I am investigating a possibility to store video streams which are coming from few sources already coded in h264 without video transcoding as the device I would like to use for this project won't be capable of transcoding combined video on the fly.
What I am looking for is two or more pictures side to side (not video concatenation) packed into mp4/avi/mkv.
I believe mkv container supports such kind of packaging but I've not been able to find appropriate options for ffmpeg or other tool to store it this way. What it does is very slow video transcoding into one big h264 stream.
If your player can handle it just make it perform the side-by-side view. No encoding or muxing required.
mpv video player
Example using mpv:
mpv --lavfi-complex="[vid1][vid2]hstack[vo];[aid1][aid2]amix[ao]" input1.mp4 --external-file=input2.mp4
The above example assumes each input has the same height. Otherwise you will have to add the scale, scale2ref, pad, and/or crop filters. Simple example using the crop filter to remove 20 pixels from the height:
mpv --lavfi-complex="[vid1]crop=iw:ih-20[c];[c][vid2]hstack[vo];[aid1][aid2]amix[ao]" input1.mp4 --external-file=input2.mp4
See the mpv documentation and FFmpeg Filters for more info.
Just specify multiple inputs.
ffmpeg -i [input 1] -i [input 2] ... -map 0 -map 1 ... -codec copy -f matroska [output]
As for the "side-to-side" part, it's up to the player to determine the presentation. If you don't control the player and you need a specific layout or presentation, then you must "burn" all these video streams into a new one and encode it as a new single stream.
Related
I have two problems with FFmpeg, when I use it to join DNG files sequence into mp4 video file. I also need to downgrade the resolution of the video from 6016x3200 to 2030x1080.
First of all I got almost black screen in the resulting video. Had to play with gamma and brightness options. But it was not enough!
New problems:
something strange happens with aspect ratio in resulting video file: in the first frame aspect is normal, just like in the original picture, but all the rest frames are getting squeezed. can't figure out why this happen!? (see picture attached).
colors are desaturated. despite the fact that I set "saturation" option to the maximum value. and also, the first frame of the video is different from the rest (while DNG files are all similar, first is no exception)
I tried prores codec as well, with the same result.
command I use is simple:
ffmpeg.exe -start_number 1 -i "K:\video\copter_R%5d.dng" -c:v libx264 -vf "fps=25,format=yuv420p, eq=gamma=3.2:brightness=0.2:contrast=1.6:saturation=3, scale=w=2030:h=1080" e:\output.mp4
I tried to use different variants of scale parameter: "scale=-1:1080" as well.
Illustration:
UPDATE: ffmpeg log report for operation:
https://drive.google.com/file/d/1H6bdpU0Eo4WfR3h-SRtgf7WBNYVFRwz2/view?usp=sharing
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
Source video is H264 in an mp4 container, I'm trying to split it into individual encoded frames. I tried with the following command line:
ffmpeg -i "input.mp4" -f image2 "%d.h264"
But that creates jpegs with the extension "h264", rather than actual H.264 frames.
It turns out the correct command line is:
ffmpeg -i "inputfile" -f image2 -vcodec copy -bsf h264_mp4toannexb "%d.h264"
There is no such thing as an "h264" image. H264 is a standard for video compression, and contains many different iterations, profiles, and also proprietary implementations of h264 encoders and decoders.
If you are trying to convert an avi video into an image sequence, you will need to determine what image format you want the exports to be. If you don't want to re-encode the media, you can use the -f image2 argument to specify an uncompressed image format. You can then save the outputs into something like a bmp, png, or tiff container. Alternatively, you can compress the images into something like a .jpg container (which perhaps FFmpeg defaulted to in your original command because you didn't tell it an image container that it understood).
.... edit: If for some reason you are trying to create a sequence of video files that only contain one frame each, it doesn't make any sense to compress them with h264. H264 is a temporally based encoding method and would require more than one frame. You could I guess make a sequence of uncompressed video files that only contain one frame each, but I can't imagine what the purpose for that would be when images would accomplish the same thing
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.
I'm attempting to write a script that will merge 2 separate video files into 1 wider one, in which both videos play back simultaneously. I have it mostly figured out, but when I view the final output, the video that I'm overlaying is extremely slow.
Here's what I'm doing:
Expand the left video to the final video dimensions
ffmpeg -i left.avi -vf "pad=640:240:0:0:black" left_wide.avi
Overlay the right video on top of the left one
ffmpeg -i left_wide.avi -vf "movie=right.avi [mv]; [in][mv] overlay=320:0" combined_video.avi
In the resulting video, the playback on the right video is about half the speed of the left video. Any idea how I can get these files to sync up?
Like the user 65Fbef05 said, the both videos must have the same framerate
use -f framerate and framerate must be the same in both videos.
To find the framerate use:
ffmpeg -i video1
ffmpeg -i video2
and look for the line which contains "Stream #0.0: Video:"
on that line you'll find the fps in movie.
Also I don't know what problems you'll encounter by mixing 2 audio tracks.
From my part I will try to use the audio from the movie which will be overlayed
over and discard the rest.