#FFMPEG CRF MAXRATE 720P#

So it can't allocate bits optimally over an entire video. With ABR the encoder doesn't know what's coming in the future (aside from the small lookahead buffer) and doesn't have a memory of what happened in the past. It is unavoidable - video compression is computationally intensive task - if your GPU support HW video compression (IMHO best video compression in HW is offered by NVidia) then you can use dedicated HW for much faster compression (albeit reduced quality and/or increased bitrate).Īll above is purely my opinion and it doesn't try to address your playout environment (such as screen type and size, content etc).ĪBR with constraints is used for live broadcast/streaming - it's live so you can't do two passes and you usually have bitrate constraints. IMHO most important baseline limitation beside to B frames is lack of CABAC - if your playout is OK then i would use B frames and CABAC - both are substantial features and quality benefits are obvious (both saving bitrate). maxbitrate = buffsize - alternatively you may try to use GOP length (or rather GOP/fps) to shape buffer size but then i would avoid anything higher than 5 seconds (once again other may disagree). Practically it's too difficult (impossible)to know which one is giving better quality Best quality results are with CRF, you can add maxbitrate and buffer size to cap (limit) variability of bitrate.īuffer size IMHO should be around 1 second for max bitrate (but some people may disagree with this) i.e. Practically it's too difficult (impossible)to know which one is giving better quality Theoretically if i encode a video with both methods at same bitrate and same settings then which one will give better visaul quality? I can go for higher bitrates to preserve quality of video and encoding speeds in constrained baseline profileīut the question is which method shall i use for speedy encodesĪverage Bitrate (ABR, also “target bitrate”) method with only specifying -b:vĬonstrained Encoding (VBV) method which requires additional settings whihch is -b:v -minrate -maxrate -bufsize etcĪnd also i dont know properly how this -minrate -maxrate -bufsize affects the video quality

Main problem is encoding speed is too loww.and thats why i use ultrafast preset with libx264 codec which actually automaticaly selects constrained baseline video profile.thats why output video only contains I and P frames (no Bframes because constrained baseline profile doesnot supports Bframes i guess)

#FFMPEG CRF MAXRATE 720P#

Playback on my pc isnt problem.my computer can play videos smothly which is encoded at high profilesīut it should be in under 720p resolution. Even you cut 'black bars' on the top and bottom, you will see them again on your TV.Ĭroppings also make 'a small zoom' on the video, that zooming reduces the quality.Ĭode: ffmpeg -i input.mp4 -vf scale=432:-2 -c:v libx264 -preset ultrafast -b:v 260k -maxrate 390k -bufsize 390k output.mp4 crop shall precede scale in video filter chain There are also many options for H264 in MeGUI.įor 'lossless cutting video clips', I guess you mean 'cutting without re-encoding', the best to use is MKVToolnix, or VirtualDubMod (which is very old but still useful).Ĭropping is not recommended. Most of them are command-line tools, but MeGUI offers you a graphical user interface, so you don't need to write or memorise any command lines. Remember that MeGUI is a package with all-needed encoding tools like dgindex, eac3to, ffmpeg, lsmash, tsmuxer, x264 and x265 encoders, etc.

First, you can extract subtitle and audio tracks from original file (via 'HD Streams Extractor', which is actually an inside-GUI to command-line tools like ' eac3to'), and later add them to the encoded file while muxing. Because ffmpeg can do many options which gui encoders does not includes.like editing meta data ,adding subtitles, adding extra tracks etcĪnd for lossless cutting video clips, croping videos ,adding some filters for that kind of oprations i use gui softwares like avidemux MeGUI also does them.

Ffmpeg crf maxrate