im using this command to change the video bitrate it works good , but it delays a lot ,
like 45 minutes - 1 hour for each video, is there other some way that is faster? ffmpeg -i 1.mkv -b 25500k -minrate 25500k -maxrate 25500k -bufsize 25500k outxd.mkv
Related
I tried various ways to make a live streaming script with a bit rate according to YouTube's recommendation of 4500 Kbps bit rate.
The code:
ffmpeg -re -stream_loop -1 -i live1.mp4 -c copy -preset veryfast -b:v 7000k -maxrate 3000k -bufsize 6000k -pix_fmt yuv420p -g 50 -c:a aac -b:a 160k -ac 2 -ar 44100 -f flv -flvflags no_duration_filesize rtmp://a.rtmp.youtube.com/live2/(streamkey)
and in my current code, there is an error when live: Use a keyframe frequency of four seconds or less. Currently, keyframes are sent infrequently which can cause buffering. The current keyframe frequency is 5.0 seconds. Please note that errors in the transfer process can cause the size of the GOP (group of images) to be incorrect.
How to fix my code?
I've tried several ways, but the bit rate is still high, and the error is in YouTube Studio
I recorded slo-mo video on an iPhone SE (2) by mistake instead of timelapse.
I know there's a lot of answers to this question here, but I'm trying again and again and always something's wrong (like a video that has a correct total no. of frames, but lasts 3 hours and is basically a freeze :D )
My recent command was
ffmpeg -i IMG_2174.MOV -vf framestep=1440,setpts=N/120/TB -c:v libx264
-preset slow -crf 22 -an -r 30 IMG_2174.timelapse.MOV
but it resulted in a one-second-long video, so way over-timelapsed. Should be several seconds IINM. The source video is 30 minutes long #240fps, 17GB.
Thx.
This command seems to do the trick:
ffmpeg -i IMG_2174.MOV -vf framestep=1440,setpts=N/30/TB -c:v libx264 -preset slow -crf 22 -an -r 30 IMG_2174.timelapse.MOV
Here is the explanation for OP's self-answer.
ffmpeg -i IMG_2174.MOV
-vf framestep=1440,setpts=N/30/TB
-r 30 -c:v libx264 -preset slow -crf 22 -an IMG_2174.timelapse.MOV
Given input video at 240 fps cfr:
framestep=1440 keep every 1440th frame, yielding 240/1440 = 1/6 fps
setpts=N/30/TB speeds up the video by x180 (30 / 1/6)
-r 30 output option: match the new pts interval set above
For a vfr video, framestep=1440 likely results in incorrect timing (though on the average correct). For such video, replace the framestep filter with fps=1/6 filter so it picks the frames based on pts rather than frame count.
[edit note: iPhone's slo-mo recording does keep 240fps cfr so the OP's solution is 100% correct, edited down just to mention a vfr-correct approach]
Currently I am using this...
ffmpeg -video_size 1920x1080 -framerate 1 -f x11grab -i :0.0+0,0 -f pulse -ac 2 -i default -t 00:00:10 Output.mkv
While ffmpeg is recording a video, I want it to significantly reduce both the size and quality compared to the ffmpeg command above.
In case you are curious, I am recording brief quality assurance videos to ensure a simple little web scraper I wrote in Python is scraping data properly (specifically, that it is clicking on a particular button, at a particular time, on a particular web page). My Python script triggers the command above to start recording my screen a few seconds before my Python script is supposed to click on that button.
Of course, to verify a button on a web page had been clicked on, low quality video resolution would normally suffice.
For libx264/libx265 the most important option to reduce both the size and quality is -crf. This option controls quality. A value of 51 provides the worst quality. If it's too terrible then use a lower number.
ffmpeg -video_size 1920x1080 -framerate 1 -f x11grab -i :0.0+0,0 -f pulse -channels 2 -i default -t 00:00:10 -c:v libx264 -crf 51 -c:a libopus Output.mkv
See FFmpeg Wiki: H.264.
For significantly reduce both the size and quality of Output.mkv you can use the next ffmpeg configuration:
crop: iw-(cut width in pixels):ih-(cut heigth in pixels)
scale: to set the ratio and resolution (example 1700x800)
crf: to set quality, where 0 is lossless, 23 is default, and 51 is worst possible. A lower value is a higher quality and a subjectively sane range is 18-28. Consider 18 to be visually lossless
bitrate value: -b:v value -minrate value and -maxrate max value (example -b:v 4000K -minrate 2000K -maxrate 6000K)
preset: in theory slow is best quality/size, and you can probe ultrafast
superfast
veryfast
faster
fast
medium – default preset
slow
slower
veryslow
Cut a part of video, changue the resolution, changue crf, and bitrate, first only video, then you can add audio in other work, dont mix, repeat, is very important, encoding/decoding audio and video separate, then you can mix all, but first the video like in this example
ffmpeg -i Output.mkv -map 0:v -vf crop=iw-150:ih-85,scale=ih*16/9:ih,scale=1072:732,setsar=1 -c:v libx264 -crf 17 -b:v 4000K -maxrate 6000K -bufsize 4M -movflags -faststart -preset veryfast -dn video-new.mkv
I am trying to make a reliable stream from my Icecast/Shoutcast servers to Youtube live. The command that I use is:
ffmpeg -v verbose -framerate 30 -loop 1 -i /var/image.jpg -re -i http://127.0.0.1:4700/radio -c:v libx264 -preset ultrafast -b:v 2250k -maxrate 6000k -bufsize 6000k -c:a copy -ab 128k -s 1920x1080 -framerate 30 -g 60 -keyint_min 60 -f flv rtmp://a.rtmp.youtube.com/live2/xxx
As you can see I am using recommended bitrate for Youtube, insert keyframes every 2 seconds and streaming at 30 frames per second.
The stream is working but after running for some time two thing are happening:
FFMPEG speed falls from 1x to something like 0.998x
Youtube starts complaining that video stream speed is slow, markes the quality as bad and sometimes video starts buffering.
Why is this happening? CPU load is normal, connectivity is ok (the stream is running on a 1Gg/s dedicated server).
Since in my example above I am streaming a single image as a logo of the stream I also tried to generate a short 30 seconds video with that image and broadcast that video instead of an image, but that did not help as well.
The command I used for conversion:
ffmpeg -framerate 30 -loop 1 -i /var/image.jpg -c:v libx264 -preset ultrafast -tune stillimage -b:v 2250k -minrate 2250k -maxrate 6000k -bufsize 6000k -framerate 30 -g 60 -keyint_min 60 -t 30 out4.mp4
And broadcast with
ffmpeg -stream_loop -1 -i out4.mp4 -re -i http://127.0.0.1:4700/radio -c:v copy -c:a copy -framerate 30 -g 60 -keyint_min 60 -f flv rtmp://a.rtmp.youtube.com/live2/xxx
ffmpeg version is 4.1.1
Are you sure that your original stream is really keeping up with the wall-clock?
Depending on how it's encoded there are possibilities that it gets heavily skewed. This ultimately leads to buffer under (or overruns if it's too fast) and the player complaining/skipping.
Can you try and dump several hours worth of stream to a file and then stream that with FFmpeg? If that works, then it's a strong indication that your original stream timing (sample rate) is off.
Getting the sample rate right is why professional/expensive sound cards use high precision Quartz-Crystal controlled oscillators. Purely virtual processing (e.g. files get encoded into a stream) can easily get skewed, especially inside virtual machines. Also, cheap USB sound cards are often among the worst offenders in terms of frequency accuracy and stability.
FFmpeg might have an option to deal with too slow input. Keywords could be 'padding' or 'missing samples'.
Youtube's error saying "...buffer....." is not a buffer issue on your PC, but simply data you are sending to youtube is too small.
1)note that [-preset ultrafast] and [-preset fast] does not make big difference.
2) change your ffmpeg comannd for broadcast one. like, [-b:v 2250k] to [-b:v 15000k],and set fps to 12→[-r 12] option.
I's gonna be.
ffmpeg -stream_loop -1 -i out4.mp4 -re -i http://127.0.0.1:4700/radio -preset fast -r 12 -framerate 30 -g 60 -video_track_timescale 1000 -b:v 15000k -f flv rtmp://a.rtmp.youtube.com/live2/xxx
I hope this will be good for you !!(^v^)Y
Using avconv (or even ffmpeg, so I can use as a reference), how can I create a time lapse video by taking only anchor/reference frames from another video? Most information I find is on how to create a time lapse video by combining images, and I'd like to do it by extracting frames from a video. Say, if a video is 30 seconds long at 30 FPS, I'd like to take 60 out of those 900 frames (900/60 = every 15 seconds) to produce a 2 second video.
To take every 15th frame, use
ffmpeg -i in.mp4 -vf select='not(mod(n,15))',setpts=N/FRAME_RATE/TB out.mp4
Another method is to use the framestep filter
ffmpeg -i in.mp4 -vf framestep=15,setpts=N/FRAME_RATE/TB out.mp4
I had a H264 video from a camera and after lots of attempts found following command that produce 16x faster video with good result and 60 FPS (option -r) that is good for the YouTube timelapse
ffmpeg -i video.avi -r 60 -filter:v "setpts=0.0625*PTS" -vcodec libx264 -an timelapse.avi
You can check the result here https://www.youtube.com/watch?v=azhRqKQ7kCU
Since you are asking for 1/15 frame it will be 1/15 ~= 0.06667 with 30 FPS result video you will need command
ffmpeg -i video.avi -r 30 -filter:v "setpts=0.06667*PTS" -vcodec libx264 -an timelapse.avi