[FFmpeg-trac] #4668(ffmpeg:new): Subtle HLS segmenting playback glitch

[FFmpeg]

#4668: Subtle HLS segmenting playback glitch
-------------------------------------+----------------------------------
             Reporter:  bmurphy1976  |                     Type:  defect
               Status:  new          |                 Priority:  normal
            Component:  ffmpeg       |                  Version:  2.6.3
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+----------------------------------
 I'm running into a problem using ffmpeg to segment files into HLS (m3u8)
 format for playback on iOS devices.  In the ffmpeg segmented version of
 this file, there is a very subtle stutter just as the two adults walk
 underneath the 9.  This appears to be some kind of single-frame glitch.

 The stutter always happen at HLS segment boundaries.  When it happens it
 is
 always visible on iOS devices (play it in Safari on an iPad) and only
 sometimes visible in QuickTime on OSX.

 I have never been able to reproduce this glitch using Apple's media file
 segmenter and the glitch is not present in the source video.

 I've tried various permutations of the segment list, segment duration, and
 segment format settings when experimenting with ffmpeg and none
 consistently address this issue across multiple videos.  All they do is
 move the glitch around depending on where the segment boundaries line up.

 Here is a 30 second clip that exhibits this behavior.  The input video
 which does not have the glitch is here:

 https://s3.amazonaws.com/1d4326f61a9a4ed596de9e1a41d48413/input.ts

 Here is the ffmpeg version which shows the glitch at 11 seconds just as
 the
 two adults walk under the 9 on both iOS and QuickTime on OSX (version 10.4
 (833.6)):

 https://s3.amazonaws.com/1d4326f61a9a4ed596de9e1a41d48413/ffmpeg/output.m3u8

 And here is a version segmented with Apple's media file segmenter that
 does
 not exhibit any issues.

 https://s3.amazonaws.com/1d4326f61a9a4ed596de9e1a41d48413/mediafilesegmenter/output.m3u8

 Here is the complete ffmpeg output from segmenting the ts file:

 {{{
 $ ffmpeg -y -i ../input.ts -c copy -segment_list output.m3u8
 -hls_list_size
 0 -segment_time 10 -f segment 'output.m3u8.%03d.ts'
 ffmpeg version 2.6.2 Copyright (c) 2000-2015 the FFmpeg developers
   built with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5)
   configuration: --disable-debug --disable-devices --disable-doc
 --disable-ffplay --disable-ffserver --disable-shared --enable-gpl
 --enable-libaacplus --enable-libfaac --enable-libfaac --enable-libfdk_aac
 --enable-libmp3lame --enable-libtheora --enable-libvo-aacenc
 --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-
 libx264
 --enable-libxvid --enable-nonfree --enable-postproc --enable-pthreads
 --enable-runtime-cpudetect --enable-version3
   libavutil      54. 20.100 / 54. 20.100
   libavcodec     56. 26.100 / 56. 26.100
   libavformat    56. 25.101 / 56. 25.101
   libavdevice    56.  4.100 / 56.  4.100
   libavfilter     5. 11.102 /  5. 11.102
   libswscale      3.  1.101 /  3.  1.101
   libswresample   1.  1.100 /  1.  1.100
   libpostproc    53.  3.100 / 53.  3.100
 [h264 @ 0x20440e0] non-existing SPS 0 referenced in buffering period
     Last message repeated 1 times
 Input #0, mpegts, from '../input.ts':
   Duration: 00:00:30.06, start: 1.415333, bitrate: 3982 kb/s
   Program 1
     Metadata:
       service_name    : Service01
       service_provider: FFmpeg
     Stream #0:0[0x100]: Video: h264 (Main) ([27][0][0][0] / 0x001B),
 yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 90k tbn, 47.95
 tbc
     Stream #0:1[0x101](und): Audio: aac (LC) ([15][0][0][0] / 0x000F),
 48000 Hz, stereo, fltp, 120 kb/s
 Output #0, segment, to 'output.m3u8.%03d.ts':
   Metadata:
     encoder         : Lavf56.25.101
     Stream #0:0: Video: h264 ([27][0][0][0] / 0x001B), yuv420p, 1280x720
 [SAR 1:1 DAR 16:9], q=2-31, 23.98 fps, 23.98 tbr, 90k tbn, 23.98 tbc
     Stream #0:1(und): Audio: aac ([15][0][0][0] / 0x000F), 48000 Hz,
 stereo, 120 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
   Stream #0:1 -> #0:1 (copy)
 Press [q] to stop, [?] for help
 [NULL @ 0x20440e0] non-existing SPS 0 referenced in buffering period
 frame=  720 fps=0.0 q=-1.0 Lsize=N/A time=00:00:30.02 bitrate=N/A
 video:12992kB audio:469kB subtitle:0kB other streams:0kB global
 headers:0kB
 muxing overhead: unknown
 $
 }}}

 Can anybody help me understand what is going on here and how we can fix
 this issue?  It is particularly bad when using an iPad play high quality
 high-motion video on a large format television.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/4668>
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