Additional frame created with tensorflow_stream example

[elemakil]

When I process an input file using the tensorflow_stream example (without applying "deepdream") the resulting output file has one extra frame. This occurs for video files of different lenght (tested with 1 sec, 10 sec, 1min, 10min). I inspect the number of frames in the input/output video using the command

ffprobe -v error -select_streams v:0 -show_entries stream=nb_frames -of default=nokey=1:noprint_wrappers=1 video.mp4

Output of ffmpeg -version:

ffmpeg version n4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 8.2.1 (GCC) 20181127
configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
libavutil      56. 22.100 / 56. 22.100
libavcodec     58. 35.100 / 58. 35.100
libavformat    58. 20.100 / 58. 20.100
libavdevice    58.  5.100 / 58.  5.100
libavfilter     7. 40.101 /  7. 40.101
libswscale      5.  3.100 /  5.  3.100
libswresample   3.  3.100 /  3.  3.100
libpostproc    55.  3.100 / 55.  3.100

[RomanSteinberg]

Hi @elemakil
My guess is that you counted frame which has no bytes actually. Anyway, you'd better provide the code snippet for counting those frames.

[elemakil]

There's no code snippet from my side. I am using the tensorflow_stream example and I count the frames using ffprobe (check my original post for command).

[kkroening]

Hmm, interesting. Marking as bug. Thanks for reporting.

[elemakil]

I figured out how to get rid of the extra frame - at least according to the nb_frames key of ffprobe. By adding vsync='0' to the output of the ffmpeg reader process, video file created by the writer process will have the same number of frames as the input file. Unfortunately I can't test this using a range of video files, but at the very least this resolves the problem on my one input file :-)