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Autres articles (36)
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Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 septembre 2013, parCertains thèmes prennent en compte trois éléments de personnalisation : l’ajout d’un logo ; l’ajout d’une bannière l’ajout d’une image de fond ;
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Les formats acceptés
28 janvier 2010, parLes commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
ffmpeg -codecs ffmpeg -formats
Les format videos acceptés en entrée
Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
Les formats vidéos de sortie possibles
Dans un premier temps on (...) -
De l’upload à la vidéo finale [version standalone]
31 janvier 2010, parLe chemin d’un document audio ou vidéo dans SPIPMotion est divisé en trois étapes distinctes.
Upload et récupération d’informations de la vidéo source
Dans un premier temps, il est nécessaire de créer un article SPIP et de lui joindre le document vidéo "source".
Au moment où ce document est joint à l’article, deux actions supplémentaires au comportement normal sont exécutées : La récupération des informations techniques des flux audio et video du fichier ; La génération d’une vignette : extraction d’une (...)
Sur d’autres sites (4604)
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How to insert frames to compensate for frames lost during capture
5 novembre 2015, par JMorMy original clip was 22:47 long. I captured the video in avi with Ut Video Lossless Codec at 29.97 fps, with pcm 16 bit unsigned audio.
I am using Virtualdub with VHScrCap driver for capture.
Virtualdub and mpc and potplayer play the captured file apparently too fast, but with the right audio pitch in the first 3-4 min, but high pitch in the rest of the video. The duration is 19:06, shorter than the original 22:47 (confirmed by mediainfo)
The cause of the problem seems to be that I am losing more frames when capturing large HD frames.Regular encoding
Encoding captured clip to mp4 :
ffmpeg -ss 3.25 -i input.avi -map 0:0 -map 0:1 -threads 0 -c:v libx264 -profile:v main \
-preset:v medium -level 3.1 -x264opts crf=26.0 -aspect 16:9 -t 1112.69 \
-y -f mp4 -vf "crop=1432:808:4:46, hqdn3d=1.5:1.5:6:6, \
scale=1216:684, pad=1280:720:32:18" -c:a ac3 -ac 2 -ar 48000 -b:a 160k \
output.mp4The output is 18:32 long, framerate is still 29:97. The audio pitch is OK in the first 2 minutes, and way too high in the rest of the video.
Trying to correct
I try to correct it in three steps by (1) encoding a video stream that is slowed down to 23.976 fps and extracting a wav audio stream, (2) slowing speed and pitch of audio and (3) remuxing video and audio :
(1)ffmpeg -ss 3.25 -i input.avi -threads 0 \
-c:v libx264 -profile:v main -preset:v medium -level 3.1 -x264opts crf=26.0 \
-aspect 16:9 -t 1390.862 -an -y -f mp4 -r 24000/1001 \
-vf "crop=1432:808:4:46, hqdn3d=1.5:1.5:6:6, scale=1216:684, pad=1280:720:32:18, \
setpts=1.25*PTS" video_out.mp4 \
-t 1112.69 -y -vn -f wav audio_out.wav(2) The wav audio stream is then slowed down with lower pitch with sox :
sox --norm audio_out.mp4.wav audio_out-24.wav speed 0.8
(3) The two streams are then remuxed with :
ffmpeg -i video_out.mp4 -i audio_out-24.wav -map 0:0 -map 1:0 -c:v copy \
-c:a ac3 -ac 2 -af aresample=resampler=soxr -ar 48000 -b:a 160k \
final_output.mp4This time, the video duration (23:10) is closer to the original, the pitch is OK for the whole video except for the first 2-3 minutes, where it is (predictably) too low.
I have a sense that (1) the capture log, and ffprobe give the frame by frame information that show what is the ’instantaneous’ real frame rate, and (2) that information is not used by ffmpeg encoding, but presumably could be used to correct the frame rate by inserting duplicate or interpolated frames to restitute the correct frame rate. I suspect I could get the information from (1), but have no clue how to do (2).
If someone familiar with this type of issue could give me some advice, and point me in the right direction, I would really appreciate.
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Compiling libstagefright with debug symbols
13 octobre 2015, par JohnI’m trying to compile a debug version of libstagefright. I have failed compiling anything from android source using android ndk, mostly because of messed up paths - if I fix one include path it will mess up another.
Although I prefer compiling from the original source, ffmpeg comes with a script called build_libstagefright. It uses git clone, but from CyanogenMod.
When I run the script :
sudo ./tools/build_libstagefright
I get :
arm-linux-androideabi-gcc is unable to create an executable file
I think one of the paths to NDK, toolchains or similar might be wrong.
How can I track down the problem ?Edit :
In the ./configure script which is being run by ./tools/build_libstagefright, it fails here :# compiler sanity check
check_exec <<eof int="int" return="return" eof="eof" if="if" test="test" then="then" echo="echo" is="is" unable="unable" to="to" create="create" an="an" executable="executable" enabled="enabled" a="a" use="use" the="the" do="do" this="this" you="you" know="know" what="what" cross="cross" compiling="compiling" fi="fi" die="die" compiler="compiler"></eof>code>Unfortunately, I’m not a bash master and I have no clue what’s going on in the rest of this script.
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Top 4 CRO Tools to Boost Your Conversion Rates in 2024
31 octobre 2023, par Erin