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• In Flutter, how to get image pixel

  12 janvier 2024, par Pianone

  my code here

  


  var response = await Dio().get(
   url,
   options: Options(responseType: ResponseType.bytes)
);
Uint8List? srcImage = Uint8List.fromList(response.data);
Uint8List? watermark = await captureWaterMark();
Image i = Image.memory(srcImage!);
//how can I get the pixel (Image i) such like 1920*1080 or just width/hight pixel
...tell me how to do...
srcImage = await addWaterMarkByFfmpegCommand(srcImage, watermark);
   final result = await ImageGallerySaver.saveImage(
      srcImage!, name: name,
   );


  


  i need get the pic pixel so that i can use it in ffmpeg command, it a func that add a watermark into srcImage, but cause their pixel ratio too diff to adapted watermark

  


  i try to get pixel from ffmpeg... but i failed

  


  /// addWaterMark by using ffmpeg Command
Future addWaterMarkByFfmpegCommand(Uint8List srcImg, Uint8List watermark) async {
  try {
    final Directory tempDir = await Directory.systemTemp.createTemp();
    final File image1File = File('${tempDir.path}/srcImg.jpg');
    await image1File.writeAsBytes(srcImg);
    final File image2File = File('${tempDir.path}/watermark.png');
    await image2File.writeAsBytes(watermark);

    final String outputFilePath = '${tempDir.path}/output.jpg';
    //when i get srcImage pixel, the positions in bold(iw*1) in the following commands will be replaced to make watermark adapted
    final String command =
        '-i ${image1File.path} -i ${image2File.path} -filter_complex "[1:v]scale=**iw*1**:-1[v1];[0:v][v1]overlay=10:10" -frames:v 1 $outputFilePath';
    await FFmpegKit.execute(command);

    final File outputFile = File(outputFilePath);
    final Uint8List outputBytes = await outputFile.readAsBytes();
    return outputBytes;
  } catch (e) {
    print('Error executing ffmpeg command: $e');
  }
  return null;
}


  


  ps : i am new to flutter and ffmpeg, plz help me, I'd appreciate, thanks alot

  


• VP8 Codec SDK "Aylesbury" Release

  28 octobre 2010, par noreply@blogger.com (John Luther)

  Today we’re making available "Aylesbury," our first named release of libvpx, the VP8 codec SDK. VP8 is the video codec used in WebM. Note that the VP8 specification has not changed, only the SDK.

  What’s an Aylesbury ? It’s a breed of duck. We like ducks, so we plan to use duck-related names for each major libvpx release, in alphabetical order. Our goal is to have one named release of libvpx per calendar quarter, each with a theme.

  You can download the Aylesbury libvpx release from our Downloads page or check it out of our Git repository and build it yourself. In the coming days Aylesbury will be integrated into all of the WebM project components (DirectShow filters, QuickTime plugins, etc.). We encourage anyone using our components to upgrade to the Aylesbury releases.

  For Aylesbury the theme was faster decoder, better encoder. We used our May 19, 2010 launch release of libvpx as the benchmark. We’re very happy with the results (see graphs below) :
  

  • 20-40% (average 28%) improvement in libvpx decoder speed
  • Over 7% overall PSNR improvement (6.3% SSIM) in VP8 "best" quality encoding mode, and up to 60% improvement on very noisy, still or slow moving source video.

  

  
  

  

  
  

  

  
  

  The main improvements to the decoder are :
  

  • Single-core assembly "hot spot" optimizations, including improved vp8_sixtap_predict() and SSE2 loopfilter functions
  • Threading improvements for more efficient use of multiple processor cores
  • Improved memory handling and reduced footprint
  • Combining IDCT and reconstruction steps
  • SSSE3 usage in functions where appropriate

  On the encoder front, we concentrated on clips in the 30-45 dB range and saw the biggest gains in higher-quality source clips (greater that 38 dB), low to medium-motion clips, and clips with noisy source material. Many code contributions made this possible, but a few of the highlights were :
  

  • Adaptive width and strength alternate reference frame noise suppression filter with optional motion compensation.
  • Transform improvements (improved accuracy and reduction in round trip error)
  • Trellis-based quantized coefficient optimization
  • Two-pass rate control and quantizer changes
  • Rate distortion changes
  • Zero bin and rounding changes
  • Work on MB-level quality control and bit allocation

  We’re targeting Q1 2011 for the next named libvpx release, which we’re calling Bali. The theme for that release will be faster encoder. We are constantly working on improvements to video quality in the encoder, so after Aylesbury we won’t tie that work to specific named releases.

  WebM at Streaming Media West

  Members of the WebM project will discuss Aylesbury during a session at the Streaming Media West conference on November 3rd (session C203 : WebM Open Video Project Update). For more information, visit www.streamingmedia.com/west.

  John Luther is Product Manager of the WebM Project.

  

• ffmpeg - spark - azure databricks - error writing trailer of "filename.mp3" : Operation not supported

  4 juillet 2021, par CRAFTY DBA

  I have been trying to figure out this tough problem.

  


  I am trying to convert *.mp4 files to *.mp3 files.

  


  I tried using MoviePy but I found out that is uses ffmpeg and was having the same issue.

  


  I used these two articles to get the latest version of ffmpeg installed on the Azure Databricks Cluster during startup. I am using a single node cluster for this POC code.

  


  Pyspark : Use ffmpeg on the driver and workers
  
https://ubuntuhandbook.org/index.php/2020/06/install-ffmpeg-4-3-via-ppa-ubuntu-18-04-16-04
  

  


  The issue is that even the simplest command results in errors.

  


  %%bash ffmpeg -i /dbfs/Craftydba/recording.mp4 /dbfs/Craftydba/recording.mp3

  


  I even tried .wav as an output format and still the same issue.

  


  I retested this command on a Data Science VM in Azure with Python and FFMPEG. It works fine on that OS/Build.

  


  It has something to do with the version of the code on the spark cluster.

  


  Any help is appreciated.

  


  Sincerely

  


  John Miner

  


  PS : I am add a dump of the OS version as well as a ffmpeg error.

  


  Os Version Dump

  


  NAME="Ubuntu"
VERSION="18.04.5 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.5 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic

  


  FFMPEG Dump

  


  ffmpeg version 4.3.2-0york0~18.04 Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
  configuration: --prefix=/usr --extra-version='0york0~18.04' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libzimg --enable-pocketsphinx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/dbfs/Craftydba/recording.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2
    creation_time   : 2021-06-18T19:07:17.000000Z
  Duration: 00:04:48.64, start: 0.000000, bitrate: 1065 kb/s
    Stream #0:0(eng): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p, 1920x1080, 1000 kb/s, 7.96 fps, 8 tbr, 10k tbn, 20k tbc (default)
    Metadata:
      creation_time   : 2021-06-18T19:07:17.000000Z
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 16000 Hz, mono, fltp, 63 kb/s (default)
    Metadata:
      creation_time   : 2021-06-18T19:07:17.000000Z
Stream mapping:
  Stream #0:1 -> #0:0 (aac (native) -> mp3 (libmp3lame))
Press [q] to stop, [?] for help
Output #0, mp3, to '/dbfs/Craftydba/recording.mp3':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2
    TSSE            : Lavf58.45.100
    Stream #0:0(eng): Audio: mp3 (libmp3lame), 16000 Hz, mono, fltp (default)
    Metadata:
      creation_time   : 2021-06-18T19:07:17.000000Z
      encoder         : Lavc58.91.100 libmp3lame
Error writing trailer of /dbfs/Craftydba/recording.mp3: Operation not supported
size=     846kB time=00:04:48.65 bitrate=  24.0kbits/s speed=86.9x    
video:0kB audio:846kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.036945%