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ED-ME-5 1-DVD
11 octobre 2011, par
Mis à jour : Octobre 2011
Langue : English
Type : Audio
Autres articles (53)
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Other interesting software
13 avril 2011, parWe don’t claim to be the only ones doing what we do ... and especially not to assert claims to be the best either ... What we do, we just try to do it well and getting better ...
The following list represents softwares that tend to be more or less as MediaSPIP or that MediaSPIP tries more or less to do the same, whatever ...
We don’t know them, we didn’t try them, but you can take a peek.
Videopress
Website : http://videopress.com/
License : GNU/GPL v2
Source code : (...) -
Déploiements possibles
31 janvier 2010, parDeux types de déploiements sont envisageable dépendant de deux aspects : La méthode d’installation envisagée (en standalone ou en ferme) ; Le nombre d’encodages journaliers et la fréquentation envisagés ;
L’encodage de vidéos est un processus lourd consommant énormément de ressources système (CPU et RAM), il est nécessaire de prendre tout cela en considération. Ce système n’est donc possible que sur un ou plusieurs serveurs dédiés.
Version mono serveur
La version mono serveur consiste à n’utiliser qu’une (...) -
Configuration spécifique d’Apache
4 février 2011, parModules spécifiques
Pour la configuration d’Apache, il est conseillé d’activer certains modules non spécifiques à MediaSPIP, mais permettant d’améliorer les performances : mod_deflate et mod_headers pour compresser automatiquement via Apache les pages. Cf ce tutoriel ; mode_expires pour gérer correctement l’expiration des hits. Cf ce tutoriel ;
Il est également conseillé d’ajouter la prise en charge par apache du mime-type pour les fichiers WebM comme indiqué dans ce tutoriel.
Création d’un (...)
Sur d’autres sites (8230)
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How to modify the bit_rate of AVFormatContext ?
27 mars 2023, par Zion LiuHello，I would like to know how to modify the bit_rate of AVFormatContext.


Here is the minimal reproducible example.This is a simple process for pushing rtmp video streams.Now I want to control the bitrate of the video it pushes.


I tried modifying the bitrate like this, but it didn't work.


AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
int64_t bit_rate = 400*1000;
....
ofmt_ctx->bit_rate = bit_rate;


Can be compiled by
g++ -Wall -o -g -I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include -I/usr/local/include -L/usr/local/lib simplt_push_streaming.cpp -o test.out -lavformat -lavcodec -lavutil -lgobject-2.0 -lglib-2.0 -lpthread

And my ffmpeg version :
ffmpeg version 4.4.2-0ubuntu0.22.04.1

#include 
extern "C"
{
#include <libavformat></libavformat>avformat.h>
#include <libavutil></libavutil>mathematics.h>
#include <libavutil></libavutil>time.h>
};

int main(int argc, char* argv[])
{
 AVOutputFormat *ofmt = NULL;
 //Input AVFormatContext and Output AVFormatContext
 AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
 AVPacket pkt;
 const char *in_filename, *out_filename;
 int ret, i;
 int videoindex=-1;
 int frame_index=0;
 int64_t start_time=0;
 int64_t bit_rate = 400*1000;
 in_filename = "/home/zion/video/mecha.flv";// Input file URL
 out_filename = "rtmp://localhost:1935/live/test";//Output URL [RTMP]
 av_register_all();
 avformat_network_init();
 avformat_open_input(&ifmt_ctx, in_filename, 0, 0);
 avformat_find_stream_info(ifmt_ctx, 0);
 for(i=0; inb_streams; i++) 
 if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
 videoindex=i;
 break;
 }
 //Output
 avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename); //RTMP
 ofmt = ofmt_ctx->oformat;
 for (i = 0; i < ifmt_ctx->nb_streams; i++) {
 //Create output AVStream according to input AVStream
 AVStream *in_stream = ifmt_ctx->streams[i];
 AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
 //Copy the settings of AVCodecContext
 ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
 out_stream->codec->codec_tag = 0;
 if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
 out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
 }
 //Open output URL
 if (!(ofmt->flags & AVFMT_NOFILE)) {
 ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
 }
 //Write file header
 avformat_write_header(ofmt_ctx, NULL);
 start_time=av_gettime();
 while (1) {
 AVStream *in_stream, *out_stream;
 //Get an AVPacket
 ret = av_read_frame(ifmt_ctx, &pkt);
 if (ret < 0)
 break;
 //Important:Delay
 if(pkt.stream_index==videoindex){
 AVRational time_base=ifmt_ctx->streams[videoindex]->time_base;
 AVRational time_base_q={1,AV_TIME_BASE};
 int64_t pts_time = av_rescale_q(pkt.dts, time_base, time_base_q);
 int64_t now_time = av_gettime() - start_time;
 if (pts_time > now_time)
 av_usleep(pts_time - now_time);
 }
 in_stream = ifmt_ctx->streams[pkt.stream_index];
 out_stream = ofmt_ctx->streams[pkt.stream_index];
 if(pkt.stream_index==videoindex){
 printf("Send %8d video frames to output URL\n",frame_index);
 frame_index++;
 }
/*I tried modifying the bitrate here and I'm not sure if this is the correct usage.*/
 ofmt_ctx->bit_rate = bit_rate;
 av_interleaved_write_frame(ofmt_ctx, &pkt);
 av_free_packet(&pkt);
 }
 //Write file trailer
 av_write_trailer(ofmt_ctx);
end:
 avformat_close_input(&ifmt_ctx);
 /* close output */
 if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
 avio_close(ofmt_ctx->pb);
 avformat_free_context(ofmt_ctx);
 return 0;
}


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Puzzled with file descriptor in Bash (ffmpeg video capture)
3 mai 2020, par ChrisAgaI am trying to use file descriptors in Bash and found a problem I cannot solve.
I have to read a video stream coming from the standard output of a command executed in a
coproc. This piece of code works as expected :


ffmpeg \
 -i <(exec cat <&${COPROC[0]}) \
 -c:v $ENCODE_VIDEO_FORMAT_LOSSLESS $ENCODE_VIDEO_OPTIONS_LOSSLESS \
 -c:a copy \
 -progress /dev/fd/1 \
 "${capfile}"



But the
catprocess is not really useful sinceffmpeg -i pipe:<file descriptor="descriptor"></file>seems to do the same. So I tried the following code which fails withpipe:63: Bad file descriptor
error.


ffmpeg \
 -i pipe:"${COPROC[0]}" \
 -c:v $ENCODE_VIDEO_FORMAT_LOSSLESS $ENCODE_VIDEO_OPTIONS_LOSSLESS \
 -c:a copy \
 -progress /dev/fd/1 \
 "${capfile}"



The actual script is something a bit complicated but here is a minimal testing code for this issue :



#!/bin/bash
#

ENCODE_VIDEO_FORMAT_LOSSLESS=ffv1
ENCODE_VIDEO_OPTIONS_LOSSLESS="-level 3 -threads 7 -coder 1 -context 1 -g 1 -slices 30 -slicecrc 1"

capfile=capure.mkv

coproc ffmpeg -i file:'Camomille.mkv' -c:v copy -c:a copy -f matroska pipe:1

capture_fd=${COPROC[0]}
echo "hk_capture_pid=${COPROC_PID}"

ffmpeg \
 -i pipe:${COPROC[0]} \
 -c:v $ENCODE_VIDEO_FORMAT_LOSSLESS $ENCODE_VIDEO_OPTIONS_LOSSLESS \
 -c:a copy \
 -progress /dev/fd/1 \
 "${capfile}"



This is the output of the second
ffmpegcommand :


ffmpeg version 4.1.4-1build2 Copyright (c) 2000-2019 the FFmpeg developers
 built with gcc 9 (Ubuntu 9.2.1-4ubuntu1)
 configuration: --prefix=/usr --extra-version=1build2 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
 libavutil 56. 22.100 / 56. 22.100
 libavcodec 58. 35.100 / 58. 35.100
 libavformat 58. 20.100 / 58. 20.100
 libavdevice 58. 5.100 / 58. 5.100
 libavfilter 7. 40.101 / 7. 40.101
 libavresample 4. 0. 0 / 4. 0. 0
 libswscale 5. 3.100 / 5. 3.100
 libswresample 3. 3.100 / 3. 3.100
 libpostproc 55. 3.100 / 55. 3.100
pipe:63: Bad file descriptor
av_interleaved_write_frame(): Broken pipe 
Error writing trailer of pipe:1: Broken pipe 
frame= 4 fps=0.0 q=-1.0 Lsize= 48kB time=00:00:00.03 bitrate=10051.1kbits/s speed=3.44x 
video:86kB audio:1kB subtitle:0kB other streams:0kB global headers:2kB muxing overhead: unknown
Conversion failed!



This one fails and if you replace
-i pipe:${COPROC[0]}by-i <(exec cat <&${COPROC[0]})a capture.mkv file is created.


I run ubuntu eoan and bash version is :
GNU bash, version 5.0.3(1)-release (x86_64-pc-linux-gnu). I upgraded several times since I started with this issue, so it wouldn't be related too much to bash and ffmpeg versions.


If someone can point me to what I do wrong with bash file descriptors I would be grateful.


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fileapi::WriteFile() doesn't send an input, if processthreadsapi::STARTUPINFO::hStdError is set (ffmpeg)
23 avril 2021, par LidekysI'm trying to capture my screen using
ffmpegin a different thread (which I create usingprocessthreadsapi::CreateProcess())so I'd be able to do something else in the main thread, and redirectffmpegoutput, so it wouldn't pop up in the console for the user to see. To stop filming, I send a 'q' input usingWriteFile(), and after that I want to saveffmpegaccumulated output usingReadFile().

However, if I set
STARTUPINFO::hStdError(note, thatffmpegoutput goes tostderr) to a pipe, from which I could read the accumulated data, the inputs I send usingWriteFile()are no longer registered and ffmpeg.exe keeps running.

I've tried redirecting
ffmpegoutput in a simple command line, but I can still stop the process by pressing the q button.

Also, if I record for less than 8 seconds, the input is registered and
ffmpeg.execloses.

Is there something wrong with my code, or is it processthreadsapi issue, any hints will be kindly appreciared !


Here's a minimal code of how I am trying to do it :



#include <iostream>

#include 
#include 

using namespace std;

HANDLE g_hChildStd_IN_Rd = NULL;
HANDLE g_hChildStd_IN_Wr = NULL;
HANDLE g_hChildStd_OUT_Rd = NULL;
HANDLE g_hChildStd_OUT_Wr = NULL;

int main()
{
 //Create IN and OUT pipes
 SECURITY_ATTRIBUTES saAttr;
 saAttr.nLength = sizeof(SECURITY_ATTRIBUTES);
 saAttr.lpSecurityDescriptor = NULL;


 if (! CreatePipe(&g_hChildStd_OUT_Rd, &g_hChildStd_OUT_Wr, &saAttr, 0) )
 cout<<"StdoutRd CreatePipe error"</Start recording
 if(!CreateProcess(NULL,
 "ffmpeg -y -f gdigrab -framerate 2 -i desktop record.avi", // command line
 NULL, // process security attributes
 NULL, // primary thread security attributes
 TRUE, // handles are inherited
 0, // creation flags
 NULL, // use parent's environment
 NULL, // use parent's current directory
 &siStartInfo, // STARTUPINFO pointer
 &piProcInfo)) // receives PROCESS_INFORMATION
 {
 cout<<"Error create process"</Record for a while
 while(getch() != 'k'){
 cout<<"While press k"</Stop recording by emulating a Q button push
 DWORD dwWritten;
 CHAR chBufW[1] = {'q'};

 if ( ! WriteFile(g_hChildStd_IN_Wr, chBufW, 1, &dwWritten, NULL) )
 cout<<"Error write file"</Save stdError (ffmpeg) data
 DWORD dwRead;
 char stdErrorData[4096];
 bool bSuccess;

 bSuccess = ReadFile( g_hChildStd_OUT_Wr, stdErrorData, 4096, &dwRead, NULL);

 if(!bSuccess || dwRead == 0)
 cout<<"Read failed"<code></iostream>

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