Am Fr., 27. Nov. 2020 um 19:50 Uhr schrieb Simon Roberts <si...@dancingcloudservices.com>:
> 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@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) Just compare the depth of the screen with its diameter;-) (Only CRT's know about fields.) > 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. The bit rate shown in ffprobe's output confirm what you write here, I believe there is an endless number of reasons why the cameras produce streams with different bitrates. > 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. ffprobe has limitations, including some that are unavoidable. If you want to know the average framerate of a video, run the following: $ ffmpeg -i input -f null - And look at the number of frames and the runtime of the stream. Carl Eugen _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".