
Recherche avancée
Médias (1)
-
Spitfire Parade - Crisis
15 mai 2011, par
Mis à jour : Septembre 2011
Langue : English
Type : Audio
Autres articles (107)
-
MediaSPIP 0.1 Beta version
25 avril 2011, parMediaSPIP 0.1 beta is the first version of MediaSPIP proclaimed as "usable".
The zip file provided here only contains the sources of MediaSPIP in its standalone version.
To get a working installation, you must manually install all-software dependencies on the server.
If you want to use this archive for an installation in "farm mode", you will also need to proceed to other manual (...) -
Mise à jour de la version 0.1 vers 0.2
24 juin 2013, parExplications des différents changements notables lors du passage de la version 0.1 de MediaSPIP à la version 0.3. Quelles sont les nouveautés
Au niveau des dépendances logicielles Utilisation des dernières versions de FFMpeg (>= v1.2.1) ; Installation des dépendances pour Smush ; Installation de MediaInfo et FFprobe pour la récupération des métadonnées ; On n’utilise plus ffmpeg2theora ; On n’installe plus flvtool2 au profit de flvtool++ ; On n’installe plus ffmpeg-php qui n’est plus maintenu au (...) -
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 ;
Sur d’autres sites (14199)
-
ffmpeg scale question.It succeed when the size is 2048,but when 4096 failed [closed]
7 septembre 2023, par 徐谷歌if :


ffmpeg -y -loop 1 -i ./rebirth/image4.png -loop 1 -t 1.4 -i temp.png -filter_complex "[0]scale=2048:2048[video0],[video0][1]xfade=transition=fade:duration=0.8:offset=0.1" -c:v libx264 -r 30 -pix_fmt yuv444p temp.mp4



it goes right.but when temp.png is bigger,it goes wrong,like :


ffmpeg -y -loop 1 -i ./rebirth/image4.png -loop 1 -t 1.4 -i temp.png -filter_complex "[0]scale=4096:4096[video0],[video0][1]xfade=transition=fade:duration=0.8:offset=0.1" -c:v libx264 -r 30 -pix_fmt yuv444p temp.mp4



I have enlarge the temp.png in the 2nd example.the size of image4.png is 1152x1152.


-
FFmpeg - Wave64 (.w64) file format : question regarding chunk GUIDs
26 janvier 2023, par pduI am having trouble understanding the headers of the Wave64 (.w64) files generated by
ffmpeg
and especially the GUIDs.

The specification


I have found this document which describes the file format and the GUIDs. I have also found other websites (here and here) that (indirectly) point to the same document. So this document is the only thing I have.


According to this document the GUIDs are 128bits/16bytes long and should start with the FourCC of the Wave file format, but in lowercase instead of uppercase (see page 3). It also says that the 64bits fields are stored in little-endian (see item 3 of the list page 1), but it does not say anything about 128bits fields (but it should be the same).
For example the GUID for the RIFF chunk is :
66666972-912E-11CF-A5D6-28DB04C10000
.

The problem


When I open a .w64 file generated by
ffmpeg
with an hex editor, I get this :72 69 66 66 2E 91 CF 11 A5 D6 28 DB 04 C1 00 00
. At the beginning,76 69 66 66
stands forriff
in ASCII. We can see that0x66666972
from the spec was indeed stored in little-endian order (so far, so good). If we continue, we have2E 91
andCF 11
, which are still little-endian for0x912E
and0x11CF
. But now it gets weird : the following group of bytes are :A5 D6
and28 DB 04 C1 00 00
for0xA5D6
and0x28DB04C10000
in the spec. So it is in big-endian now ?

For reference, the relevant
ffmpeg
source files are wavenc.c, w64.h and w64.c.
I have also found this thread where someone implemented a .wav to .w64 converter (see the .7z attachment in the first post) and the GUIDs are stored in the same way asffmpeg
.

Conclusion


Seeing that two different implementations are doing the same thing, it probably means that I am missing something. Do you have any explanation ?


-
Wave64 (.w64) file format : question regarding chunk GUIDs
24 janvier 2023, par pduI am having trouble understanding the headers of the Wave64 (.w64) files generated by
ffmpeg
and especially the GUIDs.

The specification


I have found this document which describes the file format and the GUIDs. I have also found other websites (here and here) that (indirectly) point to the same document. So this document is the only thing I have.


According to this document the GUIDs are 128bits/16bytes long and should start with the FourCC of the Wave file format, but in lowercase instead of uppercase (see page 3). It also says that the 64bits fields are stored in little-endian (see item 3 of the list page 1), but it does not say anything about 128bits fields (but it should be the same).
For example the GUID for the RIFF chunk is :
66666972-912E-11CF-A5D6-28DB04C10000
.

The problem


When I open a .w64 file generated by
ffmpeg
with an hex editor, I get this :72 69 66 66 2E 91 CF 11 A5 D6 28 DB 04 C1 00 00
. At the beginning,76 69 66 66
stands forriff
in ASCII. We can see that0x66666972
from the spec was indeed stored in little-endian order (so far, so good). If we continue, we have2E 91
andCF 11
, which are still little-endian for0x912E
and0x11CF
. But now it gets weird : the following group of bytes are :A5 D6
and28 DB 04 C1 00 00
for0xA5D6
and0x28DB04C10000
in the spec. So it is in big-endian now ?

For reference, the relevant
ffmpeg
source files are wavenc.c, w64.h and w64.c.
I have also found this thread where someone implemented a .wav to .w64 converter (see the .7z attachment in the first post) and the GUIDs are stored in the same way asffmpeg
.

Conclusion


Seeing that two different implementations are doing the same thing, it probably means that I am missing something. Do you have any explanation ?