[FFmpeg-user] ffprobe -show_frames and coded_picture_number
jiachielee at live.com
Thu Aug 15 00:27:15 CEST 2013
With the access of the sources, I can inspect the every single frame that
makes up the video. Not every scene is noticeable. And I don’t claim that I
exactly have the best eyesight to make conclusive judgment on behalf of the
others. The less noticeable scenes, are either static (or “motionless”) or
with adequate “motion blurring”.
There are reasons why I’m not exactly in favor of speeding up the video; the
playback speed is altered although I admit that not every person can
actually “feel” the “speeding up” at first look. Speeding the audio would
affect the “pitch” and other effects. I guess the best solution is to
reproduce the video frame-by-frame for 25 FPS.
To me personally, I would support the standardization of frame rate at 24
FPS for all videos/films created. For historical reasons, NTSC standard uses
29.97 FPS (interlaced) while PAL standard uses 25 FPS; the theatrical films
are created at 24 FPS. On a PC, it does not matter which frame rate the
video has used. Due to the existence of different standards, there exist PAL
DVD and NTSC DVD, both only supports interlaced contents natively. On LCD
display, undoubtedly progressive-scan video can better preserve image
quality for every single frame. The real reasons for the old standards are
still in use is more about traditions or what people already have or are
used to. Even though H.264 offers better compression compared with H.262,
Blu-ray still has to support H.262 for backward compatibility reasons.
Speaking of which, I’ve never thought of converting to 25 FPS before because
I’m in favor of standardizing on 24 FPS. I used to convert from 25 FPS and
30 FPS to 24 FPS and never quite experience “unrealistic motion” before. To
be honest, I don’t even know the reason for converting to 25 FPS from 24 FPS
other than for traditional analog broadcast. I usually keep the original
frame rate; when I do change the frame rate to 24 FPS, it’s when I actually
edit the videos (up-scaling, cropping, etc.)
Historically, it’s necessary to change the frame rate when we transfer the
film materials for TV viewing to either 29.97 FPS or 25 FPS. Is it really
necessary to change frame rate when I view film materials or digitally
created 24-FPS video on LCD display? I guess not. I conduct the experiment
mainly out of curiosity. Anyway, it’s a great learning experience.
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