[FFmpeg-trac] #8048(avformat:new): MPEG-2 muxer overshoots and corrects with undershoot in CBR mode (-muxrate)

[FFmpeg]

#8048: MPEG-2 muxer overshoots and corrects with undershoot in CBR mode (-muxrate)
------------------------------------+------------------------------------
             Reporter:  tangent     |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avformat
              Version:  git-master  |               Resolution:
             Keywords:  mpegts      |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+------------------------------------

Comment (by tangent):

 I've gotten back to the machine with a git-master build on it, updated it,
 and re-tested, and it's giving the exact same symptom on the input file.
 Here's the output:

 {{{
 $ ffmpeg -i input.mp4 -f mpegts -c copy -muxrate 13.5M -y output.ts
 ffmpeg version N-94423-ga0c1970 Copyright (c) 2000-2019 the FFmpeg
 developers
   built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-36)
   configuration: --extra-cflags='-march=native' --enable-gpl --enable-
 libx264 --enable-libvpx
   libavutil      56. 32.100 / 56. 32.100
   libavcodec     58. 55.100 / 58. 55.100
   libavformat    58. 30.100 / 58. 30.100
   libavdevice    58.  9.100 / 58.  9.100
   libavfilter     7. 58.100 /  7. 58.100
   libswscale      5.  6.100 /  5.  6.100
   libswresample   3.  6.100 /  3.  6.100
   libpostproc    55.  6.100 / 55.  6.100
 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':
   Metadata:
     major_brand     : mp42
     minor_version   : 0
     compatible_brands: mp41isom
     creation_time   : 2019-07-28T20:14:36.000000Z
   Duration: 00:01:26.63, start: 0.000000, bitrate: 2383 kb/s
     Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 /
 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 2382 kb/s, 30.30 fps,
 30.30 tbr, 30k tbn, 60 tbc (default)
     Metadata:
       creation_time   : 2019-07-28T20:14:36.000000Z
       handler_name    : VideoHandler
       encoder         : AVC Coding
 Output #0, mpegts, to 'output.ts':
   Metadata:
     major_brand     : mp42
     minor_version   : 0
     compatible_brands: mp41isom
     encoder         : Lavf58.30.100
     Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 /
 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=2-31, 2382 kb/s,
 30.30 fps, 30.30 tbr, 90k tbn, 30k tbc (default)
     Metadata:
       creation_time   : 2019-07-28T20:14:36.000000Z
       handler_name    : VideoHandler
       encoder         : AVC Coding
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
 Press [q] to stop, [?] for help
 [mpegts @ 0x449e380] dts < pcr, TS is invalid
     Last message repeated 83 times
 frame= 2625 fps=0.0 q=-1.0 Lsize=  142700kB time=00:01:26.59
 bitrate=13500.0kbits/s speed= 341x
 video:25198kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 466.314453%
 }}}

--
Ticket URL: <https://trac.ffmpeg.org/ticket/8048#comment:5>
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