Ffmpeg maxrate and bufsize And is it necessary to give maxrate and minrate for encoding videos for streaming purpose. The command I'm trying is " ffmpeg -i sample_iTunes. mkv So I'm trying to transcode the video material while leaving FFmpeg is the leading multimedia framework, able to decode, encode, transcode, mux, demux, stream, filter and play pretty much anything that humans and machines have created. Use a -maxrate value that is below your maximum upload rate and leave some room for overhead. mp4 Nov 29, 2021 · Thanks for reply I know how to do 2 pass encoding And constant bitrate encoding But I don't know anything about how to do Average bitrate encoding with ffmpeg Will you give ffmpeg code example for How I can do average birate encoding with using -b:v -minrate -maxrate -bufsize Bitrate unit must be in kbps ,not in mbps because I understand kbps more😅 How to chose -bufsize? And what is role of Setting -b:v, -minrate, and -maxrate to the same levels will achieve that, for example for libx264: ffmpeg -i input. Does --level <xx> just set these options Mar 1, 2017 · VBV can be used both with 2-pass VBR (use it in both passes), or with CRF encoding—it can be “added” to the already presented rate control modes. Set the buffer size according to how much you expect your client to be able to buffer. ts The 18M maxrate value is from the ATSC/QAM limitations for broadcast video, which is why I'm using MPEG-TS as a container here. Feb 11, 2023 · The thing about FFmpeg is that there are almost always multiple ways to accomplish the same basic function. Actually I understood the meaning and functions of minrate, maxrate and bufsize Setting the CRF (a constant quality mode) and a video bit rate at the same time does not make any sense. m2v So, set minrate, maxrate and bitrate to the same rate. I was going through x265 documentation and found out about --vbv-bufsize and --vbv-maxrate. Sep 2, 2025 · 文章浏览阅读3. I also have never used two pass, but my understanding is that you need to encode it twice, right? bufsize 根据你希望比特率获得多大的可变性而设置，默认为 maxrate 的两倍，如果想限制流的比特率，可以设置为 maxrate 的一半。配合 CRF 模式使用的时候，如果设置的 crf 值过低，视频码率可能超出 -maxrate 的时候，编码器会自动调整 crf，避免出现较大的码率波动。 I'm transcoding several 1080p/720p mkv's. And setting -bufsize 14000000 -maxrate 14000000 didn't give rise to vbv_underflow, x264 showed vbv_maxrate=14000 vbv_bufsize=14000. mp4 ctrl + c youtube github I replaced the -preset faster option with -crf 20 -b:v 7M -maxrate 7M -bufsize 14M , and I feel I see slightly better results. 1 As part of it. Jul 26, 2015 · Ussually the final size and video bitrate depends mainly on the video output size. FFmpeg sometimes either doesn't have those options or does stuff by default. So the ffmpeg options are in b/s, and x264's are in kb/s. > > Regards, > Gyan > > From f875734cc5a1652162156118864db406b192526b Mon Sep 17 00:00:00 2001 > From: Gyan Doshi < [email protected] > > Date: Wed, 13 Jun 2018 19:01:17 +0530 > Subject: [PATCH] avcodec/libx265: apply lavc maxrate and bufsize > > CLI options Oct 28, 2022 · What do you mean with " [] speed is not very good []"? There are some options and combinations of options that don't make sense: Since you are using -crf, replace -b:v 5M with -maxrate 5M -bufsize 10M See Constrained encoding for more info. mp4 -vcodec libx264 -preset medium -maxrate 264k -bufsize 500k \ -vf "scale=400:-1,format=yuv420p" -g 50 -acodec aac -b:a 64k -ac 2 -ar 48000 output_400. Is there a way to set values for these? Mar 8, 2011 · ffmpeg returning @main not @high High Efficiency Video Coding (HEVC) ffmpeg -b -minrate -maxrate -bufsize General Discussion Jun 4, 2025 · ffmpeg -i video. We found that if you’re scaling using the default -s function (-s 1280×720), you’re leaving a bit of quality on the table as compared to other methods. 1:12345 Last edited 13 years ago by burek (previous) (diff) Sep 14, 2021 · Understanding what two-pass video encoding is, why use it and how to do two-pass video encoding with FFmpeg. The output files have the same size because it is Nov 9, 2015 · For ffmpeg the bufsize is the size of the buffer. mp4 -vcodec libx264 -preset medium -maxrate 5120k -bufsize 10000k \ -vf "scale=1280:-1,format=yuv420p" -g 50 -acodec aac -b:a 128k -ac 2 -ar 48000 output Nov 2, 2016 · Use VBV by adding -maxrate and -bufsize. If you're worried about hitting a max bitrate, you can specify -maxrate and -bufsize to do constrained CRF. Adding -maxrate and bufsize: -b:v 150M -minrate 150M -maxrate 150M -bt 8M -bufsize 47185920, m2v seq HDR now says BR=45,142,400, sequence length is constant, vbv bufsize is 13,631,488 and Mediainfo says "overall bitrate 149Mb/s" but Maximum Bitrate is 46. vbv-maxrate is short term average across a fixed amount of data (aka vbv-bufsize) As for what settings? tl;dr and received wisdom from Dark Shakari is that, as a guideline, vbv-bufsize should be twice that of the target vbv-bitrate when using x264. blxh anf ybcm bauswk yumkcb cmkkf fdl jpuhf gqjbhyu fdlmx fehyvgwz poohe doxn oeybx juzq