[FFmpeg-user] out_time_us wrong or strangely inaccurate
thefoss at icybiz.com
thefoss at icybiz.com
Fri Jul 4 14:34:25 EEST 2025
I try to get the duration of a webm video file.
During testing I encountered some to me very strange output of ffmpeg.
I use this line:
ffmpeg -i "./recordedVideo.webm" -progress - -f null -stats_period 0.00015 -
With this line I get nearly every frame shown with frame number and
out_time_us on stdout.
The video file seems to have 40 frames according to ffmpeg.
Now the strange things start right with the first frame.
The first frame is not being shown as to start at "out_time_us=0000000",
as one would expect, but at "out_time_us=1020000". This is more than a
full second after zero.
Then it seems to progress ok through the frames, taking about 60000
microseconds for each frame until it hits frame 26 of 40 with indication
"out_time_us=2700000"
Then strangely all the rest of the 14 frames also show
"out_time_us=2700000".
Is this a bug in ffmpeg?
Why would this be?
Am I missing something here?
How do I get the exact duration of a video file? Best would be of course
if every frame is marked with its correct timestamp.
Please help!
Here is the full output:
=========
ffmpeg version 5.1.6-0+deb12u1 Copyright (c) 2000-2024 the FFmpeg developers
built with gcc 12 (Debian 12.2.0-14)
configuration: --prefix=/usr --extra-version=0+deb12u1
--toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu
--incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl
--disable-stripping --enable-gnutls --enable-ladspa --enable-libaom
--enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca
--enable-libcdio --enable-libcodec2 --enable-libdav1d --enable-libflite
--enable-libfontconfig --enable-libfreetype --enable-libfribidi
--enable-libglslang --enable-libgme --enable-libgsm --enable-libjack
--enable-libmp3lame --enable-libmysofa --enable-libopenjpeg
--enable-libopenmpt --enable-libopus --enable-libpulse
--enable-librabbitmq --enable-librist --enable-librubberband
--enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex
--enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora
--enable-libtwolame --enable-libvidstab --enable-libvorbis
--enable-libvpx --enable-libwebp --enable-libx265 --enable-libxml2
--enable-libxvid --enable-libzimg --enable-libzmq --enable-libzvbi
--enable-lv2 --enable-omx --enable-openal --enable-opencl
--enable-opengl --enable-sdl2 --disable-sndio --enable-libjxl
--enable-pocketsphinx --enable-librsvg --enable-libmfx
--enable-libdc1394 --enable-libdrm --enable-libiec61883
--enable-chromaprint --enable-frei0r --enable-libx264
--enable-libplacebo --enable-librav1e --enable-shared
libavutil 57. 28.100 / 57. 28.100
libavcodec 59. 37.100 / 59. 37.100
libavformat 59. 27.100 / 59. 27.100
libavdevice 59. 7.100 / 59. 7.100
libavfilter 8. 44.100 / 8. 44.100
libswscale 6. 7.100 / 6. 7.100
libswresample 4. 7.100 / 4. 7.100
libpostproc 56. 6.100 / 56. 6.100
ffmpeg stats and -progress period set to 0.00015.
Input #0, matroska,webm, from './recordedVideo.webm':
Metadata:
encoder : Chrome
Duration: N/A, start: 0.000000, bitrate: N/A
Stream #0:0(eng): Audio: opus, 48000 Hz, mono, fltp (default)
Stream #0:1(eng): Video: vp8, yuv420p(progressive), 640x480, SAR 1:1
DAR 4:3, 250 tbr, 1k tbn (default)
Metadata:
alpha_mode : 1
Stream mapping:
Stream #0:1 -> #0:0 (vp8 (native) -> wrapped_avframe (native))
Stream #0:0 -> #0:1 (opus (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, null, to 'pipe:':
Metadata:
encoder : Lavf59.27.100
Stream #0:0(eng): Video: wrapped_avframe, yuv420p(tv,
bt470bg/unknown/unknown, progressive), 640x480 [SAR 1:1 DAR 4:3],
q=2-31, 200 kb/s, 250 fps, 250 tbn (default)
Metadata:
alpha_mode : 1
encoder : Lavc59.37.100 wrapped_avframe
Stream #0:1(eng): Audio: pcm_s16le, 48000 Hz, mono, s16, 768 kb/s
(default)
Metadata:
encoder : Lavc59.37.100 pcm_s16le
frame=1 1 fps=0.0 q=-0.0 size=N/A time=00:00:01.02 bitrate=N/A speed=
167x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1020000
out_time_ms=1020000
out_time=00:00:01.020000
dup_frames=0
drop_frames=0
speed= 167x
progress=continue
frame=1 1 fps=0.0 q=-0.0 size=N/A time=00:00:01.08 bitrate=N/A speed=
139x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1080000
out_time_ms=1080000
out_time=00:00:01.080000
dup_frames=0
drop_frames=0
speed= 139x
progress=continue
frame=1 1 fps=0.0 q=-0.0 size=N/A time=00:00:01.14 bitrate=N/A speed=
144x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1140000
out_time_ms=1140000
out_time=00:00:01.140000
dup_frames=0
drop_frames=0
speed= 144x
progress=continue
frame=3 3 fps=0.0 q=-0.0 size=N/A time=00:00:01.20 bitrate=N/A speed=
146x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1200000
out_time_ms=1200000
out_time=00:00:01.200000
dup_frames=0
drop_frames=0
speed= 146x
progress=continue
frame=4 4 fps=0.0 q=-0.0 size=N/A time=00:00:01.26 bitrate=N/A speed=
148x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1260000
out_time_ms=1260000
out_time=00:00:01.260000
dup_frames=0
drop_frames=0
speed= 148x
progress=continue
frame=4 4 fps=0.0 q=-0.0 size=N/A time=00:00:01.32 bitrate=N/A speed=
152x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1320000
out_time_ms=1320000
out_time=00:00:01.320000
dup_frames=0
drop_frames=0
speed= 152x
progress=continue
frame=5 5 fps=0.0 q=-0.0 size=N/A time=00:00:01.38 bitrate=N/A speed=
156x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1380000
out_time_ms=1380000
out_time=00:00:01.380000
dup_frames=0
drop_frames=0
speed= 156x
progress=continue
frame=6 6 fps=0.0 q=-0.0 size=N/A time=00:00:01.44 bitrate=N/A speed=
160x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1440000
out_time_ms=1440000
out_time=00:00:01.440000
dup_frames=0
drop_frames=0
speed= 160x
progress=continue
frame=8 8 fps=0.0 q=-0.0 size=N/A time=00:00:01.50 bitrate=N/A speed=
162x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1500000
out_time_ms=1500000
out_time=00:00:01.500000
dup_frames=0
drop_frames=0
speed= 162x
progress=continue
frame=9 9 fps=0.0 q=-0.0 size=N/A time=00:00:01.56 bitrate=N/A speed=
166x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1560000
out_time_ms=1560000
out_time=00:00:01.560000
dup_frames=0
drop_frames=0
speed= 166x
progress=continue
frame=10 10 fps=0.0 q=-0.0 size=N/A time=00:00:01.62 bitrate=N/A speed=
169x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1620000
out_time_ms=1620000
out_time=00:00:01.620000
dup_frames=0
drop_frames=0
speed= 169x
progress=continue
frame=10 10 fps=0.0 q=-0.0 size=N/A time=00:00:01.74 bitrate=N/A speed=
178x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1740000
out_time_ms=1740000
out_time=00:00:01.740000
dup_frames=0
drop_frames=0
speed= 178x
progress=continue
frame=11 11 fps=0.0 q=-0.0 size=N/A time=00:00:01.74 bitrate=N/A speed=
174x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1740000
out_time_ms=1740000
out_time=00:00:01.740000
dup_frames=0
drop_frames=0
speed= 174x
progress=continue
frame=12 12 fps=0.0 q=-0.0 size=N/A time=00:00:01.80 bitrate=N/A speed=
176x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1800000
out_time_ms=1800000
out_time=00:00:01.800000
dup_frames=0
drop_frames=0
speed= 176x
progress=continue
frame=13 13 fps=0.0 q=-0.0 size=N/A time=00:00:01.86 bitrate=N/A speed=
177x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1860000
out_time_ms=1860000
out_time=00:00:01.860000
dup_frames=0
drop_frames=0
speed= 177x
progress=continue
frame=14 14 fps=0.0 q=-0.0 size=N/A time=00:00:01.92 bitrate=N/A speed=
179x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1920000
out_time_ms=1920000
out_time=00:00:01.920000
dup_frames=0
drop_frames=0
speed= 179x
progress=continue
frame=15 15 fps=0.0 q=-0.0 size=N/A time=00:00:01.98 bitrate=N/A speed=
180x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=1980000
out_time_ms=1980000
out_time=00:00:01.980000
dup_frames=0
drop_frames=0
speed= 180x
progress=continue
frame=16 16 fps=0.0 q=-0.0 size=N/A time=00:00:02.04 bitrate=N/A speed=
182x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2040000
out_time_ms=2040000
out_time=00:00:02.040000
dup_frames=0
drop_frames=0
speed= 182x
progress=continue
frame=17 17 fps=0.0 q=-0.0 size=N/A time=00:00:02.10 bitrate=N/A speed=
183x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2100000
out_time_ms=2100000
out_time=00:00:02.100000
dup_frames=0
drop_frames=0
speed= 183x
progress=continue
frame=18 18 fps=0.0 q=-0.0 size=N/A time=00:00:02.16 bitrate=N/A speed=
184x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2160000
out_time_ms=2160000
out_time=00:00:02.160000
dup_frames=0
drop_frames=0
speed= 184x
progress=continue
frame=19 19 fps=0.0 q=-0.0 size=N/A time=00:00:02.22 bitrate=N/A speed=
185x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2220000
out_time_ms=2220000
out_time=00:00:02.220000
dup_frames=0
drop_frames=0
speed= 185x
progress=continue
frame=19 19 fps=0.0 q=-0.0 size=N/A time=00:00:02.34 bitrate=N/A speed=
192x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2340000
out_time_ms=2340000
out_time=00:00:02.340000
dup_frames=0
drop_frames=0
speed= 192x
progress=continue
frame=20 20 fps=0.0 q=-0.0 size=N/A time=00:00:02.34 bitrate=N/A speed=
188x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2340000
out_time_ms=2340000
out_time=00:00:02.340000
dup_frames=0
drop_frames=0
speed= 188x
progress=continue
frame=21 21 fps=0.0 q=-0.0 size=N/A time=00:00:02.40 bitrate=N/A speed=
190x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2400000
out_time_ms=2400000
out_time=00:00:02.400000
dup_frames=0
drop_frames=0
speed= 190x
progress=continue
frame=22 22 fps=0.0 q=-0.0 size=N/A time=00:00:02.46 bitrate=N/A speed=
192x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2460000
out_time_ms=2460000
out_time=00:00:02.460000
dup_frames=0
drop_frames=0
speed= 192x
progress=continue
frame=23 23 fps=0.0 q=-0.0 size=N/A time=00:00:02.52 bitrate=N/A speed=
193x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2520000
out_time_ms=2520000
out_time=00:00:02.520000
dup_frames=0
drop_frames=0
speed= 193x
progress=continue
frame=24 24 fps=0.0 q=-0.0 size=N/A time=00:00:02.58 bitrate=N/A speed=
194x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2580000
out_time_ms=2580000
out_time=00:00:02.580000
dup_frames=0
drop_frames=0
speed= 194x
progress=continue
frame=25 25 fps=0.0 q=-0.0 size=N/A time=00:00:02.64 bitrate=N/A speed=
195x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2640000
out_time_ms=2640000
out_time=00:00:02.640000
dup_frames=0
drop_frames=0
speed= 195x
progress=continue
frame=26 26 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
197x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 197x
progress=continue
frame=29 29 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
193x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 193x
progress=continue
frame=30 30 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
191x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 191x
progress=continue
frame=31 31 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
183x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 183x
progress=continue
frame=33 33 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
179x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 179x
progress=continue
frame=34 34 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
175x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 175x
progress=continue
frame=35 35 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
173x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 173x
progress=continue
frame=37 37 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
171x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 171x
progress=continue
frame=38 38 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
169x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 169x
progress=continue
frame=40 40 fps=0.0 q=-0.0 size=N/A time=00:00:02.70 bitrate=N/A speed=
167x
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 167x
progress=continue
frame= 40 fps=0.0 q=-0.0 Lsize=N/A time=00:00:02.70 bitrate=N/A speed=
165x
frame=40
fps=0.00
stream_0_0_q=-0.0
bitrate=N/A
total_size=N/A
out_time_us=2700000
out_time_ms=2700000
out_time=00:00:02.700000
dup_frames=0
drop_frames=0
speed= 165x
progress=end
video:18kB audio:253kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: unknown
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