FFMPEG: only get audio compressed frames / packets. command line - command-line

I would like a command like for FFMPEG that will create a file which contains only uncompressed audio frames/packets from a file.
Example:
ffmpeg -i in.mp3 --no-decompress out
Something like this would be fantastic.

Related

Powershell ffmpeg

I am successfully u sing ffmpeg via powershell to compress video files, however I can't get the compression to occur in a single location, I only have success when I make separate inputs and outputs.
For example, this command will be successful:
ffmpeg -y -i \\path\$x -vf scale=1920:1080 \\diff_path\$x
this will not do anyhting or will corrupt the file:
ffmpeg -y -i \\path\$x -vf scale=1920:1080 \\path\$x
I think I understand why this doesn't work, but I'm having a hard time finding a solution. I want the script to address a file and compress it in it's current location, leaving only a single compressed video file.
Thanks all
Not possible. Not the answer you want, but FFmpeg is not able to perform in-place file editing, which means it has to make a new output file.

ffmpeg concat command not reading input file correctly

I am trying to concatenate two video files using ffmpeg, and I am receiving an error.
ffmpeg -f concat -safe 0 -i list.txt -c copy concat.mp4
And the error output I receive is....
[concat # 0x7ff922000000] Line 1: unknown keyword '43.mp4'
list.txt: Invalid data found when processing input
It looks like that the file names in the list have to be specially formatted to look like:
file '/path/to/file1.wav'
with a word file included. I spent a lot of time trying to guess why ffmpeg encountered an error trying to read the file names. It didn't matter if they were in the list or in the command line. So only after I utilized a command
for f in *.wav; do echo "file '$f'" >> mylist.txt; done
to make list from ffmpeg's manual I had success. The only difference was an additional word file.
Here you can read it yourself: https://trac.ffmpeg.org/wiki/Concatenate#demuxer

How to output the grabbed video into a file with mplayer?

The mplayer command can grab video when to insert usb-camera into usb slot.
mplayer -tv driver=v4l2:width=352:height=288:device=/dev/video0 tv://
The video grabed by usb-camera can be displayed on the screen,
how to output the grabbed vedio into a file with mplayer?
mplayer -tv driver=v4l2:width=352:height=288:device=/dev/video0 tv://home/test.mp4
The command can't grab video into /home/test.mp4.
Try the dumpstream option
https://www.mplayerhq.hu/DOCS/HTML/en/streaming.html
mplayer -tv driver=v4l2:width=352:height=288:device=/dev/video0 -dumpstream -dumpfile test.mp4 tv://
On my install I've sometimes had issues with mp4, so it may be worth trying a different file extension or two to see if it finds a better encoding.

How to programmatically concatenate two aac files

Does any one know how concatenate two aac audio files into one. I can do this with mp3 using ffmpeg but no luck with files with an m4a extension.
I tried the following with no luck:ffmpeg -i concat:"file1.m4a\|file2.m4a" -c copy output.m4a'
Just use cat:
cat file1.m4a file2.m4a >output.m4a

ffmpeg command line tool remove all metadata information after converting a file codec

I am converting abc.flac file to abc.mp3 using ffmpeg command line tool. But when abc.mp3 is created all metadata information get clear like artist name , album name etc. all field get empty.
i am using this command
ffmpeg -i "abc.flac" -acodec mp3 -ab 256 "abc.mp3"
this give me abc.mp3 i also try -map_metadata tag but it is not working
Have you any idea about this
Thanks in advance.