shaka-packager/docs/source
Daniel Cantarín 89376d3c4d
feat: Allow LIVE UDP WebVTT input (#1349)
An updated version of PR #1027

That previous PR was done using 2021 code, and there were many changes
in the codebase from there, so a rebase was needed and also some minor
tweak here and there. But it's the same code, just reimplemented on a
newer codebase.

If you want to take a look at this in action, after building shaka
packager with this PR's code included, try this commands in 3 different
simultaneous bash sessions:

1. Video UDP input: `ffmpeg -f lavfi -re -i
"testsrc=s=320x240:r=30,format=yuv420p" -c:v h264 -sc_threshold 0 -g 30
-keyint_min 30 -r 30 -a53cc 1 -b:v 150k -preset ultrafast -r 30 -f
mpegts "udp://127.0.0.1:10000?pkt_size=1316"`
2. WebVTT UDP input: `for sec in $(seq 0 9999) ; do printf
"%02d:%02d.000 --> %02d:%02d.000\ntest second ${sec}\n\n" "$(( ${sec} /
60 ))" "$(( ${sec} % 60 ))" "$(( (${sec} + 1) / 60 ))" "$(( (${sec} + 1)
% 60 ))" ; sleep 1 ; done > /dev/udp/127.0.0.1/12345`
3. shaka packager command line: `timeout 60
path/to/build/packager/packager
'in=udp://127.0.0.1:10000?timeout=8000000,stream_selector=0,init_segment=240_init.m4s,segment_template=240_$Number%09d$.m4s,bandwidth=150000'
'in=udp://127.0.0.1:12345?timeout=8000000,stream_selector=0,input_format=webvtt,format=webvtt+mp4,init_segment=text_init.m4s,segment_template=text_$Number%09d$.m4s,language=eng,dash_roles=subtitle'
--mpd_output ./manifest.mpd --segment_duration 3.2
--suggested_presentation_delay 3.2 --min_buffer_time 3.2
--minimum_update_period 3.2 --time_shift_buffer_depth 60
--preserved_segments_outside_live_window 1 --default_language=eng
--dump_stream_info 2>&1`

Note the added `input_format=webvtt` to the shaka packager command's
second selector. That's new from this PR. If you don't use that, shaka's
format autodetection will not detect the webvtt format from the input,
as explained in
https://github.com/shaka-project/shaka-packager/issues/685#issuecomment-1029407191.
Try the command without it if you want to.

Fixes #685
Fixes #1017

---------

Co-authored-by: Daniel Cantarín <canta@canta.com.ar>
2024-02-23 16:02:19 -08:00
..
_static Updated style for option list and field list 2017-09-19 14:52:25 -07:00
options feat: Allow LIVE UDP WebVTT input (#1349) 2024-02-23 16:02:19 -08:00
tutorials feat: Add input support for EBU Teletext in MPEG-TS (#1344) 2024-02-23 15:31:48 -08:00
build_instructions.md build: Fix absl log flags being stripped (#1340) 2024-02-14 13:59:18 -08:00
conf.py ci: Fix main workflows (#1122) 2022-10-28 15:46:33 -07:00
design.rst Added architecture diagram 2017-12-01 00:29:50 +00:00
docker_instructions.md Default multicast interface address to "0.0.0.0" if absent 2017-12-04 19:21:52 +00:00
documentation.rst chore: Update URLs after moving projects (#1042) 2022-03-07 11:56:34 -08:00
index.rst chore: Update URLs after moving projects (#1042) 2022-03-07 11:56:34 -08:00
library.rst chore: Update URLs after moving projects (#1042) 2022-03-07 11:56:34 -08:00
library_details.rst Update the tutorial and documentation for multi-DRM support. 2018-07-26 06:13:37 +00:00