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• Revert "lavc/vaapi_encode : add EQUAL_MULTI_ROWS support for slice structure"

  27 juillet 2020, par Mark Thompson

  Revert "lavc/vaapi_encode : add EQUAL_MULTI_ROWS support for slice structure"
  This reverts commit 489c5db0791f39518775b12eef6d48276c17f96f.
  Treating EQUAL_MULTI_ROWS in the same way as the arbitrary-size cases is
  
  just wrong.  Consider 9 rows, 4 slices - we pick 4 slices with sizes
  
   3, 2, 2, 2 , which EQUAL_MULTI_ROWS does not allow.  It isn't possible
  
  to split the frame into 4 slices at all with the EQUAL_MULTI_ROWS
  
  structure - the closest options are 3 slices with sizes  3, 3, 3  or 5
  
  slices with sizes  2, 2, 2, 2, 1 .
  

  • [DH] libavcodec/vaapi_encode.c

• youtube-dl - How do I ensure that the "original" video formats are downloaded ?

  25 juin 2018, par Schytheron

  I am building a C# GUI (Windows only) for youtube-dl where I allow the user to pick the desired video quality and framerate but I am having problems with format selection. youtube-dl sometimes downloads either the wrong video file or the wrong audio file (often it is audio) and after merging them I end up with a .mkv file because according to FFmpeg the files I am trying to merge are incompatible.

  These are the format selection queries I have tried to far :

  bestvideo[height<=?%height%][fps<=?%fps%]+bestaudio/best

  and

  public string[] qualities = { "4320", "2160", "1440", "1080", "720", "480", "360", "240", "144" };
  
  public string[] framerates = { "60", "50", "48", "30", "24" };
  
  private void buildFormat(int qualSkip,int fpsSkip)
  
          {
  
              string[] qualitiesMin = qualities.Skip(qualSkip).ToArray();
  
              string[] frameratesMin = framerates.Skip(fpsSkip).ToArray();
  
              format = "-f ";
  
              foreach (string quality in qualitiesMin)
  
              {
  
                  foreach (string framerate in frameratesMin)
  
                  {
  
                      format += "bestvideo[height=?" + quality + "][fps=?" + framerate + "]+bestaudio/";
  
                  }
  
              }
  
              format += "best";
  
          }

  In the first one I had a problem where on some videos youtube-dl downloaded a video in a lower framerate than what I requested (for example, if I request 1080p60FPS I get 1080p30FPS). I tried to fix this in the second method by searching for the best video for all qualities and framerates that are equal to or lower than the one I picked (for example, if I pick 1080p60FPS it would look for videos from 1080p60->1080p30->720p60->720p30->...->144p30).

  The second method however looks overly convoluted and stupid and another problem still remains. youtube-dl always picks the best audio quality no matter what video quality I choose. I want the audio quality to scale with the video quality (for example, if I pick 144p I want poor audio quality). There has got to be a better way.

  Maybe I am explaining this poorly but I basically want youtube-dl to ALWAYS (consistently) download the exact same video and audio format as the one that is displayed in the youtube video player itself for each picked video quality (see image below). How do I do that ?

  Example 1, Video and audio format codes of video in 4K (the numbers in the red circles are the format codes) :
  

  Example 2, Video and audio format of same video but this time in 720p :
  

  (should also pick a lower framerate video of same quality if that framerate is not available in the YouTube quality selector, for example 1080p30FPS in a 1080p60FPS video)

  Thanks !

• "no archive symbol table (run ranlib)" issue with static linking FFmpeg for android

  9 octobre 2017, par Programist

  I am trying to build FFmpeg for android as static libraries on a MacOS Sierra machine.

  Following is my buildscript.sh which is very much based upon the one in here

  #!/bin/bash
  
  
  
  cd ffmpeg-3.3.4
  
  
  
  NDK=/path/to/android/ndk/android-ndk-r15c
  
  SYSROOT=$NDK/platforms/android-21/arch-arm64/
  
  TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64
  
  AR=$TOOLCHAIN/bin/arm-linux-androideabi-ar
  
  CPREFIX=$TOOLCHAIN/bin/arm-linux-androideabi-
  
  CC=$TOOLCHAIN/bin/arm-linux-androideabi-gcc
  
  CXX=$TOOLCHAIN/bin/arm-linux-androideabi-g++
  
  LD=$TOOLCHAIN/bin/arm-linux-androideabi-ld
  
  RANLIB=$TOOLCHAIN/bin/arm-linux-androideabi-ranlib
  
  STRIP=$TOOLCHAIN/bin/arm-linux-androideabi-strip
  
  X264LIB=$X264/android/arm/lib/
  
  X264INC=$X264/android/arm/include/
  
  
  
  function build_ffmpeg_android {
  
  
  
  ./configure \
  
      --prefix=$PREFIX \
  
      --disable-stripping
  
      --arch=arm \
  
      --cpu=cortex-a8 \
  
      --target-os=linux \
  
      --enable-cross-compile \
  
      --enable-pic \
  
      --disable-programs \
  
      --enable-static \
  
      --disable-shared \
  
      --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
  
      --disable-doc \
  
      --enable-postproc \
  
      --enable-swscale \
  
      --enable-avfilter \
  
      --enable-avresample \
  
      --disable-opencl \
  
      --disable-securetransport \
  
      --enable-gpl \
  
      --sysroot=$SYSROOT \
  
      --extra-cflags="-Os -fpic $ADDI_CFLAGS -I$X264INC"  \
  
      --extra-ldflags="$ADDI_LDFLAGS -s -L$X264LIB -lx264" \
  
      --enable-gpl \
  
      --enable-decoders \
  
      --enable-encoders \
  
      --enable-muxers \
  
      --enable-demuxers \
  
      --enable-parsers \
  
      --enable-protocols \
  
      --enable-filters \
  
      --enable-avresample \
  
      --enable-libfreetype \
  
      --disable-indevs \
  
      --enable-indev=lavfi \
  
      --disable-outdevs \
  
      --enable-hwaccels \
  
      --enable-ffmpeg \
  
      --disable-ffplay \
  
      --disable-ffprobe \
  
      --disable-ffserver \
  
      --disable-network \
  
      --enable-libx264 \
  
      --enable-zlib \
  
      --enable-muxer=md5
  
      make clean
  
      make -j9
  
      make install
  
  }
  
  
  
  CPU=arm
  
  PREFIX=$(pwd)/android/$CPU
  
  ADDI_CFLAGS="-marm"
  
  
  
  build_ffmpeg_android

  The output of above script is placed inside ffmpeg-3.3.4/android/arm.

  Problem :
  When trying to link to these .a libraries from my app using -lavformat -lavcodec -lswscale -lavutil -lavfilter -lswresample -lavdevice,
  I get the following linker error for each of them

  :-1: error: error: avformat: no archive symbol table (run ranlib)
  
  :-1: error: error: avcodec: no archive symbol table (run ranlib)
  
  :-1: error: error: swscale: no archive symbol table (run ranlib)
  
  :-1: error: error: avutil: no archive symbol table (run ranlib)
  
  :-1: error: error: avfilter: no archive symbol table (run ranlib)
  
  :-1: error: error: swresample: no archive symbol table (run ranlib)
  
  :-1: error: error: avdevice: no archive symbol table (run ranlib)

  Looking at this discussion here, I am doing it correct by selecting arm-linux-androideabi-ar in CPREFIX.

  Trying to solve the error, I’ve also added the following configure flag for ranlib to be picked up specifically for android but doesn’t seem to help.

  RANLIB=$TOOLCHAIN/bin/arm-linux-androideabi-ranlib

  Question :
  What else am I missing here ?
  What is needed in my buildscript.sh to pick the correct ranlib & stop complaining about archive symbol table when linking from my app ?