                           : MPEG-4
  
          Format profile                   : Base Media
  
          Codec ID                         : isom
  
          File size                        : 691 KiB
  
          Duration                         : 20s 34ms
  
          Overall bit rate                 : 282 Kbps
  
          Writing application              : Lavf55.12.100
  
  
  
          Video
  
          ID                               : 1
  
          Format                           : AVC
  
          Format/Info                      : Advanced Video Codec
  
          Format profile                   : High@L3.0
  
          Format settings, CABAC           : Yes
  
          Format settings, ReFrames        : 4 frames
  
          Codec ID                         : avc1
  
          Codec ID/Info                    : Advanced Video Coding
  
          Duration                         : 20s 34ms
  
          Bit rate                         : 279 Kbps
  
          Nominal bit rate                 : 500 Kbps
  
          Width                            : 480 pixels
  
          Height                           : 360 pixels
  
          Display aspect ratio             : 4:3
  
          Frame rate mode                  : Constant
  
          Frame rate                       : 30.000 fps
  
          Color space                      : YUV
  
          Chroma subsampling               : 4:2:0
  
          Bit depth                        : 8 bits
  
          Scan type                        : Progressive
  
          Bits/(Pixel*Frame)               : 0.054
  
          Stream size                      : 683 KiB (99%)
  
          Writing library                  : x264 core 135 r2 f0c1c53
  
          Encoding settings                : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=1 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=abr / mbtree=1 / bitrate=500 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00

  How can I use ffmpeg to create a video that works in jwplayer ?