I have an .mkv video file with ITA and ENG audio tracks. ITA is the main track and I need to select ENG to listen in English. Even with full volume, I couldn't understand it properly so I used the following FFMPEG command to double the sound
ffmpeg -i input.mkv -filter:a "volume=2.0" output.mkv
But in the output file, ENG audio track is missing and only ITA is available. I am trying to double the volume of the ENG audio track and won't mind if the ITA one goes missing. Can someone help me with right FFMPEG command ? Thanks
PS: I even tried ffmpeg -i input.mkv -filter:a:1 "volume=2.0" output-vol2x.mkv based on a friend's suggestion without luck.
Add -map 0 after your input file to allow all streams to output.
Related
Let's say I have an input .mp4 file that contains 4 audio tracks.
How can I change their volumes independently and convert it to a new file that just contains all the 4 audio tracks mixed together and stored in the first audio track? For example I want the first, second and third audio tracks from the input file to be double their original volume and the fourth to be half its original volume, all saved in the output files first audio track. How would that command look like?
Here you can find many good answers: How to overlay/downmix two audio files using ffmpeg
where the most comprehensive one links to https://trac.ffmpeg.org/wiki/AudioChannelManipulation
I recently had a similar use case: freely mixing 6 mono tracks of a multi-track recording to stereo output with different volumes on either or both output channels, which can be achieved like this:
ffmpeg -i 0.flac -i 1.flac -i 2.flac -i 3.flac -i 4.flac -i 5.flac \
-filter_complex [0:a][1:a][2:a][3:a][4:a][5:a]amerge=inputs=6,pan=stereo|c0=c0+1.2*c1+1.2*c2+1.3*c3+c4|c1=c0+1.3*c3+c4+0.8*c5[a] \
-map [a] output.flac
A bit of history. I am using Plex as my media server, but for reasons unknown, it has issues transcoding the DTS-HD MA 7.1 audio to EAC3 stereo and keeps buffering (the server has plenty of horsepower on all fronts, CPU/RAM/drive space & speed, gigabit networks connections for all devices. The playback device (TCL Roku TV, with a 3rd party soundbar connected via HDMI ARC) doesn't support the built-in 7.1 audio, so I get silence if I play it back directly by putting the file on a USB stick.
Also, I am by no means a ffmpeg guru, I figured out what I do know by Google University and asking questions, so please be kind and forgive me if I ask follow-up questions that may seem n00b-ish, and please provide example commands (preferably in the context of my command below so that I can have a known point of reference to start with).
I have a movie with 4K (HEVC Main 10 HDR) video and DTS-HD MA 7.1 audio that I am looking to leave the video and audio untouched, but to add a 2nd audio track in either EAC3 or if necessary, just AC3 in stereo
So what I am looking for is as follows:
video.mkv
Existing->4k video file (no change)
Existing->7.1 audio (no change)
Convert and add->stereo audio as a 2nd audio track to the output.mkv file
Below is the command I've historically used with ffmpeg to convert and replace the audio file with the stereo audio, but since I'd prefer to leave the 7.1 audio in place, this doesn't work:
ffmpeg -i "D:\video.mkv" -c:v copy -c:a aac -b:a 128k "D:\output.mkv"
And if this cannot be done as a single command, please also let me know what steps I do need to take to be able to do it.
Thanks in advace,
Mike
ffmpeg -i input.mkv -map 0 -map 0:a -c copy -c:a:1 eac3 output.mkv
-map 0 select all streams.
-map 0:a select all audio streams. This combines with -map 0 so now you have 1 video and 2 audio streams selected.
-c copy stream copy all streams.
-c:a:1 eac3 encode output audio stream #1 with eac3 encoder. This overrides -c copy for this particular stream.
I wish to "silence" the background noise in an audio, without removing the silence entirely - so as to keep the length of the audio constant. I am trying to use volume filter in ffmpeg like
ffmpeg -i input.flac -filter:a "volume='if(lt(volume,-8dB),0,1)':eval=frame" output.flac
but this seems to output the same file as input. I checked this by seeing the volumedetect output and it is identical for input.flac and output.flac.
I am new to ffmpeg so sorry if this is preliminary; quick help or pointers to relevant examples appreciated. Thanks!
I’ve got a bunch of stereo files recorded for a documentary with a Zoom in 4 channel mode. Basically it’s sets of pairs of stereo file s— file A would be a stereo file with a lav or boom mike recording, file B of identical length would be a proper stereo recorded by Zoom itself.
Now I’m trying to convert all this into something I can correctly ingest into editing suite. Files A are a mess but I came up with a ffmpeg script which downconvert them to mono then reconvert them back to stereo (to get rid of inconsistensies). Now how do I merge two stereo files into a single WAV or AIFF file containing two separate stereo channels? I browsed around for any workflows and/or standards on that but can’t really find anything useful.
Any ideas on how to do that with ffmpeg (or anything else, really) would be appreciated!
Don't know if FCP-X reads multi track WAVs but you can output to a multi-track MOV.
ffmpeg -i file1.wav -i file2.wav -c copy -map 0 -map 1 file.mov
I'm using ffmpeg to build a short hunk of video from a machine-generated png. This is working, but the video now needs to have a soundtrack (an [audio] field) for some of the other things I'm doing with it. I don't actually want any sound in the video, so: is there a way to get ffmpeg to simply set up an empty soundtrack property in the video, perhaps as part of the call that creates the video? I guess I could make an n-second long silent mp3 and bash it in, but is there a simpler / more direct way? Thanks!
Thanks to #Alvaro for the links; one of these worked after a bit of massaging. It does seem to be a two-step process: First make the soundtrack-less video and then do:
ffmpeg -ar 44100 -acodec pcm_s16le -f s16le -ac 2 -channel_layout 2.1
-i /dev/zero -i in.mp4 -vcodec copy -acodec libfaac -shortest out.mp4
The silence comes from /dev/zero and -shortest makes the process stop at the end of the video. Argument order is significant here; -shortest needs to be down near the output file spec.
This assumes that your ffmpeg installation has libfaac installed, which it might not. But, otherwise, this seems to be working.
I guess you need to create a media file properly with audio and video stream. As far as i know, there is not a direct way.
If you know your video duration, first create the dummy audio and after when you create the video try to join the audio part.
In superuser, you can find more info link1 link2