Changes between Version 10 and Version 11 of Slideshow

Timestamp:

Nov 24, 2013, 2:42:38 PM (13 years ago)

Author:

slhck

Comment:

alternative fps option for specifying rate, see ticket #3164

Slideshow

@@ -1 +1 @@
 == Frame rates ==
 
-This will create a video slideshow (using the encoder `libx264`) from series of numerically sequential PNG images named `img001.png`, `img002.png`, `img003.png`, etc.
+This will create a video slideshow (using the encoder `libx264`) from series of numerically sequential PNG images named `img001.png`, `img002.png`, `img003.png`, etc. '''Important:''' All images in a series need to be of the same size and format.
 
-In this example each image will have a duration of 5 seconds (the inverse of 1/5 frames per second). By using a separate `-r` (frames per second) for the input and output you can control the duration at which each input is displayed and tell ffmpeg the frame rate you want for the output file. If the input `-r` is lower than the output `-r` ffmpeg will duplicate frames to reach your desired output frame rate. If the input `-r` is higher than the output `-r` ffmpeg will drop frames to reach your desired output frame rate.
+You can specify two frame rates:
 
-If you want the input and output frame rates to be the same, then just declare an input `-r` and the output will inherit the same value.
+* The rate according to which the images are read, by setting `-r` before `-i`. The default for reading input is `-r 25` which will be set if no `-r` is specified.
+* The output frame rate for the video stream, by setting `-r` after `-i`, or using the `fps` filter. If you want the input and output frame rates to be the same, then just declare an input `-r` and the output will inherit the same value.
 
-Default for input is `-r 25` which will be used if no `-r` is used.
+By using a separate `-r` (frames per second) for the input and output you can control the duration at which each input is displayed and tell ffmpeg the frame rate you want for the output file. If the input `-r` is lower than the output, `-r` ffmpeg will duplicate frames to reach your desired output frame rate. If the input `-r` is higher than the output `-r` ffmpeg will drop frames to reach your desired output frame rate.
+
+In this example each image will have a duration of 5 seconds (the inverse of 1/5 frames per second). The video stream will have a frame rate of 30 fps, by duplicating the frames accordingly:
 
 {{{
@@ -13 +16 @@
 }}}
 
-This will create a slideshow in which each image has a duration of 15 seconds:
+If your video does not show the frames correctly, setting the `fps` filter instead of the output framerate should work:
 
 {{{
-ffmpeg -r 1/15 -i img%03d.png -c:v libx264 -r 30 -pix_fmt yuv420p out.mp4
+ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
 }}}
 
-'''Important:''' All images in a series need to be of the same size and format.
 
 == Color space conversion and chroma sub-sampling ==