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Médias (91)
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MediaSPIP Simple : futur thème graphique par défaut ?
26 septembre 2013, par
Mis à jour : Octobre 2013
Langue : français
Type : Video
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avec chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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sans chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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config chosen
13 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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SPIP - plugins - embed code - Exemple
2 septembre 2013, par
Mis à jour : Septembre 2013
Langue : français
Type : Image
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GetID3 - Bloc informations de fichiers
9 avril 2013, par
Mis à jour : Mai 2013
Langue : français
Type : Image
Autres articles (103)
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MediaSPIP version 0.1 Beta
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Pour avoir une installation fonctionnelle, il est nécessaire d’installer manuellement l’ensemble des dépendances logicielles sur le serveur.
Si vous souhaitez utiliser cette archive pour une installation en mode ferme, il vous faudra également procéder à d’autres modifications (...) -
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Sur d’autres sites (10378)
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Audio loudness metadata
17 décembre 2020, par user319862Apple's HLS stream validator gives me this warning :


Audio loudness information SHOULD be provided



I want to write a test that checks loudness information is present. I cannot find what metadata keys are used to provide this information so that I can inspect them.


How would I determine if loudness normalization information is provided with a particular mp4 file using ffprobe or ffmpeg ?


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Linker error by trying example program with ffmpeg
11 mars, par ChrisI think this might be a stupid question and I'm just blind but that thing is driving me nuts for hours now.
I downloaded ffmpeg and build it. Now I want to try the thing out in a program but I can't setup cmake to link ffmpeg properly and have no idea what is wrong.


The linker always tells me this :


christoph@christoph-ThinkPad-T490:~/develop/ffmpg_example/build$ make
[ 50%] Linking CXX executable test
CMakeFiles/test.dir/main.cxx.o: In function `main':
main.cxx:(.text+0x180): undefined reference to `av_register_all()'
main.cxx:(.text+0x1a7): undefined reference to `avformat_open_input(AVFormatContext**, char const*, AVInputFormat*, AVDictionary**)'
main.cxx:(.text+0x1ce): undefined reference to `avformat_find_stream_info(AVFormatContext*, AVDictionary**)'
main.cxx:(.text+0x206): undefined reference to `av_dump_format(AVFormatContext*, int, char const*, int)'
main.cxx:(.text+0x2bb): undefined reference to `avcodec_find_decoder(AVCodecID)'
main.cxx:(.text+0x2fc): undefined reference to `avcodec_alloc_context3(AVCodec const*)'
main.cxx:(.text+0x316): undefined reference to `avcodec_copy_context(AVCodecContext*, AVCodecContext const*)'
main.cxx:(.text+0x361): undefined reference to `avcodec_open2(AVCodecContext*, AVCodec const*, AVDictionary**)'
main.cxx:(.text+0x377): undefined reference to `av_frame_alloc()'
main.cxx:(.text+0x383): undefined reference to `av_frame_alloc()'
main.cxx:(.text+0x3ba): undefined reference to `avpicture_get_size(AVPixelFormat, int, int)'
main.cxx:(.text+0x3d0): undefined reference to `av_malloc(unsigned long)'
main.cxx:(.text+0x3ff): undefined reference to `avpicture_fill(AVPicture*, unsigned char const*, AVPixelFormat, int, int)'
main.cxx:(.text+0x43d): undefined reference to `sws_getContext(int, int, AVPixelFormat, int, int, AVPixelFormat, int, SwsFilter*, SwsFilter*, double const*)'
main.cxx:(.text+0x465): undefined reference to `av_read_frame(AVFormatContext*, AVPacket*)'
main.cxx:(.text+0x49f): undefined reference to `avcodec_decode_video2(AVCodecContext*, AVFrame*, int*, AVPacket const*)'
main.cxx:(.text+0x4fd): undefined reference to `sws_scale(SwsContext*, unsigned char const* const*, int const*, int, int, unsigned char* const*, int const*)'
main.cxx:(.text+0x545): undefined reference to `av_free_packet(AVPacket*)'
main.cxx:(.text+0x556): undefined reference to `av_free(void*)'
main.cxx:(.text+0x565): undefined reference to `av_frame_free(AVFrame**)'
main.cxx:(.text+0x574): undefined reference to `av_frame_free(AVFrame**)'
main.cxx:(.text+0x580): undefined reference to `avcodec_close(AVCodecContext*)'
main.cxx:(.text+0x58f): undefined reference to `avcodec_close(AVCodecContext*)'
main.cxx:(.text+0x59e): undefined reference to `avformat_close_input(AVFormatContext**)'
collect2: error: ld returned 1 exit status
CMakeFiles/test.dir/build.make:87: recipe for target 'test' failed
make[2]: *** [test] Error 1
CMakeFiles/Makefile2:75: recipe for target 'CMakeFiles/test.dir/all' failed
make[1]: *** [CMakeFiles/test.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2



The cmake list looks like this :


cmake_minimum_required(VERSION 3.16)

project(ffmpeg_test)

add_library(avformat STATIC IMPORTED)
set_target_properties(avformat
 PROPERTIES IMPORTED_LOCATION /home/christoph/develop/FFmpeg/build/lib/libavformat.a
)
add_library(avcodec STATIC IMPORTED)
set_target_properties(avcodec
 PROPERTIES IMPORTED_LOCATION /home/christoph/develop/FFmpeg/build/lib/libavcodec.a
)
add_library(swscale STATIC IMPORTED)
set_target_properties(swscale
 PROPERTIES IMPORTED_LOCATION /home/christoph/develop/FFmpeg/build/lib/libswscale.a
)
add_library(avutil STATIC IMPORTED)
set_target_properties(avutil
 PROPERTIES IMPORTED_LOCATION /home/christoph/develop/FFmpeg/build/lib/libavutil.a
)
add_executable(test main.cxx)

target_link_libraries(test PRIVATE
 /home/christoph/develop/FFmpeg/build/lib/libavformat.a
 avcodec
 swscale
 avutil
)
target_include_directories(test PRIVATE /home/christoph/develop/FFmpeg/build/include)



And here are the ffmpeg libs :


christoph@christoph-ThinkPad-T490:~/develop/FFmpeg/build/lib$ ll
total 277840
drwxr-xr-x 3 christoph christoph 4096 Dez 7 23:59 ./
drwxr-xr-x 17 christoph christoph 4096 Dez 7 23:59 ../
-rw-r--r-- 1 christoph christoph 173479270 Dez 7 23:59 libavcodec.a
-rw-r--r-- 1 christoph christoph 2174910 Dez 7 23:59 libavdevice.a
-rw-r--r-- 1 christoph christoph 37992438 Dez 7 23:59 libavfilter.a
-rw-r--r-- 1 christoph christoph 59222040 Dez 7 23:59 libavformat.a
-rw-r--r-- 1 christoph christoph 4759514 Dez 7 23:59 libavutil.a
-rw-r--r-- 1 christoph christoph 695698 Dez 7 23:59 libswresample.a
-rw-r--r-- 1 christoph christoph 6164398 Dez 7 23:59 libswscale.a
drwxr-xr-x 2 christoph christoph 4096 Dez 7 23:59 pkgconfig/



And this is the example code :


#include

#include <libavcodec></libavcodec>avcodec.h>
#include <libavformat></libavformat>avformat.h>
#include <libswscale></libswscale>swscale.h>

// compatibility with newer API
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(55,28,1)
#define av_frame_alloc avcodec_alloc_frame
#define av_frame_free avcodec_free_frame
#endif

void SaveFrame(AVFrame *pFrame, int width, int height, int iFrame) {
 FILE *pFile;
 char szFilename[32];
 int y;
 
 // Open file
 sprintf(szFilename, "frame%d.ppm", iFrame);
 pFile=fopen(szFilename, "wb");
 if(pFile==NULL)
 return;
 
 // Write header
 fprintf(pFile, "P6\n%d %d\n255\n", width, height);
 
 // Write pixel data
 for(y=0; ydata[0]+y*pFrame->linesize[0], 1, width*3, pFile);
 
 // Close file
 fclose(pFile);
}

int main(int argc, char *argv[]) {
 // Initalizing these to NULL prevents segfaults!
 AVFormatContext *pFormatCtx = NULL;
 int i, videoStream;
 AVCodecContext *pCodecCtxOrig = NULL;
 AVCodecContext *pCodecCtx = NULL;
 AVCodec *pCodec = NULL;
 AVFrame *pFrame = NULL;
 AVFrame *pFrameRGB = NULL;
 AVPacket packet;
 int frameFinished;
 int numBytes;
 uint8_t *buffer = NULL;
 struct SwsContext *sws_ctx = NULL;

 if(argc < 2) {
 printf("Please provide a movie file\n");
 return -1;
 }
 // Register all formats and codecs
 av_register_all();
 
 // Open video file
 if(avformat_open_input(&pFormatCtx, argv[1], NULL, NULL)!=0)
 return -1; // Couldn't open file
 
 // Retrieve stream information
 if(avformat_find_stream_info(pFormatCtx, NULL)<0)
 return -1; // Couldn't find stream information
 
 // Dump information about file onto standard error
 av_dump_format(pFormatCtx, 0, argv[1], 0);
 
 // Find the first video stream
 videoStream=-1;
 for(i=0; inb_streams; i++)
 if(pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO) {
 videoStream=i;
 break;
 }
 if(videoStream==-1)
 return -1; // Didn't find a video stream
 
 // Get a pointer to the codec context for the video stream
 pCodecCtxOrig=pFormatCtx->streams[videoStream]->codec;
 // Find the decoder for the video stream
 pCodec=avcodec_find_decoder(pCodecCtxOrig->codec_id);
 if(pCodec==NULL) {
 fprintf(stderr, "Unsupported codec!\n");
 return -1; // Codec not found
 }
 // Copy context
 pCodecCtx = avcodec_alloc_context3(pCodec);
 if(avcodec_copy_context(pCodecCtx, pCodecCtxOrig) != 0) {
 fprintf(stderr, "Couldn't copy codec context");
 return -1; // Error copying codec context
 }

 // Open codec
 if(avcodec_open2(pCodecCtx, pCodec, NULL)<0)
 return -1; // Could not open codec
 
 // Allocate video frame
 pFrame=av_frame_alloc();
 
 // Allocate an AVFrame structure
 pFrameRGB=av_frame_alloc();
 if(pFrameRGB==NULL)
 return -1;

 // Determine required buffer size and allocate buffer
 numBytes=avpicture_get_size(AV_PIX_FMT_RGB24, pCodecCtx->width,
 pCodecCtx->height);
 buffer=(uint8_t *)av_malloc(numBytes*sizeof(uint8_t));
 
 // Assign appropriate parts of buffer to image planes in pFrameRGB
 // Note that pFrameRGB is an AVFrame, but AVFrame is a superset
 // of AVPicture
 avpicture_fill((AVPicture *)pFrameRGB, buffer, AV_PIX_FMT_RGB24,
 pCodecCtx->width, pCodecCtx->height);
 
 // initialize SWS context for software scaling
 sws_ctx = sws_getContext(pCodecCtx->width,
 pCodecCtx->height,
 pCodecCtx->pix_fmt,
 pCodecCtx->width,
 pCodecCtx->height,
 AV_PIX_FMT_RGB24,
 SWS_BILINEAR,
 NULL,
 NULL,
 NULL
 );

 // Read frames and save first five frames to disk
 i=0;
 while(av_read_frame(pFormatCtx, &packet)>=0) {
 // Is this a packet from the video stream?
 if(packet.stream_index==videoStream) {
 // Decode video frame
 avcodec_decode_video2(pCodecCtx, pFrame, &frameFinished, &packet);
 
 // Did we get a video frame?
 if(frameFinished) {
 // Convert the image from its native format to RGB
 sws_scale(sws_ctx, (uint8_t const * const *)pFrame->data,
 pFrame->linesize, 0, pCodecCtx->height,
 pFrameRGB->data, pFrameRGB->linesize);
 
 // Save the frame to disk
 if(++i<=5)
 SaveFrame(pFrameRGB, pCodecCtx->width, pCodecCtx->height, 
 i);
 }
 }
 
 // Free the packet that was allocated by av_read_frame
 av_free_packet(&packet);
 }
 
 // Free the RGB image
 av_free(buffer);
 av_frame_free(&pFrameRGB);
 
 // Free the YUV frame
 av_frame_free(&pFrame);
 
 // Close the codecs
 avcodec_close(pCodecCtx);
 avcodec_close(pCodecCtxOrig);

 // Close the video file
 avformat_close_input(&pFormatCtx);
 
 return 0;
}



-
Split a movie so that each GIF is under a certain file size
9 novembre 2014, par Terence EdenProblem
I want to convert a long movie into a series on animated GIFs.
Each GIF needs to be <5MB.
Is there any way to determine how large a GIF will be while it is being encoded ?
Progress So Far
I can split the movie into individual frames :
ffmpeg -i movie.ogv -r 25 frameTemp.%05d.gif
I can then use
convert
from ImageMagick to create GIFs. However, I can’t find a way to determine the likely file size before running the command.Alternatively, I can split the movie into chunks :
ffmpeg -i movie.ogv -vcodec copy -ss 00:00:00 -t 00:20:00 output1.ogv
But I’ve no way of knowing if, when I
convert
the file to a GIF it will be under 5MB.A 10 second scene with a lot of action may be over 5MB (bad !) and a static scene could be under 5MB (not a problem, but not very efficient).
Ideas
I think that what I want to do is convert the entire movie into a GIF, then find a way to split it by file size.
Looking at ImageMagick, I can split a GIF into frames, but I don’t see a way to split it into animated GIFs of a certain size / length.
So, is this possible ?