[FFmpeg-user] Video quality

Hans Guth hguth at listingsmagic.com
Mon Dec 12 18:51:27 CET 2011

I have an flv video that is about 38M and the quality is excellent.  
When I try and convert it to SWF which is format I need I can't seem to 
get a quality output file.  The original file is 1920x1088.  I want the 
output to be 640x480 but whatever I am doing it's creating a very choppy 
output file.

I have tried all sorts of different settings but if size is set to 
640x480 then I seem to get same/similar results.  Note: If I set -sameq 
then the swf output seems to get screwed up - i.e. it won't start 
playing but gets hung on frame 1?

Here's one command example.

/usr/local/bin/ffmpeg -i MOV072.flv -y -s 640x480 -r 30000/1001 -b 200k 
-bt 240k MOV072.swf

Seems stream 0 codec frame rate differs from container frame rate: 59.94 
(2997/50) -> 29.92 (359/12)
Input #0, flv, from 'MOV072.flv':
   Duration: 00:00:42.71, start: 0.000000, bitrate: 264 kb/s
     Stream #0.0: Video: h264, yuv420p, 1920x1088, 200 kb/s, 29.92 tbr, 
1k tbn, 59.94 tbc
     Stream #0.1: Audio: mp3, 22050 Hz, stereo, s16, 64 kb/s
Output #0, swf, to 'MOV072.swf':
     Stream #0.0: Video: flv, yuv420p, 640x480, q=2-31, 200 kb/s, 90k 
tbn, 29.97 tbc
     Stream #0.1: Audio: libmp3lame, 22050 Hz, stereo, s16, 64 kb/s
Stream mapping:
   Stream #0.0 -> #0.0
   Stream #0.1 -> #0.1

Does the "Seems stream 0 codec frame rate" issue have anything to do 
with it?  Any advice on how to keep the quality level high.


Hans Guth
President - ListingsMagic
866-831-8639 ext. 704

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