Newest 'ffmpeg' Questions - Stack Overflow

Les articles publiés sur le site

• FFmpeg compile for Android (configure, make)

  11 août 2013, par manutd

  I want to compile ffmpeg for Android ver.
  But everytime I try, I can't compile the source of ffmpeg.
  I think my configuration option may be invalid.

  I used this script for configure.

  #!/bin/sh
  NDK_PATH=$HOME/android-ndk-r8
  PREBUILT=$NDK_PATH/toolchains/arm-linux-androideabi-4.4.3/prebuilt/darwin-x86
  
  LDFLAGS="-Wl,-T,$PREBUILT/armelf_linux_eabi.x -Wl,-rpath-link=$NDK_PATH/platforms/android-8/arch-arm/usr/lib \
       -L$NDK_PATH/platforms/android-8/arch-arm/usr/lib -nostdlib $PREBUILT/lib/gcc/arm-linux-androideabi/4.4.3/crtbegin.o \
       $PREBUILT/lib/gcc/arm-linux-androideabi/4.4.3/crtend.o -lc -lm -ldl"
  COMMON_CONFIG="\
            ./configure --target-os=linux \
            --arch=arm \
            --enable-cross-compile \
            --cc=$PREBUILT/bin/arm-linux-androideabi-gcc \
            --as=$PREBUILT/bin/arm-linux-androideabi-gcc \
            --cross-prefix=$PREBUILT/bin/arm-linux-androideabi- \
            --sysinclude=$NDK_PATH/platforms/android-8/arch-arm/usr/include \
            --nm=$PREBUILT/bin/arm-linux-androideabi-nm \
            --extra-ldflags=\"$LDFLAGS\" \
            --extra-cflags=-I$NDK_PATH/platforms/android-8/arch-arm/usr/include \
  
  eval "$COMMON_CONFIG"
  if [ $? -ne 0 ]; then
    exit 1
  fi
  

  I have to give compiler a new header file path (by --extra-cflags) because when I typed 'make', compiler didn't know where are header files (like math.h, ctime.h)

  After configure using this scripts and type 'make', I got these error.

  CC  libavdevice/alldevices.o
  In file included from /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/stdlib.h:42,
               from ./libavutil/common.h:35,
               from ./libavutil/avutil.h:126,
               from libavdevice/avdevice.h:22,
               from libavdevice/alldevices.c:22:
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/strings.h:49: warning: redundant redeclaration of 'index'
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/string.h:47: note: previous declaration of 'index' was here
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/strings.h:50: warning: redundant redeclaration of 'strcasecmp'
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/string.h:57: note: previous declaration of 'strcasecmp' was here
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/strings.h:51: warning: redundant redeclaration of 'strncasecmp'
  /Users/gyeongmingim/android-ndk-r8/platforms/android-8/arch-arm/usr/include/string.h:58: note: previous declaration of 'strncasecmp' was here
  In file included from ./libavutil/internal.h:178,
               from ./libavutil/common.h:342,
               from ./libavutil/avutil.h:126,
               from libavdevice/avdevice.h:22,
               from libavdevice/alldevices.c:22:
  ./libavutil/libm.h:62: error: static declaration of 'lrint' follows non-static declaration
  ./libavutil/libm.h:69: error: static declaration of 'lrintf' follows non-static declaration
  ./libavutil/libm.h:76: error: static declaration of 'round' follows non-static declaration
  ./libavutil/libm.h:90: error: static declaration of 'trunc' follows non-static declaration
  make: *** [libavdevice/alldevices.o] Error 1
  

  What is the wrong?
  Does my configuration have wrong info? or any missing flag?

  OS : Mac Lion
  Android-ndk ver : android-ndk-r8

• Get .avi video's duriation in ffmpeg

  11 août 2013, par Vardan Hovhannisyan

  I would like to get .avi video duration using ffmpeg library? I have try to use code in this link: how to use libavcodec/ffmpeg to find duration of video file, but it's not work for .avi(but for .mp4 it does).

• Steps for writing NAL packets to mp4 using libavformat

  11 août 2013, par Nisar Ahmed

  I am writing h.264 NAL packets to mp4 container using libavformat but the output movie does not play on vlc player at all and ffmpeg -i output.mp4 gives "Could not find codec parameters for stream 0 (Video: h264 (avc1 / 0x31637661), 720x480, 13954 kb/s): unspecified pixel format"

  I have followed the steps mentioned in muxing.c sample but the results are same.

  Furthermore I don't want to encode frames as they are already encoded so I am bypassing avcodec_open2 function call.

  Please tell me what steps should I take in order to correctly write h264 to mp4.

• ffmpeg : 1 image + 1 audio = 1 video (how can it encode faster ?)

  11 août 2013, par user1062949

  I want ffmpeg to take a png image and a mp3 audio file as input and generate a video file of the same duration as the audio file. I'm using the following command:

   ffmpeg -loop 1 -shortest -y -i image.png -i audio.mp3 -acodec copy \
   -vcodec libx264 video.mov
  

  However, given a 40min mp3 file (160kbps) as input, it is taking more than 2 hours to encode the whole video on a MacBook Pro i5 2.5GHz.

  I tried to use the -preset ultrafast option, but it is not really improving the encoding speed significantly.

  Is there any way to encode it faster using ffmpeg?

  I was following the instructions provided in this post: ffmpeg: 1 image + 1 audio file = 1 video

  Any help will be appreciated, thank you.

• FFMPEG : How to convert 1000 jpegs and 100 mp3 seconds into video ?

  11 août 2013, par Spender

  So my programm generates JPegs and MP3 stereo track. I want to convert my programm results with FFMPEG to h264+aac or OGG (vorbis+theora) 100 seconds video. So how to do It from commandline at least (or using pure ffmpeg lib from C)?