[FFmpeg-user] Video quality
belcampo at zonnet.nl
Tue Dec 13 08:48:24 CET 2011
On 12/12/2011 06:51 PM, Hans Guth wrote:
> 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
> 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
Are you sure the source is 30000/1001 ?
What happens if you leave-out "-r 30000/1001"
> 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.
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