What I did:
# create source material
ffmpeg -y -i some.file -c:a libfdk_aac -profile:a aac_he -b:a 128k -ar 44100 source.m4a
# split into two parts
ffmpeg -y -ss 00:00:00 -i source.m4a -to 6 -c copy part1.m4a
ffmpeg -y -ss 00:00:06 -i source.m4a -c copy part2.m4a
# re-encode only the first part with the same setting as source file
fmpeg -y -i part1.m4a -c:a libfdk_aac -profile:a aac_he -b:a 128k -ar 44100 part1reencoded.m4a
# create file list to be concatenated
echo 'ffconcat version 1.0
file part1reencoded.m4a
file part2.m4a' > my.list
# finally concatenate both parts
ffmpeg -y -f concat -safe 0 -i my.list -c copy parts.m4a
# play the result
ffplay parts.m4a
Unfortunately, the result file has noises at 00:00:06.
Is it possible to split frame accurate an AAC file using FFmpeg?
You can split frame accurately, at 44100, every frame is 23 milliseconds.
What you can’t do is concatenate aac from different encodes.
Related
I want to attach/append an image (something like youtube) to first frame of the video, i tried this command :
ffmpeg -i video.mp4 -i image.png -map 1 -map 0 -c copy -disposition:0 attached_pic out.mp4
But it doesnt working, the first frame is not my custom image
my ffmpeg version:
ffmpeg version n4.4-80-gbf87bdd3f6-20210830 Copyright (c) 2000-2021 the FFmpeg developers
You will have to concatenate a frame to the beginning.
Re-encode audio in video.mp4. The audio is HE-AACv2, but you don't have a HE-AACv2 encoder. So it has to be changed to the more common AAC-LC to allow concatenation with the video generated from the image.
ffmpeg -i video.mp4 -c:v copy -c:a aac main.mp4
Make a video from image.png with silent filler audio. It has to have the same attributes as main.mp4.
ffmpeg -loop 1 -framerate 30 -i image.png -f lavfi -i anullsrc=r=48000 -frames:v 2 -c:v libx264 -vf format=yuv420p -video_track_timescale 30k -c:a aac image.mp4
-frames:v 2 is used instead of -frames:v 1 as required for the audio.
Make input.txt containing:
file 'image.mp4'
file 'main.mp4'
Concatenate:
ffmpeg -f concat -i input.txt -c copy output.mp4
ffmpeg -ss 00:11:47.970 -t 3.090 -i "file.mkv" -ss 00:11:46.470 -t 1.500 -i "file" -ss 00:11:51.060 -t 0.960 -i "file.mkv" -an -c:v libvpx -crf 31 -b:v 10000k -y -filter_complex "[0:v:0][0:a:0][1:v:0][1:a:0][2:v:0][2:a:0]concat=n=3:v=1:a=1[outv][outa];[outv]scale='min(960,iw)':-1[outv];[outv]subtitles='file.srt'[outv]" -map [outv] file_out.webm -map [outa] file.mp3
I have a filter where take three different points in a file concat them together and scale them down this part works
Im looking to see how to add to the filter_complex a sub burn in step rendering the subs from the exact timings usings a file that I specify when I use the above code it doesn't work
The subtitles filter is receiving a concatenated stream. It does not contain the timestamps from the original segments. So the subtitles filter starts from the beginning. I'm assuming this is the problem when you said, "it doesn't work".
The simple method to solve this is to make temporary files then concatenate them.
Output segments
ffmpeg -ss 00:11:47.970 -t 3.090 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp1.webm
ffmpeg -ss 00:11:46.470 -t 1.500 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp2.webm
ffmpeg -ss 00:11:51.060 -t 0.960 -copyts -i "file.mkv" -filter_complex "scale='min(960,iw)':-1,subtitles='file.srt',setpts=PTS-STARTPTS;asetpts=PTS-STARTPTS" -crf 31 -b:v 10000k temp3.webm
The timestamps are reset when fast seek is used (-ss before -i). -copytswill preserve the timestamps so the subtitles filter knows where to start the subtitles.
Make input.txt:
file 'temp1.webm'
file 'temp2.webm'
file 'temp3.webm'
Concatenate with the concat demuxer:
ffmpeg -f concat -i input.txt -c copy output.webm
-c copy enables stream copy mode so it avoids re-encoding to concatenate.
I'm using ffmpeg to cut and covert a part of a long video but when using the "-to" option ffmpeg keeps encoding till the end of the video and wont stop.
Here's my command:
ffmpeg -ss 00:22:59 -i input.mkv -to 00:23:15.5 -c:v libx264 -c:a aac output.mp4
if i change to "-t" and enter my desired duration, problem goes away. but since i have a very long video and many tasks i need to use "-to" which is easier for me.
Thanks in advance.
Basically, -ss when used as an input option, seeks to the given time and resets timestamps, so that the first selected frame has timestamp 0. So, in your command, t and to will have the same effect.
You have to either use
ffmpeg -ss 00:22:59 -copyts -i input.mkv -to 00:23:15.5 -c:v libx264 -c:a aac output.mp4
(not recommended)
or
ffmpeg -ss 00:22:59 -to 00:23:15.5 -i input.mkv -c:v libx264 -c:a aac output.mp4
(needs ffmpeg build > Nov 19 2017)
or
ffmpeg -i input.mkv -ss 00:22:59 -to 00:23:15.5 -c:v libx264 -c:a aac output.mp4
(slowest of the three)
I use ffmpeg to make video from audio/image to mp4.
I want merge/concatenate two mp4 video.
I have this to make mp4 video:
ffmpeg -i "background.png" -i "audio.mp3" -y -r 30 -b 2500k -acodec ac3 -ab 384k -vcodec mpeg4 "result.mp4"
This, it works!
To concatenate two mp4 video, I must pass by ts files.
ffmpeg -i "result.mp4" -codec copy -bsf:v hevc_mp4toannexb intermediate1.ts
But, I have this error:
I'm looking for a way to add an audio watermark, on specific time, to a video file (with existing audio) . something like: ffmpeg -i mainAVfile.mov -i audioWM.wav -filter_complex "[0:a][1:a] amix=inputs=2:enable='between(t,9,10)' [aud]; [0:v][aud]" -c:v libx264 -vf "scale=1280:720:sws_dither=ed:flags=lanczos, setdar=16:9" -c:a libfdk_aac -ac 2 -ab 96k -ar 48000 -af "aformat=channel_layouts=stereo, aresample=async=1000" -threads 0 -y output.mp4
The above command gives me this error Timeline ('enable' option) not supported with filter 'amix'. amerge didn't work as well. I kind of get lost with filter_complex syntax, specifically with the following conditions
On the main AV file, both audio and video tracks are filtered
Watermark should be between the 9th and 10th second (I already
generated a 1 second, 10k tone file)
The watermark need to survive the proceeding audio transcode
Use
ffmpeg -i mainAVfile.mov -i audioWM.wav
-filter_complex
"[0:a]aformat=channel_layouts=stereo,aresample=async=1000[main];
[1:a]atrim=0:1,adelay=9000|9000[wm];[main][wm]amix=inputs=2"
-vf "scale=1280:720:sws_dither=ed:flags=lanczos,setdar=16:9" -c:v libx264
-c:a libfdk_aac -ac 2 -ar 48000 -b:a 96k
-threads 0 -y output.mp4
It's preferable to perform all filtering in a single filtergraph. But I've kept the video filter as-is.