From 26b0b48de5507d8642ac965d72af22beeae53b6a Mon Sep 17 00:00:00 2001
From: Boris Paing <boris.paing@laposte.net>
Date: Tue, 14 Apr 2020 11:22:08 +0200
Subject: [PATCH] first commit

---
 .gitignore |  1 +
 README.md  |  3 +++
 reunite.sh | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 shard.sh   | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 109 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 README.md
 create mode 100755 reunite.sh
 create mode 100755 shard.sh

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..1e107f5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+examples
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..d4b92fc
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+# Video sharding
+
+An attemp at something weird...
diff --git a/reunite.sh b/reunite.sh
new file mode 100755
index 0000000..0184c3f
--- /dev/null
+++ b/reunite.sh
@@ -0,0 +1,52 @@
+#!/bin/bash
+
+# usage : 
+# ./reunite.sh video-name.part1.mp4
+
+filename=$(basename -- "$1")
+extension="${filename##*.}"
+filename=$(echo "${filename%.*}" | sed -r 's/(.+)\.part[0-4]{1}$/\1/g')
+
+# Extract audio track from one of the parts
+
+ffmpeg -i $1 -acodec copy $filename.aac
+
+# Let's use more explicit names for manipulation
+
+mv $filename.part1.$extension even_odd.mp4
+mv $filename.part2.$extension even_even.mp4
+mv $filename.part3.$extension odd_odd.mp4
+mv $filename.part4.$extension odd_even.mp4
+
+# Rotate the 4 sub-videos clockwise in order to merge them
+
+ffmpeg -i even_odd.mp4 -vf "transpose=1" even_90cw_odd.mp4
+ffmpeg -i even_even.mp4 -vf "transpose=1" even_90cw_even.mp4
+
+ffmpeg -i odd_odd.mp4 -vf "transpose=1" odd_90cw_odd.mp4 
+ffmpeg -i odd_even.mp4 -vf "transpose=1" odd_90cw_even.mp4
+
+
+# Merge the 4 sub-videos into 2
+
+ffmpeg -i even_90cw_odd.mp4 -i even_90cw_even.mp4 -filter_complex "[0][1]vstack,il=l=i:c=i" even_90cw.mp4
+ffmpeg -i odd_90cw_odd.mp4 -i odd_90cw_even.mp4 -filter_complex "[0][1]vstack,il=l=i:c=i" odd_90cw.mp4
+
+# Rotate the 2 videos back counter-clockwise
+
+ffmpeg -i odd_90cw.mp4 -vf "transpose=2" odd.mp4
+ffmpeg -i even_90cw.mp4 -vf "transpose=2" even.mp4
+
+# Merge the 2 videos
+
+ffmpeg -i odd.mp4 -i even.mp4 -filter_complex "[0][1]vstack,il=l=i:c=i" $filename.merged_no_sound.mp4
+
+# Merge video with audio track
+
+ffmpeg -i $filename.aac -i $filename.merged_no_sound.mp4 $filename.merged.mp4
+
+# Remove manipulation files
+
+rm even_odd.mp4 even_even.mp4 odd_odd.mp4 odd_even.mp4 even_90cw_odd.mp4 even_90cw_even.mp4 odd_90cw_odd.mp4 odd_90cw_even.mp4 even_90cw.mp4 odd_90cw.mp4 odd.mp4 even.mp4 $filename.merged_no_sound.mp4 $filename.aac
+
+
diff --git a/shard.sh b/shard.sh
new file mode 100755
index 0000000..c275757
--- /dev/null
+++ b/shard.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# See : 
+# https://stackoverflow.com/questions/49955100/how-do-i-split-a-video-to-2-separate-files-for-odd-and-even-fields-using-ffmpeg
+# Et : 
+# https://korben.info/ffmpeg-pour-les-nuls.html
+
+
+# Split the 1 video in 2
+
+ffmpeg -i $1 -filter_complex "[0]il=l=d:c=d,split[o][e];[o]crop=iw:ih/2:0:0[odd];[e]crop=iw:ih/2:0:ih/2[even]" -map "[odd]" odd.mp4 -map "[even]" even.mp4
+
+
+# Rotate the 2 videos clockwise
+
+ffmpeg -i odd.mp4 -vf "transpose=1" odd_90cw.mp4
+ffmpeg -i even.mp4 -vf "transpose=1" even_90cw.mp4
+
+
+# Split each of the 2 videos in 2
+# We now have 4 videos
+
+ffmpeg -i odd_90cw.mp4 -filter_complex "[0]il=l=d:c=d,split[o][e];[o]crop=iw:ih/2:0:0[odd];[e]crop=iw:ih/2:0:ih/2[even]" -map "[odd]" odd_90cw_odd.mp4 -map "[even]" odd_90cw_even.mp4
+ffmpeg -i even_90cw.mp4 -filter_complex "[0]il=l=d:c=d,split[o][e];[o]crop=iw:ih/2:0:0[odd];[e]crop=iw:ih/2:0:ih/2[even]" -map "[odd]" even_90cw_odd.mp4 -map "[even]" even_90cw_even.mp4
+
+# Rotate these 4 video back to normal (counter-clockwise)
+
+ffmpeg -i even_90cw_odd.mp4 -vf "transpose=2" even_odd.mp4
+ffmpeg -i even_90cw_even.mp4 -vf "transpose=2" even_even.mp4
+ffmpeg -i odd_90cw_odd.mp4 -vf "transpose=2" odd_odd.mp4
+ffmpeg -i odd_90cw_even.mp4 -vf "transpose=2" odd_even.mp4
+
+# Get filename
+
+filename=$(basename -- "$1")
+extension="${filename##*.}"
+filename="${filename%.*}"
+
+# Extract audio from original file
+
+ffmpeg -i $1 -acodec copy $filename.aac
+
+# Merge audio track into each one of the 4 videos
+
+ffmpeg -i $filename.aac -i even_odd.mp4 $filename.part1.$extension
+ffmpeg -i $filename.aac -i even_even.mp4 $filename.part2.$extension
+ffmpeg -i $filename.aac -i odd_odd.mp4 $filename.part3.$extension
+ffmpeg -i $filename.aac -i odd_even.mp4 $filename.part4.$extension
+
+# Remove useless files
+
+rm odd.mp4 even.mp4 odd_90cw.mp4 even_90cw.mp4 even_90cw_odd.mp4 even_90cw_even.mp4 odd_90cw_odd.mp4 odd_90cw_even.mp4 even_odd.mp4 even_even.mp4 odd_odd.mp4 odd_even.mp4 $filename.aac
+