[FFmpeg-trac] #7771(undetermined:new): Unable to set frame rate received from camera
FFmpeg
trac at avcodec.org
Tue Mar 5 13:18:17 EET 2019
#7771: Unable to set frame rate received from camera
-------------------------------------+-------------------------------------
Reporter: lhastie | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
I have a USB camera that is capable of H.264 on-board compression. I use
the following FFmpeg command line to grab the encoded H.264 from the
camera at 30fps and a resolution of 1280x720, and put it in a 'flv'
container:
{{{
ffmpeg -y -f dshow -video_size 1280x720 -framerate 30 -vcodec h264 -i
video="USB Camera" -vcodec copy
-copyinkf -f flv c:\temp\test.flv
}}}
The problem is that the FFmpeg input stream seems to think it is receiving
30fps but the actual output from FFmpeg shows only 5fps. See FFmpeg
standard output below :
ffmpeg -y -f dshow -video_size 1280x720 -framerate 30 -vcodec h264 -i
video="USB Camera" -vcodec copy -copyinkf -f flv c:\temp\test.flv[[BR]]
ffmpeg version N-93252-gf948082e5f Copyright (c) 2000-2019 the FFmpeg
developers
built with gcc 8.2.1 (GCC) 20190212
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-
fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-
libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame
--enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg
--enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr
--enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack
--enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2
--enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-
libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa
--enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx
--enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-
nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt
libavutil 56. 26.100 / 56. 26.100
libavcodec 58. 47.102 / 58. 47.102
libavformat 58. 26.101 / 58. 26.101
libavdevice 58. 6.101 / 58. 6.101
libavfilter 7. 48.100 / 7. 48.100
libswscale 5. 4.100 / 5. 4.100
libswresample 3. 4.100 / 3. 4.100
libpostproc 55. 4.100 / 55. 4.100
Input #0, dshow, from 'video=USB Camera':
Duration: N/A, start: 2445085.764000, bitrate: N/A
Stream #0:0: Video: h264 (Main) (H264 / 0x34363248), yuv420p,
1280x720, '''30 fps''', 30 tbr, 10000k tbn, 20000k tbc
Output #0, flv, to 'c:\temp\test.flv':
Metadata:
encoder : Lavf58.26.101
Stream #0:0: Video: h264 (Main) ([7][0][0][0] / 0x0007), yuv420p,
1280x720, q=2-31, '''30 fps''', 30 tbr, 1k tbn, 10000k tbc
Stream mapping:
Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
frame= 60 '''fps=5.7''' q=-1.0 Lsize= 1324kB time=00:00:11.79
bitrate= 919.5kbits/s speed=1.12x
video:1322kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB
muxing overhead: 0.109154%
Not sure if there is something I am missing on the command line? Any
suggestions would be much appreciated.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/7771>
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