That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. slow is a good balance between encoding time and. Other valid options are baseline, main-preset slow: sets encoding preset for x264 slower presets give more quality at same bitrate, but need more time to encode.

You can however convert a video to MP4 using FFmpeg. tells FFmpeg to encode video to H.264 using libx264 library-profile:v high: sets H.264 profile to High as per Step 2. Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. You use it to decode, filter and/or encode audio and video files.

Ffmpeg encode h264 example