When ffmpeg is given a command to output a file with a particular extension it presumably runs an internal algorithm do determine what encoder and/or muxer to use with it. Is there a command to find out whether a particular output extension is supported or not? Like in imagemagick with a command magick identify -list format?
ffmpeg -h muxer=mp4 does not work with image formats like jpg and png even though ffmpeg is capable of outputting images of these formats.
ffmpeg -formats does not seem reliable enough as well as instead of jpg it has singlejpg and does not include png (only apng and png_pipe).
Related
I'm using framemd5 to check lossless transcoding to FFV1.mkv and am getting mismatches between my source and FFV1 files.
If I generate the framemd5 files in Windows, I get presentation timestamp mismatches on the audio between the source file and FFV1. The MD5s themselves match.
If I generate the framemd5 files for the FFV1 in Linux (WSL), everything matches just fine.
Is there something I am doing wrong, or is this just a quirk of the ffmpeg/FFV1/Windows combination?
I am using ffmpeg version 2022-07-14-git-882aac99d2-full_build-www.gyan.dev in Windows and
ffmpeg version 4.4.2-0ubuntu1~20.04.sav2 in WSL.
Many thanks!
Jim
I'm trying to grab content from http://tv.nrk.no and the content is downloaded as *.flv. But VLC cannot play that file, no errors or other information.
I have tried to reinstall ffmpeg with additional codes: brew reinstall ffmpeg --with-libvpx and convert the flv file to mp4. But getting error *.flv: could not find codec parameters.
So how can I either download in another format? Or convert the file to mkv/mp4?
I cannot download the content, so I can't try the input video from http://tv.nrk.no
And, what is your command line? Can you post it?
It seems that you don't have some codec.
Maybe you can download ffmpeg-static to transcode the video.
I have an mp4 which I want to convert from color to black and white using the terminal.
How?
EDIT: My question is NOT a duplicate because I want to do this with an mp4 (video, not image).
If you install ffmpeg (cross-platform video converter), you can do it with a one line command by filtering the saturation to 0.
ffmpeg -i <inputfile> -vf hue=s=0 -acodec copy <outputfile>
Maybe overkill but GStreamer could probably achieve that. It's mainly for streaming media but you can use it to manipulate local files also.
https://gstreamer.freedesktop.org/
It can either be executed as a command taking your mp4 as argument along with a long series of other arguments directly from the terminal or the framework can be imported in a project. Takes some time to get the hang of it tho and it's probably an easier way.
I found this screenshot which shows that you can add a cover image to an mkv file in a way that it is displayed as the icon of the file in the Windows explorer using Shark007+icaros.
But these tools are messing with the system in a really bad way. A lot of people are having problems with it and I too very much regret that I've installed it. I'm really glad I got my Windows to boot again...
Anyway, how could I programmatically add a cover image to an mkv file?
And would I need to change something in the registry to make Windows display them?
I'm not neccessarely looking for code, I'm more looking for something like the format the cover needs to have and the byte at which I have to inject/insert/attach the image file and maybe a registry entry that would cause the tagged images to be displayed etc.
You can use the FFmpeg multimedia framework to attach an image as MKV metadata. More Windows builds can be found at Zeranoe.
Example CLI usage:
ffmpeg -i input.mkv -c copy -attach image.jpg -metadata:s:t \
mimetype=image/jpeg output.mkv
-c copy copy all streams in the source file without re-encoding
-attach image.jpg attach a JPEG image
-metadata:s:t mimetype=image/jpeg set the attachement MIME type
On *nix the same can be accomplished with MKVToolNix.
Ubuntu demo:
Programmatic approach:
use the ffmpeg C libraries to attach or replace the cover art
write a custom Shell Extension to read the MKV format and display the image attachement as thumbnail.
When trying to convert a .swf file to .flv in ffmpeg, I get this error. Is there any way to decompress or bypass this error in ffmpeg, or is there any other command line video conversion tool that can do this conversion for me with a compressed .swf?
Yes, there are conversion tools, and one comes with ffmpeg actually. It's called cws2fws. You can find the source file at "ffmpeg_root/tools/cws2fws.c". I'm not sure if you need to pass additional options to your ./configure script to make it compile.