[FFmpeg-trac] #1177(avfilter:new): movie source: seek_point does not allow for accurate seeking (keyframe only)

FFmpeg trac at avcodec.org
Sun Apr 8 16:07:13 CEST 2012


#1177: movie source: seek_point does not allow for accurate seeking (keyframe
only)
----------------------------------+--------------------------------------
             Reporter:  ls        |                     Type:  defect
               Status:  new       |                 Priority:  normal
            Component:  avfilter  |                  Version:  git-master
             Keywords:            |               Blocked By:
             Blocking:            |  Reproduced by developer:  0
Analyzed by developer:  0         |
----------------------------------+--------------------------------------
 The movie source does not seem to allow for accurate seeking since it
 locks to keyframes:

 Generate sample with:
 {{{
 $ ffmpeg -f lavfi -i
 "color=white,drawtext=fontfile=/usr/share/fonts/truetype/freefont/FreeSans.ttf:x=20:y=50:fontsize=50:rate=25/1:timecode='00\\:00\\:00\\:00'"
 -t 30 out.mp4
 }}}

 Test with movie source:
 {{{
 $ ffplay -f lavfi 'movie=out.mp4:sp=15.0'
 ffplay version git-2012-04-08-069cf86 Copyright (c) 2003-2012 the FFmpeg
 developers
   built on Apr  8 2012 14:30:11 with gcc 4.6.1
   configuration: --prefix=/home/ls/ffmpeg --enable-shared --disable-static
 --enable-gpl --enable-nonfree --enable-libmp3lame --enable-libx264
 --enable-libxvid --enable-sram --cpu=core2 --enable-hwaccel=h264_vaapi
 --enable-hwaccel=mpeg2_vaapi --enable-hwaccel=mpeg4_vaapi --enable-libfaac
 --disable-ffserver --enable-libass --enable-libfreetype --enable-libvpx
 --enable-libvorbis --enable-x11grab
   libavutil      51. 45.100 / 51. 45.100
   libavcodec     54. 14.100 / 54. 14.100
   libavformat    54.  3.100 / 54.  3.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 67.101 /  2. 67.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0. 10.100 /  0. 10.100
   libpostproc    52.  0.100 / 52.  0.100
 [movie @ 0xed2100] seek_point:15000000 format_name:(null)
 file_name:out.mp4 stream_index:0
 [lavfi @ 0xe8a3a0] Estimating duration from bitrate, this may be
 inaccurate
 Input #0, lavfi, from 'movie=out.mp4:sp=15.0':
   Duration: N/A, start: 10.000000, bitrate: N/A
     Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 320x240
 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
 1333893780.90 A-V:  0.000 fd=   0 aq=    0KB vq=  675KB sq=    0B f=0/0
   10.04 A-V:  0.000 fd=   0 aq=    0KB vq=  562KB sq=    0B f=0/0
   10.09 A-V:  0.000 fd=   0 aq=    0KB vq=  675KB sq=    0B f=0/0
   10.13 A-V:  0.000 fd=   0 aq=    0KB vq=  675KB sq=    0B f=0/0
 [...]
 }}}

 In this case the result is 5s off the desired seek point.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1177>
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