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SPIP - plugins - embed code - Exemple
2 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
Autres articles (97)
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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 (...) -
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. -
MediaSPIP Core : La Configuration
9 novembre 2010, parMediaSPIP Core fournit par défaut trois pages différentes de configuration (ces pages utilisent le plugin de configuration CFG pour fonctionner) : une page spécifique à la configuration générale du squelettes ; une page spécifique à la configuration de la page d’accueil du site ; une page spécifique à la configuration des secteurs ;
Il fournit également une page supplémentaire qui n’apparait que lorsque certains plugins sont activés permettant de contrôler l’affichage et les fonctionnalités spécifiques (...)
Sur d’autres sites (5818)
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Prevent ffmpeg from collapsing multivalue metadata when converting formats
30 août 2022, par brjagaWhen using ffmpeg to convert FLAC files to Opus, I'm finding that multivalue metadata fields are getting collapsed into single values.


Here's the command I used :


ffmpeg -i steely_dan-fm.flac steely_dan-fm.opus


And here is one of the resulting tags when viewed with the mutagen library in Python :


>>> flac_metadata['performer']
['Walter Becker (electric guitar, bass)', 'Jeff Porcaro (drums, percussion)', 'Donald Fagen (vocals, piano)', 'Victor Feldman (percussion)', 'Glenn Frey (backing vocals)', 'Don Henley (backing vocals)', 'Tim Schmit (backing vocals)']
>>> opus_metadata['performer']
['Walter Becker (electric guitar, bass);Jeff Porcaro (drums, percussion);Donald Fagen (piano);Victor Feldman (percussion);Donald Fagen (vocals);Glenn Frey (backing vocals);Don Henley (backing vocals);Tim Schmit (backing vocals)']


Note that the former is a list of 9 strings, whereas the latter is a list of only one string.


Relevant section of the Vorbis Comment specification :




Field names are not required to be unique (occur once) within a comment header. As an example, assume a track was recorded by three well know [sic] artists ; the following is permissible, and encouraged :




ARTIST=Dizzy Gillespie 
 ARTIST=Sonny Rollins 
 ARTIST=Sonny Stitt 


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save a serial of images(cv::Mat) to a mp4 file in Variable Frame Rate mode by using ffmpeg library, how to set the pts ?
2 mai 2023, par ollydbg23In C++ code, I can correctly save a serial of images(opencv's
cv::Mat) to a mp4 file by usingffmpeglibrary, see the question and answer here : avformat_write_header() function call crashed when I try to save several RGB data to a output.mp4 file

Now here comes another question :


Rotem' answer in that question can have the
output.mp4saved correctly. When play the mp4 file, I see the frames(OpenCV'scv::Matimage) shows in a const rate.

What I can do if I have got the frames not in a const frequency, for example, the I got the first frame at the
0ms, and the second frame at the50msthe third frame at75ms, so that the each frame as associated time stamp, for example, those time stamp array are something like below :

int timestamp[100] = {0, 50, 75, ...};


What is the method to modify the Rotem's answer to reflect this ? It looks like I have to change the
ptsfield of eachframe. Because I just test the code, if I change this :

yuvFrame->pts = av_rescale_q(frame_count*frame_count, outCodecCtx->time_base, outStream->time_base); //Set PTS timestamp

// note I change from frame_count to frame_count*frame_count


Then the
output.mp4plays slower and slower, because the later frame has largeptsvalues.

Thanks.


EDIT


This is the code I'm currently used :


#include <iostream>
#include <vector>
#include <cstring>
#include <fstream>
#include <sstream>
#include <stdexcept>
#include <opencv2></opencv2>opencv.hpp>
extern "C" {
#include <libavutil></libavutil>imgutils.h>
#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>opt.h>
}

#include<cstdlib> // to generate time stamps

using namespace std;
using namespace cv;

int main()
{
 // Set up input frames as BGR byte arrays
 vector<mat> frames;

 int width = 640;
 int height = 480;
 int num_frames = 100;
 Scalar black(0, 0, 0);
 Scalar white(255, 255, 255);
 int font = FONT_HERSHEY_SIMPLEX;
 double font_scale = 1.0;
 int thickness = 2;

 for (int i = 0; i < num_frames; i++) {
 Mat frame = Mat::zeros(height, width, CV_8UC3);
 putText(frame, std::to_string(i), Point(width / 2 - 50, height / 2), font, font_scale, white, thickness);
 frames.push_back(frame);
 }

 // generate a serial of time stamps which is used to set the PTS value
 // suppose they are in ms unit, the time interval is between 30ms to 59ms
 vector<int> timestamps;

 for (int i = 0; i < num_frames; i++) {
 int timestamp;
 if (i == 0)
 timestamp = 0;
 else
 {
 int random = 30 + (rand() % 30);
 timestamp = timestamps[i-0] + random;
 }

 timestamps.push_back(timestamp);
 }

 // Populate frames with BGR byte arrays

 // Initialize FFmpeg
 //av_register_all();

 // Set up output file
 AVFormatContext* outFormatCtx = nullptr;
 //AVCodec* outCodec = nullptr;
 AVCodecContext* outCodecCtx = nullptr;
 //AVStream* outStream = nullptr;
 //AVPacket outPacket;

 const char* outFile = "output.mp4";
 int outWidth = frames[0].cols;
 int outHeight = frames[0].rows;
 int fps = 25;

 // Open the output file context
 avformat_alloc_output_context2(&outFormatCtx, nullptr, nullptr, outFile);
 if (!outFormatCtx) {
 cerr << "Error: Could not allocate output format context" << endl;
 return -1;
 }

 // Open the output file
 if (avio_open(&outFormatCtx->pb, outFile, AVIO_FLAG_WRITE) < 0) {
 cerr << "Error opening output file" << std::endl;
 return -1;
 }

 // Set up output codec
 const AVCodec* outCodec = avcodec_find_encoder(AV_CODEC_ID_H264);
 if (!outCodec) {
 cerr << "Error: Could not find H.264 codec" << endl;
 return -1;
 }

 outCodecCtx = avcodec_alloc_context3(outCodec);
 if (!outCodecCtx) {
 cerr << "Error: Could not allocate output codec context" << endl;
 return -1;
 }
 outCodecCtx->codec_id = AV_CODEC_ID_H264;
 outCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
 outCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
 outCodecCtx->width = outWidth;
 outCodecCtx->height = outHeight;
 outCodecCtx->time_base = { 1, fps*1000 }; // 25000
 outCodecCtx->framerate = {fps, 1}; // 25
 outCodecCtx->bit_rate = 4000000;

 //https://github.com/leandromoreira/ffmpeg-libav-tutorial
 //We set the flag AV_CODEC_FLAG_GLOBAL_HEADER which tells the encoder that it can use the global headers.
 if (outFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
 {
 outCodecCtx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER; //
 }

 // Open output codec
 if (avcodec_open2(outCodecCtx, outCodec, nullptr) < 0) {
 cerr << "Error: Could not open output codec" << endl;
 return -1;
 }

 // Create output stream
 AVStream* outStream = avformat_new_stream(outFormatCtx, outCodec);
 if (!outStream) {
 cerr << "Error: Could not allocate output stream" << endl;
 return -1;
 }

 // Configure output stream parameters (e.g., time base, codec parameters, etc.)
 // ...

 // Connect output stream to format context
 outStream->codecpar->codec_id = outCodecCtx->codec_id;
 outStream->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 outStream->codecpar->width = outCodecCtx->width;
 outStream->codecpar->height = outCodecCtx->height;
 outStream->codecpar->format = outCodecCtx->pix_fmt;
 outStream->time_base = outCodecCtx->time_base;

 int ret = avcodec_parameters_from_context(outStream->codecpar, outCodecCtx);
 if (ret < 0) {
 cerr << "Error: Could not copy codec parameters to output stream" << endl;
 return -1;
 }

 outStream->avg_frame_rate = outCodecCtx->framerate;
 //outStream->id = outFormatCtx->nb_streams++; <--- We shouldn't modify outStream->id

 ret = avformat_write_header(outFormatCtx, nullptr);
 if (ret < 0) {
 cerr << "Error: Could not write output header" << endl;
 return -1;
 }

 // Convert frames to YUV format and write to output file
 int frame_count = -1;
 for (const auto& frame : frames) {
 frame_count++;
 AVFrame* yuvFrame = av_frame_alloc();
 if (!yuvFrame) {
 cerr << "Error: Could not allocate YUV frame" << endl;
 return -1;
 }
 av_image_alloc(yuvFrame->data, yuvFrame->linesize, outWidth, outHeight, AV_PIX_FMT_YUV420P, 32);

 yuvFrame->width = outWidth;
 yuvFrame->height = outHeight;
 yuvFrame->format = AV_PIX_FMT_YUV420P;

 // Convert BGR frame to YUV format
 Mat yuvMat;
 cvtColor(frame, yuvMat, COLOR_BGR2YUV_I420);
 memcpy(yuvFrame->data[0], yuvMat.data, outWidth * outHeight);
 memcpy(yuvFrame->data[1], yuvMat.data + outWidth * outHeight, outWidth * outHeight / 4);
 memcpy(yuvFrame->data[2], yuvMat.data + outWidth * outHeight * 5 / 4, outWidth * outHeight / 4);

 // Set up output packet
 //av_init_packet(&outPacket); //error C4996: 'av_init_packet': was declared deprecated
 AVPacket* outPacket = av_packet_alloc();
 memset(outPacket, 0, sizeof(outPacket)); //Use memset instead of av_init_packet (probably unnecessary).
 //outPacket->data = nullptr;
 //outPacket->size = 0;

 yuvFrame->pts = av_rescale_q(timestamps[frame_count], outCodecCtx->time_base, outStream->time_base); //Set PTS timestamp

 // Encode frame and write to output file
 int ret = avcodec_send_frame(outCodecCtx, yuvFrame);
 if (ret < 0) {
 cerr << "Error: Could not send frame to output codec" << endl;
 return -1;
 }
 while (ret >= 0) {
 ret = avcodec_receive_packet(outCodecCtx, outPacket);
 if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
 break;
 } else if (ret < 0) {
 cerr << "Error: Could not receive packet from output codec" << endl;
 return -1;
 }

 //av_packet_rescale_ts(&outPacket, outCodecCtx->time_base, outStream->time_base);

 outPacket->stream_index = outStream->index;

 outPacket->duration = av_rescale_q(1, outCodecCtx->time_base, outStream->time_base); // Set packet duration

 ret = av_interleaved_write_frame(outFormatCtx, outPacket);
 av_packet_unref(outPacket);
 if (ret < 0) {
 cerr << "Error: Could not write packet to output file" << endl;
 return -1;
 }
 }

 av_frame_free(&yuvFrame);
 }

 // Flush the encoder
 ret = avcodec_send_frame(outCodecCtx, nullptr);
 if (ret < 0) {
 std::cerr << "Error flushing encoder: " << std::endl;
 return -1;
 }

 while (ret >= 0) {
 AVPacket* pkt = av_packet_alloc();
 if (!pkt) {
 std::cerr << "Error allocating packet" << std::endl;
 return -1;
 }
 ret = avcodec_receive_packet(outCodecCtx, pkt);

 // Write the packet to the output file
 if (ret == 0)
 {
 pkt->stream_index = outStream->index;
 pkt->duration = av_rescale_q(1, outCodecCtx->time_base, outStream->time_base); // <---- Set packet duration
 ret = av_interleaved_write_frame(outFormatCtx, pkt);
 av_packet_unref(pkt);
 if (ret < 0) {
 std::cerr << "Error writing packet to output file: " << std::endl;
 return -1;
 }
 }
 }


 // Write output trailer
 av_write_trailer(outFormatCtx);

 // Clean up
 avcodec_close(outCodecCtx);
 avcodec_free_context(&outCodecCtx);
 avformat_free_context(outFormatCtx);

 return 0;
}
</int></mat></cstdlib></stdexcept></sstream></fstream></cstring></vector></iostream>

Especially, I have those changes to the original Rotem's answer :


Fist, I have some code to generate a time stamp array :


// generate a serial of time stamps which is used to set the PTS value
 // suppose they are in ms unit, the time interval is between 30ms to 59ms
 vector<int> timestamps;

 for (int i = 0; i < num_frames; i++) {
 int timestamp;
 if (i == 0)
 timestamp = 0;
 else
 {
 int random = 30 + (rand() % 30);
 timestamp = timestamps[i-0] + random;
 }

 timestamps.push_back(timestamp);
 }
</int>

Second, I just set the PTS by those values :


yuvFrame->pts = av_rescale_q(timestamps[frame_count], outCodecCtx->time_base, outStream->time_base); //Set PTS timestamp


Note that I have set the fps like below :


outCodecCtx->time_base = { 1, fps*1000 }; // 25000
 outCodecCtx->framerate = {fps, 1}; // 25


Now, when I run the program, I got a lot of warnings in the console :


[libx264 @ 0000022e7fa621c0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0000022e7fa621c0] profile High, level 3.0, 4:2:0, 8-bit
[libx264 @ 0000022e7fa621c0] 264 - core 164 r3094M bfc87b7 - H.264/MPEG-4 AVC codec - Copyleft 2003-2022 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=4000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] non-strictly-monotonic PTS
[libx264 @ 0000022e7fa621c0] invalid DTS: PTS is less than DTS
[mp4 @ 0000022e090b2300] pts (592) < dts (1129348497) in stream 0
Error: Could not write packet to output file


Any ideas ?
Thanks.


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Getting error on video with Ruby on Rails 4 App
30 avril 2016, par D.GravesSo this is the error I get right after I try and upload my video
This is my post show
<%= video_tag @post.video.url(:medium), controls: true, style: "max-width: 100%;" %>
<p>
<strong>Description:</strong>
<%= @post.description %>
</p>
<% if @post.user == current_user %>
<%= link_to 'Edit', edit_post_path(@post) %>
<% end %>|
<%= link_to 'Back', posts_path %>This is my post model
class Post < ActiveRecord::Base
belongs_to :user
has_attached_file :video, styles: {
:medium => {
:geometry => "640x480",
:format => 'mp4'
},
:thumb => { :geometry => "160x120", :format => 'jpeg', :time => 10}
}, :processors => [:transcoder]
validates_attachment_content_type :video, content_type: /\Avideo\/.*\Z/
endI am curious if anyone has run into this before and I am wondering if I can get any help on how to fix this. I am using paperclip av-transcoder gem, ffmpeg and paperclip gem. I can add any more information if needed
Here is my post controller if this helps
def index
@posts = Post.all
end
def show
end
def new
@post = current_user.posts.build
end
def edit
end
def create
@post = current_user.posts.build(post_params)
if @post.save
redirect_to @post, notice: 'Post was successfully created.'
else
render :new
end
end
def update
if @post.update(post_params)
redirect_to @post, notice: 'Post was successfully updated.'
else
render :edit
end
end
def destroy
@post.destroy
redirect_to posts_url
end
private
def set_post
@post = Post.find_by(id: params[:id])
end
def correct_user
@post = current_user.posts.find_by(id: params[:id])
redirect_to posts_path, notice: "Not authorized to edit this post" if @post.nil?
end
def post_params
params.require(:post).permit(:description, :video)
end
end
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