Recherche avancée
Médias (29)
-
#7 Ambience
16 octobre 2011, par
Mis à jour : Juin 2015
Langue : English
Type : Audio
-
#6 Teaser Music
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#5 End Title
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#3 The Safest Place
16 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#4 Emo Creates
15 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
-
#2 Typewriter Dance
15 octobre 2011, par
Mis à jour : Février 2013
Langue : English
Type : Audio
Autres articles (43)
-
Participer à sa traduction
10 avril 2011Vous pouvez nous aider à améliorer les locutions utilisées dans le logiciel ou à traduire celui-ci dans n’importe qu’elle nouvelle langue permettant sa diffusion à de nouvelles communautés linguistiques.
Pour ce faire, on utilise l’interface de traduction de SPIP où l’ensemble des modules de langue de MediaSPIP sont à disposition. ll vous suffit de vous inscrire sur la liste de discussion des traducteurs pour demander plus d’informations.
Actuellement MediaSPIP n’est disponible qu’en français et (...) -
L’utiliser, en parler, le critiquer
10 avril 2011La première attitude à adopter est d’en parler, soit directement avec les personnes impliquées dans son développement, soit autour de vous pour convaincre de nouvelles personnes à l’utiliser.
Plus la communauté sera nombreuse et plus les évolutions seront rapides ...
Une liste de discussion est disponible pour tout échange entre utilisateurs. -
Pas question de marché, de cloud etc...
10 avril 2011Le vocabulaire utilisé sur ce site essaie d’éviter toute référence à la mode qui fleurit allègrement
sur le web 2.0 et dans les entreprises qui en vivent.
Vous êtes donc invité à bannir l’utilisation des termes "Brand", "Cloud", "Marché" etc...
Notre motivation est avant tout de créer un outil simple, accessible à pour tout le monde, favorisant
le partage de créations sur Internet et permettant aux auteurs de garder une autonomie optimale.
Aucun "contrat Gold ou Premium" n’est donc prévu, aucun (...)
Sur d’autres sites (5774)
-
Record video stream in rust
19 novembre 2024, par El_LocoI have bought a stereo camera with global shutter and a frame rate of at most 120 fps. https://www.amazon.com/dp/B0D8T3ZSL4?ref_=pe_386300_442618370_TE_sc_as_ri_0#


My next step is to write a program that can show and record a video with desired fps and resolution.


use opencv::{
 core, highgui,
 prelude::*,
 videoio::{self, VideoCapture},
 Result,
};

fn open_camera() -> Result<videocapture> {
 let capture = videoio::VideoCapture::new(2, videoio::CAP_ANY)?;
 return Ok(capture);
}
fn main() -> Result<()> {
 let window = "video capture";
 highgui::named_window(window, highgui::WINDOW_AUTOSIZE)?;
 let mut cam = open_camera()?;
 let opened = videoio::VideoCapture::is_opened(&cam)?;
 if !opened {
 panic!("Unable to open default camera!");
 }
 let width = 3200.0;
 let height = 1200.0;
 cam.set(videoio::CAP_PROP_FRAME_WIDTH, width)?;
 cam.set(videoio::CAP_PROP_FRAME_HEIGHT, height)?;

 // Set the frame rate (FPS)
 let fps = 60.0;
 
 let fourcc = videoio::VideoWriter::fourcc('M', 'J', 'P', 'G')?;
 let mut writer = videoio::VideoWriter::new(
 "video_output.avi",
 fourcc,
 fps,
 core::Size::new(width as i32, height as i32),
 true,
 )?;

 if !writer.is_opened()? {
 println!("Error: Could not open the video writer.");
 }

 let mut frame = core::Mat::default();
 let mut ctr = 0;
 while cam.read(&mut frame)? {
 if frame.empty() {
 break;
 }
 writer.write(&frame)?;
 highgui::imshow(window, &frame)?;
 
 let key = highgui::wait_key(1)?;
 if key > 0 {
 break;
 }
 ctr += 1;
 if ctr == 600 {
 break;
 }
 }
 cam.release()?;
 writer.release()?;
 Ok(())
}
</videocapture>

When I run this code the frame rate is terrible. Like 1 fps or something. For debugging I tried to run in cheese. There I got 30 fps with full resolution
3200x1200. But I cannot change the fps to 60 fps what I can see.

Then I tried to capture a video using ffmpeg :


ffmpeg -f v4l2 -framerate 60 -video_size 3200x1200 -i /dev/video2 output.mp4

With the following output :


[video4linux2,v4l2 @ 0x5a72cbbd1400] The driver changed the time per frame from 1/60 to 1/2
Input #0, video4linux2,v4l2, from '/dev/video2':
 Duration: N/A, start: 2744.250608, bitrate: 122880 kb/s
 Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 3200x1200, 122880 kb/s, 2 fps, 2 tbr, 1000k tbn
File 'output.mp4' already exists. Overwrite? [y/N]


The frame rate is lowered to 2 fps.


Then I tried to run
v4l2-ctl --list-formats-ext -d 2with the following output :

ioctl: VIDIOC_ENUM_FMT
 Type: Video Capture

 [0]: 'MJPG' (Motion-JPEG, compressed)
 Size: Discrete 3200x1200
 Interval: Discrete 0.017s (60.000 fps)
 Interval: Discrete 0.033s (30.000 fps)
 Interval: Discrete 0.040s (25.000 fps)
 Interval: Discrete 0.050s (20.000 fps)
 Interval: Discrete 0.067s (15.000 fps)
 Interval: Discrete 0.100s (10.000 fps)
 Size: Discrete 2560x720
 Interval: Discrete 0.017s (60.000 fps)
 Interval: Discrete 0.033s (30.000 fps)
 Interval: Discrete 0.040s (25.000 fps)
 Interval: Discrete 0.050s (20.000 fps)
 Interval: Discrete 0.067s (15.000 fps)
 Interval: Discrete 0.100s (10.000 fps)
 Size: Discrete 1600x600
 Interval: Discrete 0.008s (120.000 fps)
 Interval: Discrete 0.017s (60.000 fps)
 Interval: Discrete 0.033s (30.000 fps)
 Interval: Discrete 0.040s (25.000 fps)
 Interval: Discrete 0.050s (20.000 fps)
 Interval: Discrete 0.067s (15.000 fps)


I then tried to open the camera using
qv4land there it seemed to work. Does not seem like I can record a video though.

I am using Rust to learn. I want to be able to programmatically be able to record a video somehow and then do computer vision. The easiest would be to do it in Rust. But other solutions are ok.


Edit
I have found some more this morning :


v4l2-ctl -d 2 --list-formats-ext
ioctl: VIDIOC_ENUM_FMT
 Type: Video Capture

 [0]: 'MJPG' (Motion-JPEG, compressed)
 Size: Discrete 3200x1200
 Interval: Discrete 0.017s (60.000 fps)
 Interval: Discrete 0.033s (30.000 fps)
 Interval: Discrete 0.040s (25.000 fps)
 Interval: Discrete 0.050s (20.000 fps)
 Interval: Discrete 0.067s (15.000 fps)
 Interval: Discrete 0.100s (10.000 fps)

 [1]: 'YUYV' (YUYV 4:2:2)
 Size: Discrete 3200x1200
 Interval: Discrete 0.500s (2.000 fps)
 Size: Discrete 2560x720
 Interval: Discrete 0.500s (2.000 fps)
 Size: Discrete 1600x600
 Interval: Discrete 0.100s (10.000 fps)


I also found here that order of flags was important for
ffmpeg. Running this I can actually record a video with 60 fps :

ffmpeg -framerate 60 -f v4l2 -video_size 3200x1200 -input_format mjpeg -i /dev/video2 output.avi

A drawback is that the images does not look very sharp. You can clearly see the pixels. (I am new to video formats etc as well. Before it has just worked.)


If I change from
avitomkvit is slow again.

In the link above I also saw a suggestion to first do :


ffmpeg -framerate 60 -f v4l2 -video_size 3200x1200 -input_format mjpeg -i /dev/video2 -c copy mjpeg.mkv

and then :


ffmpeg -i mjpeg.mkv -c:v libx264 -crf 23 -preset medium -pix_fmt yuv420p out.mkv

which worked. But I am not sure those flags are ideal for the camera I have. I think it is a good start to make it run as expected using command line and ffmpeg. So I know what format to use and that it actually works as intended before doing it programmatically.


-
Can I convert a django video upload from a form using ffmpeg before storing the video ?
5 mai 2014, par GetItDoneI’ve been stuck for weeks trying to use ffmpeg to convert user uploaded videos to flv. I use heroku to host my website, and store my static and media files on amazon S3 with s3boto. The initial video file will upload fine, however when I retrieve the video and run a celery task (in the same view where the initial video file is uploaded), the new file won’t store on S3. I’ve been trying to get this to work for over a month, with no luck, and really no good resources available for learning how to do this, so I figure maybe if I can get the ffmpeg task to run before storing the video I may be able to get it to work. Unfortunately I’m still not a very advanced at python (or django), so I don’t even know if/how this is possible. Anyone have any ideas ? I am willing to use any solution at this point no matter how ugly, as long as it successfully takes video uploads and converts to flv using ffmpeg, with the resulting file being stored on S3. It doesn’t seem that my situation is very common, because no matter where I look, I cannot find a solution that explains what I should be trying to do. Therefore I will be very appreciative of any guidance. Thanks. My relevant code follows :
#models.py
def content_file_name(instance, filename):
ext = filename.split('.')[-1]
new_file_name = "remove%s.%s" % (uuid.uuid4(), ext)
return '/'.join(['videos', instance.teacher.username, new_file_name])
class BroadcastUpload(models.Model):
title = models.CharField(max_length=50, verbose_name=_('Title'))
description = models.TextField(max_length=100, verbose_name=_('Description'))
teacher = models.ForeignKey(User, null=True, blank=True, related_name='teacher')
created_date = models.DateTimeField(auto_now_add=True)
video_upload = models.FileField(upload_to=content_file_name)
flvfilename = models.CharField(max_length=100, null=True, blank=True)
videothumbnail = models.CharField(max_length=100, null=True, blank=True)
#tasks.py
@task(name='celeryfiles.tasks.convert_flv')
def convert_flv(video_id):
video = BroadcastUpload.objects.get(pk=video_id)
print "ID: %s" % video.id
id = video.id
print "VIDEO NAME: %s" % video.video_upload.name
teacher = video.teacher
print "TEACHER: %s" % teacher
filename = video.video_upload
sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
vidfilename = "%s_%s.flv" % (teacher, video.id)
targetfile = "%svideos/flv/%s" % (settings.MEDIA_URL, vidfilename)
ffmpeg = "ffmpeg -i %s %s" % (sourcefile, vidfilename)
try:
ffmpegresult = subprocess.call(ffmpeg)
#also tried separately with following line:
#ffmpegresult = commands.getoutput(ffmpeg)
print "---------------FFMPEG---------------"
print "FFMPEGRESULT: %s" % ffmpegresult
except Exception as e:
ffmpegresult = None
print("Failed to convert video file %s to %s" % (sourcefile, targetfile))
print(traceback.format_exc())
video.flvfilename = vidfilename
video.save()
@task(name='celeryfiles.tasks.ffmpeg_image')
def ffmpeg_image(video_id):
video = BroadcastUpload.objects.get(pk=video_id)
print "ID: %s" %video.id
id = video.id
print "VIDEO NAME: %s" % video.video_upload.name
teacher = video.teacher
print "TEACHER: %s" % teacher
filename = video.video_upload
sourcefile = "%s%s" % (settings.MEDIA_URL, filename)
imagefilename = "%s_%s.png" % (teacher, video.id)
thumbnailfilename = "%svideos/flv/%s" % (settings.MEDIA_URL, thumbnailfilename)
grabimage = "ffmpeg -y -i %s -vframes 1 -ss 00:00:02 -an -vcodec png -f rawvideo -s 320x240 %s" % (sourcefile, thumbnailfilename)
try:
videothumbnail = subprocess.call(grabimage)
#also tried separately following line:
#videothumbnail = commands.getoutput(grabimage)
print "---------------IMAGE---------------"
print "VIDEOTHUMBNAIL: %s" % videothumbnail
except Exception as e:
videothumbnail = None
print("Failed to convert video file %s to %s" % (sourcefile, thumbnailfilename))
print(traceback.format_exc())
video.videothumbnail = imagefilename
video.save()
#views.py
def upload_broadcast(request):
if request.method == 'POST':
form = BroadcastUploadForm(request.POST, request.FILES)
if form.is_valid():
upload=form.save()
video_id = upload.id
image_grab = ffmpeg_image.delay(video_id)
video_conversion = convert_flv.delay(video_id)
return HttpResponseRedirect('/current_classes/')
else:
form = BroadcastUploadForm(initial={'teacher': request.user,})
return render_to_response('videos/create_video.html', {'form': form,}, context_instance=RequestContext(request))
#settings.py
DEFAULT_FILE_STORAGE = 'myapp.s3utils.MediaRootS3BotoStorage'
DEFAULT_S3_PATH = "media"
STATICFILES_STORAGE = 'myapp.s3utils.StaticRootS3BotoStorage'
STATIC_S3_PATH = "static"
AWS_STORAGE_BUCKET_NAME = 'my_bucket'
CLOUDFRONT_DOMAIN = 'domain.cloudfront.net'
AWS_ACCESS_KEY_ID = 'MY_KEY_ID'
AWS_SECRET_ACCESS_KEY = 'MY_SECRET_KEY'
MEDIA_ROOT = '/%s/' % DEFAULT_S3_PATH
MEDIA_URL = 'http://%s/%s/' % (CLOUDFRONT_DOMAIN, DEFAULT_S3_PATH)
...
#s3utils.py
from storages.backends.s3boto import S3BotoStorage
from django.utils.functional import SimpleLazyObject
StaticRootS3BotoStorage = lambda: S3BotoStorage(location='static')
MediaRootS3BotoStorage = lambda: S3BotoStorage(location='media')I can add any other info if needed to help me solve my problem.
-
avcodec/pngdec : Fix APNG_DISPOSE_OP_BACKGROUND
20 août 2022, par Andreas Rheinhardtavcodec/pngdec : Fix APNG_DISPOSE_OP_BACKGROUND
APNG works with a single reference frame and an output frame.
According to the spec, decoding APNG works by decoding
the current IDAT/fdAT chunks (which decodes to a rectangular
subregion of the whole image region), followed by either
overwriting the region of the output frame with the newly
decoded data or by blending the newly decoded data with
the data from the reference frame onto the current subregion
of the output frame. The remainder of the output frame
is just copied from the reference frame.
Then the reference frame might be left untouched
(APNG_DISPOSE_OP_PREVIOUS), it might be replaced by the output
frame (APNG_DISPOSE_OP_NONE) or the rectangular subregion
corresponding to the just decoded frame has to be reset
to black (APNG_DISPOSE_OP_BACKGROUND).The latter case is not handled correctly by our decoder :
It only performs resetting the rectangle in the reference frame
when decoding the next frame ; and since commit
b593abda6c642cb0c3959752dd235c2faf66837f it does not reset
the reference frame permanently, but only temporarily (i.e.
it only affects decoding the frame after the frame with
APNG_DISPOSE_OP_BACKGROUND). This is a problem if the
frame after the APNG_DISPOSE_OP_BACKGROUND frame uses
APNG_DISPOSE_OP_PREVIOUS, because then the frame after
the APNG_DISPOSE_OP_PREVIOUS frame has an incorrect reference
frame. (If it is not followed by an APNG_DISPOSE_OP_PREVIOUS
frame, the decoder only keeps a reference to the output frame,
which is ok.)This commit fixes this by being much closer to the spec
than the earlier code : Resetting the background is no longer
postponed until the next frame ; instead it is applied to
the reference frame.Fixes ticket #9602.
(For multithreaded decoding it was actually already broken
since commit 5663301560d77486c7f7c03c1aa5f542fab23c24.)Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Syndiquer tout le site
