Let’s start analyzing a sample command line to encode in H.264 :įfmpeg -i INPUT -r 25 -b 1000k –s 640×360 -c:v libx264 -flags +loop -me_method hex -g 250 -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -bf 3 -b_strategy 1 -i_qfactor 0.71 -cmp +chroma -subq 8 -me_range 16 -coder 1 -sc_threshold 40 -flags2 +bpyramid+wpred+mixed_refs+dct8x8+fastpskip -keyint_min 25 -refs 3 -trellis 1 –level 30 -directpred 1 -partitions -parti8x8-parti4x4-partp8x8-partp4x4-partb8x8 -threads 0 -acodec libfaac -ar 44100 -ab 96k -y OUTPUT.mp4 To know more about the technical principles of H.264 encoding, I suggest also to take a look at the first part of my presentions at MAX2008, MAX2009 and MAX2010. Therefore, if you want to go deeper in the parameterization of FFmpeg, I can suggest you to read this article to know the meaning of each x264 parameters and the mapping between FFmpeg and x264. So I’ll describe only the most important and provide some useful samples.

ES: -x264opt bitrate=1000:profile=baseline:level=4.1…etc.Įxplain the meaning of all the parameters is a long task and it is not the aim of this article. x264opt accept parameters as key=value pairs separated by “:”. UPDATE: FFmpeg allows to specify directly the parameters to the underling x264 lib using the option -x264opt. However you have to know that FFmpeg applies a parameter name re-mapping and doesn’t offer the whole set of x264 options.

x264 offers a very wide set of parameters and therefore an accurate control over compression. In this third part we will look more closely at the parameters you need to know to encode to H.264.įFmpeg uses x264 library to encode to H.264. PART IV – FFmpeg for streaming (revised 0) PART II – Parameters and recipes (revised 0)

Ffmpeg h264 reference frames