This page last changed on Feb 27, 2009 by stepheneb.

The attached excel spreadsheet testing_flash_movie_downloads.xls, details each of the requests made over the web when this page is loaded:

The flash app that runs the movie is 36 KB:

Here are details about the original and flash version of the movie:

file length s frames per second image size data size MB notes url
radishes.mp4 45 15 480x320 5.2 the original source
radishes-final.flv 45 15 480x320 2.95 the Flash movie flv file

The flash movie radishes-final.flv was created using the default settings in the Adobe Flash CS Video Encoder which comes as part of the Adobe Creative Suite package.

ffmpeg conversion of the Radish movie

Here is the same radish movie converted to flash flv using the command line unix tool ffmpeg:

These are raw flv files so you will need an application like to play them.

Converted to Flash flv, 480x360 at 15fps

  1. high quality: radishes_no_audio_q8_480x320_15fps.flv (4696kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 8  -s 480x360 -f flv -an -y  radishes_no_audio_q8_480x320_15fps.flv}}
    frame=  689 fps= 64 q=8.0 Lsize=    4696kB time=45.93 bitrate= 837.5kbits/s    
    video:4685kB audio:0kB global headers:0kB muxing overhead 0.233702%
  2. medium quality: radishes_no_audio_q16_480x320_15fps.flv (2056kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 16 -s 480x360 -f flv -an -y radishes_no_audio_q16_480x320_15fps.flv}}
    frame=  689 fps= 68 q=16.0 Lsize=    2056kB time=45.93 bitrate= 366.6kbits/s    
    video:2045kB audio:0kB global headers:0kB muxing overhead 0.535468%
  3. low quality: radishes_no_audio_q28_480x320_15fps.flv (1012kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 28 -s 480x360 -f flv -an -y radishes_no_audio_q28_480x320_15fps.flv
    frame=  689 fps= 70 q=28.0 Lsize=    1011kB time=45.93 bitrate= 180.3kbits/s    
    video:1000kB audio:0kB global headers:0kB muxing overhead 1.094821%

Converted to Flash flv, 240x280 at 15fps

  1. high quality: radishes_no_audio_q8_240x180_15fps.flv (1024kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 8  -s 240x180 -f flv -an -y  radishes_no_audio_q8_240x180_15fps.flv
    frame=  689 fps=149 q=8.0 Lsize=    1202kB time=45.93 bitrate= 214.3kbits/s    
    video:1191kB audio:0kB global headers:0kB muxing overhead 0.919394%
  2. medium quality: radishes_no_audio_q16_240x180_15fps.flv (548kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 16 -s 240x180 -f flv -an -y radishes_no_audio_q16_240x180_15fps.flv
    frame=  689 fps=156 q=16.0 Lsize=     547kB time=45.93 bitrate=  97.6kbits/s    
    video:536kB audio:0kB global headers:0kB muxing overhead 2.040731%
  3. low quality: radishes_no_audio_q28_240x180_15fps.flv (308kB)
    $ ffmpeg -i radishes.mp4 -vcodec flv -r 15 -qscale 28 -s 240x180 -f flv -an -y radishes_no_audio_q28_240x180_15fps.flv
    frame=  689 fps=162 q=28.0 Lsize=     304kB time=45.93 bitrate=  54.2kbits/s    
    video:293kB audio:0kB global headers:0kB muxing overhead 3.735344%

ffmpeg conversion of the NetLogo Model Camtasia screen capture

This is a movie of a screen capture sequence with cartoon ballon callouts added by Camtasia. This is a very different type of original material may require different settings to produce optimal results.

The text quality is poor. A useful strategy if the small sizes are useful is to enlarge the Camtasia callout balloons and the text it encloses.

Here's a high-quality QuickTime movie:

Here's a much smaller Camtasia movie mebedded in a swf file: NLphotosynth_intro2.swf

Converted to Flash flv, 472x372, 15fps with audio

  1. high quality: nl_photosynth_intro_q8_472x372_15fps.flv (3110kB)
    $ ffmpeg -i -r 15 -qscale 8 -s 472x372 -f flv -ab 32k -y nl_photosynth_intro_q8_472x372_15fps.flv
    frame=  516 fps=105 q=8.0 Lsize=    3274kB time=34.40 bitrate= 779.6kbits/s    
    video:3110kB audio:135kB global headers:0kB muxing overhead 0.891790%
  2. medium quality: nl_photosynth_intro_q16_472x372_15fps.flv (1811kB)
    $ ffmpeg -i -r 15 -qscale 16 -s 472x372 -f flv -ab 32k -y nl_photosynth_intro_q16_472x372_15fps.flv
    frame=  516 fps=107 q=16.0 Lsize=    1974kB time=34.40 bitrate= 470.1kbits/s    
    video:1811kB audio:135kB global headers:0kB muxing overhead 1.487588%
  3. low quality: nl_photosynth_intro_q28_472x372_15fps.flv (1217kB)
    $ ffmpeg -i -r 15 -qscale 28 -s 472x372 -f flv -ab 32k -y nl_photosynth_intro_q28_472x372_15fps.flv
    frame=  516 fps=110 q=28.0 Lsize=    1381kB time=34.40 bitrate= 328.8kbits/s    
    video:1217kB audio:135kB global headers:0kB muxing overhead 2.140829%

Converted to Flash flv, 236x186, 15fps with audio

  1. high quality: nl_photosynth_intro_q8_236x186_15fps.flv (834kB)
    $ ffmpeg -i -r 15 -qscale 8 -s 236x186 -f flv -ab 32k -y nl_photosynth_intro_q8_236x186_15fps.flv
    frame=  516 fps=156 q=8.0 Lsize=     998kB time=34.40 bitrate= 237.6kbits/s    
    video:834kB audio:135kB global headers:0kB muxing overhead 2.986371%
  2. medium quality: nl_photosynth_intro_q16_236x186_15fps.flv (412kB)
    $ ffmpeg -i -r 15 -qscale 16 -s 236x186 -f flv -ab 32k -y nl_photosynth_intro_q16_236x186_15fps.flv
    frame=  516 fps=161 q=16.0 Lsize=     575kB time=34.40 bitrate= 137.0kbits/s    
    video:412kB audio:135kB global headers:0kB muxing overhead 5.297019%
  3. low quality: nl_photosynth_intro_q28_236x186_15fps.flv (236kB)
    $ ffmpeg -i -r 15 -qscale 28 -s 236x186 -f flv -ab 32k -y nl_photosynth_intro_q28_236x186_15fps.flv
    frame=  516 fps=165 q=28.0 Lsize=     399kB time=34.40 bitrate=  95.1kbits/s    
    video:236kB audio:135kB global headers:0kB muxing overhead 7.814882%


ffmpeg documentation:

Abbreviated list of ffmpeg command line parameters:

set video framerate to 15 fps -r 15
set video bitrate to 32kb/s -b 32k
set output image size (default = same as source) to 480 x 360 -s 480x360
force input video code to 'flv' -vcodec flv
set video output format to 'flv' -f flv
use two pass encoding -pass 2
set two pass logfile -passlogfile file
set audio sampling frequency to 22050 Hz -ar 22050
set audio bitrate to 32Kbps -ab 32k
disable audio recording -an
force input audio code -acodec ???
attempts constant quality encoding (1=best, 31=worst) -qscale 8
overwrite previous output file -y

Building ffmpeg



ffac and ffad2:

In both directories:

sudo make install

git clone git:// ffmpeg.git
cd ffmpeg.git
git clone git://
./configure --enable-gpl --enable-libmp3lame --disable-vhook --enable-shared --enable-libfaac --enable-libfaad --disable-mmx
sudo make install

testing_flash_movie_downloads.xls (application/
radishes_no_audio_q28_240x180_15fps.flv (application/octet-stream)
radishes_no_audio_q28_480x320_15fps.flv (application/octet-stream)
radishes_no_audio_q16_240x180_15fps.flv (application/octet-stream)
radishes_no_audio_q8_240x180_15fps.flv (application/octet-stream)
radishes_no_audio_q16_480x320_15fps.flv (application/octet-stream)
radishes_no_audio_q8_480x320_15fps.flv (application/octet-stream)
nl_photosynth_intro_q28_236x186_15fps.flv (application/octet-stream)
nl_photosynth_intro_q16_236x186_15fps.flv (application/octet-stream)
nl_photosynth_intro_q8_236x186_15fps.flv (application/octet-stream)
nl_photosynth_intro_q28_472x372_15fps.flv (application/octet-stream)
nl_photosynth_intro_q16_472x372_15fps.flv (application/octet-stream)
nl_photosynth_intro_q8_472x372_15fps.flv (application/octet-stream)
NLphotosynth_intro2.swf (application/x-shockwave-flash) (video/quicktime)
testing_flash_movie_downloads.xls (application/
Document generated by Confluence on Jan 27, 2014 16:56