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  • Undefined Referernce Errors FFMPEG + QT + Ubuntu 12.04.2 LTS

    19 juillet 2013, par Cits

    i have 2 machines with Ubuntu 12.04.2 LTS (64 mb) and the other is a snow leopard OS.
    In my mac i work with ffmpeg without any trouble but then i try to use ffmpeg in ubuntu and 6700 (!) errors appear :

    error: undefined reference to `av_freep'
    error: undefined reference to `av_strstart'
    error: undefined reference to `av_freep'
    ...

    I use QT 4.8.5 and g++ x86 64b
    I installed ffmpeg following http://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide without errors or warnings.

    My test code is :

    .h

    QT += core gui

    INCLUDEPATH += \
       /usr/local/Include

    LIBS += /usr/local/lib/libavcodec.a
    LIBS += /usr/local/lib/libavutil.a
    LIBS += /usr/local/lib/libavformat.a
    LIBS += /usr/local/lib/libswscale.a


    SOURCES += main.cpp

    .cpp :

    extern "C"
    {
    #ifndef __STDC_CONSTANT_MACROS
    #  define __STDC_CONSTANT_MACROS
    #endif

    #include "libavcodec/avcodec.h"
    #include "libavformat/avformat.h"
    }

    #include

    int main()
    {
       AVFormatContext *pFormatCtx;
       av_register_all();

       const char* fil = "/home/cits/Desktop/movFile.mov";

       if(avformat_open_input(&pFormatCtx, fil, NULL, NULL)!=0)
       {
           return -1; // Couldn't open file
       }

       if(avformat_find_stream_info(pFormatCtx, NULL)<0)
       {
           return -1; // Couldn't find stream information
       }

       return 0;
    }

    Any ideas ??

    Thanks in advance.

  • FFmpeg : How do i use this script to concatenate incoming segments

    5 juillet 2017, par NGage

    I’d like to use this script but i don’t know how it should be applied. I was going to use it for encoding tv-shows and be able to start encoding as i had cut out the first segment.

    According to the ffmpeg-wiki (where i found the script) it says : "Concatenation becomes troublesome, if next clip for concatenation does not exist at the moment, because decoding won’t start until the whole list is read. However, it is possible to refer another list at the end of the current list :"

    Bear in mind that i dont know to much about bash

    #!/bin/bash

    fn_concat_init() {
    echo "fn_concat_init"
    concat_pls=`mktemp -u -p . concat.XXXXXXXXXX.txt`
    concat_pls="${concat_pls#./}"
    echo "concat_pls=${concat_pls:?}"
    mkfifo "${concat_pls:?}"
    echo
    }

    fn_concat_feed() {
    echo "fn_concat_feed ${1:?}"
    {
       >&2 echo "removing ${concat_pls:?}"
       rm "${concat_pls:?}"
       concat_pls=
       >&2 fn_concat_init
       echo 'ffconcat version 1.0'
       echo "file '${1:?}'"
       echo "file '${concat_pls:?}'"
    } >"${concat_pls:?}"
    echo
    }

    fn_concat_end() {
    echo "fn_concat_end"
    {
       >&2 echo "removing ${concat_pls:?}"
       rm "${concat_pls:?}"
       # not writing header.
    } >"${concat_pls:?}"
    echo
    }

    fn_concat_init

    echo "launching ffmpeg ... all.mkv"
    timeout 60s ffmpeg -y -re -loglevel warning -i "${concat_pls:?}" -pix_fmt
    yuv422p all.mkv &

    ffplaypid=$!


    echo "generating some test data..."
    i=0; for c in red yellow green blue; do
    ffmpeg -loglevel warning -y -f lavfi -i testsrc=s=720x576:r=12:d=4 -pix_fmt
    yuv422p -vf "drawbox=w=50:h=w:t=w:c=${c:?}" test$i.mkv
    fn_concat_feed test$i.mkv
    ((i++));
    echo
    done
    echo "done"

    fn_concat_end

    wait "${ffplaypid:?}"

    echo "done encoding all.mkv"
  • ffmpeg encode single input to multiple outputs simultaneously

    23 août 2019, par jippyjoe4

    Suppose I have a single input file that I would like to transcode into two different formats (ProRes and Mp4). Individually, the two commands I would use look like this :

    To convert it to mp4, I would use :

    ffmpeg -i in.mov -c:v libx264 -x264-params "nal-hrd=cbr" -b:v 30M -minrate 30M -maxrate 30M -bufsize 60M "out.mp4"

    And to convert it to ProRes, I would use :

    ffmpeg -i in.mov -c:v prores_ks -profile:v 2 -bits_per_mb 540 -vendor apl0 -pix_fmt yuv422p10le "out.mov"

    Rather than running these two commands sequentially to do the conversion, I think ffmpeg can encode to both formats simultaneously and save time. I’ve read this page (https://trac.ffmpeg.org/wiki/Creating%20multiple%20outputs), but I find it confusing. I tried something along the lines of :

    ffmpeg -i "in.mov" \
    -c:v libx264 -x264-params "nal-hrd=cbr" -b:v 30M -minrate 30M -maxrate 30M -bufsize 60M "out.mp4" \
    -c:v prores_ks -profile:v 2 -bits_per_mb 540 -vendor apl0 -pix_fmt yuv422p10le "out.mov"

    But attempting to run this just gives me the error :

    Unable to find a suitable output format for '\

    I don’t quite understand what’s going wrong. How can I encode my single input to both outputs simultaneously ?