Step 3: Similar to convert MKV HEVC to H264 MP4 with FFmpeg, you need enter a command line. button and enter Path for variable name c:\ffmpeg\bin for Variable value. Enable FFmpeg in the command line: right-click on Computer and choose Properties > Advanced system settings > Environment Variables. Take Windows 7 (32 bit) as an example, unzip file and open the command prompt with administrator's right. Please note that you should download the right one based on system type.
Step 1: Free download FFmpeg static zip file on your computer. ffmpeg -i h264.mp4 -c:v libvpx-vp9 -row-mt 1 -threads 48 -cpu-used X -deadline good -crf X -b:v 0 outputXYZ.Convert H264 to H265 with FFmpeg row-mt 1 and -threads 48 stayed consistent through the whole testing process. The basis of the testing commands for this part is below, obviously the -cpu-used and -crf values changed throughout. This file comes in MKV format but was copied (-c copy) to MP4 for the testing. At 4k resolution (3840×2160) 29.97 fps, 30 seconds long, 250Mbps bitrate and file size of 895MB. The input media is from with the H.264 testing file here. The operating system was Ubuntu 18.04 and the FFMpeg version was 3.4.8-0ubuntu0.2. Thanks to exception0x876 at wishosting for the opportunity to use this. The server used for testing had dual Intel Xeon E5-2687W v4 CPU’s set 3.50GHz, meaning 24 cores and 48 threads in total. The testing is using the constant quality option (crf) and the differences with different deadlines along with the cpu used parameter, these effect speed and the outcome quality. To see the encoding options for VP9 WebM with FFmpeg see my post here. In this part 1 see FFmpeg encoding speed, fps, size and bitrate for an h264 MP4 video file to VP9 WebM using -deadline good with -crf values 15-30 and -cpu-used 0-5.
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