Good day,
I'm currently writing a bash script which records the screen under certain conditions. The problem is that only avi works as a file extension for recording the screen. This script is going to be used on an Raspberry Pi and currently I get on a decent virtual machine only 10-20 fps (goal would be around 30 fps). I think .avi is not suited for my project. But .mpeg and .mp4 are not working for recording. I tried recording with .avi and then converting it in .mp4, but I have limited memory and .avi ist just too big in size. I use currently the following command:
ffmpeg -f x11grab -y -r 30 -s 960x750 -i :0.0+0,100 -vcodec huffyuv ./Videos/out_$now.avi
//$now is the current date and time
So I wanted to know if I need some special packages from ffmpeg to record with for example .mp4 or if there are other file formats available for ffmpeg screen recording.
Edit:
I found that the codec libx264 for mp4 works, but the fps drop until they hit5 fps, which is definetly too low. The recorded video appeared like being a fast forward version of the recorded screen.
With mpeg4 for mpeg I reached over 30 fps, but the video qualitywas very bad.
It appears that even my big avi-files look like being played fast forward. Is there something I do wrong?
Is there a good middle way, where I get a decend video quality, good fps (20+) and a file which isn't too big?
Edit 2:
I tried recording it with .avi and converting it afterwards. Just converting with ffmpeg -i test.avi -c:a aac -b:a 128k -c:v libx264 -crf 23 output.mp4
resulted in the same framedrops as if I was recording with .mp4. But when I cut a littlebit of the beginning of the video and named the outputfile .mp4, the size became much smaller. But when I started the cutting at 0:00:00 (so tried just converting), it just changed the file format without converting it (so the size stayed the same). Any ideas?
Related
I'm trying to serve a large video of timelapses generated from a series of images.
Using FFmpeg I have encoded the video as an h264 mp4.
ffmpeg -framerate 24 -i "/app/download/%d.jpeg" -c:v libx264 -crf 23 -preset fast -tune animation -report -vf "format=yuv420p" -y /app/output.mp4
I'm running into compatibility issues where the videos are not playable on iOS (safari) as well as on Windows (all browsers except chrome). Where I'm getting the following error:
Error Code: NS_ERROR_DOM_MEDIA_FATAL_ERR (0x806e0005) Details: mozilla::MediaResult __cdecl mozilla::WMFVideoMFTManager::ValidateVideoInfo(void): Can't decode H.264 stream because its resolution is out of the maximum limitation
See the full FFmpeg log here: https://pastebin.com/QUEPh3q2
I'm just looking for some resource or knowledge of how to encode my media for maximum compatibility while still preserving high quality and resolution.
Problem:
Which options I should be using in FFmpeg to maximize compatibility?
From comments: "My videos are maximally of size 4056x3040 or 3040x4056".
I don't have Apple device(s) but you might be hitting some image size limitation on Windows.
Firefox uses the built-in Windows H264 decoder where the maximum height is 2304.
Replace the old command:
ffmpeg -framerate 24 -i "/app/download/%d.jpeg" -c:v libx264 -crf 23 -preset fast -tune animation -report -vf "format=yuv420p" -y /app/output.mp4
With this new one:
ffmpeg -framerate 24 -i "/app/download/%d.jpeg" -vf scale=3069:2300,setsar=1:1 -c:v libx264 -pix_fmt yuv420p -profile:v high -crf 23 -preset fast -movflags +faststart -report -y /app/output.mp4
The above command changes the size to 3069x2300 (within Windows resolution limits) but I recommend a smaller size like 1441x1080 for maximum device / O.S / browser compatibility.
I would leave out -tune animation, add it back if its removal affects your specific image quality.
Now added is +faststart which allows the MP4 header to be at front of file (usually is placed last at back) meaning playback can begin without first downloading all videos just to reach header data (which has the decoder settings needed to begin playback).
I think your bigger issue will be trying to send 4056x3040 video over mobile networks. You're going to have lots of stalling and poor playback over many types of connections that cannot support the bandwidth you'll need. Nor does a mobile device have a big enough screen to actually playback the video dimensions you would be sending.
I'd suggest you look at HLS streaming - and adaptive bitrates. That way, you can create your huge version, a 1080p version, a 720p version (etc.) the video player will deliver the correctly sized video to the device - no wasted data/pixels, fewer stalls, and it still looks great.
I used a number of jpeg files to create a timelapse video with ffmpeg. Individually they are visually ok.
These source images are captured by a mirrorless DSL camera in JPEG format.
If I upload the timelapsevideo to youtube, the video is clear and without any artifact: https://www.youtube.com/watch?v=Qs-1ahCrb0Y
However if I play the video file locally on MacOS in Photo or Quicktime apps or in iOS, there are artifacts in the video. Here are some of the examples:
1.
2.
This is the ffmpeg command I used to generate the video:
ffmpeg -framerate 30 -pattern_type glob -i "DSCF*.JPG" -pix_fmt yuv420p -profile baseline output.mp4
What additional parameter I can use to remove those artifacts?
Edit:
File info
The video plays without issue in VLC.
The H.264 codec standard defines levels. The level represents the resources required by a decoder to smoothly process a stream. Usually, levels are only pertinent for hardware players. However, some software players may have been designed with a level ceiling. Apparently, that's the case with Apple's players.
Your video's frame size is 6000x4000 for which the player has to support level 6.0, which is a recent addition to the standard (~2 years). I suggest you halve the resolution,
ffmpeg -framerate 30 -pattern_type glob -i "DSCF*.JPG" -vf scale=iw/2:ih/2,format=yuv420p -profile baseline out.mp4
I created several MP4 files using ffmpeg. All of the videos have same settings and codec. Only difference is frames per second and duration. I then concatenated the videos using command below.
ffmpeg -f concat myList.txt -c copy output.mp4
I notice that when launching/opening the output.mp4 file in windows media player, it stops/freezes on the first frame of the video for about three four seconds and then starts playing, rest of the videos has correct fps and runs smoothly. Has anyone encountered this issue. I would like the video to start as soon as it is launched. Any suggestions to mitigate this issue?
Update: So far, I have found that the video length is exactly what I expect it to be.
ffprobe -i output.mp4
When i ffplay the video, it runs smoothly, but when I use windows media player, it gets stuck in first frame for about 4-5 seconds then plays smoothly. So I am going to assume that this issue is related to media players (buffers/loading before playing). Can't be sure though.
I solved this problem by converting my input files to avi and resizing them to the same size.
And then run
ffmpeg -i "concat:file1.avi|file2.avi|" -c copy out.avi
So I have a Raspberry Pi app that records output from the on-board camera. These files are recorded as H264. After a user presses a button I want to display a portion of that video with OMXPlayer. OMXPlayer always needs an MP4 container ( it always ignores FPS ).
I don't want to wrap the entire H264 into an MP4 as that takes too much time.
My solution would be trim the last 30 seconds and place into MP4 container. Can I do this in one step without copying the entire content of the H264 into the MP4 first?
I don't want to re-encode this and I'm looking for the fastest operation possible.
This will be fast, just do a stream copy of the file to an mp4 container.
ffmpeg -i INPUTFILE -sseof 30 -c:v copy -c:a copy -pix_fmt yuv420p out.mp4
I would like to transcode video stream using ffmpeg tool and change only the video stream resolution, i.e. the video and audio parameters should remain the same.
According to the man page of the ffmpeg the following command line should provide the desired result:
ffmpeg -i input.mp4 -vcodec copy -acodec copy -s WxH output.avi
The Video codec of the input stream is compatible with avi container.
The actual result is that the resolution remains unchanged and it seems that the stream is just repacked in avi container.
The resolution of the output stream is changed successfully without -vcodec copy option, but the video codec is changed: h264 (Constrained Baseline) - > mpeg4 (Simple Profile).
When you copy a video stream, you cannot change any of its paramters, since… well, you're copying it. ffmpeg won't touch it in any way, so it can't change the dimensions, frame rate, et cetera.
Also, ffmpeg always chooses a default video codec if you don't specify one. For AVI files, that's mpeg4.
If you want H.264 video, choose -c:v libx264 instead (or -vcodec libx264 which is the same). If you need to keep the original profile, use -profile:v baseline.
Two things:
When you change the size, you will recode the video. This lowers the quality and might considerably harm the video. To compensate for this, you might need to set a higher quality level. You do this by setting the Constant Rate Factor to anything below the default of 23, e.g. with -crf 20. Experiment and see how your video looks like. If you have the time, add the -preset slow (or slower, veryslow), which will give you better compression.
Not that it matters in your case, since your input uses the Constrained Baseline profile, but note that H.264 in AVI is not properly supported, at least when using B pictures. Baseline doesn't support B pictures though, so you should be fine. It could happen that file can't be played back on some devices or players if you use the Main profile or anything above. I would rather mux it into an MP4 or MKV container, especially if your input file is MP4 anyway.