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Bug de détection d’ogg
22 mars 2013, par
Mis à jour : Avril 2013
Langue : français
Type : Video
Autres articles (51)
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Les deux manières demandent les mêmes choses fonctionnent à peu près de la même manière, le futur utilisateur doit remplir une série de champ de formulaire permettant tout d’abord aux administrateurs d’avoir des informations quant à (...) -
Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir -
Taille des images et des logos définissables
9 février 2011, parDans beaucoup d’endroits du site, logos et images sont redimensionnées pour correspondre aux emplacements définis par les thèmes. L’ensemble des ces tailles pouvant changer d’un thème à un autre peuvent être définies directement dans le thème et éviter ainsi à l’utilisateur de devoir les configurer manuellement après avoir changé l’apparence de son site.
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Sur d’autres sites (8418)
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How to fix the "No working C compiler found." problem for compiling x264 in Linux ?
27 février 2023, par gc xuFirstly I have read all other solutions related to this problem, including adding path and reinstall yasm, nasm, gcc...
I git clone the source code from https://code.videolan.org/videolan/x264.git.
Then, I run command ./configure, it shows


./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
No working C compiler found.


I check the file "config.log". It shows :


checking for -Werror=unknown-warning-option... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=unknown-warning-option -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=unknown-attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=unknown-attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=ignored-attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=ignored-attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
x264 configure script
Command line options: "--enable-shared" "--enable-static"

checking whether gcc works... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -m64 -Wall -I. -I$(SRCPATH) -m64 -lm -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
DIED: No working C compiler found.


Plus I wonder is there something to do with nasm ? Becasuse I install nasm with some C grammer problems :


./config/config.h:659:16: error: duplicate ‘unsigned’
 659 | #define size_t unsigned int
 | ^~~~~~~~
./config/config.h:659:25: error: two or more data types in declaration specifiers
 659 | #define size_t unsigned int
 | ^~~
In file included from /usr/include/string.h:633,
 from ./include/compiler.h:89,
 from asm/nasm.c:38:
./include/compiler.h:241:7: error: expected identifier or ‘(’ before ‘__extension__’
 241 | char *strsep(char **, const char *);
 | ^~~~~~
./include/compiler.h:241:7: error: expected identifier or ‘(’ before ‘)’ token
 241 | char *strsep(char **, const char *);
 | ^~~~~~
make[1]: *** [asm/nasm.o] Error 1
make[1]: Leaving directory `/mnt/nfs0/gengcheng/ffmpeg-5.0.2/nasm-2.15.05'
make: *** [all] Error 2


I have read all other solutions related to this problem, including adding path and reinstall yasm, nasm, gcc...
I want to install x264 to configure it in ffmpeg. Thanks for all your answers !


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How to fix the "No working C compiler found." problem for compiling x264 in Linux ?
27 février 2023, par gc xuFirstly I have read all other solutions related to this problem, including adding path and reinstall yasm, nasm, gcc...
I git clone the source code from https://code.videolan.org/videolan/x264.git.
Then, I run command ./configure, it shows


./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
./configure: line 169: conftest.log: Invalid argument
No working C compiler found.


I check the file "config.log". It shows :


checking for -Werror=unknown-warning-option... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=unknown-warning-option -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=unknown-attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=unknown-attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
checking for -Werror=ignored-attributes... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -Wall -I. -I$(SRCPATH) -Werror=ignored-attributes -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
x264 configure script
Command line options: "--enable-shared" "--enable-static"

checking whether gcc works... no
Failed commandline was:
--------------------------------------------------
gcc conftest.c -m64 -Wall -I. -I$(SRCPATH) -m64 -lm -o conftest
cc1: error: ‘-Werror=unknown-warning-option’: no option -Wunknown-warning-option
--------------------------------------------------
Failed program was:
--------------------------------------------------
int main (void) { return 0; }
--------------------------------------------------
DIED: No working C compiler found.


Plus I wonder is there something to do with nasm ? Becasuse I install nasm with some C grammer problems :


./config/config.h:659:16: error: duplicate ‘unsigned’
 659 | #define size_t unsigned int
 | ^~~~~~~~
./config/config.h:659:25: error: two or more data types in declaration specifiers
 659 | #define size_t unsigned int
 | ^~~
In file included from /usr/include/string.h:633,
 from ./include/compiler.h:89,
 from asm/nasm.c:38:
./include/compiler.h:241:7: error: expected identifier or ‘(’ before ‘__extension__’
 241 | char *strsep(char **, const char *);
 | ^~~~~~
./include/compiler.h:241:7: error: expected identifier or ‘(’ before ‘)’ token
 241 | char *strsep(char **, const char *);
 | ^~~~~~
make[1]: *** [asm/nasm.o] Error 1
make[1]: Leaving directory `/mnt/nfs0/gengcheng/ffmpeg-5.0.2/nasm-2.15.05'
make: *** [all] Error 2


I have read all other solutions related to this problem, including adding path and reinstall yasm, nasm, gcc...
I want to install x264 to configure it in ffmpeg. Thanks for all your answers !


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Best logical formula to determine perceptual / "experienced" quality of a video, given resolution / fps and bitrate ?
20 mars 2023, par JamesKI am looking for a formula that can provide me with a relatively decent approximation of a Video's playback quality that can be calculated based off of four metrics : width, height, fps, and bitrate (bits/sec). Alternatively, I can also use FFMPEG or similar tools to calculate a Video's playback quality, if any of those tools provide something like what I am looking for here.


An example of what a Video might look like in my problem is as follows :


interface Video {
 /** The width of the Video (in pixels). */
 width: number
 /** The height of the Video (in pixels). */
 height: number
 /** The frame rate of the Video (frames per second). */
 fps: number
 /** The bitrate of the video, in bits per second (e.g. 5_000_000 = 5Mbit/sec) */
 bitrate: number
}


I came up with the following function to compute the average amount of bits available for any given pixel per second :


const computeVideoQualityScalar = (video: Video): number => {
 // The amount of pixels pushed to the display, per frame.
 const pixelsPerFrame = video.width * video.height
 
 // The amount of pixels pushed to the display, per second.
 const pixelsPerSecond = pixelsPerFrame * video.fps
 
 // The average amount of bits used by each pixel, each second,
 // to convey all data relevant to that pixel (e.g. color data, etc)
 const bitsPerPixelPerSecond = video.bitrate / pixelsPerSecond
 
 return bitsPerPixelPerSecond
}


While my formula does do a good job of providing a more-or-less "standardized" assessment of mathematical quality for any given video, it falls short when I try to use it to compare videos of different resolutions to one another. For example, a 1080p60fps video with a bitrate of 10Mbit/sec has a greater visual fidelity (at least, subjectively speaking, to my eyes) than a 720p30fps video with a bitrate of 9Mbit/sec, but my formula would score the 720p30fps video significantly higher than the 1080p60fps video because the 720p video has more bits available per pixel per second than the 1080p video.


I am struggling to come up with ideas as to how to either come up with a different way to calculate the "subjective video quality" for a given video, or extend upon my existing idea here.


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