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Autres articles (38)
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Encoding and processing into web-friendly formats
13 avril 2011, parMediaSPIP automatically converts uploaded files to internet-compatible formats.
Video files are encoded in MP4, Ogv and WebM (supported by HTML5) and MP4 (supported by Flash).
Audio files are encoded in MP3 and Ogg (supported by HTML5) and MP3 (supported by Flash).
Where possible, text is analyzed in order to retrieve the data needed for search engine detection, and then exported as a series of image files.
All uploaded files are stored online in their original format, so you can (...) -
Menus personnalisés
14 novembre 2010, parMediaSPIP utilise le plugin Menus pour gérer plusieurs menus configurables pour la navigation.
Cela permet de laisser aux administrateurs de canaux la possibilité de configurer finement ces menus.
Menus créés à l’initialisation du site
Par défaut trois menus sont créés automatiquement à l’initialisation du site : Le menu principal ; Identifiant : barrenav ; Ce menu s’insère en général en haut de la page après le bloc d’entête, son identifiant le rend compatible avec les squelettes basés sur Zpip ; (...) -
Emballe médias : à quoi cela sert ?
4 février 2011, parCe plugin vise à gérer des sites de mise en ligne de documents de tous types.
Il crée des "médias", à savoir : un "média" est un article au sens SPIP créé automatiquement lors du téléversement d’un document qu’il soit audio, vidéo, image ou textuel ; un seul document ne peut être lié à un article dit "média" ;
Sur d’autres sites (5785)
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How do I alter my FFMPEG command to make my HTTP Live Streams more efficient ?
17 octobre 2014, par RobertI want to reduce the muxing overhead when creating .ts files using FFMPEG.
Im using FFMPEG to create a series of transport stream files used for HTTP live streaming.
./ffmpeg -i myInputFile.ismv \
-vcodec copy \
-acodec copy \
-bsf h264_mp4toannexb \
-map 0 \
-f segment \
-segment_time 10\
-segment_list_size 999999 \
-segment_list output/myVarientPlaylist.m3u8 \
-segment_format mpegts \
output/myAudioVideoFile-%04d.tsMy input is in ismv format and contains a video and audio stream :
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 320x240, 348 kb/s, 29.97 tbr, 10000k tbn, 59.94 tbc
Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 63 kb/sThere is an issues related to muxing that is causing a large amout of overhead to be added to the streams. This is how the issue was described to me for the audio :
So for a given aac stream, the overhead will be 88% (since 200 bytes will map to 2 x 188 byte packets).
For video, the iframe packets are quite large, so they translate nicely into .ts packets, however, the diffs can be as small as an audio packet, therefore they suffer from the same issue.
The solution is to combine several aac packets into one larger stream before packaging them into .ts. Is this possible out of the box with FFMPEG ?
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Revision 17292 : Update Skeleton/OggIndex support to Skeleton 4.0. ffmpeg2theora now ...
16 juin 2010, par j — LogUpdate Skeleton/OggIndex ? support to Skeleton 4.0.
ffmpeg2theora now writes Skeleton 4.0 with index by default.
Patch by Chris Pearce -
can't read mp4 in opencv3.2 (ubuntu, python3)
28 mars 2017, par lhkI’ve ran into a problem with my opencv installation, it is unable to open an mp4 video. My system is ubuntu 16.04, 64bit, opencv3.2 used from python 3.5.
VideoCapture.read
returnsFalse
andNone
.There are other questions with this problem, but they target different platforms or different opencv versions.
Apparently, I’m missing the proper codec.
So I ranmake uninstall
from my build directory, purgedopencv*
with apt and built from source again. This time making sure thatffmpeg
was installed before the compilation.Here are my steps :
- clone opencv and opencv_contrib
cd opencv/
mkdir build
cd build
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D INSTALL_PYTHON_EXAMPLES=ON -D INSTALL_C_EXAMPLES=OFF -D OPENCV_EXTRA_MODULES_PATH=../../opencv_contrib/modules -D BUILD_EXAMPLES=ON ..
make -j 8
sudo make install
I checked the output of cmake, ffmpeg is there :
Video I/O:
-- DC1394 1.x: NO
-- DC1394 2.x: NO
-- FFMPEG: YES
-- avcodec: YES (ver 56.60.100)
-- avformat: YES (ver 56.40.101)
-- avutil: YES (ver 54.31.100)
-- swscale: YES (ver 3.1.101)
-- avresample: NO
-- GStreamer: NO
-- OpenNI: NO
-- OpenNI PrimeSensor Modules: NO
-- OpenNI2: NO
-- PvAPI: NO
-- GigEVisionSDK: NO
-- Aravis SDK: NO
-- UniCap: NO
-- UniCap ucil: NO
-- V4L/V4L2: NO/YES
-- XIMEA: NO
-- Xine: NO
-- gPhoto2: NOBut the problem persists. How can I fix this ?
UPDATE
I had to manually remove some .so files from /usr/local.
Then I installed all avi related codecs I could find.
https://wiki.ubuntuusers.de/Codecs/
plus libavcodec-extra and ffmpegThen I recompiled and now it works.