From 2ea28bba24d41e3ab872a8cb1f451e8a64ba1c22 Mon Sep 17 00:00:00 2001 From: Romain Bouqueau Date: Mon, 27 May 2024 07:27:34 -0400 Subject: [PATCH 1/2] scte35 documentation --- docs/Howtos/scte35-markers.md | 92 +++++++++++++++++++++++++++++++++++ 1 file changed, 92 insertions(+) create mode 100644 docs/Howtos/scte35-markers.md diff --git a/docs/Howtos/scte35-markers.md b/docs/Howtos/scte35-markers.md new file mode 100644 index 00000000..ec95230d --- /dev/null +++ b/docs/Howtos/scte35-markers.md @@ -0,0 +1,92 @@ +# Overview + +We discuss here about the ability to deal with dynamic metadata such as SCTE-35 in GPAC Filters. +The information is this page applies to other metadata such as ID3 markers (e.g. Nielsen), timecodes (TEMI, QT), or virtually any type of dynamic metadata. + +A special [dec_scte35 filter](dec_scte35) allows to segment SCTE-35 content for 23001-18 CMAF Event Track creation. + +GPAC is able to: +- inspect, +- remux or transmux, +- segment for DASH, +- create 23001-18 ISOBMFF Event Track (with ```emib``` and ```emeb``` boxes), +- edit these data to some extend. + +# Inspection + +The content can be inspect like any other content in GPAC. +Packet-based inspection may allow to dump useful information for analysis and reprocessing. + +## GPAC inspect + +``` +gpac -i input inspect:analyze=full:deep:props +``` + +would output: + +``` +[...] + + + + + + + + + +[...] +``` + +## MP4Box -dxml + +``` +MP4Box -dxml scte35.mp4 +``` + +scte35_dump.xml would contain for instance such descriptions for a sample: + +``` +[...] + + + + + + + + + + +[...] +``` + + +# Remux and transmux + +GPAC is able to remux any to any, including but not limited to: +- TS to TS +- MP4 (23001-18) to MP4 (23001-18) +- TS to MP4 (23001-18) + +See specific instructions in the next section when segmenting for OTT packaging (MPEG-DASH, HLS). + +The command-line is trivial: + +``` +gpac -i input -o output +``` + +The format is selected automatically depending on the file extension (or can be forced with ```:ext=```). + +# Segmentation and 23001-18 ISOBMFF Event Track + +Adaptive streaming with DASH or HLS requires the content to be segmented. Simple segmentation (where content can be replicated over several segments without any change) works for all kind of streams. + +For SCTE-35 streams the [dec_scte35 filter](dec_scte35) must be explicitly loaded. +Note that it can detect the segment duration from the [dasher](dasher) to create the right segmentation for you): + +``` +gpac -i input scte35dec -o output.mpd:segdur=2 +``` From e6923a3c60c11289094750104c5ae97e4798df60 Mon Sep 17 00:00:00 2001 From: Romain Bouqueau Date: Mon, 27 May 2024 14:43:16 -0400 Subject: [PATCH 2/2] updating index --- mkdocs.yml | 1 + 1 file changed, 1 insertion(+) diff --git a/mkdocs.yml b/mkdocs.yml index 0267141f..ee568569 100644 --- a/mkdocs.yml +++ b/mkdocs.yml @@ -89,6 +89,7 @@ nav: - GPAC and Python: Howtos/python.md - Simulating Real-Time sources: Howtos/realtime.md - ROUTE & ATSC3.0 services: Howtos/route.md + - SCTE-35, id3 markers, dynamic metadata: Howtos/scte35-markers.md - DASH & HLS: - Introduction: Howtos/dash/DASH-intro.md - MPEG-DASH basics: Howtos/dash/DASH-basics.md