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Keeping control of your media in your hands
13 avril 2011, parThe vocabulary used on this site and around MediaSPIP in general, aims to avoid reference to Web 2.0 and the companies that profit from media-sharing.
While using MediaSPIP, you are invited to avoid using words like "Brand", "Cloud" and "Market".
MediaSPIP is designed to facilitate the sharing of creative media online, while allowing authors to retain complete control of their work.
MediaSPIP aims to be accessible to as many people as possible and development is based on expanding the (...) -
Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
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Creating farms of unique websites
13 avril 2011, parMediaSPIP platforms can be installed as a farm, with a single "core" hosted on a dedicated server and used by multiple websites.
This allows (among other things) : implementation costs to be shared between several different projects / individuals rapid deployment of multiple unique sites creation of groups of like-minded sites, making it possible to browse media in a more controlled and selective environment than the major "open" (...)
Sur d’autres sites (6363)
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When using libva* (ffmpeg) encoded GIF images, an error is reported when compiling the demo
10 août 2023, par yangjinhui2936issuse : I need to use the GIF encoding feature in FFMPEG to encode argb images as gifs.Because the encoding effect of using GIF library is not as good as the effect of FFMPEG.
However, several libraries like avcodec were too bulky, so I did some cropping.I just want to keep the functionality of GIF encoding.
Below is my makefile for cropping ffmpeg :


#!/bin/sh
# ./configure --prefix=$(pwd)/output --arch=arm --target-os=linux --enable-cross-compile --disable-asm --cross-prefix=arm-linux-gnueabihf- 
./configure --prefix=$(pwd)/output --target-os=linux --disable-asm \
--disable-gpl --enable-nonfree --enable-error-resilience --enable-debug --enable-shared --enable-small --enable-zlib \
--disable-ffmpeg --disable-ffprobe --disable-ffplay --disable-programs --disable-symver\
 --disable-doc --disable-htmlpages --disable-manpages --disable-podpages --disable-decoder=h264 --enable-avformat \
 --disable-txtpages --enable-avcodec --enable-avutil \
 --disable-avresample --disable-avfilter --disable-avdevice --disable-postproc \
 --disable-swscale --enable-decoder=gif --enable-demuxer=gif --enable-muxer=gif --disable-iconv \
 --disable-v4l2-m2m --disable-indevs --disable-outdevs

make clean
make -j8

make install



Then link the compiled so to the gif demo.
Blew is gif demo code(He was automatically generated by chatgpt, and I want to verify it) :


#include 
// #include "output/include/imgutils.h"
#include "libavcodec/avcodec.h"
#include "libavformat/avformat.h"
#include "libavutil/avutil.h"

int main() {
 AVCodec *enc_codec;
 AVCodecContext *enc_ctx = NULL;
 AVStream *stream = NULL;
 int ret;

 AVFormatContext *fmt_ctx = avformat_alloc_context();
 if (!fmt_ctx) {
 fprintf(stderr, "Could not allocate format context\n");
 return 1;
 }
 
 AVInputFormat *input_fmt = av_find_input_format("image2");
 if ((ret = avformat_open_input(&fmt_ctx, "input.bmp", input_fmt, NULL)) < 0) {
 fprintf(stderr, "Could not open input file %d\n", ret);
 return ret;
 }

 AVCodec *dec_codec = avcodec_find_decoder(AV_CODEC_ID_BMP);
 if (!dec_codec) {
 fprintf(stderr, "Decoder not found\n");
 return 1;
 }
 
 AVCodecContext *dec_ctx = avcodec_alloc_context3(dec_codec);
 if (!dec_ctx) {
 fprintf(stderr, "Could not allocate decoder context\n");
 return 1;
 }

 if ((ret = avcodec_open2(dec_ctx, dec_codec, NULL)) < 0) {
 fprintf(stderr, "Could not open decoder\n");
 return 1;
 }

 AVOutputFormat *out_fmt = av_guess_format("gif", NULL, NULL);
 if (!out_fmt) {
 fprintf(stderr, "Could not find output format\n");
 return 1;
 }

 AVFormatContext *out_ctx = NULL;
 if ((ret = avformat_alloc_output_context2(&out_ctx, out_fmt, NULL, NULL)) < 0) {
 fprintf(stderr, "Could not allocate output context\n");
 return 1;
 }

 stream = avformat_new_stream(out_ctx, NULL);
 if (!stream) {
 fprintf(stderr, "Could not create new stream\n");
 return 1;
 }

 enc_codec = avcodec_find_encoder(AV_CODEC_ID_GIF);
 if (!enc_codec) {
 fprintf(stderr, "Encoder not found\n");
 return 1;
 }

 enc_ctx = avcodec_alloc_context3(enc_codec);
 if (!enc_ctx) {
 fprintf(stderr, "Could not allocate encoder context\n");
 return 1;
 }

 if ((ret = avcodec_parameters_from_context(stream->codecpar, dec_ctx)) < 0) {
 fprintf(stderr, "Could not copy decoder parameters\n");
 return 1;
 }

 if ((ret = avcodec_open2(enc_ctx, enc_codec, NULL)) < 0) {
 fprintf(stderr, "Could not open encoder\n");
 return 1;
 }
 
 enc_ctx->pix_fmt = AV_PIX_FMT_RGB8; 
 enc_ctx->width = dec_ctx->width; 
 enc_ctx->height = dec_ctx->height; 
 enc_ctx->time_base = (AVRational){1, 25}; 

 avformat_init_output(out_ctx, NULL);

 if (!(out_fmt->flags & AVFMT_NOFILE)) {
 if ((ret = avio_open(&out_ctx->pb, "output.gif", AVIO_FLAG_WRITE)) < 0) {
 fprintf(stderr, "Could not open output file\n");
 return ret;
 }
 }

 avformat_write_header(out_ctx, NULL);

 AVFrame *frame = av_frame_alloc();
 AVPacket pkt;
 int frame_count = 0;

 while (av_read_frame(fmt_ctx, &pkt) >= 0) {
 avcodec_send_packet(dec_ctx, &pkt);
 while (avcodec_receive_frame(dec_ctx, frame) == 0) {
 avcodec_send_frame(enc_ctx, frame);
 while (avcodec_receive_packet(enc_ctx, &pkt) == 0) {
 pkt.stream_index = stream->index;
 av_interleaved_write_frame(out_ctx, &pkt);
 av_packet_unref(&pkt);
 }

 frame_count++;
 printf("Encoded frame %d\n", frame_count);
 }
 av_packet_unref(&pkt);
 }

 av_write_trailer(out_ctx);

 avcodec_close(enc_ctx);
 avcodec_free_context(&enc_ctx);
 avcodec_close(dec_ctx);
 avcodec_free_context(&dec_ctx);
 av_frame_free(&frame);

 avformat_close_input(&fmt_ctx);
 avformat_free_context(fmt_ctx);
 avio_close(out_ctx->pb);
 avformat_free_context(out_ctx);

 return 0;
}




Belw is shell of compile script for gif :


#!/bin/sh
gcc -o x2gif x2gif.c -L ./output/lib/ -l:libavformat.a -l:libavcodec.a -l:libavutil.a -lz -I ./output/include/



Unfortunately, the compilation did not pass.
How can I troubleshoot and resolve this issue ?


./output/lib/libavutil.a(lfg.o): In function `av_bmg_get':
/data1/yang/tool/ffmpeg-3.4.4/libavutil/lfg.c:59: undefined reference to `log'
./output/lib/libavutil.a(hwcontext_cuda.o): In function `cuda_free_functions':
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:175: undefined reference to `dlclose'
./output/lib/libavutil.a(hwcontext_cuda.o): In function `cuda_load_functions':
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:192: undefined reference to `dlopen'
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:194: undefined reference to `dlsym'
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:195: undefined reference to `dlsym'
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:196: undefined reference to `dlsym'
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:197: undefined reference to `dlsym'
/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:198: undefined reference to `dlsym'
./output/lib/libavutil.a(hwcontext_cuda.o):/data1/yang/tool/ffmpeg-3.4.4/./compat/cuda/dynlink_loader.h:199: more undefined references to `dlsym' follow
./output/lib/libavutil.a(rational.o): In function `av_d2q':
/data1/yang/tool/ffmpeg-3.4.4/libavutil/rational.c:120: undefined reference to `floor'
./output/lib/libavutil.a(eval.o): In function `eval_expr':
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:184: undefined reference to `exp'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:185: undefined reference to `exp'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:189: undefined reference to `floor'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:190: undefined reference to `ceil'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:191: undefined reference to `trunc'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:192: undefined reference to `round'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:263: undefined reference to `pow'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:300: undefined reference to `floor'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:309: undefined reference to `pow'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:315: undefined reference to `hypot'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:316: undefined reference to `atan2'
./output/lib/libavutil.a(eval.o): In function `ff_exp10':
/data1/yang/tool/ffmpeg-3.4.4/libavutil/ffmath.h:44: undefined reference to `exp2'
./output/lib/libavutil.a(eval.o): In function `parse_primary':
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:417: undefined reference to `sinh'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:418: undefined reference to `cosh'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:419: undefined reference to `tanh'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:420: undefined reference to `sin'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:421: undefined reference to `cos'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:422: undefined reference to `tan'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:423: undefined reference to `atan'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:424: undefined reference to `asin'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:425: undefined reference to `acos'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:426: undefined reference to `exp'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:427: undefined reference to `log'
/data1/yang/tool/ffmpeg-3.4.4/libavutil/eval.c:428: undefined reference to `fabs'



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FFMPEG libav gdigrab capturing with wrong colors
7 mars 2018, par user1496491I’m capturing screen with code below, and it gets me the picture with wrong colors.
The picture on left is raw data which I assumed in ARGB the picture in right is encoded as YUV. I’ve tried different formats, the pictures slighly changing, but it’s never looks ow it should be. In what format gdigrab gives its output ? What’s the right way to encode it ?
#include "MainWindow.h"
#include <qguiapplication>
#include <qlabel>
#include <qscreen>
#include <qtimer>
#include <qlayout>
#include <qimage>
#include <qtconcurrent></qtconcurrent>QtConcurrent>
#include <qthreadpool>
#include "ScreenCapture.h"
MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
resize(800, 600);
label = new QLabel();
label->setAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
auto layout = new QHBoxLayout();
layout->addWidget(label);
auto widget = new QWidget();
widget->setLayout(layout);
setCentralWidget(widget);
init();
initOutFile();
collectFrame();
}
MainWindow::~MainWindow()
{
avformat_close_input(&inputFormatContext);
avformat_free_context(inputFormatContext);
QThreadPool::globalInstance()->waitForDone();
}
void MainWindow::init()
{
av_register_all();
avcodec_register_all();
avdevice_register_all();
auto screen = QGuiApplication::screens()[1];
QRect geometry = screen->geometry();
inputFormatContext = avformat_alloc_context();
AVDictionary* options = NULL;
av_dict_set(&options, "framerate", "30", NULL);
av_dict_set(&options, "offset_x", QString::number(geometry.x()).toLatin1().data(), NULL);
av_dict_set(&options, "offset_y", QString::number(geometry.y()).toLatin1().data(), NULL);
av_dict_set(&options, "preset", "ultrafast", NULL);
av_dict_set(&options, "probesize", "10MB", NULL);
av_dict_set(&options, "pix_fmt", "yuv420p", NULL);
av_dict_set(&options, "video_size", QString(QString::number(geometry.width()) + "x" + QString::number(geometry.height())).toLatin1().data(), NULL);
AVInputFormat* inputFormat = av_find_input_format("gdigrab");
avformat_open_input(&inputFormatContext, "desktop", inputFormat, &options);
// AVDictionary* options = NULL;
// av_dict_set(&options, "framerate", "30", NULL);
// av_dict_set(&options, "preset", "ultrafast", NULL);
// av_dict_set(&options, "vcodec", "h264", NULL);
// av_dict_set(&options, "s", "1280x720", NULL);
// av_dict_set(&options, "crf", "0", NULL);
// av_dict_set(&options, "rtbufsize", "100M", NULL);
// AVInputFormat *format = av_find_input_format("dshow");
// avformat_open_input(&inputFormatContext, "video=screen-capture-recorder", format, &options);
av_dict_free(&options);
avformat_find_stream_info(inputFormatContext, NULL);
videoStreamIndex = av_find_best_stream(inputFormatContext, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
inputCodec = avcodec_find_decoder(inputFormatContext->streams[videoStreamIndex]->codecpar->codec_id);
if(!inputCodec) qDebug() << "Не найден кодек входящего потока!";
inputCodecContext = avcodec_alloc_context3(inputCodec);
inputCodecContext->codec_id = inputCodec->id;
avcodec_parameters_to_context(inputCodecContext, inputFormatContext->streams[videoStreamIndex]->codecpar);
if(avcodec_open2(inputCodecContext, inputCodec, NULL)) qDebug() << "Не удалось открыть входной кодек!";
}
void MainWindow::initOutFile()
{
const char* filename = "C:/Temp/output.mp4";
if(avformat_alloc_output_context2(&outFormatContext, NULL, NULL, filename) < 0) qDebug() << "Не удалось создать выходной контекст!";
outCodec = avcodec_find_encoder(AV_CODEC_ID_MPEG4);
if(!outCodec) qDebug() << "Не удалось найти кодек!";
videoStream = avformat_new_stream(outFormatContext, outCodec);
videoStream->time_base = {1, 30};
const AVPixelFormat* pixelFormat = outCodec->pix_fmts;
while (*pixelFormat != AV_PIX_FMT_NONE)
{
qDebug() << "OUT_FORMAT" << av_get_pix_fmt_name(*pixelFormat);
++pixelFormat;
}
outCodecContext = videoStream->codec;
outCodecContext->bit_rate = 400000;
outCodecContext->width = inputCodecContext->width;
outCodecContext->height = inputCodecContext->height;
outCodecContext->time_base = videoStream->time_base;
outCodecContext->gop_size = 10;
outCodecContext->max_b_frames = 1;
outCodecContext->pix_fmt = AV_PIX_FMT_YUV420P;
if (outFormatContext->oformat->flags & AVFMT_GLOBALHEADER) outCodecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;
if(avcodec_open2(outCodecContext, outCodec, NULL)) qDebug() << "Не удалось открыть выходной кодек!";
swsContext = sws_getContext(inputCodecContext->width,
inputCodecContext->height,
// inputCodecContext->pix_fmt,
AV_PIX_FMT_ABGR,
outCodecContext->width,
outCodecContext->height,
outCodecContext->pix_fmt,
SWS_BICUBIC, NULL, NULL, NULL);
if(avio_open(&outFormatContext->pb, filename, AVIO_FLAG_WRITE) < 0) qDebug() << "Не удалось открыть файл!";
if(avformat_write_header(outFormatContext, NULL) < 0) qDebug() << "Не удалось записать заголовок!";
}
void MainWindow::collectFrame()
{
AVFrame* inFrame = av_frame_alloc();
inFrame->format = inputCodecContext->pix_fmt;
inFrame->width = inputCodecContext->width;
inFrame->height = inputCodecContext->height;
int size = av_image_alloc(inFrame->data, inFrame->linesize, inFrame->width, inFrame->height, inputCodecContext->pix_fmt, 1);
qDebug() << size;
AVFrame* outFrame = av_frame_alloc();
outFrame->format = outCodecContext->pix_fmt;
outFrame->width = outCodecContext->width;
outFrame->height = outCodecContext->height;
qDebug() << av_image_alloc(outFrame->data, outFrame->linesize, outFrame->width, outFrame->height, outCodecContext->pix_fmt, 1);
AVPacket packet;
av_init_packet(&packet);
av_read_frame(inputFormatContext, &packet);
// while(av_read_frame(inputFormatContext, &packet) >= 0)
// {
if(packet.stream_index == videoStream->index)
{
memcpy(inFrame->data[0], packet.data, size);
sws_scale(swsContext, inFrame->data, inFrame->linesize, 0, inputCodecContext->height, outFrame->data, outFrame->linesize);
QImage image(inFrame->data[0], inFrame->width, inFrame->height, QImage::Format_ARGB32);
label->setPixmap(QPixmap::fromImage(image).scaled(label->size(), Qt::KeepAspectRatio));
AVPacket outPacket;
av_init_packet(&outPacket);
int encodeResult = avcodec_receive_packet(outCodecContext, &outPacket);
while(encodeResult == AVERROR(EAGAIN))
{
if(avcodec_send_frame(outCodecContext, outFrame)) qDebug() << "Ошибка отправки фрейма на кодирование!";
encodeResult = avcodec_receive_packet(outCodecContext, &outPacket);
}
if(encodeResult != 0) qDebug() << "Ошибка во время кодирования!" << encodeResult;
if(outPacket.pts != AV_NOPTS_VALUE) outPacket.pts = av_rescale_q(outPacket.pts, videoStream->codec->time_base, videoStream->time_base);
if(outPacket.dts != AV_NOPTS_VALUE) outPacket.dts = av_rescale_q(outPacket.dts, videoStream->codec->time_base, videoStream->time_base);
av_write_frame(outFormatContext, &outPacket);
av_packet_unref(&outPacket);
}
// }
av_packet_unref(&packet);
av_write_trailer(outFormatContext);
avio_close(outFormatContext->pb);
}
</qthreadpool></qimage></qlayout></qtimer></qscreen></qlabel></qguiapplication> -
Matomo Launches Global Partner Programme to Deepen Local Connections and Champion Ethical Analytics
25 juin, par Matomo Core Team — Press Releases