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Personnaliser en ajoutant son logo, sa bannière ou son image de fond
5 September 2013, byCertains 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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Ecrire une actualité
21 June 2013, byPrésentez les changements dans votre MédiaSPIP ou les actualités de vos projets sur votre MédiaSPIP grâce à la rubrique actualités.
Dans le thème par défaut spipeo de MédiaSPIP, les actualités sont affichées en bas de la page principale sous les éditoriaux.
Vous pouvez personnaliser le formulaire de création d’une actualité.
Formulaire de création d’une actualité Dans le cas d’un document de type actualité, les champs proposés par défaut sont : Date de publication ( personnaliser la date de publication ) (...) -
Publier sur MédiaSpip
13 June 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
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Strange error with ffmpeg and unoconv in python script
27 May 2015, by Avery Ripoll CrockerI am creating a python script that can be used by other people to convert files. However when I use this script I keep getting a weird error when I run the subprocess for unoconv, this error is:
Traceback (most recent call last):
File "conversion.py", line 15, in <module>
check_call(["unoconv", "-f", Fileextension, filename])
File "/usr/lib/python2.7/subprocess.py", line 540, in check_call
raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['unoconv', '-f', '.pdf', 'journal.doc']' returned non-zero exit status 1
</module>I have looked through various resources for this, but the one answer I have been receiving is that I must have set up the unoconv line incorrectly. I have checked several times that the code is correct, and it is. The other peculiar thing is that my code for ffmpeg works. Does anybody have an idea as to why this happens.
Here is my program:
print "If at any point you wish to quit the program hit Ctrl + C"
filetype = raw_input("What kind of file would you like to convert? Audio, Image, Video or Document: ")
if filetype == "Document":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .txt: ")
from subprocess import check_call
check_call(["unoconv", "-f", Fileextension, filename])
elif filetype == "Audio":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .mp3: ")
body, ext = os.path.splitext("filename")
from subprocess import check_call
check_call(["ffmpeg" ,"-i", filename, body + Fileextension])
elif filetype == "Video":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .mp4: ")
body, ext = os.path.splitext("filename")
from subprocess import check_call
check_call(["ffmpeg" ,"-i", filename, body + Fileextension])
elif filetype == "Image":
path = raw_input("Please drag and drop the directory in which the file is stored into the terminal:")
os.chdir(path[1:-2])
filename = raw_input("Please enter the name of the file you would like to convert, including the file-type. e.g. test.txt, however please do make sure that the file-name does not have any spaces:")
Fileextension = raw_input("What filetype would you like the program to convert your file to. E.g. .Jpeg: ")
body, ext = os.path.splitext("filename")
from subprocess import check_call
check_call(["ffmpeg" ,"-i", filename, body + Fileextension]) -
avcodec/dpx: fix check of minimal data size for unpadded content
19 October 2022, by Jerome Martinezavcodec/dpx: fix check of minimal data size for unpadded content
stride value is not relevant with unpadded content and the total count
of pixels (width x height) must be used instead of the rounding based on
width only then multiplied by heightunpadded_10bit value computing is moved sooner in the code in order to
be able to use it during computing of minimal content size. Also make sure to
only set it for 10bit.Fix 'Overread buffer' error when the content is not lucky enough to have
(enough) padding bytes at the end for not being rejected by the formula
based on the stride valueFixes ticket #10259.
Signed-off-by: Jerome Martinez <jerome@mediaarea.net>
Signed-off-by: Marton Balint <cus@passwd.hu> -
Why is ffmpeg faster than this minimal example?
23 July 2022, by Dave CeddiaI'm wanting to read the audio out of a video file as fast as possible, using the libav libraries. It's all working fine, but it seems like it could be faster.


To get a performance baseline, I ran this ffmpeg command and timed it:


time ffmpeg -threads 1 -i file -map 0:a:0 -f null -


On a test file (a 2.5gb 2hr .MOV with pcm_s16be audio) this comes out to about 1.35 seconds on my M1 Macbook Pro.


On the other hand, this minimal C code (based on FFmpeg's "Demuxing and decoding" example) is consistently around 0.3 seconds slower.


#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>

static int decode_packet(AVCodecContext *dec, const AVPacket *pkt, AVFrame *frame)
{
 int ret = 0;

 // submit the packet to the decoder
 ret = avcodec_send_packet(dec, pkt);

 // get all the available frames from the decoder
 while (ret >= 0) {
 ret = avcodec_receive_frame(dec, frame);
 av_frame_unref(frame);
 }

 return 0;
}

int main (int argc, char **argv)
{
 int ret = 0;
 AVFormatContext *fmt_ctx = NULL;
 AVCodecContext *dec_ctx = NULL;
 AVFrame *frame = NULL;
 AVPacket *pkt = NULL;

 if (argc != 3) {
 exit(1);
 }

 int stream_idx = atoi(argv[2]);

 /* open input file, and allocate format context */
 avformat_open_input(&fmt_ctx, argv[1], NULL, NULL);

 /* get the stream */
 AVStream *st = fmt_ctx->streams[stream_idx];

 /* find a decoder for the stream */
 AVCodec *dec = avcodec_find_decoder(st->codecpar->codec_id);

 /* allocate a codec context for the decoder */
 dec_ctx = avcodec_alloc_context3(dec);

 /* copy codec parameters from input stream to output codec context */
 avcodec_parameters_to_context(dec_ctx, st->codecpar);

 /* init the decoder */
 avcodec_open2(dec_ctx, dec, NULL);

 /* allocate frame and packet structs */
 frame = av_frame_alloc();
 pkt = av_packet_alloc();

 /* read frames from the specified stream */
 while (av_read_frame(fmt_ctx, pkt) >= 0) {
 if (pkt->stream_index == stream_idx)
 ret = decode_packet(dec_ctx, pkt, frame);

 av_packet_unref(pkt);
 if (ret < 0)
 break;
 }

 /* flush the decoders */
 decode_packet(dec_ctx, NULL, frame);

 return ret < 0;
}


I tried measuring parts of this program to see if it was spending a lot of time in the setup, but it's not – at least 1.5 seconds of the runtime is the loop where it's reading frames.


So I took some flamegraph recordings (using cargo-flamegraph) and ran each a few times to make sure the timing was consistent. There's probably some overhead since both were consistently higher than running normally, but they still have the 0.3 second delta.


# 1.812 total
time sudo flamegraph ./minimal file 1

# 1.542 total
time sudo flamegraph ffmpeg -threads 1 -i file -map 0:a:0 -f null - 2>&1


Here are the flamegraphs stacked up, scaled so that the faster one is only 85% as wide as the slower one. (click for larger)




The interesting thing that stands out to me is how long is spent on
readin the minimal example vs. ffmpeg:



The time spent on
lseekis also a lot longer in the minimal program – it's plainly visible in that flamegraph, but in the ffmpeg flamegraph,lseekis a single pixel wide.

What's causing this discrepancy? Is ffmpeg actually doing less work than I think it is here? Is the minimal code doing something naive? Is there some buffering or other I/O optimizations that ffmpeg has enabled?


How can I shave 0.3 seconds off of the minimal example's runtime?


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