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• vf_crop : make config_props work properly when called multiple times.

  18 mars 2013, par Anton Khirnov

  vf_crop : make config_props work properly when called multiple times.
  Do not leak the x/y expressions.
  

  • [DBH] libavfilter/vf_crop.c

• Ffmpeg video overlay enable between/gte only works with times and not frames

  30 septembre 2021, par jgjr

  I am trying to overlay one video on top of another, at a specific time (either between two times or after one time). I had previously been doing this with enable='between(t,2,4)' (or gte) for example, but when I needed to place another overlay directly after it I would sometimes get a one frame gap in between them. Because of this I decided to switch to specifying the frames with enable='between(n,60,120)', which works well with other types of overlays but not videos. When the overlay comes at the start of the main video, it works fine, however when the overlay starts later on, nothing appears. The following command works perfectly, with the overlay video coming in a 5.779 seconds and staying until the end.

  


  /opt/ffmpeg -loglevel error -y \
-ss 3.56 -t 7.860 -i "main_video.mp4" \
-ss 1.5 -i "overlay_video.mp4" \
-i "overlay_image.png" \
-filter_complex "\
[0:v:0] setpts=PTS-STARTPTS [0_p]; \
[1:v:0] setpts=PTS-STARTPTS+5.779/TB [1_p]; \
[0_p] [1_p] overlay=y=0:x=0:enable='gte(t,5.779)':shortest=1 [0_p_o]; \
[0_p_o] [2:0] overlay=y=0:x=0 [0_p_o_o]; \
[0_p_o_o] drawbox=x=38:y=460:w=492:h=116:t=fill:color=#000000@0.7:enable='between(n,0,173)' 
[0_p_o_o_b]; \
-framerate 29.97 -c:v libx264 -crf 23 -pix_fmt yuv420p -vsync 2 \
-video_track_timescale 90000 \
-map "[0_p_o_o_b]" -t 7.860 "output.mp4"


  


  However this command does not work, and the only change is the enable='gte(n,173)' instead of enable='gte(t,5.779)'

  


  /opt/ffmpeg -loglevel error -y \
-ss 3.56 -t 7.860 -i "main_video.mp4" \
-ss 1.5 -i "overlay_video.mp4" \
-i "overlay_image.png" \
-filter_complex "\
[0:v:0] setpts=PTS-STARTPTS [0_p]; \
[1:v:0] setpts=PTS-STARTPTS+5.779/TB [1_p]; \
[0_p] [1_p] overlay=y=0:x=0:enable='gte(n,173)':shortest=1 [0_p_o]; \
[0_p_o] [2:0] overlay=y=0:x=0 [0_p_o_o]; \
[0_p_o_o] drawbox=x=38:y=460:w=492:h=116:t=fill:color=#000000@0.7:enable='between(n,0,173)' 
[0_p_o_o_b]; \
-framerate 29.97 -c:v libx264 -crf 23 -pix_fmt yuv420p -vsync 2 \
-video_track_timescale 90000 \
-map "[0_p_o_o_b]" -t 7.860 "output.mp4"


  


  My guess is that it has to do with the PTS, and I tried playing around with the setpts on the overlay video but the best I was able to achieve was displaying the last frame of the overlay video for the duration of its appearance on screen, or one frame flashing up at 5.779 seconds and nothing more.

  


  Could this be a bug in Ffmpeg ? Or is there something else I need to do to get the overlay filter to work when specifying frames instead of times ? Could the videos having different timescales affect things ?

  


• avformat/img2dec : support nanosecond file times

  25 mai 2013, par Michael Niedermayer

  avformat/img2dec : support nanosecond file times
  Signed-off-by : Michael Niedermayer <michaelni@gmx.at>
  

  • [DH] doc/demuxers.texi
  • [DH] libavformat/img2dec.c