[FFmpeg-trac] #730(undetermined:open): Encoded video plays too fast for network input (was: Generate timestamps for source (like do-timestamp=true in gstreamer))

FFmpeg trac at avcodec.org
Sat Dec 10 17:19:56 CET 2011


#730: Encoded video plays too fast for network input
-------------------------------------+-------------------------------------
             Reporter:  hackeron     |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:               |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  1
-------------------------------------+-------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * version:  unspecified => git-master
 * type:  enhancement => defect
 * reproduced:  0 => 1


Comment:

 Received input is recorded as 25fps, but is actually a magnitude "slower".
 ffmpeg -analyzeduration 1 -f mjpeg -r 3.5 -i
 http://admin:@82.13.197.168:82/video.cgi works better from here, but
 assuming the stream is VFR, it cannot work.
 {{{
 $ time ./ffmpeg -f mjpeg -i http://admin:@82.13.197.168:82/video.cgi
 out.avi
 ffmpeg version N-35633-g5207f95, Copyright (c) 2000-2011 the FFmpeg
 developers
   built on Dec 10 2011 16:57:53 with gcc 4.5.3
   configuration: --cc='/usr/local/gcc-4.5.3/bin/gcc -m32'
   libavutil    51. 32. 0 / 51. 32. 0
   libavcodec   53. 42. 0 / 53. 42. 0
   libavformat  53. 24. 0 / 53. 24. 0
   libavdevice  53.  4. 0 / 53.  4. 0
   libavfilter   2. 52. 0 /  2. 52. 0
   libswscale    2.  1. 0 /  2.  1. 0
 [mjpeg @ 0x8da4ae0] Estimating duration from bitrate, this may be
 inaccurate
 Input #0, mjpeg, from 'http://admin:@82.13.197.168:82/video.cgi':
   Duration: N/A, bitrate: N/A
     Stream #0:0: Video: mjpeg, yuvj422p, 640x480, 25 fps, 25 tbr, 1200k
 tbn, 25 tbc
 Incompatible pixel format 'yuvj422p' for codec 'mpeg4', auto-selecting
 format 'yuv420p'
 [buffer @ 0x8dbaea0] w:640 h:480 pixfmt:yuvj422p tb:1/1000000 sar:0/1
 sws_param:
 [buffersink @ 0x8db7ae0] auto-inserting filter 'auto-inserted scale 0'
 between the filter 'src' and the filter 'out'
 [scale @ 0x914c2e0] w:640 h:480 fmt:yuvj422p -> w:640 h:480 fmt:yuv420p
 flags:0x4
 Output #0, avi, to 'out.avi':
   Metadata:
     ISFT            : Lavf53.24.0
     Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 640x480,
 q=2-31, 200 kb/s, 25 tbn, 25 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (mjpeg -> mpeg4)
 Press [q] to stop, [?] for help
 frame=  747 fps=  4 q=31.0 Lsize=    1153kB time=00:00:29.88 bitrate=
 316.1kbits/s
 video:1130kB audio:0kB global headers:0kB muxing overhead 2.073742%

 real    3m29.035s
 user    0m5.007s
 sys     0m0.136s
 }}}

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/730#comment:5>
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