
Recherche avancée
Autres articles (30)
-
Gestion générale des documents
13 mai 2011, parMédiaSPIP ne modifie jamais le document original mis en ligne.
Pour chaque document mis en ligne il effectue deux opérations successives : la création d’une version supplémentaire qui peut être facilement consultée en ligne tout en laissant l’original téléchargeable dans le cas où le document original ne peut être lu dans un navigateur Internet ; la récupération des métadonnées du document original pour illustrer textuellement le fichier ;
Les tableaux ci-dessous expliquent ce que peut faire MédiaSPIP (...) -
La file d’attente de SPIPmotion
28 novembre 2010, parUne file d’attente stockée dans la base de donnée
Lors de son installation, SPIPmotion crée une nouvelle table dans la base de donnée intitulée spip_spipmotion_attentes.
Cette nouvelle table est constituée des champs suivants : id_spipmotion_attente, l’identifiant numérique unique de la tâche à traiter ; id_document, l’identifiant numérique du document original à encoder ; id_objet l’identifiant unique de l’objet auquel le document encodé devra être attaché automatiquement ; objet, le type d’objet auquel (...) -
Use, discuss, criticize
13 avril 2011, parTalk to people directly involved in MediaSPIP’s development, or to people around you who could use MediaSPIP to share, enhance or develop their creative projects.
The bigger the community, the more MediaSPIP’s potential will be explored and the faster the software will evolve.
A discussion list is available for all exchanges between users.
Sur d’autres sites (6037)
-
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 ?
-
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.