Closed JamesTharakan closed 1 month ago
Hi @JamesTharakan,
livesim2 does not yet support wvtt subtitles. Issue #46 is about adding support for sources with wvtt segments. However, your content is not VTT but STPP (TTML) according to the manifest.
stpp
should be supported. I suspect this is an issue about a zero-byte end character in a utf8list in the stpp box as decoded by mp4ff. Could you upload the init segment of the asset as an attachment? Ideally with a non-mp4 file extension like ".init" to avoid having Github convert the link into a player link.
Update the text_init.mp4
$ MP4Box -info 1.m4s [iso file] Movie fragment but no moov (yet) - possibly broken parsing! File is a segment - 1 movie fragments - Brand mp41 (version 0): Fragment #1 size 377 (moof 104) {TKID 1 TFDT 0}
$ MP4Box -info text_init.mp4 Movie Info - 1 track - TimeScale 1000 Duration 00:00:00.000 Fragmented: yes - duration 02:09:52.000 0 fragments - 0 SegmentIndexes Progressive (moov before mdat) Major Brand mp41 - version 0 - compatible brands: iso8 isom mp41 dash cmfc Created: GMT Fri Jul 26 06:24:55 2024
Movie Meta type: "ID32" - 0 resource item(s)
Track 1 Info - ID 1 - TimeScale 1000 Media Duration 00:00:00.000 Track flags: Enabled In Movie In Preview Media Language: English (eng) Media Samples: 0 Fragmented track: 0 samples - Media Duration 00:00:00.000 Fragment sample defaults: duration 8000 size 0 stsd 1 sync 1 padding 0 degradation_priority 0 Media Type: subt:stpp XML Subtitle Stream - namespace http://www.w3.org/ns/ttml Size 0 x 0 - Translation X=0 Y=0 - Layer 0 RFC6381 Codec Parameters: stpp.ttml All samples are sync Max sample duration: 0 / 1000
$ mp4dump 1.m4s [styp] size=8+28 [sidx] size=12+32 reference_ID = 1 timescale = 1000 earliest_presentation_time = 0 first_offset = 0 [moof] size=8+96 [mfhd] size=12+4 sequence number = 1 [traf] size=8+72 [tfhd] size=12+20, flags=2003a track ID = 1 sample description index = 1 default sample duration = 8000 default sample size = 185 default sample flags = 0 [tfdt] size=12+8, version=1 base media decode time = 0 [trun] size=12+8, flags=1 sample count = 1 data offset
$ mp4info 1.m4s No movie found in the file
I looked at the file with mp4ff-info and it works fine. The root problem with stpp size mismatch goes back to https://github.com/Eyevinn/mp4ff/issues/228
It was solved in v0.43 of mp4ff which was included in livesim2 v1.3.0. Which version of livesim2 do you use?
Thanks, once I took the latest version, problem is solved.
The subtitle in vtt format is packaged with shakaPackager, below is the generated mpd segment. When loading in livesim2 we are getting the below error message.