Hi, I am trying to encode an 8-bit 4K video at 3Mbps by using ffmpeg + x264 and I see a considerable difference in speed when I use ffmpeg and pipe the output to x264 (by using linux pipes), and when I use libx264. The speed difference is nearly 2X with the encoding being considerably faster when using libx264. When I use just x264, I see that the speed is comparable to using libx264 in ffmpeg.
My command lines are below Using ffmpeg + x264: ffmpeg -s 3840x2160 -r 50 -i Samsung_UHD_Soccer_Barcelona_Atletico_Madrid_8bit.yuv -f rawvideo - | ./x264 --input-res 3840x2160 --fps 50 --keyint 100 --preset ultrafast -o /dev/null --bitrate 5000 --vbv-maxrate 5000 --vbv-bufsize 6000 - (runs at approx 70fps) Using ffmpeg + libx264: ffmpeg -s 3840x2160 -r 50 -i /home/mcw/Videos/Samsung_UHD_Soccer_Barcelona_Atletico_Madrid_8bit.yuv -c:v libx264 -preset ultrafast -b:v 5000k -f mp4 Barca_libx264.mp4 (runs at approx 128fps) Has anyone else experienced such a stark difference in speed? Are the limits of linux pipes the reason for this difference, or is there something else going on here? Pradeep. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
