WEBVTT Region parsing error on regionanchor

[vish91]

System info

Operating System: any
Shaka Packager Version: packager version v2.5.1-9f11077768-release

Issue and steps to reproduce the problem

Issue generating HLS or DASH output packages with VTT that has REGION and STYLE in them... from what I understand STYLE is ignored which is ok but the REGION validation is failing on us when it is actually as per the WEBVTT spec.

Packager Command:
packager 'in=audio.mp4,stream=audio,segment_template=/tmp/shaka/seg_$Number$.ts,lang=en,playlist_name=audio-en/stream.m3u8,hls_group_id=audio_aac,hls_name=English,drm_label=audio' 'in=video_375.mp4,stream=video,segment_template=/tmp/shaka/video_375/seg_$Number$.ts,iframe_playlist_name=video_375/stream_iframe.m3u8,playlist_name=video_375/stream.m3u8,drm_label=sd' 'in=/tmp/shaka/vtt_muxed.vtt,stream=text,segment_template=/tmp/shaka/vtt_muxed/seg_$Number$.vtt,playlist_name=vtt_muxed/stream_vtt.m3u8,hls_group_id=en_webvtt,language=en-us,hls_name=en-us' --clear_lead 0 --segment_duration 6 --hls_master_playlist_output /tmp/shaka/fp_hls/master.m3u8 --enable_raw_key_encryption --keys label=audio:key_id=...--iv ... --protection_scheme cbcs --pssh 0000.... --hls_key_uri ...

What is the expected result?
Generates the hls / dash package outputs correctly

What happens instead?
[1109/191212:ERROR:webvtt_parser.cc(355)] Invalid WebVTT REGION regionanchor: 0%,100%
[1109/191212:ERROR:packager_main.cc(551)] Packaging Error: 8 (PARSER_FAILURE): Cannot parse media file /tmp/shaka/vtt_muxed.vtt

Sample VTT:

WEBVTT

REGION
id:btc_region_initial
regionanchor:50%,100%
viewportanchor:50%,90%

STYLE
::cue {
	color:rgba(255, 255, 255, 1);
	background-color:rgba(0, 0, 0, 0.5);
	text-align:center;
}

00:00:06.033 --> 00:00:08.466 region:btc_region_initial line:85.0% position:50.0% size:8.0% align:middle
♪ ♪

00:00:08.533 --> 00:00:09.566 region:btc_region_initial line:85.0% position:40.0% size:43.0% align:middle
Congrats, Reagan.

00:00:10.066 --> 00:00:10.633 region:btc_region_initial line:85.0% position:48.0% size:23.0% align:middle
For what?

00:00:11.066 --> 00:00:13.400 region:btc_region_initial line:79.0% position:10.0% size:55.0% align:start
Jason Lipkis goes down
for three murders

00:00:13.666 --> 00:00:15.800 region:btc_region_initial line:79.0% position:10.0% size:68.0% align:start
and will never see sunlight
as a free man again.

00:00:16.366 --> 00:00:18.033 region:btc_region_initial line:79.0% position:50.0% size:63.0% align:middle
But all three of his vics
are still dead.

00:00:18.966 --> 00:00:21.033 region:btc_region_initial line:79.0% position:48.0% size:43.0% align:middle
Well, that's...
out of our hands.

[kqyang]

Yes, that is a bug.

https://github.com/google/shaka-packager/blob/cfbe5c08c2285bd22f1ba900629e9a6fcac4dde4/packager/media/formats/webvtt/webvtt_parser.cc#L87

Line 87 should be temp > 100 instead of temp >= 100. Can you try if adjusting it fix your issue? If it does, can you send a PR to fix it? Thanks.