Carl Karsten wrote:
Wondering why changing the fps from 6 to 1 (-f 6, -f 1) would cause the
file size to go from 60m to 158m?
Carl K
transcode -i files.txt \
-x imlist,null \
-g 1440x900 \
--use_rgb \
-z \
-y ffmpeg,null \
-F mpeg4 \
-o chipy090214.avi \
-H 0 \
-f 6
[EMAIL PROTECTED]:/media/disk$ ls -lh chipy090214*.avi
-rw-r--r-- 1 carl carl 60M 2008-02-16 00:49 chipy090214.avi
-rw-r--r-- 1 carl carl 158M 2008-02-16 01:09 chipy090214b.avi
[EMAIL PROTECTED]:/media/disk$ tcprobe -i chipy090214.avi
[tcprobe] RIFF data, AVI video
[avilib] V: 6.000 fps, codec=DIVX, frames=1649, width=1440, height=900
[tcprobe] summary for chipy090214.avi, (*) = not default, 0 = not detected
import frame size: -g 1440x900 [720x576] (*)
frame rate: -f 6.000 [25.000] frc=0 (*)
no audio track: use "null" import module for audio
length: 1649 frames, frame_time=166 msec, duration=0:04:34.833
[EMAIL PROTECTED]:/media/disk$ tcprobe -i chipy090214b.avi
[tcprobe] RIFF data, AVI video
[avilib] V: 1.000 fps, codec=DIVX, frames=1649, width=1440, height=900
[tcprobe] summary for chipy090214b.avi, (*) = not default, 0 = not detected
import frame size: -g 1440x900 [720x576] (*)
frame rate: -f 1.000 [25.000] frc=9 (*)
no audio track: use "null" import module for audio
length: 1649 frames, frame_time=1000 msec, duration=0:27:29.000
I am guessing it is keyframes, but given I am shooting for .5 fps, I really need
to do a key frame every 20 seconds or so. apparently 1000 is the max I can set
with -w, anything higher i get:
[mpeg4 @ 0xb13fba68]Warning keyframe interval too large! reducing it
the only ref to keyint I can find is
http://www.transcoding.org/cgi-bin/transcode?Export_Modules/Export_Ffmpeg
keyint 0-300 (maximum interval between keyframes)
keyframes are needed for seeking as seeking is only possible to a
keyframe but they need more space than non-keyframes so larger numbers
here
mean slightly smaller files, but less precise seeking
0 no keyframes
>300 is not recommended as the quality might be bad (depends upon
decoder, encoder and luck)
for strict mpeg1/2/4 compliance this would have to be <=132
TRANSCODE: use -w X,X,keyint
Is interval time or frames?
also, when I put it in ffmpeg.conf, I get:
[export_ffmpeg.so] Key 'keyint' is not a valid option.
Carl K
