Boston Linux & UNIX was originally founded in 1994 as part of The Boston Computer Society. We meet on the third Wednesday of each month at the Massachusetts Institute of Technology, in Building E51.

BLU Discuss list archive


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Discuss] Video sync problems with BLU livestream



At last night's BLU meeting, there was a problem with the livestream
to youtube where it appeared to be streaming to youtube correctl, but
after the meeting I discovered that the audio had failed completely.

As a backup, I had also recorded the audio separately, to a WAV file,
which ffmpeg shows as

    Stream #0:0: Audio: adpcm_ima_wav ([17][0][0][0] / 0x0011), 24000
Hz, stereo, s16p, 192 kb/s

When I downloaded the video from youtube and tried to use kdenlive to
combine the audio and video tracks, I can't get them to sync properly.
When I manage to get it properly aligned at one spot, it gradually
gets further and further out of sync after the spot where it's
properly aligned.

What do I need to do to the WAV file to get it to sync correctly with the video?

The downloaded video's video stream shows
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661),
yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], 278 kb/s, 23.98 fps,
23.98 tbr, 90k tbn, 47.95 tbc (default)

The downloaded video's silent audio stream shows
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz,
stereo, fltp, 125 kb/s (default)



-- 
John Abreau / Executive Director, Boston Linux & Unix
Email: abreauj at gmail.com / WWW http://www.abreau.net / PGP-Key-ID 0x920063C6
PGP-Key-Fingerprint A5AD 6BE1 FEFE 8E4F 5C23  C2D0 E885 E17C 9200 63C6



BLU is a member of BostonUserGroups
BLU is a member of BostonUserGroups
We also thank MIT for the use of their facilities.

Valid HTML 4.01! Valid CSS!



Boston Linux & Unix / webmaster@blu.org