This will determine the file size and also how quality is distributed.

Rate control decides how many bits will be used for each frame. There are two rate control modes that are usually suggested for general use: Constant Rate Factor (CRF) or Two-Pass ABR. See HWAccelIntro for information on supported hardware H.264 encoders. If you need help compiling and installing see one of our compiling guides. It assumes you have ffmpeg compiled with -enable-libx264. 720p should have a minimum of 1,5mbps bitrate and 1080p 3mbps.įor your future questions, don't forget to post the input/output logs from ffmpeg, they're always helpful :-). If you wish to target such a low bitrate, I suggest you downscale to 480p (854x480). Also, don't forget about presets !Īs a side note, 500k for 1080p is way too low and you will get poor results. If you absolutely want to target an average bitrate, you should checkout 2-pass encoding. Increasing it will mean lower bitrate and worse quality, lowering it vice versa. You're free to experiment with the crf value.

you target a certain quality and the encoder decides which average bitrate is the best for your file : ffmpeg -i. Instead, you should try encoding with 'constant rate factor', i.e. Please note however that this will use a 1-pass average bitrate method which is pretty bad for quality. I suggest you re-encode with the H.264 codec which you can do like this : ffmpeg -i. My guess is that ffmpeg tries to use the mpeg4 codec by default, and it refuses to use less than 2mbps because it simply can't go below with such a high resolution. When re-encoding a file, you shouldn't just specify a bitrate.

Ffmpeg crf bitrate