Build a custom boot animation

The boot animation is the OEM's first impression and one of the easiest things to get wrong in a way that costs boot time. The format is simple; the packaging is fussy and unforgiving.

Step 1 — Understand the format#

A bootanimation.zip is a stored (uncompressed) zip containing a desc.txt and one directory of PNG frames per part.

1920 720 30
p 1 0 part0
p 0 12 part1

Line 1 is width height fps. Then one line per part:

p <loop count> <pause frames> <directory>

• loop count — how many times to play; 0 means loop forever
• pause frames — frames to hold after the part
• directory — the folder of PNGs, played in filename order

So the example above plays part0 once, then loops part1 forever with a 12-frame pause each cycle — the standard "intro then loop until boot completes" shape.

Step 2 — Produce the frames#

mkdir -p bootanim/part0 bootanim/part1
 
# Intro: 30 frames at 1920x720
ffmpeg -i intro.mp4 -vf "scale=1920:720,fps=30" -frames:v 30 \
  bootanim/part0/%04d.png
 
# Loop: 60 frames
ffmpeg -i loop.mp4 -vf "scale=1920:720,fps=30" -frames:v 60 \
  bootanim/part1/%04d.png

# Every byte is read from flash during the busiest seconds of boot
optipng -o5 bootanim/part*/*.png
# or, much faster and nearly as good:
pngquant --quality=70-90 --ext .png --force bootanim/part*/*.png
 
du -sh bootanim/

Step 3 — Package it correctly#

cd bootanim
 
# -0 means no compression. bootanimation mmaps the entries; a deflated zip
# either fails to play or costs decompression time you cannot afford.
zip -0 -r ../bootanimation.zip desc.txt part0 part1
 
cd .. && unzip -v bootanimation.zip | head
# The Method column must read "Stored" for every entry

Step 4 — Install it into the product#

PRODUCT_COPY_FILES += \
    device/oem/vega/bootanimation.zip:$(TARGET_COPY_OUT_PRODUCT)/media/bootanimation.zip

The search order is /product/media, then /oem/media, then /system/media. Placing yours on /product means it wins without touching the system image.

m -j && emulator -wipe-data -no-snapshot &

# 1. It landed in the image
adb shell ls -la /product/media/bootanimation.zip
 
# 2. It is stored, not deflated
adb pull /product/media/bootanimation.zip /tmp/ba.zip
unzip -v /tmp/ba.zip | awk '{print $3}' | sort -u    # expect: Stored
 
# 3. bootanimation ran and did not complain
adb logcat -b all | grep -i bootanimation
 
# 4. Play it on demand, without rebooting
adb shell setprop service.bootanim.exit 0
adb shell start bootanim
sleep 6
adb shell setprop service.bootanim.exit 1

Step 5 — Measure what it cost#

adb shell bootstat --print
adb logcat -b events | grep boot_progress

Compare against your baseline from before the animation. If the delta is more than a fraction of a second, the frames are too large or too many.

Step 6 — Match the real display#

adb shell dumpsys display | grep -E 'real [0-9]+ x [0-9]+|density'
adb shell wm size
adb shell wm density

The first line of desc.txt must match. A mismatch produces a stretched or letterboxed animation, and on a multi-display cockpit the boot animation plays on the primary display only — check which one that is on your board.

Troubleshooting#

What you have now#

Every customisation surface in the platform track is now yours: a product, a daemon, policy, a HAL, properties, framework services, apps, theming, audio and branding. That is the full set an OEM programme actually touches.