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--- ffmpeg [2022-03-18 17:43:16]
mi
+++ ffmpeg [2025-03-20 19:39:18] (current)
mi [Add pseudo-timecode]
@@ Line 4: / Line 4: @@
   ffmpeg -i "$in"
+==webm to mp4
+Example:
+<code bash>
+ffmpeg -i "$in" -tune film -crf 20 -preset slow -b:a 192k -movflags +faststart "${in%%.webm}.mp4"
+</code>
 ==h264
@@ Line 19: / Line 27: @@
 -maxrate 6M -bufsize 6M
 </code>
+Or set an average bitrate, without using ''-crf'' (see [[https://trac.ffmpeg.org/wiki/Limiting%20the%20output%20bitrate|Limiting the output bitrate]])
+<code bash>
+-b:v 4M -maxrate 6M -bufsize 10M
+</code>
 ==prores
   * Prores proxy: -profile:v 0
@@ Line 45: / Line 61: @@
 -vf "scale=iw/2:-2"   # same (half width and height), but height divisible by 2
 etc.
+</code>
+==Deinterlace
+See https://ffmpeg.org/ffmpeg-filters.html#yadif :
+> yadif=mode:parity:deint
+> defaults: 0(send_frame=one frame for each frame) : -1(auto=auto detection of field order) : 0(all=all frames)
+<code bash>
+-vf "yadif=0:-1:0"
 </code>
@@ Line 76: / Line 103: @@
   ffmpeg -i input.flv -vf "select='eq(pict_type,PICT_TYPE_I)'" -vsync vfr thumb%04d.png
+Find all .mov files under some directory, and extract a single Jpeg:
+<code bash>
+pos=2 # get frame at $pos seconds from start of file
+search_in=/mnt/x/y
+ext="mov"
+find "$search_in" -type f -name "*.$ext" -not -name ".*" \
+| while read f; do
+    n=$(basename "$f")
+    [ -f "$n" ] && n="$n-$RANDOM"
+    ffmpeg -nostdin -hide_banner -loglevel error -ss $pos -i "$f" \
+      -r 1 -vframes 1 -f image2 "$n.jpg" \
+    && echo "OK $n.jpg"
+done
+</code>
@@ Line 90: / Line 134: @@
 See also ffmpeg's  [[https://trac.ffmpeg.org/wiki/Create%20a%20thumbnail%20image%20every%20X%20seconds%20of%20the%20video|Create a thumbnail image every X seconds of the video]].
-==Frames to animated webp
+==Images to video
+With numbered frames, the numbering must start at 0: "frame0000.png", "frame0001.png", "frame0002.png", ...
+===Animated webp
+Frames to animated .webp :
 <code bash>
@@ Line 97: / Line 146: @@
 </code>
-==Audio AAC
+Animated .gif to .webp (copied from [[https://ozzyczech.cz/bash/convert-gif-to-web-m-with-ffmpeg/|Convert GIF to WebM with ffmpeg]])
 <code bash>
--c:a aac -b:a 192k
+ffmpeg -i my-animation.gif -c vp9 -b:v 0 -crf 41 my-animation.webm
 </code>
-==faststart
+===Jpegs to mp4
-Move "moov" atom to start of file (https://ffmpeg.org/ffmpeg-formats.html#Options-8). (Implies file copy after encoding)
+.jpg image = 1 frame :
-<code>-movflags faststart
+<code bash>
+in="image%03d.jpg" # image000.jpg to image999.jpg
+out="image-to-video.mp4"
+ffmpeg -framerate 25 -i "$in" -c:v libx264 -crf 18 -pix_fmt yuv420p "$out"
 </code>
-==Remap 2 mono audio to stereo
+To start on a specific numbered frame, use ''-start_number''. Example staring at "image150.jpg":
-I think that since ''-map'' is used, ''-map:v'' must be added too or the output is without video.
-<code bash>-filter_complex "[0:a:0][0:a:1]amerge,channelmap=channel_layout=stereo[st]" -map 0:v -map "[st]"
+<code bash>
+in="image%03d.jpg" # image000.jpg to image999.jpg
+out="image-to-video.mp4"
+ffmpeg -start_number 150 framerate 25 -i "$in" -c:v libx264 -crf 18 -pix_fmt yuv420p "$out"
 </code>
-==Change framerate
+Slideshow with 1 .jpg = 1 second :
-''-r 25'' or ''-vf "fps=fps=25"''
+<code bash>
+fps=25
+out="slideshow-glob.mp4"
+ffmpeg -framerate 1 -pattern_type glob -i '*.jpeg' -c:v libx264 -crf 20 -g $fps -pix_fmt yuv420p -r $fps "$out"
+</code>
-Example to check what it does:
+If the size of the frames is uneven (eg. 512x459), it needs to be set to an even size, or there will be this error:
-  ffmpeg -f lavfi -i testsrc=duration=10:size=854x480:rate=60 \
+> ''height not divisible by 2 (512x459)''
-  -vf "drawtext=text=%{n}:fontsize=72:r=60:x=(w-tw)/2: y=h-(2*lh):fontcolor=white:box=1:boxcolor=0x00000099" test.mp4
+> ''Error initializing output stream 0:0 -- Error while opening encoder for output stream #0:0 - maybe incorrect parameters such as bit_rate, rate, width or height''
-== FLAC
+In this case, specify the size. For example: ''-s 512x460''
-=== FLAC to MP3
+==Audio
+===Audio AAC
+<code bash>
+-c:a aac -b:a 192k
+</code>
+===AC3 5.1 to Stereo
+Using defaults:
+  ffmpeg -i input.ac3 -ac 2 output.ac3
+Or manual:
+ ... -af "pan=stereo|FL < 1.0*FL + 0.707*FC + 0.707*BL|FR < 1.0*FR + 0.707*FC + 0.707*BR" ...
+See also: https://forum.videohelp.com/threads/404278-Ac3-5-1-audio-track-convert-to-stereo
+===Remap 2 mono audio to stereo
+I think that since ''-map'' is used, ''-map:v'' must be added too or the output is without video.
+<code bash>-filter_complex "[0:a:0][0:a:1]amerge,channelmap=channel_layout=stereo[st]" -map 0:v -map "[st]"
+</code>
+=== FLAC
+==== FLAC to MP3
 <code bash>
@@ Line 143: / Line 230: @@
 The metadata from FLAC is preserved by default, and written to a ID3v2.4 header. To write an ID3v2.3 header instead, add the ''-id3v2_version 3'' option.
-=== WAV to FLAC
+==== WAV to FLAC
 Can be done with ''flac'' instead of ffmpeg:
@@ Line 153: / Line 240: @@
 </code>
+=== Detect silence
-== Detect silence
+==== volumedetect
-=== volumedetect
 This was slow? 330 mn. for a 167 mn. / 600GB file with 16 audio channels. Not slow on 30GB 16channels quicktime. But doesn't separate channels!
   time ffmpeg -i "$in" -map 0:a -af "volumedetect" -f null - 2>&1 | tee "$in-volumedetect.txt"
-=== astats
+==== astats
   ffmpeg -i "$in" -vn -sn -dn -map 0:a -af "astats=measure_overall=none" -f null - 2>&1
 See also https://ffmpeg.org/ffmpeg-filters.html#toc-ebur128-1
-=== EBU stats
+==== EBU stats
 For a file with 12 mono audio tracks:
@@ Line 171: / Line 257: @@
-== Add pseudo-timecode
+==Delay track
+To add a delay to the start of an input, use ''-itsoffset offset'' before the input file.
+See [[https://superuser.com/a/983153/53547|this answer]] for [[https://superuser.com/questions/982342/|In ffmpeg, how to delay only the audio of a .mp4 video without converting the audio?]]
+For example, to merge an audio and a video file, but having the audio start 440 ms. later (11 frames at 25 fps):
+  ffmpeg -i "$video_file" -itsoffset 0.440 -i "$audio_file" -map 0:v -map 1:a -c copy "ff-resync-video_audio.mp4"
+===Syntax for time duration
+''[-][HH:]MM:SS[.m...]'' or ''[-]S+[.m...][s|ms|us]''
+See https://ffmpeg.org/ffmpeg-utils.html#time-duration-syntax
+==faststart
+Move "moov" atom to start of file (https://ffmpeg.org/ffmpeg-formats.html#Options-8). (Implies file copy after encoding)
+<code>-movflags faststart
+</code>
+==Change framerate
+''-r 25'' or ''-vf "fps=fps=25"''
+Example to check what it does:
+  ffmpeg -f lavfi -i testsrc=duration=10:size=854x480:rate=60 \
+  -vf "drawtext=text=%{n}:fontsize=72:r=60:x=(w-tw)/2: y=h-(2*lh):fontcolor=white:box=1:boxcolor=0x00000099" test.mp4
+== Timecode
+=== Change existing timecode
+  f=OriginalFile.mxf
+  newtc="00:00:00:00"
+  out=NewTC_File.mxf
+  ffmpeg -i "$f" -map 0:v -map 0:a -codec copy -movflags use_metadata_tags -timecode "$newtc" "$out"
+=== Add pseudo-timecode
 Example with Fuji .MOV files, to add the "Create Date" time as a timecode:
@@ Line 198: / Line 321: @@
   done
 </code>
+If the exiftool command gives the error "End of processing at large atom (LargeFileSupport not enabled)", add the ''-api largefilesupport=1'' option so the exiftool line becomes:
+<code bash>t=$(exiftool -api largefilesupport=1 -CreateDate "$f" | awk '{print $NF}');</code>
+For .wav files from a Zoom, instead of ''-CreateDate'', use ''-DateTimeOriginal'' :
+<code bash>t=$(exiftool -DateTimeOriginal "$f" | awk '{print $NF}'); tc="$t:00";</code>
 ==Diff
@@ Line 231: / Line 361: @@
   $  ffmpeg -i "$filename" -map 0:a -codec copy -hide_banner -loglevel warning -f md5 -
-  $  ffmpeg -i input.mp4 -map 0 -c copy -f streamhash -hash md5 -
+  $  ffmpeg -i "$filename" -map 0 -c copy -f streamhash -hash md5 -
   ...
 ,v,MD5=50224fec84bc6dfde90d742bcf1d2e01
 ,a,MD5=1d2a32ed72798d66e0110bd02df2be65
+  $  ffmpeg -i "$f" -map 0 -c copy -f streamhash -hash md5 "$f.stream.md5"
 See also:
@@ Line 251: / Line 383: @@
 # or
 -hide_banner -loglevel info -stats</code>
+===Edit metadata===
+See [[https://superuser.com/questions/834244/how-do-i-name-an-audio-track-with-ffmpeg/835069|How do I name an audio track with ffmpeg]]:
+  ffmpeg -i input.mp4 -map 0 -c copy -metadata:s:a:0 title="One" -metadata:s:a:1 title="Two" -metadata:s:a:0 language=eng -metadata:s:a:1 language=spa output.mp4
 ==Examples

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