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Autres articles (100)
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Multilang : améliorer l’interface pour les blocs multilingues
18 février 2011, parMultilang est un plugin supplémentaire qui n’est pas activé par défaut lors de l’initialisation de MediaSPIP.
Après son activation, une préconfiguration est mise en place automatiquement par MediaSPIP init permettant à la nouvelle fonctionnalité d’être automatiquement opérationnelle. Il n’est donc pas obligatoire de passer par une étape de configuration pour cela. -
ANNEXE : Les plugins utilisés spécifiquement pour la ferme
5 mars 2010, parLe site central/maître de la ferme a besoin d’utiliser plusieurs plugins supplémentaires vis à vis des canaux pour son bon fonctionnement. le plugin Gestion de la mutualisation ; le plugin inscription3 pour gérer les inscriptions et les demandes de création d’instance de mutualisation dès l’inscription des utilisateurs ; le plugin verifier qui fournit une API de vérification des champs (utilisé par inscription3) ; le plugin champs extras v2 nécessité par inscription3 (...)
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L’agrémenter visuellement
10 avril 2011MediaSPIP est basé sur un système de thèmes et de squelettes. Les squelettes définissent le placement des informations dans la page, définissant un usage spécifique de la plateforme, et les thèmes l’habillage graphique général.
Chacun peut proposer un nouveau thème graphique ou un squelette et le mettre à disposition de la communauté.
Sur d’autres sites (12458)
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Segmentation fault with avcodec_encode_video2() while encoding H.264
16 juillet 2015, par Baris DemirayI’m trying to convert a
cv::Matto anAVFrameto encode it then in H.264 and wanted to start from a simple example, as I’m a newbie in both. So I first read in a JPEG file, and then do the pixel format conversion withsws_scale()fromAV_PIX_FMT_BGR24toAV_PIX_FMT_YUV420Pkeeping the dimensions the same, and it all goes fine until I callavcodec_encode_video2().I read quite a few discussions regarding an
AVFrameallocation and the question segmetation fault while avcodec_encode_video2 seemed like a match but I just can’t see what I’m missing or getting wrong.Here is the minimal code that you can reproduce the crash, it should be compiled with,
g++ -o OpenCV2FFmpeg OpenCV2FFmpeg.cpp -lopencv_imgproc -lopencv_highgui -lopencv_core -lswscale -lavutil -lavcodec -lavformatIt’s output on my system,
cv::Mat [width=420, height=315, depth=0, channels=3, step=1260]
I'll soon crash..
Segmentation faultAnd that
sample.jpgfile’s details byidentifytool,~temporary/sample.jpg JPEG 420x315 420x315+0+0 8-bit sRGB 38.3KB 0.000u 0:00.000Please note that I’m trying to create a video out of a single image, just to keep things simple.
#include <iostream>
#include <cassert>
using namespace std;
extern "C" {
#include <libavcodec></libavcodec>avcodec.h>
#include <libswscale></libswscale>swscale.h>
#include <libavformat></libavformat>avformat.h>
}
#include <opencv2></opencv2>core/core.hpp>
#include <opencv2></opencv2>highgui/highgui.hpp>
const string TEST_IMAGE = "/home/baris/temporary/sample.jpg";
int main(int /*argc*/, char** argv)
{
av_register_all();
avcodec_register_all();
/**
* Initialise the encoder
*/
AVCodec *h264encoder = avcodec_find_encoder(AV_CODEC_ID_H264);
AVFormatContext *cv2avFormatContext = avformat_alloc_context();
/**
* Create a stream and allocate frames
*/
AVStream *h264outputstream = avformat_new_stream(cv2avFormatContext, h264encoder);
avcodec_get_context_defaults3(h264outputstream->codec, h264encoder);
AVFrame *sourceAvFrame = av_frame_alloc(), *destAvFrame = av_frame_alloc();
int got_frame;
/**
* Pixel formats for the input and the output
*/
AVPixelFormat sourcePixelFormat = AV_PIX_FMT_BGR24;
AVPixelFormat destPixelFormat = AV_PIX_FMT_YUV420P;
/**
* Create cv::Mat
*/
cv::Mat cvFrame = cv::imread(TEST_IMAGE, CV_LOAD_IMAGE_COLOR);
int width = cvFrame.size().width, height = cvFrame.size().height;
cerr << "cv::Mat [width=" << width << ", height=" << height << ", depth=" << cvFrame.depth() << ", channels=" << cvFrame.channels() << ", step=" << cvFrame.step << "]" << endl;
h264outputstream->codec->pix_fmt = destPixelFormat;
h264outputstream->codec->width = cvFrame.cols;
h264outputstream->codec->height = cvFrame.rows;
/**
* Prepare the conversion context
*/
SwsContext *bgr2yuvcontext = sws_getContext(width, height,
sourcePixelFormat,
h264outputstream->codec->width, h264outputstream->codec->height,
h264outputstream->codec->pix_fmt,
SWS_BICUBIC, NULL, NULL, NULL);
/**
* Convert and encode frames
*/
for (uint i=0; i < 250; i++)
{
/**
* Allocate source frame, i.e. input to sws_scale()
*/
avpicture_alloc((AVPicture*)sourceAvFrame, sourcePixelFormat, width, height);
for (int h = 0; h < height; h++)
memcpy(&(sourceAvFrame->data[0][h*sourceAvFrame->linesize[0]]), &(cvFrame.data[h*cvFrame.step]), width*3);
/**
* Allocate destination frame, i.e. output from sws_scale()
*/
avpicture_alloc((AVPicture *)destAvFrame, destPixelFormat, width, height);
sws_scale(bgr2yuvcontext, sourceAvFrame->data, sourceAvFrame->linesize,
0, height, destAvFrame->data, destAvFrame->linesize);
/**
* Prepare an AVPacket for encoded output
*/
AVPacket avEncodedPacket;
av_init_packet(&avEncodedPacket);
avEncodedPacket.data = NULL;
avEncodedPacket.size = 0;
// av_free_packet(&avEncodedPacket); w/ or w/o result doesn't change
cerr << "I'll soon crash.." << endl;
if (avcodec_encode_video2(h264outputstream->codec, &avEncodedPacket, destAvFrame, &got_frame) < 0)
exit(1);
cerr << "Checking if we have a frame" << endl;
if (got_frame)
av_write_frame(cv2avFormatContext, &avEncodedPacket);
av_free_packet(&avEncodedPacket);
av_frame_free(&sourceAvFrame);
av_frame_free(&destAvFrame);
}
}
</cassert></iostream>Thanks in advance !
EDIT : And the stack trace after the crash,
Thread 2 (Thread 0x7fffe5506700 (LWP 10005)):
#0 0x00007ffff4bf6c5d in poll () at /lib64/libc.so.6
#1 0x00007fffe9073268 in () at /usr/lib64/libusb-1.0.so.0
#2 0x00007ffff47010a4 in start_thread () at /lib64/libpthread.so.0
#3 0x00007ffff4bff08d in clone () at /lib64/libc.so.6
Thread 1 (Thread 0x7ffff7f869c0 (LWP 10001)):
#0 0x00007ffff5ecc7dc in avcodec_encode_video2 () at /usr/lib64/libavcodec.so.56
#1 0x00000000004019b6 in main(int, char**) (argv=0x7fffffffd3d8) at ../src/OpenCV2FFmpeg.cpp:99EDIT2 : Problem was that I hadn’t
avcodec_open2()the codec as spotted by Ronald. Final version of the code is at https://github.com/barisdemiray/opencv2ffmpeg/, with leaks and probably other problems hoping that I’ll improve it while learning both libraries. -
How to restream IPTV playlist with Nginx RTMP, FFmpeg, and Python without recording, but getting HTTP 403 error ? [closed]
1er avril, par boyuna1720I have an IPTV playlist from a provider that allows only one user to connect and watch. I want to restream this playlist through my own server without recording it and in a lightweight manner. I’m using Nginx RTMP, FFmpeg, and Python TCP for the setup, but I keep getting an HTTP 403 error when trying to access the stream.


Here’s a summary of my setup :


Nginx RTMP : Used for streaming.


FFmpeg : Used to handle the video stream.


Python TCP : Trying to handle the connection between my server and the IPTV source.


#!/usr/bin/env python3

import sys
import socket
import threading
import requests
import time

def accept_connections(server_socket, clients, clients_lock):
 """
 Continuously accept new client connections, perform a minimal read of the
 client's HTTP request, send back a valid HTTP/1.1 response header, and
 add the socket to the broadcast list.
 """
 while True:
 client_socket, addr = server_socket.accept()
 print(f"[+] New client connected from {addr}")
 threading.Thread(
 target=handle_client,
 args=(client_socket, addr, clients, clients_lock),
 daemon=True
 ).start()

def handle_client(client_socket, addr, clients, clients_lock):
 """
 Read the client's HTTP request minimally, send back a proper HTTP/1.1 200 OK header,
 and then add the socket to our broadcast list.
 """
 try:
 # Read until we reach the end of the request headers
 request_data = b""
 while b"\r\n\r\n" not in request_data:
 chunk = client_socket.recv(1024)
 if not chunk:
 break
 request_data += chunk

 # Send a proper HTTP response header to satisfy clients like curl
 response_header = (
 "HTTP/1.1 200 OK\r\n"
 "Content-Type: application/octet-stream\r\n"
 "Connection: close\r\n"
 "\r\n"
 )
 client_socket.sendall(response_header.encode("utf-8"))

 with clients_lock:
 clients.append(client_socket)
 print(f"[+] Client from {addr} is ready to receive stream.")
 except Exception as e:
 print(f"[!] Error handling client {addr}: {e}")
 client_socket.close()

def read_from_source_and_broadcast(source_url, clients, clients_lock):
 """
 Continuously connect to the source URL (following redirects) using custom headers
 so that it mimics a curl-like request. In case of connection errors (e.g. connection reset),
 wait a bit and then try again.
 
 For each successful connection, stream data in chunks and broadcast each chunk
 to all connected clients.
 """
 # Set custom headers to mimic curl
 headers = {
 "User-Agent": "curl/8.5.0",
 "Accept": "*/*"
 }

 while True:
 try:
 print(f"[+] Fetching from source URL (with redirects): {source_url}")
 with requests.get(source_url, stream=True, allow_redirects=True, headers=headers) as resp:
 if resp.status_code >= 400:
 print(f"[!] Got HTTP {resp.status_code} from the source. Retrying in 5 seconds.")
 time.sleep(5)
 continue

 # Stream data and broadcast each chunk
 for chunk in resp.iter_content(chunk_size=4096):
 if not chunk:
 continue
 with clients_lock:
 for c in clients[:]:
 try:
 c.sendall(chunk)
 except Exception as e:
 print(f"[!] A client disconnected or send failed: {e}")
 c.close()
 clients.remove(c)
 except requests.exceptions.RequestException as e:
 print(f"[!] Source connection error, retrying in 5 seconds: {e}")
 time.sleep(5)

def main():
 if len(sys.argv) != 3:
 print(f"Usage: {sys.argv[0]} <port>")
 sys.exit(1)

 source_url = sys.argv[1]
 port = int(sys.argv[2])

 # Create a TCP socket to listen for incoming connections
 server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
 server_socket.bind(("0.0.0.0", port))
 server_socket.listen(5)
 print(f"[+] Listening on port {port}...")

 # List of currently connected client sockets
 clients = []
 clients_lock = threading.Lock()

 # Start a thread to accept incoming client connections
 t_accept = threading.Thread(
 target=accept_connections,
 args=(server_socket, clients, clients_lock),
 daemon=True
 )
 t_accept.start()

 # Continuously read from the source URL and broadcast to connected clients
 read_from_source_and_broadcast(source_url, clients, clients_lock)

if __name__ == "__main__":
 main()
</port>

When i write command
python3 proxy_server.py 'http://channelurl' 9999
I getting error.

[+] Listening on port 9999...
[+] Fetching from source URL (with redirects): http://ate91060.cdn-akm.me:80/dc31a19e5a6a/fc5e38e28e/325973
[!] Got HTTP 403 from the source. Retrying in 5 seconds.
^CTraceback (most recent call last):
 File "/home/namepirate58/nginx-1.23.1/proxy_server.py", line 127, in <module>
 main()
 File "/home/namepirate58/nginx-1.23.1/proxy_server.py", line 124, in main
 read_from_source_and_broadcast(source_url, clients, clients_lock)
 File "/home/namepirate58/nginx-1.23.1/proxy_server.py", line 77, in read_from_source_and_broadcast
 time.sleep(5)
KeyboardInterrupt
</module>

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What is “interoperable TTML” ?
1er janvier 2014, par silviaI’ve just tried to come to terms with the latest state of TTML, the Timed Text Markup Language.
TTML has been specified by the W3C Timed Text Working Group and released as a RECommendation v1.0 in November 2010. Since then, several organisations have tried to adopt it as their caption file format. This includes the SMPTE, the EBU (European Broadcasting Union), and Microsoft.
Both, Microsoft and the EBU actually looked at TTML in detail and decided that in order to make it usable for their use cases, a restriction of its functionalities is needed.
EBU-TT
The EBU released EBU-TT, which restricts the set of valid attributes and feature. “The EBU-TT format is intended to constrain the features provided by TTML, especially to make EBU-TT more suitable for the use with broadcast video and web video applications.” (see EBU-TT).
In addition, EBU-specific namespaces were introduce to extend TTML with EBU-specific data types, e.g. ebuttdt:frameRateMultiplierType or ebuttdt:smpteTimingType. Similarly, a bunch of metadata elements were introduced, e.g. ebuttm:documentMetadata, ebuttm:documentEbuttVersion, or ebuttm:documentIdentifier.
The use of namespaces as an extensibility mechanism will ascertain that EBU-TT files continue to be valid TTML files. However, any vanilla TTML parser will not know what to do with these custom extensions and will drop them on the floor.
Simple Delivery Profile
With the intention to make TTML ready for “internet delivery of Captions originated in the United States”, Microsoft proposed a “Simple Delivery Profile for Closed Captions (US)” (see Simple Profile). The Simple Profile is also a restriction of TTML.
Unfortunately, the Microsoft profile is not the same as the EBU-TT profile : for example, it contains the “set” element, which is not conformant in EBU-TT. Similarly, the supported style features are different, e.g. Simple Profile supports “display-region”, while EBU-TT does not. On the other hand, EBU-TT supports monospace, sans-serif and serif fonts, while the Simple profile does not.
Thus files created for the Simple Delivery Profile will not work on players that expect EBU-TT and the reverse.
Fortunately, the Simple Delivery Profile does not introduce any new namespaces and new features, so at least it is an explicit subpart of TTML and not both a restriction and extension like EBU-TT.
SMPTE-TT
SMPTE also created a version of the TTML standard called SMPTE-TT. SMPTE did not decide on a subset of TTML for their purposes – it was simply adopted as a complete set. “This Standard provides a framework for timed text to be supported for content delivered via broadband means,…” (see SMPTE-TT).
However, SMPTE extended TTML in SMPTE-TT with an ability to store a binary blob with captions in another format. This allows using SMPTE-TT as a transport format for any caption format and is deemed to help with “backwards compatibility”.
Now, instead of specifying a profile, SMPTE decided to define how to convert CEA-608 captions to SMPTE-TT. Even if it’s not called a “profile”, that’s actually what it is. It even has its own namespace : “m608 :”.
Conclusion
With all these different versions of TTML, I ask myself what a video player that claims support for TTML will do to get something working. The only chance it has is to implement all the extensions defined in all the different profiles. I pity the player that has to deal with a SMPTE-TT file that has a binary blob in it and is expected to be able to decode this.
Now, what is a caption author supposed to do when creating TTML ? They obviously cannot expect all players to be able to play back all TTML versions. Should they create different files depending on what platform they are targeting, i.e. a EBU-TT version, a SMPTE-TT version, a vanilla TTML version, and a Simple Delivery Profile version ? Should they by throwing all the features of all the versions into one TTML file and hope that the players will pick out the right things that they require and drop the rest on the floor ?
Maybe the best way to progress would be to make a list of the “safe” features : those features that every TTML profile supports. That may be the best way to get an “interoperable TTML” file. Here’s me hoping that this minimal set of features doesn’t just end up being the usual (starttime, endtime, text) triple.
UPDATE :
I just found out that UltraViolet have their own profile of SMPTE-TT called CFF-TT (see UltraViolet FAQ and spec). They are making some SMPTE-TT fields optional, but introduce a new @forcedDisplayMode attribute under their own namespace “cff :”.
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