In Flutter, How to use data in FFMPEG commands (input & output).
Like:
ffmpeg -i 1.mp3 -i 2.mp3 -i 3.mp3 -i 4.mp3 -filter_complex "[0:a][1:a][2:a][3:a]amerge=inputs=4[aout]" -map "[aout]" output.mp3
2 Question regarding this command:
What is the path to bring the '1.mp3', '2.mp3'... to the FFMPEG.
Where is the 'output.mp3' goes to? eventually?
Didn't find any solution, let's speak locally and after that remotely (API/SERVER).
What is the path to bring the '1.mp3', '2.mp3'... to the FFMPEG.
Your ffmpeg command in your question assumes 1.mp3 and 2.mp3 are in the current working directory that ffmpeg is being executed in.
For example, in Linux if the files are in /home/aix/music, then you would have to navigate to /home/aix/music in your terminal (such as by running cd /home/aix/music) before running the ffmpeg command shown in your question.
Or, provide the full path to the files and the current directory will not matter:
ffmpeg -i /home/aix/videos/1.mp4 -i /home/aix/videos/2.mp4 ...
Where is the 'output.mp3' goes to? eventually?
output.mp3 goes wherever you tell it to. Because no path was provided the ffmpeg command in your question it will output output.mp3 into the current directory.
Or, provide the full path to output output.mp3 in the desired directory:
ffmpeg -i input.mp3 /home/aix/music/encoded/output.mp3
I'm using FFMPEG to stream RMTP to a server. I wish to change what I'm streaming without breaking the connection to this server.
My current FFMPEG command looks like so:
ffmpeg -f v4l2 -s 1280x720 -r 10 -i /dev/video0 -c:v libx264 -f flv -r 30 -pix_fmt yuv420p "rtmp://server live=true pubUser=user pubPasswd=pass playpath=stream"
If I wanted to change from /dev/video0 to /dev/video1 then I need to stop this program and re-run the command swapping out the -i bit.
Since FFMPEG can read from stdin as well as files, I believe it should be possible to switch the input source on the fly by either piping the output of a different program, or utilizing UNIX sockets. There may also be a solution built into FFMPEG which I'm not aware of.
My question now is: what's the simplest / least code / most recommended way of switching these inputs? Is there a third-party tool that's recommended? Does FFMPEG have an alternate command-line parameter I've never heard of? If I do use a UNIX socket of stdin, is there a recommended way to change what's being written to them?
One of my concerns is that if I have FFMPEG read in from a UNIX socket and in a separate shell I have a different instance of FFMPEG writing to this UNIX socket, during the brief period when I'm switching sources the first instance of FFMPEG (which is doing the broadcasting) would die, as it couldn't find any video data to stream.
I am trying to stream image to fb live video using this command :
ffmpeg -loop 1 -re -i "input.jpg" -pix_fmt yuv420p -profile:v baseline -s 720x480 -bufsize 6000k -vb 400k -maxrate 1500k -deinterlace -t 60 -vcodec libx264 -preset veryfast -g 30 -r 30 -f flv "rtmp_link"
This command works perfectly for one single input file. But the problem is that I want ffmpeg to stream the latest and updated version of "input.jpg" file because my app is updating this "input.jpg" after every 2-3 seconds but the image that is streamed is the older version, not the updated one.
If I try to restart this loop, then streaming stops for approx. 4-5 seconds which is sufficient enough for FB live video to consider that streaming has been stopped and it then ends the live video.
So, is it possible to use the latest available version of input file for streaming in this loop? I don't know much about FFMPEG and I tried to search this issue but all in vain.
I have finally figured out a solution for this. When I was directly overwriting ‘input.jpg’ file using my rails app, this process was taking a few miliseconds but during this time too, ffmpeg was streaming this file which was incomplete for few miliseconds.
So, the solution for this issue is that first write the updated image to a temp file like ‘input.tmp.img’ and then move this file to the original file using script or using terminal like
mv input.tmp.img input.jpg
As moving process hardly takes any time, this solved the problem for me.
I tried '-N' and '--no-clobber' but the only result that I get is to retrieve a new copy of the existing example.exe with number a number added using this synax 'example.exe.1'. This is not what I'd like to get. I just need to download and overwrite the file example.exe in the same folder where I already saved a copy of example.com without that wget verifies if the mine is older or newer respect the on example.exe file already present in my download folder. Do you think is i possible or I need to create a script that delete the example.exe file or maybe something that change his modification date etc?
If you specify the output file using the -O option it will overwrite any existing file.
For example:
wget -O index.html bbc.co.uk
Run multiple times will keep over-writting index.html.
wget doesn't let you overwrite an existing file unless you explicitly name the output file on the command line with option -O.
I'm a bit lazy and I don't want to type the output file name on the command line when it is already known from the downloaded file. Therefore, I use curl like this:
curl -O http://ftp.vim.org/vim/runtime/spell/fr.utf-8.spl
Be careful when downloading files like this from unsafe sites. The above command will write a file named as the connected web site wishes to name it (inside the current directory though). The final name may be hidden through redirections and php scripts or be obfuscated in the URL. You might end up overwriting a file you don't want to overwrite.
And if you ever find a file named ls or any other enticing name in the current directory after using curl that way, refrain from executing the downloaded file. It may be a trojan downloaded from a rogue or corrupted web site!
wget --backups=1 google.com
renames original file with .1 suffix and writes new file to the intended filename.
Not exactly what was requested, but could be handy in some cases.
-c or --continue
From the manual:
If you use ‘-c’ on a non-empty file, and the server does not support
continued downloading, Wget will restart the download from scratch and
overwrite the existing file entirely.
I like the -c option. I started with the man page then the web but I've searched for this several times. Like if you're relaying a webcam so the image needs to always be named image.jpg. Seems like it should be more clear in the man page.
I've been using this for a couple years to download things in the background, sometimes combined with "limit-rate = " in my wgetrc file
while true
do
wget -c -i url.txt && break
echo "Restarting wget"
sleep 2
done
Make a little file called url.txt and paste the file's URL into it. Set this script up in your path or maybe as an alias and run it. It keeps retrying the download until there's no error. Sometimes at the end it gets into a loop displaying
416 Requested Range Not Satisfiable
The file is already fully retrieved; nothing to do.
but that's harmless, just ctrl-c it. I think it's always gotten the file I wanted even if wget runs out of retries or the connection temporarily goes away. I've downloaded things for days at a time with it. A CD image on dialup, yes, always with wget.
My use case involves two different URLs, sometimes the second one doesn't exist, but if it DOES exist, I want it to overwrite the first file.
The problem of using wget -O is that, when the second file DOESN'T exist, it will overwrite the first file with a BLANK file.
So the only way I could find is with an if statement:
--spider checks if a file exists, and returns 0 if it does
--quiet fail quietly, with no output
-nv is quiet, but still reports errors
wget -nv https://example.com/files/file01.png -O file01.png
# quietly check if a different version exists
wget --quiet --spider https://example.com/custom-files/file01.png
if [ $? -eq 0 ] ; then
# A different version exists, so download and overwrite the first
wget -nv https://example.com/custom-files/file01.png -O file01.png
fi
It's verbose, but I found it necessary. I hope this is helpful for someone.
Here is an easy way to get it done with parameter trimming
url=https://example.com/example.exe ; wget -nv $url -O ${url##*/}
Or you can use basename
url=https://example.com/example.exe ; wget -nv $url -O $( basename $url )
For those who do not want to use -O and want to specify the output directory only, the following command can be used.
wget \
--directory-prefix "$dest" \
--backups 0 \
-- "$link"
the first command will download from the source with the wget command
the second command will remove the older file
wget \
--directory-prefix "$dest" \
--backups 0 \
-- "$link"; \
rm '$file.1' -f;
I am trying to copy several segments of one video file to a single output video file
I can do it for one segment only by using the following code:
avconv -i input.flv -ss 00:04:50 -t 00:04:00 -codec copy outputfile.flv
Is there any way to do it with several segments?