<p>I know about presets but faster presets lose the video quality. Are there any hardware requirements I need to consider? Or are there any settings that I need to tweak? And lastly where do I place the <code>-threads</code> flag to encode video (before input or after input), I saw topics on thread but they were confusing.</p>

<p>This is the command I am using now:</p>

<pre><code>ffmpeg -i input.mp4 \
            -codec:v libx264 -tune zerolatency -profile:v main -preset medium -crf 23 -maxrate 1000k -bufsize 10000k -s hd720 -codec:a libfdk_aac -pix_fmt yuv420p -movflags +faststart -threads 4 highoutput.mp4 \
            -codec:v libx264 -tune zerolatency -profile:v main -preset medium -crf 23 -maxrate 500k -bufsize 5000k -s hd480 -codec:a libfdk_aac -pix_fmt yuv420p -movflags +faststart -threads 4 lowoutput.mp4
</code></pre>

<p>Your help and guidance will be very much appreciated. Thank you.</p>

CC BY-SA 3.0
2015-08-15T13:49:51.500Z
Faster presets do less work to come up with the same quality if you're using Constant Rate Factor (-crf). So AFAIK the trade-off isn't less quality, but bigger files.
stib
CC BY-SA 3.0
2015-08-15T16:52:55.233Z
@stib Is there any way to maintain the bitrate?
Robin
CC BY-SA 3.0
2015-08-15T20:13:03.680Z
Doesn't using `-crf` override any bitrate options on the command line? I seem to recall that being the case.
WineSoaked
CC BY-SA 3.0
2015-08-16T09:58:38.057Z
@WineSoaked Is it? I saw  this [post](http://trac.ffmpeg.org/wiki/Encode/H.264#CRFwithmaximumbitrate) telling me otherwise.
Robin
<video><ffmpeg><encoding><transcoding><recommendation>
Fast encoding with ffmpeg
Robin
# Fast encoding with ffmpeg

(Asked by: username_0 on 2015-08-13)

I know about presets but faster presets lose the video quality. Are there any hardware requirements I need to consider? Or are there any settings that I need to tweak? And lastly where do I place the -threads flag to encode video (before input or after input), I saw topics on thread but they were confusing.
This is the command I am using now:
ffmpeg -i input.mp4 \
            -codec:v libx264 -tune zerolatency -profile:v main -preset medium -crf 23 -maxrate 1000k -bufsize 10000k -s hd720 -codec:a libfdk_aac -pix_fmt yuv420p -movflags +faststart -threads 4 highoutput.mp4 \
            -codec:v libx264 -tune zerolatency -profile:v main -preset medium -crf 23 -maxrate 500k -bufsize 5000k -s hd480 -codec:a libfdk_aac -pix_fmt yuv420p -movflags +faststart -threads 4 lowoutput.mp4

Your help and guidance will be very much appreciated. Thank you.

**Tags:** video, ffmpeg, encoding, transcoding, recommendation

> **Comments:**
> **username_1**: Faster presets do less work to come up with the same quality if you're using Constant Rate Factor (-crf). So AFAIK the trade-off isn't less quality, but bigger files.  
> **username_0**: @username_1 Is there any way to maintain the bitrate?  
> **username_2**: Doesn't using `-crf` override any bitrate options on the command line? I seem to recall that being the case.  
> **username_0**: @username_2 Is it? I saw  this [post](http://trac.ffmpeg.org/wiki/Encode/H.264#CRFwithmaximumbitrate) telling me otherwise.  

---

## 0 answers

