Resolve bitrate and speed from bits (not simply height).

1 files changed, 21 insertions, 11 deletions

diff --git a/bin/capture+encode+serve b/bin/capture+encode+serve
index 26c5f40..9c78374 100755
--- a/bin/capture+encode+serve
+++ b/bin/capture+encode+serve
@@ -43,51 +43,61 @@ chomp @ADEVICES;
 
 #use Data::Dump; die dd @ADEVICES;
 
-my $HEIGHT    = 240;
+my $HEIGHT    = 288;
 my $FRAMERATE = 25;
 my $AUDIORATE = 48000;
 
-# * height steps and bitrates based on https://developer.apple.com/library/content/documentation/General/Reference/HLSAuthoringSpec/Requirements.html
+my $RATIO_NUM = 4;
+my $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
 # * speeds tuned to just below 100% cpu usage for each combination on a multi-core computer
-# TODO: adjust height steps or bitrates for 4:3 aspect ratio
-# TODO: resolve steps from source height using http://aarmstrong.org/tutorials/aspect-ratios-and-h264
 # TODO: Externalize speeds to site-specific configfile
-my ( $VBITRATE, $SPEED_X264, $SPEED_X264_ALONE );
-if ( $HEIGHT le 234 ) {
+my ( $VBITRATE, $SPEED_X264, $SPEED_X264_ALONE, $SPEED_VP8,
+	$SPEED_VP8_ALONE );
+$RATIO_NUM ||= 16;
+$RATIO_DEN ||= 9;
+my $WIDTH  ||= $HEIGHT * $RATIO_NUM / $RATIO_DEN;
+$BITS = $WIDTH * $HEIGHT;
+
+if ( $BITS le 110592 ) {    # 234p → 97344
 	$VBITRATE         = 145000;
 	$SPEED_X264       = 'fast';
 	$SPEED_X264_ALONE = 'fast';
 	$SPEED_VP8        = 3;
 	$SPEED_VP8_ALONE  = 2;
 }
-elsif ( $HEIGHT le 270 ) {
+elsif ( $BITS le 150528 ) {    # 270p → 129600
 	$VBITRATE         = 365000;
 	$SPEED_X264       = 'faster';
 	$SPEED_X264_ALONE = 'fast';
 	$SPEED_VP8        = 4;
 	$SPEED_VP8_ALONE  = 2;
 }
-elsif ( $HEIGHT le 360 ) {
+elsif ( $BITS le 196608 ) {    # 360p → 172800
 	$VBITRATE         = 730000;
 	$SPEED_X264       = 'veryfast';
 	$SPEED_X264_ALONE = 'fast';
 	$SPEED_VP8        = 5;
 	$SPEED_VP8_ALONE  = 3;
 }
-elsif ( $HEIGHT le 432 ) {
+elsif ( $BITS le 331776 ) {    # 432p → 331776
 	$VBITRATE         = 1100000;
 	$SPEED_X264       = 'ultrafast';
 	$SPEED_X264_ALONE = 'fast';
 	$SPEED_VP8        = 8;
 	$SPEED_VP8_ALONE  = 4;
 }
-elsif ( $HEIGHT le 540 ) {
+elsif ( $BITS le 589824 ) {    # 540p → 518400
 	$VBITRATE         = 2000000;
 	$SPEED_X264       = 'toofast';
 	$SPEED_X264_ALONE = 'veryfast';
 	$SPEED_VP8_ALONE  = 5;
 }
-elsif ( $HEIGHT le 720 ) {
+elsif ( $BITS le 921600 ) {    # 720p → 921600
 	$VBITRATE         = 3000000;
 	$SPEED_X264       = 'toofast';
 	$SPEED_X264_ALONE = 'ultrafast';