Sur d’autres sites (3558)

• Why this shell command doesn't work ? ('command' works but 'command|cat' doesn't work)

  16 octobre 2018, par yabee

  Problem

  The following code outputs like...

  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep -A 2 key_frame=1
  
  key_frame=1
  
  pkt_pts=0
  
  pkt_pts_time=0:00:00.000000
  
  --
  
  key_frame=1
  
  pkt_pts=41041
  
  pkt_pts_time=0:00:01.710042
  
  --
  
  key_frame=1
  
  pkt_pts=64064
  
  pkt_pts_time=0:00:02.669333
  
  --
  
  key_frame=1
  
  pkt_pts=87087
  
  pkt_pts_time=0:00:03.628625
  
  --
  
  ...

  But the folowing one outputs nothing.

  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep -A 2 key_frame=1|cat

  And...

  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep key_frame=1
  
  key_frame=1
  
  key_frame=1
  
  key_frame=1
  
  key_frame=1
  
  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep key_frame=1|cat
  
  # Nothing outputted.

  Why ?

  Expected result

  What actually I want to do is

  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep -A 2key_frame=1|grep time
  
  pkt_pts_time=0:00:00.000000
  
  pkt_pts_time=0:00:01.710042
  
  pkt_pts_time=0:00:02.669333
  
  pkt_pts_time=0:00:03.628625
  
  ...

  But its result is

  $ ffprobe -show_frames -select_streams v test.mp4 2>/dev/null|grep -A 2key_frame=1|grep time
  
  # Nothing outputted.

  Grep works correctory exept it’s after ffprobe.

  $ seq 30|grep 1|grep 2
  
  12
  
  21

  Environment

  • Bash on Ubuntu on Windows 10 Pro
    • Windows version : 1803
    • Windows OS build : 17134.345

  Environment of Ubuntu :

  $ cat /etc/lsb-release
  
  DISTRIB_ID=Ubuntu
  
  DISTRIB_RELEASE=18.04
  
  DISTRIB_CODENAME=bionic
  
  DISTRIB_DESCRIPTION="Ubuntu 18.04.1 LTS"
  
  
  
  $ bash --version
  
  GNU bash, version 4.4.19(1)-release (x86_64-pc-linux-gnu)
  
  Copyright (C) 2016 Free Software Foundation, Inc.
  
  License GPLv3+: GNU GPL version 3 or later /gnu.org/licenses/gpl.html>
  
  
  
  This is free software; you are free to change and redistribute it.
  
  There is NO WARRANTY, to the extent permitted by law.
  
  
  
  $ ffprobe
  
  ffprobe version 3.4.4-0ubuntu0.18.04.1 Copyright (c) 2007-2018 the FFmpeg developers
  
    built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
  
    configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
  
    libavutil      55. 78.100 / 55. 78.100
  
    libavcodec     57.107.100 / 57.107.100
  
    libavformat    57. 83.100 / 57. 83.100
  
    libavdevice    57. 10.100 / 57. 10.100
  
    libavfilter     6.107.100 /  6.107.100
  
    libavresample   3.  7.  0 /  3.  7.  0
  
    libswscale      4.  8.100 /  4.  8.100
  
    libswresample   2.  9.100 /  2.  9.100
  
    libpostproc    54.  7.100 / 54.  7.100
  
  Simple multimedia streams analyzer
  
  usage: ffprobe [OPTIONS] [INPUT_FILE]
  
  
  
  You have to specify one input file.
  
  Use -h to get full help or, even better, run 'man ffprobe'.

  What is problem ?

  Does grep or ffprobe change its behavior by existence of pipe in this case ?
  Thanks.

• ffmpeg hls m3u8 streaming only works for the first frame

  12 septembre 2018, par Bilel Azri

  Im now trying to get vlc to work with m3u8(actually it is supposed to do so), however, vlc does not work with them. It only gives me the first frame and it’s then just stuck on that frame for -hls_time secs and finally "quit". if i look in mu m3u8 file the frames work fine.
  this example of frame is work fine

  #EXTINF:20.000000,
  
  http://server.com:80/videos/amfSyubTEw/GyvlIYrgEF/1_14.ts

  my problem is the vlc not complete runing the stream.
  here is my ffmpeg command

  sudo ffmpeg -probesize 15000000 -analyzeduration 9000000 -user_agent "LuckyPanel" -i "http://adtv.ercdn.net/adsport1/adsport1_720p.m3u8" -c copy -c:a copy -b:a 128k -hls_flags delete_segments -hls_time 10 -hls_base_url http://server.com/ -hls_list_size 10 /var/www/html/1_.m3u8 

• cmake build error with libswresample, works fine with clang

  19 août 2018, par Dan Gordon

  I’m building an FFmpeg project with CLion which uses cmake to compile the code. Everything has been working great until I started to use the libswresample library. For some reason, cmake isn’t seeing the dylib and won’t build the code.

  /Applications/CLion.app/Contents/bin/cmake/mac/bin/cmake --build /Users/user/CLionProjects/IC4D/cmake-build-debug --target all -- -j 4
  
  [ 50%] Linking C executable IC4D
  
  Undefined symbols for architecture x86_64:
  
    "_swr_alloc_set_opts", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_convert", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_free", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_init", referenced from:
  
        _audio_decode_frame in main.c.o
  
    "_swr_set_compensation", referenced from:
  
        _audio_decode_frame in main.c.o
  
  ld: symbol(s) not found for architecture x86_64
  
  clang: error: linker command failed with exit code 1 (use -v to see invocation)
  
  make[2]: *** [IC4D] Error 1
  
  make[1]: *** [CMakeFiles/IC4D.dir/all] Error 2
  
  make: *** [all] Error 2

  But if I run this clang code, it compiles just fine

  clang -I/usr/local/include -L/usr/local/lib -lavcodec -lavcodec -lswscale -lavformat -lswresample -lSDL2 -lavutil -o IC4D2 ../main.c

  Here’s my CMakeList.txt file :

  cmake_minimum_required(VERSION 3.10)
  
  project(IC4D C)
  
  
  
  set(CMAKE_C_STANDARD 99)
  
  
  
  include_directories( /Users/user/CLionProjects/IC4D/include/ )
  
  link_directories( /Users/user/CLionProjects/IC4D/lib/ )
  
  
  
  find_path(AVDEVICE_INCLUDE_DIR include/libavdevice/avdevice.h)
  
  find_library(AVDEVICE_LIBRARY lib/libavdevice.58.dylib)
  
  
  
  find_path(AVFORMAT_INCLUDE_DIR include/libavformat/avformat.h)
  
  find_library(AVFORMAT_LIBRARY lib/libavformat.58.dylib)
  
  
  
  find_path(AVCODEC_INCLUDE_DIR include/libavcodec/avcodec.h)
  
  find_library(AVCODEC_LIBRARY lib/libavcodec.58.dylib)
  
  
  
  find_path(SWSCALE_INCLUDE_DIR include/libswscale/swscale.h)
  
  find_library(SWSCALE_LIBRARY lib/libswscale.5.dylib)
  
  
  
  find_path(AVUTIL_INCLUDE_DIR include/libavutil/avutil.h)
  
  find_library(AVUTIL_LIBRARY lib/libavutil.56.dylib)
  
  
  
  find_path(SWRESAMPLE_INCLUDE_DIR include/libswresample/swresample.h)
  
  find_library(SWRESAMPLE_LIBRARY lib/libswresample.3.dylib)
  
  
  
  find_package(SDL2 REQUIRED)
  
  
  
  add_executable(IC4D main.c)
  
  
  
  target_include_directories(IC4D PRIVATE ${SDL2_INCLUDE_DIRS} ${AVDEVICE_INCLUDE_DIR} ${AVFORMAT_INCLUDE_DIR} ${AVCODEC_INCLUDE_DIR} ${SWSCALE_INCLUDE_DIR} ${AVUTIL_INCLUDE_DIR} ${SWRESAMPLE_INCLUDE_DIR})
  
  target_link_libraries(IC4D PRIVATE ${SDL2_LIBRARIES} ${AVDEVICE_LIBRARY} ${AVFORMAT_LIBRARY} ${AVCODEC_LIBRARY} ${SWSCALE_LIBRARY} ${AVUTIL_LIBRARY} ${SWRESAMPLE_LIBRARY})

  What am I doing wrong with cmake ?

  Thanks