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The Great Big Beautiful Tomorrow
28 octobre 2011, par
Mis à jour : Octobre 2011
Langue : English
Type : Texte
Autres articles (79)
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Contribute to documentation
13 avril 2011Documentation is vital to the development of improved technical capabilities.
MediaSPIP welcomes documentation by users as well as developers - including : critique of existing features and functions articles contributed by developers, administrators, content producers and editors screenshots to illustrate the above translations of existing documentation into other languages
To contribute, register to the project users’ mailing (...) -
Le profil des utilisateurs
12 avril 2011, parChaque utilisateur dispose d’une page de profil lui permettant de modifier ses informations personnelle. Dans le menu de haut de page par défaut, un élément de menu est automatiquement créé à l’initialisation de MediaSPIP, visible uniquement si le visiteur est identifié sur le site.
L’utilisateur a accès à la modification de profil depuis sa page auteur, un lien dans la navigation "Modifier votre profil" est (...) -
Selection of projects using MediaSPIP
2 mai 2011, parThe examples below are representative elements of MediaSPIP specific uses for specific projects.
MediaSPIP farm @ Infini
The non profit organizationInfini develops hospitality activities, internet access point, training, realizing innovative projects in the field of information and communication technologies and Communication, and hosting of websites. It plays a unique and prominent role in the Brest (France) area, at the national level, among the half-dozen such association. Its members (...)
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Dividing, processing and merging files with ffmpeg
9 novembre 2015, par João Carlos SantosI am trying to build an application that will divide an input video file (usually mp4) into chunks so that I can apply some processing to them concurrently and then merge them back into a single file.
To do this, I have outlined 4 steps :
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Forcing keyframes at specific intervals so to make sure that each
chunk can be played on its own. For this I am using the following
command :ffmpeg -i input.mp4 -force_key_frames
"expr:gte(t,n_forced*chunk_length)" keyframed.mp4where chunk_length is the duration of each chunk.
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Dividing keyframed.mp4 into multiple chunks.
Here is where I have my problem. I am using the following command :`ffmpeg -i keyframed.mp4 -ss 00:00:00 -t chunk_length -vcodec copy -acodec copy test1.mp4`
to get the first chunk from my keyframed file but it isn’t capturing
the output correctly, since it appears to miss the first keyframe.On other chunks, the duration of the output is also sometimes
slightly less than chunk_length, even though I am always using the
same -t chunk_length option -
Processing each chunk For this task, I am using the following
commands :ffmpeg -y -i INPUT_FILE -threads 1 -pass 1 -s 1280x720 -preset
medium -vprofile baseline -c:v libx264 -level 3.0 -vf
"format=yuv420p" -b:v 2000k -maxrate:v 2688k -bufsize:v 2688k -r 25
-g 25 -keyint_min 50 -x264opts "keyint=50:min-keyint=50:no-scenecut" -an -f mp4 -movflags faststart /dev/nullffmpeg -y -i INPUT_FILE -threads 1 -pass 2 -s 1280x720 -preset
medium -vprofile baseline -c:v libx264 -level 3.0 -vf
"format=yuv420p" -b:v 2000k -maxrate:v 2688k -bufsize:v 2688k -r 25
-g 25 -keyint_min 50 -x264opts "keyint=50:min-keyint=50:no-scenecut" -acodec libfaac -ac 2 -ar 48000 -ab 128k -f mp4 -movflags faststart OUTPUT_FILE.mp4This commands are not allowed to be modified, since my goal here is
to parallelize this process. -
Finally, to merge the files I am using concat and a list of the
outputs of the 2nd step, as follows :ffmpeg -f concat -i mylist.txt -c copy final.mp4
In conclusion, I am trying to find out a way to solve the problem with step 2 and also get some opinions if there is a better way to do this.
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Organic Traffic : What It Is and How to Increase It
19 septembre 2023, par Erin — Analytics Tips -
SOLVED - Compiling FFMPEG on Windows with Cywin and NDK r5
19 mai 2012, par protectedmemberThis isn't a question - it's an answer for alll of you who have been facing the same problems as I have. I've been trying to compile this thing for a while now and I know of the numerous posts floating around the internet offering help. I have read and tried most of the suggestions and wanted to colate my success into this single post for others to benefit from.
Since I don't have a blog, I thought it wouldn't hurt to post on here instead.
I have managed to compile FFMPEG 0.10.3 (Freedom) on Windows 7 (32 bit) using NDK r5 and Cygwin. The steps :
1 - Download/install Cygwin in the root of your C drive. I'm not going to give instructions on this, it's simple enough and there are plenty of tutorials on this.
2 - Download NDK r5 from here and extract to the root of your C drive.
3 - Download FFMPEG 0.10.3 from here and extract to the root of your C drive.
4 - Open the file 'configure' in the root of the FFMPEG directory in a text editor.
5 - Comment out lines 2073, 2074 and 2075.
6 - Below 2075, add the following line :
TMPDIR=c :/cygwin/tmp
7 - Download this script (thankyou roman10) and place it inside your FFMPEG root directory. Rename the file to
build_android.sh
8 - Open the script in a text editor and edit line 17 to read
c :/android-ndk-r5
9 - Click start > run and type "bash" (without the speech marks) and press enter.
10 - Type the following and press enter :
cd /cygdrive/c/ffmpeg-0.10.3
11 - Type the following and press enter :
./build_android.sh
12 - Sit back and wait... libffmpeg.so will soon appear in your "c :\ffmpeg-0.10.3\android\" directory (where is defined in the bottom of the script from roman10's blog). The default architecture is armv7-a.
The script from roman10's blog will actually compile quite a large shared object (.so) file. The compiler flags can be adjusted to suit your needs in the script from roman10's blog.
I hope this helps,
P.