Use MEDIAINFO to examine video files indepth (f.e. find out whether the FPS is constant)
=====================
Ratio-Calc_(for_rolling): E:\Dropbox\Public\Texte + Bilder\Computer Tipps & Tricks\Excel\Ratio_Calc_KKV_GGT.ods
Rolling image calc/screen aspect ratio: 
         *http://andrew.hedges.name/experiments/aspect_ratio/
          *http://www.umrechnung.org/mathematik-kgv-ggt-berechnen/gemeinsames-vielfaches-teiler.htm
Convert Subitle (multi via zip): https://lab.sorz.org/tools/asstosrt/
Loop-video-x-times: https://www.media.io/de/loop-video.html
Merge/Combine video: https://www.media.io/merge-video.html
https://online-video-cutter.com/de/
=============
DLD_FFMPEG: https://ffmpeg.zeranoe.com/builds/
_____________________________________________________________________________________________
>>>>>>>> ONLINE_CONVERT_ALTERNATIVE: https://cloudconvert.com/gif-to-mp4 [Container: MPEG4  Customres: 640x1136]<<<<<<<<<<<<
________________________________________________________________________
*convert-videoformats *remuxvi-deoformats *convert-audioformats



mp4 to animated gif
-------------------------------

ffmpeg -i *.mp4 -vf "fps=10,scale=-1:-1:flags=lanczos" -c:v gif output.gif

____________________

Cut first 50 sec of mp3 discard rest
-------------------------------------

ffmpeg -i *.mp3 -ss 0 -t 50 output_file.mp3

_________________________

Change audio loudness / volume:
-------------------------------

ffmpeg -i scrollclick.mp3 -filter:a "volume=2.5" scrollclick.mp3

mkdir -p gain && for file in *.mp3; do ffmpeg -i "$file" -filter:a "volume=2.5" "gain/$file"; done

________________________________


Concat mp4s in curr folder in one:
---------------------------------

files=""
for f in *.mp4; do
  files+="file '$PWD/$f'\n"
done
echo -e "$files" > input.txt
ffmpeg -f concat -safe 0 -i input.txt -c copy output.mp4

_____________________


Fix "too many packets buffered" error:
------------------------


 -max_muxing_queue_size 1024

( https://stackoverflow.com/questions/49686244/ffmpeg-too-many-packets-buffered-for-output-stream-01 )

____________________________________________


Extract 2nd Audiostream and remux only it to video:
----------------------------------------------------

set "input_dir=D:\Videos\1_Serien\Anime\Death Note\Death Note [GER][ENG][JAPnSub]"
set "output_dir=C:\Videoconvert"
for %%F in ("%input_dir%\*") do (
  ffmpeg -i "%%F" -map 0:v -map 0:a:1 -c:v copy -c:a:2 copy "%output_dir%\%%~nF.mkv"
)

___________________________________

Downscale video to 640*480 mp4
---------------------------------------------------
cd /storage/emulated/0/Download
 ffmpeg -i *.mp4 -vf "scale=640:480:force_original_aspect_ratio=decrease,pad=640:480:(ow-iw)/2:(oh-ih)/2" -c:v libx264 -crf 23 -preset medium -c:a aac -b:a 128k output_video.mp4

_____________________________________

Concat 2 videos:
-----------------

(echo file '0.wmv' & echo file 'tai.mp4' )>list.txt
ffmpeg -safe 0 -f concat -i list.txt -c copy output.mp4

https://stackoverflow.com/questions/7333232/how-to-concatenate-two-mp4-files-using-ffmpeg

________________________

Combine animated gif with mp3/audio:
-----------------

ffmpeg -i song.mp3 -ignore_loop 0 -i gif.gif -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" -shortest -strict -2 -c:v libx264 -threads 4 -c:a aac -b:a 192k -pix_fmt yuv420p -shortest out.mp4

(Source: https://stackoverflow.com/questions/48370185/convert-audio-to-video-ffmpeg-with-a-gif-as-the-background-but-keep-the-audio-le )

____________

Multiple (video) to mp3:
-------------------------------------
Linux:
for i in *.wmv; do ffmpeg -i "$i" "${i%.*}.mp3"; done

Windows:
n/A

(Source: https://stackoverflow.com/questions/5784661/how-do-you-convert-an-entire-directory-with-ffmpeg )

________________________________
Add BG(video) to alredy existant video:
---------------------------------------

ffmpeg -i in.mp4 -i bg.mp4 -filter_complex blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)' -preset ultrafast out.mp4

(Source: https://stackoverflow.com/questions/22344959/ffmpeg-how-to-create-a-effect-video-like-flower-fall)
________________________________

Batch convert m4a to mp3
---------------------------------------

for f in *.m4a; do ffmpeg -i "$f" -codec:v copy -codec:a libmp3lame -q:a 2 "${f%.m4a}.mp3"; done 

(Source:  https://superuser.com/questions/704493/ffmpeg-convert-m4a-to-mp3-without-significant-loss )
_______________________________________________________________
FFMpeg fix video (unseekable stream)
--------------------
 ffmpeg -err_detect ignore_err -i *.mp4 -c copy video_fixed.mkv

 (Source: https://video.stackexchange.com/questions/18220/fix-bad-files-and-streams-with-ffmpeg-so-vlc-and-other-players-would-not-crash)
__________________

Delete every 2nd file in dir: (unix) 
-------------------------------------
 ls | sed -n "p;N;" | xargs rm -r 

(Source: https://www.unix.com/unix-for-dummies-questions-and-answers/193727-shell-input-remove-every-second-file-directory.html )
_______________________________________________________________

Files to sequential numbering: (unix)
----------------------
x=1; for i in *png; do counter=$(printf %03d $x); mv "$i" "$counter".png; x=$(($x+1)); done 

(Source: https://superuser.com/questions/624567/how-to-create-a-video-from-images-using-ffmpeg)


_______

Images to video (unsorted\no file form):
--------------------

cat *.png | ffmpeg -f image2pipe -i - output.mp4

OR
ffmpeg -framerate 30 -pattern_type glob -i '*.png' \ -c:v libx264 -pix_fmt yuv420p out.mp4 

(Source: https://stackoverflow.com/questions/24961127/how-to-create-a-video-from-images-with-ffmpeg )

___________________________________________
Color Correct (/Brightness correct):
------------------------------------
ffmpeg -i INPUT.MOV -vf eq=brightness=0.06:saturation=2 -c:a copy OUTPUT.MOV  ffmpeg -i vid.mp4 -vf eq=brightness=0.06:saturation=2 -c:a copy out.mp4

https://video.stackexchange.com/questions/20962/ffmpeg-color-correction-gamma-brightness-and-saturation



----------------------------------
Align gif to video space \ overlay:

VideoWatermarkPro:
1) Download and install the application from your web browser. Launch it afterward.
2) Upload your video by clicking the “Add Video” tab.Then “Add Image” button to insert your GIF
3) "Run" to finish rendering
Single frame to mp4
ffmpeg -loop 1 -i image.png -c:v libx264 -t 15 -pix_fmt yuv420p out.mp4
https://beecut.com/add-animated-gif-to-video.html

=> Result:
https://www.artstation.com/artwork/X1JQmL

________________________
Convert ogg to mp3:
-------------------
for %x in (*.ogg) do ffmpeg -i "%x" -vn -ar 44100 -ac 2 -b:a 192k "%x".mp3

(Source: https://stackoverflow.com/questions/3255674/convert-audio-files-to-mp3-using-ffmpeg)
__________________________________________________________
Combine (concat) mp4 with sim encoding):
---------------------------------------

(for %i in (*.mp4) do @echo file '%i') > list.txt 
ffmpeg -safe 0 -f concat -i list.txt -c copy output.mp4

Alt: www.gihosoft.com/download/adr/JJSVideoEditor_V2.exe

(Source: https://stackoverflow.com/questions/7333232/how-to-concatenate-two-mp4-files-using-ffmpeg)

__________________________________________________________
Render vgm music
------------------

FFmpeg can make use of the Game Music Emu library to read audio from supported video game music file formats. 
Pass --enable-libgme to configure to enable it.
 See https://bitbucket.org/mpyne/game-music-emu/overview.  
 https://www.ffmpeg.org/general.html

___________________________________________________________
Mp3 equalizer with backgroundimage and changable waveform color:    overlay=shortest=1:main_h-overlay_h+106 (h-overlay changes the y-position)
----------------------------------------------------------------
-Middle screen eq-
ffmpeg -i song.mp3 -loop 1 -i song.jpg -filter_complex "[0:a]showwaves=s=640x360:mode=cline:colors=blue[fg];  [1:v]scale=640:-1,crop=iw:360[bg];  [bg][fg]overlay=shortest=1:main_h-overlay_h-30,format=yuv420p[out]" -map "[out]" -map 0:a -c:v libx264 -preset fast -crf 18 song.mp4

-Bottom screen eq-
ffmpeg -i song.mp3 -loop 1 -i song.jpg -filter_complex "[0:a]showwaves=s=640x360:mode=cline:colors=blue[fg];  [1:v]scale=640:-1,crop=iw:360[bg];  [bg][fg]overlay=shortest=1:main_h-overlay_h+106,format=yuv420p[out]" -map "[out]" -map 0:a -c:v libx264 -preset fast -crf 18 song.mp4


(Source: https://stackoverflow.com/questions/45885460/using-hex-colors-with-ffmpegs-showwaves)
(Source: https://stackoverflow.com/questions/34675160/ffmpeg-generate-overlay-complex-filter-for-audio-with-background-image)
http://underpop.online.fr/f/ffmpeg/help/showwaves.htm.gz 
https://stackoverflow.com/questions/61111568/ffmpeg-showwaves-change-color-of-waveform-on-top-of-an-image
https://stackoverflow.com/questions/49415973/ffmpeg-showaves-with-both-color-and-colorkey)
____________________________________________________________
Mp3 to equalizer - video:
-------------------------
ffmpeg -i song.mp3 -filter_complex "[0:a]showwaves=s=1280x720:mode=line:rate=25,format=yuv420p[v]" -map "[v]" -map 0:a out.mp4
(Source: https://www.inmotionhosting.com/support/website/audio-spectrum-visuals-ffmpeg/)

__________________________________________________________
Create timelaps (from photos):
-------------------------------

ffmpeg -framerate 30 -pattern_type glob -i "folder-with-photos/*.JPG" -s:v 1440x1080 -c:v libx264 -crf 17 -pix_fmt yuv420p my-timelapse.mp4 

(Source: https://medium.com/@sekhar.rahul/creating-a-time-lapse-video-on-the-command-line-with-ffmpeg-1a7566caf877 )
__________________________________________________________
Loop video until audio over: (rq's new ffmpeg ver)
-----------------------------
ffmpeg -y -stream_loop -1 -i video -i audio.mp3 -fflags +shortest -max_interleave_delta 50000 -c copy output.mp4 

(Source: https://video.stackexchange.com/questions/23390/ffmpeg-loop-video-to-the-length-of-audio)

__________________________________________________________
Loop (added) audio until video is finished: 
--------------------------------------------
ffmpeg  -i input.mp4 -stream_loop -1 -i input.mp3 -shortest -map 0:v:0 -map 1:a:0 out.mp4

(Source: https://stackoverflow.com/questions/5015771/merge-video-and-audio-with-ffmpeg-loop-the-video-while-audio-is-not-over)


Flip Video:
-----------
for %x in (*.mp4) do ffmpeg -i %x -vf hflip -c:a copy out.mp4

https://duxyng.wordpress.com/2013/04/07/rotateflip-video-with-ffmpeg/

__________________________________________________________
Overlay image over frame(s) (supports transparency!):
-----------------------------------
ffmpeg -i in.mp4 -i input.png -filter_complex "[1][0]scale2ref[img][vid];[vid][img]overlay=enable='between(t,49,57)'" -c:a copy outz.mp4
(Source: https://unix.stackexchange.com/questions/588667/ffmpeg-replace-part-of-a-video-by-a-jpg-file-for-5-seconds)

___________________________________________________________
Webm to mp3 (or opus to mp3)
-----------
for %x in (*.opus) do ffmpeg -i "%x" -vn -ab 128k -ar 44100 -y %x.mp3

ffmpeg -i input.webm -vn -ab 128k -ar 44100 -y out.mp3 

https://bytefreaks.net/gnulinux/bash/ffmpeg-extract-audio-from-webm-to-mp3

___________________________________________________________

Replace mp4s audio with new one from mp3:
----------------------------------------
ffmpeg -i test.mp4 -i test.mp3 -c:v copy -c:a aac -map 0:v:0 -map 1:a:0 output.mp4

(Source: https://superuser.com/questions/277642/how-to-merge-audio-and-video-file-in-ffmpeg)

___________________________________________________________
Picture and mp3 to video:
-------------------------
ffmpeg -loop 1 -i image.jpg -i audio.mp3 -c:a copy -c:v libx264 -shortest out.mp4 
(Source: https://stackoverflow.com/questions/25381086/convert-mp3-video-with-static-image-ffmpeg-libav-bash

_____________________________________________

Combine mp3s in txt together
-------------------------------------

ffmpeg -f concat -safe 0 -i out.txt -c copy output.mp4

(Source: https://stackoverflow.com/questions/3886295/how-do-i-list-one-filename-per-output-line-in-linux)

______________________________________________________________________________________________________

Merge two *.wav files => Single stereo wav file:
-------------------------------------------------------
ffmpeg -i front_left.wav -i front_right.wav -codec:a aac -strict -2 -filter_complex "[0:a][1:a]amix" -ac 2 -f flv out.wav
(Source: https://superuser.com/questions/767722/ffmpeg-combine-two-mono-live-audio-stream-to-single-stereo-stream)

___________________________________________________________________________________________________
Pan audio channels:
--------------------------
--Pan to right--
ffmpeg -i in.mp3 -af "pan=stereo:c0=0*c0|c1=1*c1" out.wav

--Pan to center--

(Source: https://stackoverflow.com/questions/43372275/change-volume-in-only-one-of-the-audio-channels-with-ffmpeg)
(Source: https://stackoverflow.com/questions/10178459/panning-all-audio-channels-center-in-ffmpeg)
https://superuser.com/questions/685910/ffmpeg-stereo-channels-into-two-mono-channels
ffmpeg.org/ffmpeg-filters.html#pan
_______________________________
Extract stereo channels => 2x mono channel:
----------------------------------------------------------
for %x in (*.mp3) do ffmpeg -i "%x" -map_channel 0.0.0 left.wav -map_channel 0.0.1 right.wav
(Source: https://superuser.com/questions/685910/ffmpeg-stereo-channels-into-two-mono-channels)
______________________________________________________________________________________________
Extract Video to Audio Stream:AC3 (mkv -> ac3 file)[important for 5.1 audio extraction]
------------------------------------------------------
for %x in (*.mkv) do ffmpeg -i %x -acodec copy %x.ac3
(Source: http://www.savvyadmin.com/extract-ac3-dolby-digital-with-ffmpeg/)
______________________________________________________________________________________________
Extract Audio AC3 to wav channels: (works directly from mkv aswell)
 -------------------------------------------------
ffmpeg -i out.ac3 -filter_complex "channelsplit=channel_layout=5.1[FL][FR][FC][LFE][BL][BR]" -map "[FL]" front_left.wav -map "[FR]" front_right.wav -map "[FC]" front_center.wav -map "[LFE]" lfe.wav -map "[BL]" back_left.wav -map "[BR]" back_right.wav

(Source: https://randocity.com/2016/04/10/audio-tip-how-to-decode-5-1-dts-ac3-to-6-wav-files/)

_____________________________________________________________________________________________

Downmix (5.1) Stream to x (no multiple channels !)
---------------------------------------

Downmix to WAV
for %%x in (*.mkv) do ffmpeg -i "%%x" -c pcm_s16le -ac 2 out.wav

Downmix to DTS:
for %%x in (*.mkv) do ffmpeg -i "%%x" -strict -2 -c:a dca -ac 2 -vol 425 out.dts

(Source: https://superuser.com/questions/852400/properly-downmix-5-1-to-stereo-using-ffmpeg)
______________________________________________________________________________________________________

Change speed of media
--------------------------------
mkdir out
for %x in (*.mp3) do ffmpeg  -i "%x" -filter:a "atempo=2.0" -vn out/"%x"
for %x in (*.mp4) do ffmpeg -i %x -filter:v "setpts=0.5*PTS" out/"%x"
(Source: https://stackoverflow.com/questions/33957747/how-do-i-reduce-the-speed-of-a-voice-mp3-file-with-sox-to-75)
______________________________________________________________________________________________________

Extract subtitles
-----------------------
for %x in (*.mkv) do ffmpeg -txt_format text -i %x  %x_.srt


(source: https://trac.ffmpeg.org/wiki/ExtractSubtitles)

______________________________________________________________________________________________________



MP3GAIN to change volume (curr folder): mp3gain /g -30 *.mp3
------------------------------------------------------------------------------------
MP3GAIN to change volume (all subdirs): FOR /R "%~dp0" %%x in (*.mp3) do mp3gain /g -30 "%%x"

______________________________________________________________________________________________________

Multi mp3 to video:
--------------------------
for %%x in (*.mp3) do ffmpeg -loop 1 -i cover.jpg -i %%x -c:v libx264 -tune stillimage -c:a aac -strict experimental -b:a 192k -pix_fmt yuv420p -shortest %%x.mp4


Convert images to video:  [!!!!! REGARDING IMG -2-> VIDEO Conversions: MAKE. SURE. THE. DIMENSIONS ARE divisble by 2 !!!!!] USE GIF'S FOR VIDEO CREATION !!! (BMP's cause problems)
______________________________________________________________________________________________________
[Image to - MP4]
ffmpeg -r 20 -f image2 -i %03d.gif -f mp4 -q:v 0 -vcodec mpeg4 -r 24 myVideo.mp4
|
[Image to - WMV-HQ]
ffmpeg -r 10 -f image2 -i %03d.gif -q:a 2 -q:v 2 -vcodec msmpeg4 -acodec wmav2 myvideo.wmv
|
**Alternate mode:
ffmpeg -y -r 20 -f image2 -i %04d.gif -f mp4 -pix_fmt yuv420p outds.mp4
**Alternate colormode (reverse):
ffmpeg -r 20 -f image2 -i %04d.gif -f mp4 -c:v libx264 -pix_fmt bgr24 res.mp4
|
%02.gif  FOR 00.gif
%03.gif  FOR 000.gif
%04.gif  FOR 0000.gif input files
(http://stackoverflow.com/questions/31222186/ffmpeg-frames-to-mp4-windows)

___________________________________________________________________________________________________________
Convert wmv to mp4 (android compatible):
----------------------------------------------------------
for %x in (*.wmv) do ffmpeg -i %x -s 640x1136 -vcodec mpeg4 -acodec aac -strict -2 -ac 1 -ar 16000 -r 13 -ab 32000 %x.mp4
(Source: https://stackoverflow.com/questions/14171826/converting-video-for-android-using-ffmpeg)


___________________________________________________________________________________________________________
Convert xyz to mp4 (playback)
----------------------------------------------------------
for %x in (*.mkv) do ffmpeg -i %x -s 1280x720 -vcodec mpeg4 -acodec aac -strict -2 -ac 1 -ar 16000 -r 24 -ab 32000 %~nx.mp4
______________________________________________________________________________________________________________

Cut Video length with FFMPEG:
----------------------------------------------

for file in *.mp4; do ffmpeg -i "$file" -ss 00:18:20 -t 00:01:14 -c copy "cut_$file"; done

Variable version (start, end)
for %%x in (*mp4) do ffmpeg -i %%x -ss 00:00:55 -t 00:03:15 -async 1 cut.mp4
https://stackoverflow.com/questions/18444194/cutting-the-videos-based-on-start-and-end-time-using-ffmpeg


Fixed version (reqs start, end, duration)s
for %x in (*.mp4) do ffmpeg -i %x -ss 60 -t 60 -acodec copy -vcodec copy %x-
(superuser.com/questions/138331/using-ffmpeg-to-cut-up-video?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa)


______________________________________________________________________________________________________________________________
Extract Frames from video:  
https://averagelinuxuser.com/video-to-images-with-vlc-media-player/
https://ezgif.com/video-to-png/
         
--------------------------- 
for %x in (*mp4) do   ffmpeg -i  %x "%03d.png"
for %x in (*wmv) do   ffmpeg -i  %x "%03d.png"
    EMERGENCY CMND: for %x in (*wmv) do ffmpeg -i %x -r 24 image-%04d.jpg


___________________________________________________________________________________________________________________________

Extract Album Art:
--------------------------
for %x in (*mp3) do ffmpeg -i "%x" "%x".jpg

  -- Batch album art extract via MP3Tag:
        Use the action type Export cover to file As format string use Folder to create a Folder.ext image in each directory. 
      Extension is added automatically.
         http://community.mp3tag.de/t/extract-cover-art-from-multiple-directories/9471
____________________________________________________________________________________________________________________________


Edit MP3 Tag via FFMPEG:
---------------------------------------

ffmpeg -i file.mp3 -metadata album_artist="ALBUM ARTIST written by ffmpeg" file_ffmpeg.mp3

(SOURCE: www.synology-forum.de/showthread.html?60221-ID3-Tags-mit-FFMPEG-verändern)
___________________________________________________________________________________________________________________________

Combine jpg and mp3 to video (youtube upload)
---------------------------------------------------------------------
ffmpeg -loop 1 -i *.jpg -i *.mp3 -c:v libx264 -tune stillimage -c:a aac -strict experimental -b:a 192k -pix_fmt yuv420p -shortest out.mp4

___________________________________________________________________________________________________________________________

Downscale video (forced ratio) BUT KEEP audiostreams AS IS (for multi language mkvs)
------------------------------------------------------------------------------------
for %x in (*.mkv) do ffmpeg -i %x -filter:v scale=960:540 -map 0 -c copy -c:v libx265 _%x

(Source: https://stackoverflow.com/questions/39685629/re-encode-video-stream-only-with-ffmpeg-and-with-all-audio-streams)

___________________________________________________________________

Downscale_video (forced ratio)
------------------------------------------------
--960x540----(1/2  1920x1080)--:
for %x in (*.mkv) do ffmpeg -i %x -filter:v scale=960:540 -c:a copy out/_%x

---640x480--:
for %x in (*.mkv) do ffmpeg -i %x -filter:v scale=640:480 -c:a copy _%x
(https://trac.ffmpeg.org/wiki/Scaling)

_____________________________________________________________


Convert MKV (5.1 audio) to MKV (stereo audio)
----------------------------

for %x in (*.mkv) do ffmpeg -i "%x" -c:v copy -ac 2 -af "pan=stereo|FL=FC+0.30*FL+0.30*BL|FR=FC+0.30*FR+0.30*BR" output_stereo.mkv
(Source: https://superuser.com/questions/852400/properly-downmix-5-1-to-stereo-using-ffmpeg)

_____________________________________________________________________________________


Animated gif to mp4
------------------------------

for %x in (*gif) do ffmpeg -i %x -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" video.mp4

(SOURCE: https://unix.stackexchange.com/questions/40638/how-to-do-i-convert-an-animated-gif-to-an-mp4-or-mv4w-on-the-command-line?utm_medium=organic&utm_source=google_rich_qa&utm_campaign=google_rich_qa)
______________________________________________________________________________________________________________________________
Extract Frames from animated gif:
-------------------------------------------------
for %x in (*gif) do ffmpeg -i %x %05d.png

www.raymond.cc/blog/split-or-break-gif-animation-into-individual-frames/

______________________________________________________________________________________________________________________________
Convert video directly to animated gif:
------------------------------------------------------
ffmpeg -i "%~dpnx1"  -r 10 -f image2pipe -vcodec ppm - |  convert -delay 0 -loop 0 -  out.gif

##ffmpeg -i "%~dpnx1" -vf scale=320:-1 -r 10 -f image2pipe -vcodec ppm - | convert -delay 5 -loop 0 - gif:- | convert -layers Optimize - output.gif 

superuser.com/questions/556029/how-do-i-convert-a-video-to-gif-using-ffmpeg-with-reasonable-quality

______________________________________________________________________________________________________________________________

Extract From 00:00:30  (with 5 sec duraction):
---------------------------
ffmpeg -ss 00:00:30 -t 00:00:005 -i original.mp4 -vcodec copy -acodec copy output.mp4

________________________________________________________________________________________________________________________________
 Change video framerate:
-------------------------

ffmpeg -i input.wmv -sameq -r 10 -y output.wmv

(superuser.com/questions/1187149/change-frame-rate-without-changing-film-speed-duration)


________________________________________________________________________________________________________________________________

There is no need to rename files if using the -start_number switch like so: 

ffmpeg -start_number n -i test_%d.jpg -vcodec mpeg4 test.avi 

where n is the start of the sequence of stills.

superuser.com/questions/624567/how-to-create-a-video-from-images-using-ffmpeg

______________________________________________________________________________________________________________________________



Show ffmpeg pixel formats (if curr video doesn't convert corr):
---------------------------------------------------------------

ffmpeg -pix_fmts
______________________________________________________________________________________________________________________________

Reduce music volume
---------------------
for  %%x in (*.mp3) do ffmpeg -i "%%x" -af volume=0.7 "%%x"
OR
for  %%x in (*.mp3) do ffmpeg -i "%%x" -af volume=70dB "%%x"


OR (older FFMPPEG versions
  for  %%x in (*.mp3) do ffmpeg -f lavfi -i "amovie=%%x,volume=0.7" "%%x"

______________________________________________________________________________________________________________________________

Increase music volume: 
-----------------------              
for %%x in (*mp3) do ffmpeg -i "%%x" -vol 200 "%%x"
(Source: http://www.die-unbelehrbaren.de/software/konverter/mit-ffmpeg-die-lautstarke-von-audiodateien-erhohen/)


________________________________________________________________________________________________________________________________


image to false color video: (rgb pixel value)
----------------------------
ffmpeg -r 20 -f image2 -i %05d.bmp -f mp4 -pix_fmt rgb24 out.mp4

_______________________________________________________________________________________________________________________________

Repack video:
--------------
for %x in (*mp4) do   ffmpeg -i  %x "%04d.bmp"
ffmpeg -r 20 -f image2 -i %04d.bmp -f mp4 -q:v 0 -vcodec mpeg4 -r 24 myVideo.mp4

______________________________________________________________________________________________________________________________
Extract mp4 & recompress w. new settings:
----------------------------------------------------
for %x in (*mp4) do   ffmpeg -i  %x "%04d.bmp"
ffmpeg -r 12 -f image2 -i %04d.bmp -f mp4 -q:v 0 -vcodec mpeg4 -r 24 myVideo.mp4

_________________________________________________________________________________________________________

Merge videos side-by-side: ffmpeg -i a.mp4 -i b.mp4 -filter_complex "[0:v:0]pad=iw*2:ih[bg]; [bg][1:v:0]overlay=w" output.mp4
--------------------------  (SOURCE: https://lists.ffmpeg.org/pipermail/ffmpeg-user/2013-June/015662.html )

________________________________________________________________________________________________________________________________


Join two pictures/frames in one picture:   for /L %%i in (1,1, 4000) do convert a%%i.png b%%i.png -monitor +append c%%i.png
----------------------------------------   (4000 = Videoframes)



________________________________________________________________________________________________________________________________

Crop video:     ffmpeg -i a.mp4 -filter:v "crop=320:480:40:0" -crf 20 -maxrate 400k -bufsize 1835k a1.mp4 && MOVE a1.mp4 a.mp4
----------              ( 320: x crop,  480 y crop, 40 x offset, 0 y ofset)

f
________________________________________________________________________________________________________________________________

Convert Video:            for %x in (*.avi) do ffmpeg -i %x -acodec libfaac -b:a 128k -vcodec mpeg4 -b:v 1200k -flags +aic+mv4 %x.mp4
---------------                       (Avi to MP4 in this case)
                                (SOURCE:  http://andrebluehs.net/blog/converting-avi-to-mp4-with-ffmpeg/)

_____________________________________________________________________________________
*************************************************************************************
*************************************************************************************

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~Convert-videoformats:~~~~~~~~~~~~~~~~~~~~
----------------------
Burn in mkv embeded subtitles (with constant 24 fps):
-----------------------------------------------------------------------
for %x in (*.mkv) do ffmpeg -r 24 -i "%x" -filter_complex "[0:v][0:s]overlay[v]" -map "[v]" -map 0:a  E:\Z_[SERIES]\"%~nx.mp4"

If you have multiple subtitle streams, you can select which one to use by replacing [0:s] with [0:s:0] to select the first subtitle stream or [0:s:1] to select the second subtitle stream, and so on.
(Source: https://trac.ffmpeg.org/wiki/HowToBurnSubtitlesIntoVideo)
_________________________________

Burn in srt/ass Subtitles (with constant 24 fps):
-------------------------
for %x in (*.m4v) do ffmpeg -r 24 -i "%x" -vf subtitles="%~nx".ass "K:\Zygodm\%~nx".mp4
  for %x in (*.m4v) do ffmpeg -r 24 -i "%x" -vf subtitles="%~nx".ass "K:\Zygodm\%~nx".mp4

(Source: https://trac.ffmpeg.org/wiki/HowToBurnSubtitlesIntoVideo)
____________________________________

======================================
==mkv -> mp4 (with constant 24 fps=

for %x in (*.mp4) do ffmpeg -r 24 -i "%x" -codec copy K:\zsatsu\"%~nx.mp4"

=====================
===copy codec (no reconversion)

for %x in (*.mkv) do ffmpeg -i "%x" -codec copy  E:\Z_[SERIES]\"%~nx.mp4"
(SOURCE: https://askubuntu.com/questions/396883/how-to-simply-convert-video-files-i-e-mkv-to-mp4)
(https://stackoverflow.com/questions/40077681/ffmpeg-converting-from-mkv-to-mp4-without-re-encoding)

================
==mkv -> mp4=====
for %x in (*mkv) do ffmpeg -i %x -b:a 128k -codec:v libx264 -pix_fmt yuv420p -crf 20 E:\Z_[SERIES]\%~nx.mp4
(Source: https://gist.github.com/dvlden/b9d923cb31775f92fa54eb8c39ccd5a9)

#way too high bitrate
#for %x in (*mkv) do ffmpeg -i %x -b:a 128k -codec:v libx264 -pix_fmt yuv420p -b:v 4500k -minrate 4500k -maxrate 9000k -bufsize 9000k E:\Z_[SERIES]\%~nx.mp4

=================
===*mp4 -> wmv:  ===
 [HQ] for %x in (*wmv) do ffmpeg -i %x -q:a 2 -q:v 2 -vcodec msmpeg4 -acodec wmav2 %x1.mp4
 (https://walterebert.com/blog/creating-wmv-videos-with-ffmpeg/)

==============
===wmv -> avi:===
for %x in (*wmv) do ffmpeg -i %x %x1.mp4


______________________________________________________________
~~~~Convert n resize:~~~~

for %x in (*.wmv) do ffmpeg -i %x -vf scale=640:1136 %~nx.mp4

(Source: https://unix.stackexchange.com/questions/190431/convert-a-video-to-a-fixed-screen-size-by-cropping-and-resizing)
________________________________________________________________

Downscale_video (correct_aspect_ratio):
--------------------------------------
for %x in (*.*) do ffmpeg -i %x -filter:v scale=640:-0.5 -c:a K:\zygodm\%~nx.mp4

for %x in (*.mp4) do ffmpeg -i %x -filter:v scale=640:-0.5 -c:a copy _%x

(source: https://superuser.com/questions/624563/how-to-resize-a-video-to-make-it-smaller-with-ffmpeg)


________________________________________________________________________________________________________________________________
Change video resolution: (give x, y will be calculated automatically)
------------------------
ffmpeg -y -i video.mp4 -vf scale=800:-2,setsar=1:1 -c:v libx264 -c:a copy video_shrink.mp4"

(Source: https://stackoverflow.com/questions/34391499/change-video-resolution-ffmpeg  ) 
______________________________________________________________________________________________________________

Scale/Resize Videos                                    
-------------------
 ffmpeg -i a.mp4 -vf scale=iw/1.25:-1 a1.mp4

                                                        (1.25 in this case is the new x and y resolution, for
                                                        example: 320:1.25 = 256 )
                                                        (SOURCE: http://trac.ffmpeg.org/wiki/FilteringGuide)

__________________________________________________________

these two lines in a batch file will demux h.264 video and aac audio to elementry streams when you drag/drop an MP4 file onto it
-------------------------------------------------
ffmpeg -i %1 -vcodec copy %~n1.h264
ffmpeg -i %1 -acodec copy %~n1.aac


__________________________________________________________


this batch file will remux to an MKV file.
---------------------------------------------
ffmpeg -i %1 -c copy %~n1.mkv

(SOURCE: https://forum.videohelp.com/threads/384950-Need-a-tsMuxer-type-program-to-demux-AVI-files)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~convert-audioformats~~~~~~~~~~~~~~~~~~~~~~~

*m4a -> mp3 (linux/android):
for x in *m4a; do
ffmpeg -i "$x" -vn -c:a libmp3lame -ab 192k -ar 48000 -f mp3 "$x".mp3
done


===================
==remuxvideoformats===

MKVToolnix Remux to mkv ("%~nx" instead of "%x" to omit extra .avi)
--------------------------------------
for %x in (*.avi) do "C:/Program Files/MKVToolNix\mkvmerge.exe" --ui-language de --output ^"C:/out/%~nx.mkv^" --language 0:und --language 1:und --language 2:und ^"^(^" ^"%x^" ^"^)^" --track-order 0:0,0:1,0:2



HANDBRAKE:

===========================================
------MKV -> M4V w. subtitle burn in--(CONSTANT framerate)
for %x in (*) do "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1 -o "E:\Z_Series\%~nx.mp4"  -f  mp4 --strict-anamorphic -e x264 -q 22 -r 24 --cfr -a 1 -E faac -B 128 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 --subtitle 1 --subtitle-burn=1 --markers="C:\Users\%Username%\AppData\Local\Temp\%~nx.csv" -x ref=1:weightp=1:subq=2:rc-lookahead=10:trellis=0:8x8dct=0 --verbose=1
=======================================================
==MKV -> MP4---640 x 480-with subtitles burn in--(constant framerate)==
for %x in (*.mkv) do "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1 -o "E:\Z_Series\%~nx.mp4" -f  mp4 -w 640 -l 480 -e x264 -q 22 -r 24 --cfr -a 1 -E faac -B 128 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 --subtitle 1 --subtitle-burn=1 --markers="C:\Users\%Username%\AppData\Local\Temp\%~nx.csv" -x ref=1:weightp=1:subq=2:rc-lookahead=10:trellis=0:8x8dct=0 --verbose=1
============================================
----xxx -> MP4 w. SRT file burn in (CONSTANT framerate)=
for %x in (*mkv) do "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1 -o "E:\Z_Series\%~nx.mp4"  -f mp4 --strict-anamorphic  -e x264 -q 20 --cfr  -a 1 -E faac -B 160 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 --srt-file "%~nx.srt" --srt-codeset UTF-8 --srt-offset 0 -srt-lang eng -x ref=1:weightp=1:subq=2:rc-lookahead=10:trellis=0:8x8dct=0 --verbose=1
================================
==mkv to mp4 (640x480)=constant framerate=
for %x in (*) do "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1 -o "E:\Z_SERIES\%~nx.mp4"  -f  mp4 -w 640 -l 480 -e x264 -q 22 -r 24 --cfr  -a 1 -E faac -B 128 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 -x weightp=0:cabac=0 --verbose=1
=================================
-------MKV -> M4V with subtitles burn in----(variable framerate)-
for %x in (*.mkv) do  "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1-9 -o "E:\Z_[SERIES]\%~nx.mp4"  -f mp4 --strict-anamorphic  -e x264 -q 20 --vfr  -a 1 -E faac -B 160 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 --subtitle 1 --subtitle-burn=1 --markers="C:\Users\Pascal\AppData\Local\Temp\%~nx.csv" -x ref=1:weightp=1:subq=2:rc-lookahead=10:trellis=0:8x8dct=0 --verbose=1
=====================================
 =mkv to mp4 (640x480) WITH subtitle-burn-in=variable===
for %x in (*.mkv) do  "E:\Dropbox\Public\Useful_Handy_Winprogs\iOS_related\[PC_Software]\Video_Converter\Handbrake\HandBrakeCLI.exe" -i "%x" -t 1 -c 1-9 -o "K:/Z5DS/%~nx.mp4" -f mp4 -w 480 -l 360 -e x264 -q 20 --vfr  -a 1 -E faac -B 160 -6 dpl2 -R Auto -D 0 --gain=0 --audio-copy-mask none --audio-fallback ffac3 -x ref=1:weightp=1:subq=2:rc-lookahead=10:trellis=0:8x8dct=0 --verbose=1 --subtitle 1 --subtitle-burn=1