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• How to extract 16-bit PNG frame from lossless x264 video

  29 mai 2017, par whiskeyspider

  I encoded a series of 16-bit grayscale PNGs to a lossless video with the following command :

  ffmpeg -i image%04d.png -crf 0 -c:v libx264 -preset veryslow output.mp4

  I am now trying to verify that the conversion to video was truly lossless by pulling out the PNGs at the same quality. The command I’m using :

  ffmpeg -i output.mp4 image%04d.png

  However, this is outputting 8-bit PNGs. I’ve tried various options I’ve read about such as -vcodec png and -qscale 0 but so far nothing appears to make it output 16-bit PNGs.

  How do I extract all frames from the video at the same quality as they were going in ? Or did I make a mistake in creating the lossless video in the first place ?

  Edit : I get this error message when trying to use -pix_fmt gray16be.

  [swscaler @ 0x7fef1a8f0800] deprecated pixel format used, make sure
  you did set range correctly

  Full output :

  ffmpeg -i output.mp4 -pix_fmt gray16be  image%04d.png
  
  ffmpeg version 3.3.1 Copyright (c) 2000-2017 the FFmpeg developers
  
    built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
  
    configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.1 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
  
    libavutil      55. 58.100 / 55. 58.100
  
    libavcodec     57. 89.100 / 57. 89.100
  
    libavformat    57. 71.100 / 57. 71.100
  
    libavdevice    57.  6.100 / 57.  6.100
  
    libavfilter     6. 82.100 /  6. 82.100
  
    libavresample   3.  5.  0 /  3.  5.  0
  
    libswscale      4.  6.100 /  4.  6.100
  
    libswresample   2.  7.100 /  2.  7.100
  
    libpostproc    54.  5.100 / 54.  5.100
  
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.71.100
  
    Duration: 00:00:09.76, start: 0.000000, bitrate: 1337 kb/s
  
      Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuvj444p(pc), 512x512, 1336 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (h264 (native) -> png (native))
  
  Press [q] to stop, [?] for help
  
  [swscaler @ 0x7fef1a8f0800] deprecated pixel format used, make sure you did set range correctly
  
  Output #0, image2, to 'image%04d.png':
  
    Metadata:
  
      major_brand     : isom
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      encoder         : Lavf57.71.100
  
      Stream #0:0(und): Video: png, gray16be, 512x512, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
  
      Metadata:
  
        handler_name    : VideoHandler
  
        encoder         : Lavc57.89.100 png
  
  frame=  244 fps=0.0 q=-0.0 Lsize=N/A time=00:00:09.76 bitrate=N/A speed=  21x    
  
  video:4038kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

  I’m happy to use a non-ffmpeg solution if there is one.

• How to build FFMPEG for all architecture of android device ?

  13 juillet 2017, par Prakash U

  I am trying to build ffmpeg for android in windows 8.1 using CYGWIN

  I am following This question & How to compile FFMPEG under Cygwin . I succsessfully compile but it is not generate FFMPEG.so but it generate ffmpeg.exe file

  I don’t want any prebuild ffmpeg library . I want to build it for my requirement.

  I perform this steps In CYGWIN BASE

  1. git clone git ://source.ffmpeg.org/ffmpeg.git ffmpeg
  2. dos2unix configure
  3. dos2unix build_ffmpeg.sh
  4. make distclean
  5. ./configure –enable-static –disable-shared
  6. make
  7. make install

  my build_ffmpeg.sh is

  # !/bin/bash

  NDK=/cygdrive/e/android/sdk/ndk-bundle
  PLATFORM=$NDK/platforms/android-24/arch-arm
  TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/windows
  CPU=arm
  PREFIX=$(pwd)/android/$CPU
  ADDI_CFLAGS="-marm"

  pushd ffmpeg
  # Configure
  ./configure \
  —target-os=android \
  —prefix=$PREFIX \
  —enable-cross-compile \
  —enable-runtime-cpudetect \
  —disable-asm \
  —arch=arm \
  —cc=$TOOLCHAIN/bin/arm-linux-androideabi-gcc \
  —cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
  —disable-stripping \
  —nm=$TOOLCHAIN/bin/arm-linux-androideabi-nm \
  —sysroot=$PLATFORM \
  —disable-programs \
  —disable-doc \
  —enable-protocol=file \
  —disable-avresample \
  —enable-gpl \
  —enable-version3 \
  —enable-nonfree \
  —disable-ffplay \
  —disable-ffserver \
  —disable-ffmpeg \
  —disable-ffprobe \
  —extra-cflags="-fPIC -DANDROID -D__thumb__ -mthumb -Wfatal-errors -Wno-deprecated $ADDI_CFLAGS" \
  —extra-libs="-lgcc" \
  —extra-ldflags="-L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog"
  # Make
  make clean
  make -j5
  make -j5 install

  popd

  My LOG file is here

  My question is how to build ffmpeg for all architecture of android device ?

• MPlayer not playing HTTP video stream for a specific type of content from the same source

  2 août 2017, par Joel

  Implementation overview

  Before I dive into the question, I need to establish the context from the start.

  I am currently implementing a cloud gaming solution utilising the following :

  • Nvidia Capture SDK
  • Nvidia Video Codec SDK
  • FFmpeg
  • MPlayer

  The Nvidia Capture SDK is used to produce a shim layer (via DXGI.dll), intercepting and capturing DirectX frames so that they can be passed to the Nvidia Video Codec SDK to be encoded into an h264 video format. All this is done within DXGI.dll.

  I then pass the encoded video to FFmpeg. FFmpeg acts as an HTTP server that broadcasts the video stream for MPlayer to play.

  Problem

  I am running an Unreal Engine 4 game called "Epic Survival Game Series". The Nvidia Capture SDK’s shim layer kicks off when the game starts, and FFmpeg launches the HTTP server to start streaming. However, when I start MPlayer to receive the stream, MPlayer stops at the following message, and nothing happens after that.

  libavformat version 57.72.101 (internal)
Stream not seekable!
H264-ES file format detected

  The thing is, when I play the same video using ffplay, it works without any issue. This is not the only quirk. When I launch a different Unreal Engine 4 game called "First Person Shooter Template", MPlayer can play that video as well. Also, if I modify the Survival Game to load directly into the game level by skipping the menu, MPlayer is also able to play the video.

  Using FFmpeg to write the video to a file instead of streaming it to a video also works, no matter the game or whether I loaded into the menu or game level.

  This is very strange and I do not have any idea why this is the case. Any ideas ?

  Edit : One strange quirk I forgot to mention is that MPlayer does manage to play the video in very rare occasions - maybe once every 10-20 tries or so.

  Implementation Details

  Additional details of how certain parts are implemented.

  (1) For the Nvidia Capture SDK, I use the provided DXIFRShim example that is provided in the SDK

  (2) for the Nvidia Video Codec SDK, I use the provided NvEncoder example that is provided in the SDK

  (3) The FFmpeg command I use is this :
  ffmpeg -i - -listen 1 -threads 1 -vcodec copy -preset ultrafast -an -tune zerolatency -f h264 http://address:port
  The encoded frames from Nvidia Video Codec SDK is piped to FFmpeg.

  (4) The MPlayer command I use is this :
  mplayer -quiet -vo gl -nosound -benchmark http://address:port

  Things I’ve tried

  I am suspecting MPlayer to be the cause, so I’ve only played around with MPlayer parameters.
  mplayer http://address:port

  mplayer -fps 30 -vo gl -nosound -benchmark http://address:port

  mplayer -fps 30 -screenw 720 -screenh 1280 -vo gl -nosound -benchmark http://address:port

  mplayer -fps 30 -vo directx -nosound -benchmark http://address:port

  mplayer -fps 30 -vo null -nosound -benchmark http://address:port

  None of these worked.