Add a few makefiles for various operations.

mk/audio.mk

@@ -0,0 +1,24 @@
+#		-prf "asendcmd=0.0 afftdn sn start,asendcmd=2 afftdn sn stop,afftdn=nr=10:nf=-40" \
+
+SRC ?= tmp.opus
+record-audio:
+	record-audio.sh $(SRC)
+
+record-video:
+	record-video.sh $(SRC)
+
+OUTPUT ?= tmp.opus
+extract-audio:
+	ffmpeg -i $(SRC) $(OUTPUT)
+
+normalize:
+	@# f: force overriding previous files
+	@# koa: keep original audio
+	@# pr: progress
+	@# -nt {ebu,rms,peak}: normalization type (default is "ebu", which is what we want)
+	@# -t TARGET_LEVEL: target db/LUFS level (default is "-23")
+	@# (for EBU) -lrt LOUDNESS_RANGE_TARGET: max audio range (default is "7")
+	@#
+	@# ffmpeg options
+	@# -c:a AUDIO_CODEC
+	ffmpeg-normalize -f -koa -pr -c:a libopus $(SRC)

mk/random.mk

@@ -0,0 +1,8 @@
+APP ?= my-app
+strace-pid:
+	@# strace an already running application
+	sudo strace -p $$(pidof $(APP))
+
+strace:
+	@# --decode-fds = get file names
+	sudo strace --decode-fds -e desc,network $(APP)

mk/zram.mk

@@ -0,0 +1,44 @@
+PDNSDIR ?= /tmp/zram
+
+# Currently not working with alpine linux.
+zram: mkdir zram-module zram-create zram-format zram-mount
+unzram: zram-umount zram-free
+
+btrzram: mkdir zram-module zram-create btrzram-format zram-mount
+
+mkdir:; -mkdir $(PDNSDIR) 2>/dev/null
+
+zram-module:; modprobe zram
+zram-create:; zramctl --find --size 50000M -a zstd
+
+# -b 2048    block size, cannot be used (mkfs.ext4 wants 4k blocks minimum)
+# -N xxx     nb of inodes
+# -i xxx     higher inode ratio
+zram-format:; mkfs.ext4 -N 50000000 /dev/zram0
+zram-mount:; mount /dev/zram0 $(PDNSDIR)
+
+zram-umount:; -umount $(PDNSDIR)
+zram-free:; -zramctl -r /dev/zram0
+
+BTRFS_DIR ?= /tmp/btrfs
+BTRFS_IMG ?= /tmp/btrfs.img
+BTRFS_SIZ ?= 5000
+BTRFS_SECTOR_SIZE ?= 4096
+BTRFS_NODE_SIZE ?= 4096  # Minimal accepted value.
+BTRFS_LOOP ?= /dev/loop100
+BTRFS_COMP ?= zstd:8
+
+# apt install btrfs-progs
+btrfs: btrfs-mkdir btrfs-create btrfs-loop btrfs-format btrfs-mount btrfs-chown
+btrfs-mkdir:; [ ! -d $(BTRFS_DIR) ] && mkdir $(BTRFS_DIR) 2>/dev/null || :
+btrfs-create:
+	[ ! -f $(BTRFS_IMG) ] && su karchnu -c "dd if=/dev/zero of=$(BTRFS_IMG) bs=1M count=$(BTRFS_SIZ)" || :
+btrfs-loop:; losetup --sector-size $(BTRFS_SECTOR_SIZE) $(BTRFS_LOOP) $(BTRFS_IMG)
+btrfs-format:; mkfs.btrfs -s $(BTRFS_SECTOR_SIZE) -n $(BTRFS_NODE_SIZE) -L BTRDATA $(BTRFS_LOOP)
+btrfs-mount:; mount -o compress=$(BTRFS_COMP) $(BTRFS_LOOP) $(BTRFS_DIR)
+btrfs-chown:; chown karchnu $(BTRFS_DIR)
+
+unbtrfs: btrfs-umount btrfs-unloop btrfs-rm
+btrfs-unloop:; [ -b $(BTRFS_LOOP) ] && losetup -d $(BTRFS_LOOP) || :
+btrfs-umount:; umount $(BTRFS_DIR)
+btrfs-rm:; rm $(BTRFS_IMG)