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Rennes Emotion Map 2010-11
19 octobre 2011, par
Mis à jour : Juillet 2013
Langue : français
Type : Texte
Autres articles (43)
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Les formats acceptés
28 janvier 2010, parLes commandes suivantes permettent d’avoir des informations sur les formats et codecs gérés par l’installation local de ffmpeg :
ffmpeg -codecs ffmpeg -formats
Les format videos acceptés en entrée
Cette liste est non exhaustive, elle met en exergue les principaux formats utilisés : h264 : H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 m4v : raw MPEG-4 video format flv : Flash Video (FLV) / Sorenson Spark / Sorenson H.263 Theora wmv :
Les formats vidéos de sortie possibles
Dans un premier temps on (...) -
Ajouter notes et légendes aux images
7 février 2011, parPour pouvoir ajouter notes et légendes aux images, la première étape est d’installer le plugin "Légendes".
Une fois le plugin activé, vous pouvez le configurer dans l’espace de configuration afin de modifier les droits de création / modification et de suppression des notes. Par défaut seuls les administrateurs du site peuvent ajouter des notes aux images.
Modification lors de l’ajout d’un média
Lors de l’ajout d’un média de type "image" un nouveau bouton apparait au dessus de la prévisualisation (...) -
Websites made with MediaSPIP
2 mai 2011, parThis page lists some websites based on MediaSPIP.
Sur d’autres sites (9464)
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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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lavfi/dnn : Remove DNN native backend
27 avril 2023, par Ting Fulavfi/dnn : Remove DNN native backend
According to discussion in
https://etherpad.mit.edu/p/FF_dev_meeting_20221202 and the proposal in
http://ffmpeg.org/pipermail/ffmpeg-devel/2022-December/304534.html,
the DNN native backend should be removed at first step.
All the DNN native backend related codes are deleted.Signed-off-by : Ting Fu <ting.fu@intel.com>
- [DH] libavfilter/Makefile
- [DH] libavfilter/dnn/Makefile
- [DH] libavfilter/dnn/dnn_backend_native.c
- [DH] libavfilter/dnn/dnn_backend_native.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_avgpool.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_avgpool.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_conv2d.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_conv2d.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_dense.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_dense.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_depth2space.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_depth2space.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_mathbinary.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_mathbinary.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_mathunary.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_mathunary.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_maximum.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_maximum.h
- [DH] libavfilter/dnn/dnn_backend_native_layer_pad.c
- [DH] libavfilter/dnn/dnn_backend_native_layer_pad.h
- [DH] libavfilter/dnn/dnn_backend_native_layers.c
- [DH] libavfilter/dnn/dnn_backend_native_layers.h
- [DH] libavfilter/dnn/dnn_backend_tf.c
- [DH] libavfilter/dnn_interface.h
- [DH] libavfilter/tests/dnn-layer-avgpool.c
- [DH] libavfilter/tests/dnn-layer-conv2d.c
- [DH] libavfilter/tests/dnn-layer-dense.c
- [DH] libavfilter/tests/dnn-layer-depth2space.c
- [DH] libavfilter/tests/dnn-layer-mathbinary.c
- [DH] libavfilter/tests/dnn-layer-mathunary.c
- [DH] libavfilter/tests/dnn-layer-maximum.c
- [DH] libavfilter/tests/dnn-layer-pad.c
- [DH] libavfilter/vf_derain.c
- [DH] libavfilter/vf_dnn_processing.c
- [DH] libavfilter/vf_sr.c
- [DH] tests/Makefile
- [DH] tests/fate/dnn.mak
-
FFMPEG hangs (sometimes) when trying to take a photo from USB camera ?
13 mai 2022, par dezmanI am attempting to write a script that takes a photo every 3 seconds from camera source "1", the -pix_fmt I think is unique to my USB camera.


Here is the script :


#!/bin/bash

set -e

while :
do
 nice_num=$(date +%s)
 
 ffmpeg -ss 00:00:00 -f avfoundation -pix_fmt yuyv422 -r 30.000030 -i "1" -t 1 -frames:v 1 -q:v 2 "image_$nice_num_%03d.jpg"
 
 wait

 sleep 3
done


The issue is half the time it successfully takes the photo, and half the time it just hangs forever echoing this (not useful) :


ffmpeg version 5.0.1 Copyright (c) 2000-2022 the FFmpeg developers
 built with Apple clang version 13.1.6 (clang-1316.0.21.2)
 configuration: --prefix=/usr/local/Cellar/ffmpeg/5.0.1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libdav1d --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox
 libavutil 57. 17.100 / 57. 17.100
 libavcodec 59. 18.100 / 59. 18.100
 libavformat 59. 16.100 / 59. 16.100
 libavdevice 59. 4.100 / 59. 4.100
 libavfilter 8. 24.100 / 8. 24.100
 libswscale 6. 4.100 / 6. 4.100
 libswresample 4. 3.100 / 4. 3.100
 libpostproc 56. 3.100 / 56. 3.100


Then I CTRL-C 3 times and get :


^C^C^CReceived > 3 system signals, hard exiting


Other methods of "taking a photo every n seconds from bash" are also appreciated.


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