Advanced search
Medias (91)
-
999,999
26 September 2011, by
Updated: September 2011
Language: English
Type: Audio
-
The Slip - Artworks
26 September 2011, by
Updated: September 2011
Language: English
Type: Text
-
Demon seed (wav version)
26 September 2011, by
Updated: April 2013
Language: English
Type: Audio
-
The four of us are dying (wav version)
26 September 2011, by
Updated: April 2013
Language: English
Type: Audio
-
Corona radiata (wav version)
26 September 2011, by
Updated: April 2013
Language: English
Type: Audio
-
Lights in the sky (wav version)
26 September 2011, by
Updated: April 2013
Language: English
Type: Audio
Other articles (103)
-
MediaSPIP 0.1 Beta version
25 April 2011, byMediaSPIP 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 (...) -
MediaSPIP version 0.1 Beta
16 April 2011, byMediaSPIP 0.1 beta est la première version de MediaSPIP décrétée comme "utilisable".
Le fichier zip ici présent contient uniquement les sources de MediaSPIP en version standalone.
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 (...) -
Amélioration de la version de base
13 September 2013Jolie sélection multiple
Le plugin Chosen permet d’améliorer l’ergonomie des champs de sélection multiple. Voir les deux images suivantes pour comparer.
Il suffit pour cela d’activer le plugin Chosen (Configuration générale du site > Gestion des plugins), puis de configurer le plugin (Les squelettes > Chosen) en activant l’utilisation de Chosen dans le site public et en spécifiant les éléments de formulaires à améliorer, par exemple select[multiple] pour les listes à sélection multiple (...)
On other websites (10378)
-
Audio loudness metadata
17 December 2020, by 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?


-
Linker error by trying example program with ffmpeg
11 March, by 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 November 2014, by 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.gifI can then use
convertfrom 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.ogvBut I’ve no way of knowing if, when I
convertthe 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?
Subscribe to the whole site
