[FFmpeg-user] Understanding ffprobe output
Simon Roberts
simon at dancingcloudservices.com
Fri Nov 27 20:50:23 EET 2020
Hi all,
I've been making video using the monitor outputs of a pair of Sony A6000
cameras (bypassing the 30 minute limit while gaining other limitations). I
take each camera's output through a splitter, one side goes to a monitor,
and the other to the recording machine.
One camera feeds to a monitor that's only capable of a 60 Hz vertical. The
monitor just says "1080 at 60 Hz". The other camera feeds a different type of
monitor that runs at 30 Hz vertical. (Note, I don't really know what
"vertical" means, frame? field? can't tell. I also don't know if the higher
rate one is running interlaced. I have some vague recollection that I had
noticed hints that it's progressive, but I don't recall what those hints
were)
Anway, everything works, and the recordings are fine. But I noticed that
the file size for the "60 Hz" camera was nearly double that of the other
camera. Both cameras have identical settings internally, and are actually
set at 1080p output.
But these are the outputs of ffprobe on two files made side by side,
"mostly" at a static green screen. The first is the one made with the
higher vertical rate, and the second with the 30 Hz screen. I see the
bitrate difference that correlates to the file sizes, but to my uneducated
eyes they both claim to be "30 fps" (whatever that means--fields? frames?
fairies--I'm certainly doubting my basic knowledge here! :) both say
"progressive" and I see no other differences.
Can anyone help my education?
Many thanks,
Simon
----------------------------------------------------------------
$ ffprobe P-0005-b\ CAM\ 2.mp4
ffprobe version N-98470-g7772666 Copyright (c) 2007-2020 the FFmpeg
developers
built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
configuration: --prefix=/home/simon/ffmpeg_build
--pkg-config-flags=--static
--extra-cflags='-I/home/simon/ffmpeg_build/include
-I/home/simon/ffmpeg_sources/BMD_SDK/include'
--extra-ldflags=-L/home/simon/ffmpeg_build/lib --extra-libs='-lpthread -lm'
--bindir=/home/simon/bin --enable-gpl --enable-libass --enable-libfdk-aac
--enable-libfreetype --enable-libmp3lame --enable-libopus
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
--enable-nonfree --enable-decklink
libavutil 56. 55.100 / 56. 55.100
libavcodec 58. 95.100 / 58. 95.100
libavformat 58. 48.100 / 58. 48.100
libavdevice 58. 11.101 / 58. 11.101
libavfilter 7. 87.100 / 7. 87.100
libswscale 5. 8.100 / 5. 8.100
libswresample 3. 8.100 / 3. 8.100
libpostproc 55. 8.100 / 55. 8.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'P-0005-b CAM 2.mp4':
Metadata:
major_brand : isom
minor_version : 1
compatible_brands: iso4avc1isom
creation_time : 2020-11-25T19:56:12.000000Z
com.blackmagic-design.camera.dateRecorded: 2020:11:25
com.blackmagic-design.camera.timelineID: 00c74876
com.apple.proapps.clipID: P-0005-b CAM 2
com.apple.proapps.cameraName: 2
com.blackmagic-design.camera.uuid: AC427EDA14364C178BABEA7BC35FED1C-2
Duration: 00:51:16.00, start: 0.000000, bitrate: 28780 kb/s
Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv,
bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 28647 kb/s, 30 fps, 30
tbr, 30 tbn, 60 tbc (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Apple Video Media Handler
encoder : H264/AVC
timecode : 12:56:11:23
Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Time Code Media Handler
timecode : 12:56:11:23
Stream #0:2(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
fltp, 128 kb/s (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Apple Sound Media Handler
timecode : 12:56:11:23
Unsupported codec with id 0 for input stream 1
----------------------------------------------------------------
ffprobe version N-98470-g7772666 Copyright (c) 2007-2020 the FFmpeg
developers
built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
configuration: --prefix=/home/simon/ffmpeg_build
--pkg-config-flags=--static
--extra-cflags='-I/home/simon/ffmpeg_build/include
-I/home/simon/ffmpeg_sources/BMD_SDK/include'
--extra-ldflags=-L/home/simon/ffmpeg_build/lib --extra-libs='-lpthread -lm'
--bindir=/home/simon/bin --enable-gpl --enable-libass --enable-libfdk-aac
--enable-libfreetype --enable-libmp3lame --enable-libopus
--enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265
--enable-nonfree --enable-decklink
libavutil 56. 55.100 / 56. 55.100
libavcodec 58. 95.100 / 58. 95.100
libavformat 58. 48.100 / 58. 48.100
libavdevice 58. 11.101 / 58. 11.101
libavfilter 7. 87.100 / 7. 87.100
libswscale 5. 8.100 / 5. 8.100
libswresample 3. 8.100 / 3. 8.100
libpostproc 55. 8.100 / 55. 8.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'P-0005-b CAM 1.mp4':
Metadata:
major_brand : isom
minor_version : 1
compatible_brands: iso4avc1isom
creation_time : 2020-11-25T19:56:12.000000Z
com.blackmagic-design.camera.dateRecorded: 2020:11:25
com.blackmagic-design.camera.timelineID: 00c74876
com.apple.proapps.clipID: P-0005-b CAM 1
com.apple.proapps.cameraName: 1
com.blackmagic-design.camera.uuid: AC427EDA14364C178BABEA7BC35FED1C-1
Duration: 00:51:16.00, start: 0.000000, bitrate: 17868 kb/s
Stream #0:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv,
bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 17735 kb/s, 30 fps, 30
tbr, 30 tbn, 60 tbc (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Apple Video Media Handler
encoder : H264/AVC
timecode : 12:56:11:23
Stream #0:1(eng): Data: none (tmcd / 0x64636D74) (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Time Code Media Handler
timecode : 12:56:11:23
Stream #0:2(eng): Audio: aac (mp4a / 0x6134706D), 48000 Hz, stereo,
fltp, 128 kb/s (default)
Metadata:
creation_time : 2020-11-25T19:56:12.000000Z
handler_name : ?Apple Sound Media Handler
timecode : 12:56:11:23
Unsupported codec with id 0 for input stream 1
----------------------------------------------------------------
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