I seem to be having issues seeking accurately in HLS videos, but it works fine in other containers (mp4, mkv, etc)
tried with ffmpeg version 3.4.4 and master If I create an HLS video like this mkdir a;ffmpeg -y -s 640x480 -f rawvideo -pix_fmt rgb24 -r 25 -i /dev/zero -vf "drawtext=fontfile=/usr/share/fonts/truetype/freefont/FreeMono.ttf: text=%{n}: x=(w-tw)/2: y=h-(2*lh): fontcolor=white: box=1: boxcolor=0x000000FF" -an -vcodec libx264 -preset medium -tune stillimage -crf 24 -pix_fmt yuv420p -shortest -force_key_frames "expr:gte(t,n_forced*5)" -bf 0 -hls_time 5 -hls_list_size 0 -hls_wrap 0 -hls_allow_cache 1 -hls_segment_filename "a/a_%04d.ts" -t 60 a/a.m3u8 And also create it's mp4 counterpart: ffmpeg -i a/a.m3u8 -codec copy a.mp4 And try to seek in any segment: F=130;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a/a.m3u8 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got frame 250 (bad) F=126;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a/a.m3u8 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got frame 250 (bad) F=125;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a/a.m3u8 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got frame 125 (good) F=124;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a/a.m3u8 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got frame 125 (bad) Now try the same with the mp4 and you'll always get the exact right frame F=130;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a.mp4 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got 130 (good) F=126;rm -f f.png;ffmpeg -y -ss `awk "BEGIN {print (${F})/25}"` -i a.mp4 -f image2 -q:v 1 -vframes 1 f.png ; feh f.png Got 126 (good) etc it seems to be seeking on segment boundaries only. Of course, if I put -ss after the input '-i' I seek accurately but it's an output parameter now so it takes much longer since it's decoding all the frames (also doesn't work with multiple input maps). And according to 'https://trac.ffmpeg.org/wiki/Seeking' input seeking should be accurate Is this a bug or I am missing a parameter? (BTW, I posted this same question in Nov 2016 without a valid answer. If no one can answer this time, I'll open a bug) Thanks Louis _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".