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  • play a .sdp file describing a UDP/RTP H264 stream iOS 8+

    26 avril 2017, par Alex

    I´m looking into how to implement a simple app that can play a .sdp file (like VLC can do) in order to open a RTP stream made by GStreamer:

    gst-launch-1.0 rpicamsrc bitrate=10000000 ! video/x-h264,width=1280,height=720,framerate=30/1  ! h264parse config-interval=1 ! rtph264pay ! udpsink host=192.168.100.123 port=1234

    What would be the easiest way to do this in Swift/Objecvtive-C? Are there any built in functions or libraries I should know of?

  • ffmpeg send udp stream

    26 avril 2017, par Luzwitz

    I stream my screen and i want send stream on a server with udp.

    So, I have this command :

    ffmpeg -ss 00:00:00 -s 1920x1080 -f x11grab -i :0.0+0,0 -copyts -vf "scale=-1:min(ih*1920/iw\,1080),pad=1920:1080:(1920-iw)/2:(1080-ih)/2:black" -c:v libvpx -b:v 4M -crf 16 -quality realtime -cpu-used 8 -c:a libvorbis -f webm udp://127.0.0.1:8080

    And server in C :

    int sock, clientlen, n, port = 8080;
char buf[1024], *host;

FILE *file;

struct sockaddr_in serveraddr;
struct sockaddr_in clientaddr;
struct hostent *hostp;

sock = socket(AF_INET, SOCK_DGRAM, 0);

bzero((char *) &serveraddr, sizeof(serveraddr));

serveraddr.sin_family = AF_INET;
serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
serveraddr.sin_port = htons((unsigned short)port);

if(bind(sock, (struct sockaddr *) &serveraddr, sizeof(serveraddr)) < 0) 
    clientlen = sizeof(clientaddr);

file = fopen("out.webm", "wb"));

printf("En attente de données...\n");

while(1)
{
    bzero(buf, 1024);

    n = recvfrom(sock, buf, 1024, 0, (struct sockaddr *) &clientaddr, &clientlen);

    hostp = gethostbyaddr((const char *)&clientaddr.sin_addr.s_addr, sizeof(clientaddr.sin_addr.s_addr), AF_INET);

    host = inet_ntoa(clientaddr.sin_addr);

    fwrite(buf, n, 1, file);
}

    And, when i play out.webm, i haven't video.

  • Probabilistic-Volumetric-3D-Reconstruction ubuntu ffmpeg [on hold]

    26 avril 2017, par 董学强

    I download the code from enter link description here.Then I mkdir build .cd build. cmake .. ererything goes well. But when i make i meet with this error as following :

    [ 34%] Built target vgui_test_drawpix_speed2
[ 34%] Built target vgui_test_template_include
[ 35%] Built target vidl
[ 35%] Built target vidl_gui
[ 35%] Built target vidl_gui_test_include
[ 35%] Built target vidl_test_template_include
[ 35%] Built target vidl_test_include
[ 35%] Built target vidl_test_all
[ 35%] Linking CXX executable ../../../bin/vidl_transcode_video
../../../lib/libvidl.a(vidl_ffmpeg_istream.cxx.o): In function `vidl_ffmpeg_istream::open(std::string const&)':
vidl_ffmpeg_istream.cxx:(.text+0x3d5): undefined reference to `av_frame_alloc'
../../../lib/libvidl.a(vidl_ffmpeg_ostream.cxx.o): In function `vidl_ffmpeg_ostream::close()':
vidl_ffmpeg_ostream.cxx:(.text+0x124f): undefined reference to `av_packet_unref'
../../../lib/libvidl.a(vidl_ffmpeg_ostream.cxx.o): In function `vidl_ffmpeg_ostream::write_frame(vil_smart_ptr const&)':
vidl_ffmpeg_ostream.cxx:(.text+0x16f5): undefined reference to `av_frame_alloc'
vidl_ffmpeg_ostream.cxx:(.text+0x1b3b): undefined reference to `av_packet_unref'
collect2: error: ld returned 1 exit status
make[2]: *** [bin/vidl_transcode_video] Error 1
make[1]: *** [core/vidl/examples/CMakeFiles/vidl_transcode_video.dir/all] Error 2
make: *** [all] Error 2

    Here are the code of vidl_ffmpeg_ostream.cxx and vidl_ffmpeg_istream.cxx：

      // This is core/vidl/vidl_ffmpeg_ostream.cxx
    #include "vidl_ffmpeg_ostream.h"

    #include vidl_config.h>

    #if VIDL_HAS_FFMPEG

    // The ffmpeg API keeps changing, so we use different implementations
    // depending on which version of ffmpeg we have.

    extern "C" {
    // some versions of FFMPEG require this definition before including
    // the headers for C++ compatibility
    #define __STDC_CONSTANT_MACROS
    #if FFMPEG_IN_SEVERAL_DIRECTORIES
    #include avcodec.h>
    #else
    #include avcodec.h>
    #endif
    }
    #include "vidl_ffmpeg_convert.h"

    #if LIBAVCODEC_BUILD < ((51<<16)+(49<<8)+0)  // ver 51.49.0
    # include "vidl_ffmpeg_ostream_v1.hxx"
    #elif LIBAVCODEC_BUILD < ((52<<16)+(10<<8)+0)  // before ver 52.10.0
    # include "vidl_ffmpeg_ostream_v2.hxx"
    #elif LIBAVCODEC_BUILD < ((53<<16)+(0<<8)+0)  // before ver 53.0.0
    # include "vidl_ffmpeg_ostream_v3.hxx"
    #elif LIBAVCODEC_BUILD < ((53<<16)+(24<<8)+0)  // before ver 53.24.0
    # include "vidl_ffmpeg_ostream_v4.hxx"
    #elif LIBAVCODEC_BUILD < ((54<<16)+(23<<8)+100)  // before ver 54.23.100
    # include "vidl_ffmpeg_ostream_v0.9.hxx"
    #elif LIBAVCODEC_BUILD < ((56<<16)+(0<<8)+100)  // before ver 56.0.100
    # include "vidl_ffmpeg_ostream_v0.11.hxx"
    #else
    # include "vidl_ffmpeg_ostream_v56.hxx"
    #endif

    #else // VIDL_HAS_FFMPEG

    # include "vidl_ffmpeg_ostream_stub.hxx"

    #endif // VIDL_HAS_FFMPEG

    emphasized text

    // This is core/vidl/vidl_ffmpeg_istream.cxx
#include "vidl_ffmpeg_istream.h"

#include vidl_config.h>

#if VIDL_HAS_FFMPEG

#include "vidl_ffmpeg_ostream.h"

// The ffmpeg API keeps changing, so we use different implementations
// depending on which version of ffmpeg we have.

extern "C" {
// some versions of FFMPEG require this definition before including
// the headers for C++ compatibility
#define __STDC_CONSTANT_MACROS
#if FFMPEG_IN_SEVERAL_DIRECTORIES
#include avformat.h>
#else
#include avformat.h>
#endif
}

#if LIBAVFORMAT_BUILD < ((52<<16)+(2<<8)+0)  // before ver 52.2.0
# include "vidl_ffmpeg_istream_v1.hxx"
#elif LIBAVFORMAT_BUILD < ((53<<16)+(0<<8)+0)  // before ver 53.0.0
# include "vidl_ffmpeg_istream_v2.hxx"
#elif LIBAVFORMAT_BUILD < ((53<<16)+(24<<8)+0)  // before ver 53.24.0
# include "vidl_ffmpeg_istream_v3.hxx"
#elif LIBAVFORMAT_VERSION_MAJOR < 56            // before avformat ver 57.0
# include "vidl_ffmpeg_istream_v3.hxx"
#else
# include "vidl_ffmpeg_istream_v56.hxx"
#endif

#else // VIDL_HAS_FFMPEG

# include "vidl_ffmpeg_istream_stub.hxx"

#endif // VIDL_HAS_FFMPEG

    I don't know what's wrong I have got .What i need to do ？Anyone can help me ?

  • Can we limit max fps by using FFMPEG ?

    26 avril 2017, par Alexandr

    I want to limit max fps when I process a video.
    For example: set limit up to 30 frames per second.
    If I process a video with 24 fps then I don't change fps but if I process the video with 60 fps then I change fps to 30.
    Can it be done by using only FFmpeg (with filters or something else)?
    I think that it can be done by using filter like this:

    -filter:v "fps=fps='min($CURRENT_FPS,30)'"

    But I don't know is it possible to get current fps from an expression.

  • FFmpeg - Convert MP4 to Webm very slow

    26 avril 2017, par Luzwitz

    I need convert MP4 to webm with ffmpeg. So, i use :

    ffmpeg -i input.mp4 -c:v libvpx -crf 10 -b:v 1M -c:a libvorbis output.webm

    But it's very long.

    Is there faster ?

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