From 6f794349b9c0e7da1190235fdbd5229de533165f Mon Sep 17 00:00:00 2001
From: Jonas Smedegaard <dr@jones.dk>
Date: Thu, 18 May 2017 01:53:42 +0200
Subject: Resolve bitrate and speed from bits (not simply height).

---
 bin/decode+edit+encodeDV | 24 +++++++++++++++++-------
 1 file changed, 17 insertions(+), 7 deletions(-)

(limited to 'bin/decode+edit+encodeDV')

diff --git a/bin/decode+edit+encodeDV b/bin/decode+edit+encodeDV
index 6586b8a..ac64d2c 100755
--- a/bin/decode+edit+encodeDV
+++ b/bin/decode+edit+encodeDV
@@ -10,18 +10,28 @@ OUTPUT=../tmp/omni/show0/earth.dv
 
 HEIGHT=360
 
-# inspired by Apple HLS recommendations
-if [ $HEIGHT -le 234 ]; then
+RATIO_NUM=4
+RATIO_DEN=3
+
+# * bitrates and bits in parens based on https://developer.apple.com/library/content/documentation/General/Reference/HLSAuthoringSpec/Requirements.html
+#   + bits rounded up to include nearby modulo 16 formats
+#   + best (i.e. high-modulo) 16:9 heights: 216 288 360 432 576 720
+#   + best (i.e. high-modulo) 4:3 heights: 288 312 384 480 624 816
+RATIO_NUM=${RATION_NUM:-16}
+RATIO_DEN=${RATION_DEN:-9}
+WIDTH=${WIDTH:-$((HEIGHT*RATIO_NUM/RATIO_DEN))}
+BITS=$((WIDTH*HEIGHT))
+if [ $BITS -le 110592 ]; then # 234p → 97344
  VBITRATE=145000
-elif [ $HEIGHT -le 270 ]; then
+elif [ $BITS -le 150528 ]; then # 270p → 129600
  VBITRATE=365000
-elif [ $HEIGHT -le 360 ]; then
+elif [ $BITS -le 196608 ]; then # 360p → 172800
  VBITRATE=730000
-elif [ $HEIGHT -le 432 ]; then
+elif [ $BITS -le 331776 ]; then # 432p → 331776
  VBITRATE=1100000
-elif [ $HEIGHT -le 540 ]; then
+elif [ $BITS -le 589824 ]; then # 540p → 518400
  VBITRATE=2000000
-elif [ $HEIGHT -le 720 ]; then
+elif [ $BITS -le 921600 ]; then # 720p → 921600
  VBITRATE=3000000
 fi
 
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