[FFmpeg-user] filter pipeline 'PTS' -- int64_t?

Mark Filipak (ffmpeg) markfilipak at bog.us
Tue Mar 2 02:43:50 EET 2021


The ffmpeg filter pipeline assigns a 'PTS' to each frame, frame by frame. Is *that* 'PTS' an int64_t?

Things I have found.

https://ffmpeg.org/ffmpeg-filters.html#fps-1
   "...trim any frames with a negative PTS."
That implies that PTS can be negative (ergo, is a signed integer).

http://svn.ffmpeg.org/doxygen/1.0/structAVFrame.html
Is AVFrame the structure of frames in the filter pipeline? If so, then
"int64_t 	pts
" 	presentation timestamp in time_base units (time when frame should be shown to user) If 
"AV_NOPTS_VALUE then frame_rate = 1/time_base will be assumed."
appears to answer my question, unless it's a different 'frame'...

...What exactly is 'AVFrame'?

http://svn.ffmpeg.org/doxygen/1.0/avformat_8h-source.html
   "00320 typedef struct AVFrac {
   "00321     int64_t val, num, den;
   "00322 } AVFrac;"
http://svn.ffmpeg.org/doxygen/1.0/structAVFrac.html#_details
   "The exact value of the fractional number is: 'val + num / den'."
That appears to be a definition of something called "PTS" but seems to not be what's assigned to a 
frame in the filter pipeline.

The label (name) of what is actually assigned to frames in the filter pipeline as 'PTS' is unknown 
to me.

Thanks for the guidance,
Mark.

-- 
In U.S. History: The House Un-American Activities Committee was a committee of the House of 
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