user2445: I have a video which is a bit dark that I'd like to re-encode and brighten up with ffmpeg.
As a smarter/faster alternative to running ffmpeg in trial/error mode, is there a way to simply use ffplay to find how much to brighten things up, before running ffmpeg with the same settings?
"ffplay -h" returns so much infos that it's hard for newbies :-/
Thank you.

user1760: You can use simple filtergraphs easily with ffplay.
Example using colorlevels filter in ffplay:
ffplay -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 input.mp4

Then you can use the same filter in ffmpeg:
ffmpeg -i input.mp4 -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 -c:a copy output.mp4

This example will stream copy the audio.

2445: <p>I have a video which is a bit dark that I'd like to re-encode and brighten up with ffmpeg.</p>

<p>As a smarter/faster alternative to running ffmpeg in trial/error mode, is there a way to simply use ffplay to find how much to brighten things up, before running ffmpeg with the same settings?</p>

<p>"ffplay -h" returns so much infos that it's hard for newbies :-/</p>

<p>Thank you.</p>
 1760: <p>You can use <a href="http://ffmpeg.org/ffmpeg.html#Simple-filtergraphs" rel="nofollow">simple filtergraphs</a> easily with <code>ffplay</code>.</p>

<p>Example using <a href="http://ffmpeg.org/ffmpeg-filters.html#colorlevels" rel="nofollow">colorlevels</a> filter in <code>ffplay</code>:</p>

<pre><code>ffplay -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 input.mp4
</code></pre>

<p>Then you can use the same filter in <code>ffmpeg</code>:</p>

<pre><code>ffmpeg -i input.mp4 -vf colorlevels=rimax=0.902:gimax=0.902:bimax=0.902 -c:a copy output.mp4
</code></pre>

<p>This example will <a href="http://ffmpeg.org/ffmpeg.html#Stream-copy" rel="nofollow">stream copy</a> the audio.</p>
