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Revolution of Open-source and film making towards open film making
6 octobre 2011, par
Mis à jour : Juillet 2013
Langue : English
Type : Texte
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Vous pouvez personnaliser le formulaire de création d’une actualité.
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Revision 7ab9a9587b : Remove Wextra warnings from vp9_sad.c As a side-effect, the max_sad check is re
13 mai 2014, par Deb MukherjeeChanged Paths :
Modify /test/sad_test.cc
Modify /vp8/common/rtcd_defs.pl
Modify /vp8/common/sad_c.c
Modify /vp8/common/variance.h
Modify /vp8/encoder/mcomp.c
Modify /vp8/encoder/rdopt.c
Modify /vp9/common/vp9_rtcd_defs.pl
Modify /vp9/encoder/vp9_encodeframe.c
Modify /vp9/encoder/vp9_mbgraph.c
Modify /vp9/encoder/vp9_mcomp.c
Modify /vp9/encoder/vp9_rdopt.c
Modify /vp9/encoder/vp9_sad.c
Modify /vp9/encoder/vp9_variance.h
Remove Wextra warnings from vp9_sad.cAs a side-effect, the max_sad check is removed from the
C-implementation of VP8, for consistency with VP9, and to
ensure that the SAD tests common to VP8/VP9 pass.
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Revision 56d048c412 : Moving mv entropy encodings calculation to the encoder side. Moved arrays : vp
26 novembre 2013, par Dmitry KovalevChanged Paths :
Modify /vp9/common/vp9_alloccommon.c
Modify /vp9/common/vp9_entropymv.c
Modify /vp9/common/vp9_entropymv.h
Modify /vp9/encoder/vp9_encodemv.c
Modify /vp9/encoder/vp9_encodemv.h
Modify /vp9/encoder/vp9_onyx_if.c
Moving mv entropy encodings calculation to the encoder side.Moved arrays :
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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;
}


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