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  • D’autres logiciels intéressants

    12 avril 2011, par

    On ne revendique pas d’être les seuls à faire ce que l’on fait ... et on ne revendique surtout pas d’être les meilleurs non plus ... Ce que l’on fait, on essaie juste de le faire bien, et de mieux en mieux...
    La liste suivante correspond à des logiciels qui tendent peu ou prou à faire comme MediaSPIP ou que MediaSPIP tente peu ou prou à faire pareil, peu importe ...
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    Videopress
    Site Internet : (...)

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    27 avril 2010, par

    Mediaspip core
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  • Publier sur MédiaSpip

    13 juin 2013

    Puis-je poster des contenus à partir d’une tablette Ipad ?
    Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir

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  • FFMPEG - Multi Track, Multi Channel file to discrete mono files

    26 novembre 2020, par vade

    I have files which are multi track, and multi channel (ie, track 1 may be 5.1, track 2 may be stereo, track 3 may be stereo etc)

    


    I am looking to output every channel from every track into its own 'unrolled' discrete mono file.

    


    example media :

    


    ffprobe version 4.3.1-0york0~18.04 Copyright (c) 2007-2020 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
[mxf @ 0x55d3e7fc2680] wrapping of stream 0 is unknown
[jpeg2000 @ 0x55d3e805ce00] End mismatch 1
    Last message repeated 1 times
Input #0, mxf, from 'redacted.mxf':
  Metadata:
    operational_pattern_ul: 060e2b34.04010101.0d010201.01010900
    modification_date: 2019-10-03T09:58:16.368000Z
    uid             : f6267ae2-680e-4357-9b1d-c77c045d3cd7
    generation_uid  : e7e6f5a1-6f15-4df5-aea8-a41f3ef535d6
    company_name    : redacted
    product_name    : redacted
    product_version : 11.6.1.5.301404
    product_uid     : 84ae5ffc-4710-11dd-a6fe-0010c629ec73
    application_platform: 4KICR1
    material_package_umid: 0x060A2B340101010501010D2013000000BE3608F3135E48AD99E4340643E47F22
    timecode        : 00:59:20:00
  Duration: 00:26:16.07, start: 0.000000, bitrate: 139194 kb/s
    Stream #0:0: Video: jpeg2000, yuv422p10le(progressive), 1920x1080, SAR 1:1 DAR 16:9, 23.98 tbr, 23.98 tbn, 23.98 tbc
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Picture
    Stream #0:1: Audio: pcm_s24le, 48000 Hz, 6 channels, s32 (24 bit), 6912 kb/s
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Sound
    Stream #0:2: Audio: pcm_s24le, 48000 Hz, 2 channels, s32 (24 bit), 2304 kb/s
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Sound
    Stream #0:3: Audio: pcm_s24le, 48000 Hz, 2 channels, s32 (24 bit), 2304 kb/s
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Sound
    Stream #0:4: Audio: pcm_s24le, 48000 Hz, 2 channels, s32 (24 bit), 2304 kb/s
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Sound
    Stream #0:5: Data: none
    Metadata:
      file_package_umid: 0x060A2B340101010501010D201300000091A43E578B86490698045924FA9EECC5
      track_name      : Auxiliary Data
      data_type       : vbi_vanc_smpte_436M
Unsupported codec with id 0 for input stream 5


    


    These files are vendor qualified masters, and the track / channel combinations vary between vendors, so some might be stereo, 5.1, 7.1 order, some might be all discrete mono already, some might be discrete stereo, 5.1, and mono tracks. Its all a mix. So im looking for some general strategy that gracefully handles all channels from all tracks.

    


    Now I have seen various strategies documented to handle discretizing audio via ffmpeg docs, but none of them seem to show how to target different channels from different tracks. Im sure its a pebkac error, but I'd love some guidance.

    


    I have tried both a map_channel approach as well as a -filtercomplex channelsplit approach.

    


    ffmpeg -i redacted.mxf -ss 60 \
-map_channel 0.1.0 -t 10 track_1_0.wav \
-map_channel 0.1.1 -t 10 track_1_1.wav \
-map_channel 0.1.2 -t 10 track_1_2.wav \
-map_channel 0.1.3 -t 10 track_1_3.wav \
-map_channel 0.1.4 -t 10 track_1_4.wav \
-map_channel 0.1.5 -t 10 track_1_5.wav \
-map_channel 0.2.0 -t 10 track_2_0.wav \
-map_channel 0.2.1 -t 10 track_2_1.wav \
-map_channel 0.3.0 -t 10 track_3_0.wav \
-map_channel 0.3.1 -t 10 track_3_1.wav \
-map_channel 0.4.0 -t 10 track_4_0.wav \
-map_channel 0.4.1 -t 10 track_4_1.wav 


    


    However, the output files are not all mono, some are marked as 5.1. I dont believe they are inheriting a sane / correct channel layout (mono) - but the output files that are marked 5.1 are nonsensical, as they are all sourced from stereo tracks. ie track_2_0.wav track_2_1.wav, track_3_0.wav, track_3_1.wav, track_4_0.wav, track_4_1.wav. Which seems odd. Track 1_0 from the above command outputs a sane media info :

    


    File size                                : 938 KiB
Duration                                 : 10s 0ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 768 Kbps
Writing application                      : Lavf58.45.100

Audio
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : 1
Duration                                 : 10s 0ms
Bit rate mode                            : Constant
Bit rate                                 : 768 Kbps
Channel(s)                               : 1 channel
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Stream size                              : 938 KiB (100%)



    


    However the second and 3rd track have the wrong channel layout and an unexpected codec id :

    


    Format                                   : Wave
File size                                : 5.49 MiB
Duration                                 : 10s 0ms
Overall bit rate mode                    : Constant
Overall bit rate                         : 4 608 Kbps
Writing application                      : Lavf58.45.100

Audio
Format                                   : PCM
Format settings                          : Little / Signed
Codec ID                                 : 00000001-0000-0010-8000-00AA00389B71
Duration                                 : 10s 0ms
Bit rate mode                            : Constant
Bit rate                                 : 4 608 Kbps
Channel(s)                               : 6 channels
Channel layout                           : L R C LFE Lb Rb
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Stream size                              : 5.49 MiB (100%)



    


    Additionally re : map_channel, there are some docs that cast doubt that its the right approach :

    


    


    Note that currently each output stream can only contain channels from a single input stream ; you can’t for example use "-map_channel" to pick multiple input audio channels contained in different streams (from the same or different files) and merge them into a single output stream. It is therefore not currently possible, for example, to turn two separate mono streams into a single stereo stream. However splitting a stereo stream into two single channel mono streams is possible.

    


    


    Using filter complex, the docs/bug tracker have an example of discretizing 5.1 and marking mono. I can target the tracks I want, and get a valid filter chain as seen in debug log reporting, however I only get audio for the 1st track :

    


    ffmpeg -y -v 40 -i redacted.mxf -ss 60 \
    -disposition:a default \
    -filter_complex \
    "[0:a:0]channelsplit=channel_layout=5.1[c1][c2][c3][c4][c5][c6],\
    [c1]aformat=channel_layouts=mono[c1],\
    [c2]aformat=channel_layouts=mono[c2],\
    [c3]aformat=channel_layouts=mono[c3],\
    [c4]aformat=channel_layouts=mono[c4],\
    [c5]aformat=channel_layouts=mono[c5],\
    [c6]aformat=channel_layouts=mono[c6],\
    [0:a:1]channelsplit=channel_layout=stereo[c7][c8],\
    [c7]aformat=channel_layouts=mono[c7],\
    [c8]aformat=channel_layouts=mono[c8],\
    [0:a:2]channelsplit=channel_layout=stereo[c9][c10],\
    [c9]aformat=channel_layouts=mono[c9],\
    [c10]aformat=channel_layouts=mono[c10],\
    [0:a:3]channelsplit=channel_layout=stereo[c11][c12],\
    [c11]aformat=channel_layouts=mono[c11],\
    [c12]aformat=channel_layouts=mono[c12]"\
     -map  "[c1]" -t 10 1.wav\
     -map  "[c2]" -t 10 2.wav\
     -map  "[c3]" -t 10 3.wav\
     -map  "[c4]" -t 10 4.wav\
     -map  "[c5]" -t 10 5.wav\
     -map  "[c6]" -t 10 6.wav\
     -map  "[c7]" -t 10 7.wav\
     -map  "[c8]" -t 10 8.wav\
     -map  "[c9]" -t 10 9.wav\
     -map  "[c10]" -t 10 10.wav\
     -map  "[c11]" -t 10 11.wav\
     -map  "[c12]" -t 10 12.wav


    


    TL/DR ;

    


    In short, how does one export every channel of every track as a discrete mono audio track (regardless of the channel layouts ?)

    


    Thank you !

    


  • Stage-Whisper is not working because of missing files

    24 novembre 2023, par Tingtong

    I tried to install this here : https://github.com/Stage-Whisper/Stage-Whisper

    


    Once i put the audio file in it, it is still loading and loading but not transcribing it.

    


    So after that i checked the requirements and packages, if there is something missing and there is. I installed those here :

    


    Node (required for Electron)
Yarn (required for Electron)
Python 3.x (required for backend)
Rust (required for backend)
ffmpeg (required for backend)
Poetry (required for backend)


    


    I installed them with homebrew. There are some errors showing up, once i launch the electron programm with "yarn dev" : ERROR : "could not locate binding files"

    


    I also tried "poetry run python stagewhisper —input /path/to/audio/file.mp3", but got following message. Poetry could not find a pyproject.toml file in /Users/Administrator/Desktop/Stage-Whisper or its parents.

    


    Where do i have to put the file pyproject.toml and what do i have to write in it ?

    


    So i checked with brew info all tools which i need for Stage-Whisper. Screenshots :enter image description here
[enter image description here](https://i.stack.imgur.com/sirb3.png)

    


    What i tried was to update those packages/requirements which where missing, with "sudo port install requirementPackageName ". But after checking with brew info again, those parts are still missing. So does that actually work or do i have to install those missing stuff with homebrew ? I have Mac Mojave 10.14.6 and Homebrew 4.1.18 Version.

    


    I also got an error, while i installed those tools with homebrew :

    


    ERROR : You are using macOS 10.14.
We (and Apple) do not provide support for this old version. It is expected behaviour that some formulae will fail to build in this old version... etc

    


    Thank you for your help guys.

    


    Edit :

    


    


    yarn install v1.22.19 warning ../../../package.json : No license field
[1/4] 🔍 Resolving packages... [2/4] 🚚 Fetching packages... [3/4]
🔗 Linking dependencies... warning "@emotion/react >
@emotion/babel-plugin@11.10.2" has unmet peer dependency
"@babel/core@^7.0.0". warning "@emotion/react > @emotion/babel-plugin

    


    


    @babel/plugin-syntax-jsx@7.18.6" has unmet peer dependency "@babel/core@^7.0.0-0". warning " > autoprefixer@10.4.4" has unmet
peer dependency "postcss@^8.1.0". warning " >
eslint-config-airbnb@19.0.4" has unmet peer dependency
"eslint-plugin-react-hooks@^4.3.0".
[----------------------------------------------------------------------------------------------------------------------------------------------------------------------------] 0/890^[4/4] 🔨 Building fresh packages... [1/7] ⠁ better-sqlite3
[-/7] ⠁ waiting... [3/7] ⠁ sqlite3 [4/7] ⠁ esbuild error
/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/better-sqlite3 :
Command failed. Exit code : 1 Command : prebuild-install || npm run
build-release Arguments : Directory :
/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/better-sqlite3
Output : prebuild-install warn install No prebuilt binaries found
(target=20.9.0 runtime=node arch=x64 libc= platform=darwin)

    


    


    


    better-sqlite3@7.6.2 build-release
node-gyp rebuild —release

    


    


    gyp info it worked if it ends with ok gyp info using node-gyp@9.3.0
gyp info using node@20.9.0 | darwin | x64 gyp info find Python using
Python version 3.9.14 found at "/usr/local/bin/python3" gyp info spawn
/usr/local/bin/python3 gyp info spawn args [ gyp info spawn args
    
'/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/electron-rebuild/node_modules/node-gyp/gyp/gyp_main.py',
gyp info spawn args 'binding.gyp', gyp info spawn args '-f', gyp
info spawn args 'make', gyp info spawn args '-I', gyp info spawn
args
    
'/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/better-sqlite3/build/config.gypi',
gyp info spawn args '-I', gyp info spawn args
    
'/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/electron-rebuild/node_modules/node-gyp/addon.gypi',
gyp info spawn args '-I', gyp info spawn args
    
'/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/common.gypi',
gyp info spawn args '-Dlibrary=shared_library', gyp info spawn args
'-Dvisibility=default', gyp info spawn args
    
'-Dnode_root_dir=/Users/administrator/Library/Caches/node-gyp/20.9.0',
gyp info spawn args
    
'-Dnode_gyp_dir=/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/electron-rebuild/node_modules/node-gyp',
gyp info spawn args
    &#xA;'-Dnode_lib_file=/Users/administrator/Library/Caches/node-gyp/20.9.0/<(target_arch)/node.lib',&#xA;gyp info spawn args
    &#xA;'-Dmodule_root_dir=/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/better-sqlite3',&#xA;gyp info spawn args '-Dnode_engine=v8', gyp info spawn args
    &#xA;'—depth=.', gyp info spawn args '—no-parallel', gyp info spawn&#xA;args '—generator-output', gyp info spawn args 'build', gyp info&#xA;spawn args '-Goutput_dir=.' gyp info spawn args ] gyp info spawn&#xA;make gyp info spawn args [ 'BUILDTYPE=Release', '-C', 'build' ]
    &#xA;TOUCH ba23eeee118cd63e16015df367567cb043fed872.intermediate ACTION&#xA;deps_sqlite3_gyp_locate_sqlite3_target_copy_builtin_sqlite3&#xA;ba23eeee118cd63e16015df367567cb043fed872.intermediate TOUCH&#xA;Release/obj.target/deps/locate_sqlite3.stamp CC(target)&#xA;Release/obj.target/sqlite3/gen/sqlite3/sqlite3.o LIBTOOL-STATIC&#xA;Release/sqlite3.a CXX(target)&#xA;Release/obj.target/better_sqlite3/src/better_sqlite3.o In file&#xA;included from ../src/better_sqlite3.cpp:4 : In file included from&#xA;./src/better_sqlite3.lzz:11 : In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/node.h:73 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8.h:24 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-array-buffer.h:12 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-local-handle.h:12 :&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:465:30 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;SHARED_EXTERNAL_POINTER_TAGS(CHECK_SHARED_EXTERNAL_POINTER_TAGS)&#xA;^ /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:465:30 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:465:30 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:465:30 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:465:30 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;PER_ISOLATE_EXTERNAL_POINTER_TAGS(CHECK_NON_SHARED_EXTERNAL_POINTER_TAGS)&#xA;^ /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:466:35 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:693:61 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;static_assert(kJSObjectType + 1 == kFirstJSApiObjectType) ;&#xA;^&#xA;, "" /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:694:55 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;static_assert(kJSObjectType < kLastJSApiObjectType) ;&#xA;^&#xA;, "" /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-internal.h:695:63 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;static_assert(kFirstJSApiObjectType < kLastJSApiObjectType) ;&#xA;^&#xA;, "" In file included from ../src/better_sqlite3.cpp:4 : In file included from&#xA;./src/better_sqlite3.lzz:11 : In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/node.h:73 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8.h:24 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-array-buffer.h:13 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-object.h:9 :&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-maybe.h:106:45 :&#xA;error : no template named 'is_lvalue_reference_v' in namespace 'std' ;&#xA;did you mean 'is_lvalue_reference' ? template >&#xA; ^ &#xA;is_lvalue_reference /Library/Developer/CommandLineTools/usr/include/c++/v1/type_traits:780:50 :&#xA;note : 'is_lvalue_reference' declared here template struct&#xA;_LIBCPP_TEMPLATE_VIS is_lvalue_reference : public false_type {} ;&#xA;^ In file included from ../src/better_sqlite3.cpp:4 : In file included from&#xA;./src/better_sqlite3.lzz:11 : In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/node.h:73 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8.h:24 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-array-buffer.h:13 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-object.h:9 :&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-maybe.h:106:69 :&#xA;error : expected '(' for function-style cast or type construction
    &#xA;template     >&#xA; ^ /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-maybe.h:123:43 :&#xA;error : no template named 'is_lvalue_reference_v' in namespace 'std' ;&#xA;did you mean 'is_lvalue_reference' ? template * = nullptr>&#xA; ^ &#xA;is_lvalue_reference /Library/Developer/CommandLineTools/usr/include/c++/v1/type_traits:780:50 :&#xA;note : 'is_lvalue_reference' declared here template struct&#xA;_LIBCPP_TEMPLATE_VIS is_lvalue_reference : public false_type {} ;&#xA;^ In file included from ../src/better_sqlite3.cpp:4 : In file included from&#xA;./src/better_sqlite3.lzz:11 : In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/node.h:73 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8.h:24 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-array-buffer.h:13 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-object.h:9 :&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-maybe.h:123:67 :&#xA;error : expected '(' for function-style cast or type construction&#xA;template * =&#xA;nullptr>&#xA; ^ In file included from ../src/better_sqlite3.cpp:4 : In file included from&#xA;./src/better_sqlite3.lzz:11 : In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/node.h:73 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8.h:33 :&#xA;In file included from&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-function.h:11 :&#xA;/Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-function-callback.h:151:66 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;kReturnValueDefaultValueIndex - kReturnValueIndex) ;&#xA;^&#xA;, "" /Users/administrator/Library/Caches/node-gyp/20.9.0/include/node/v8-function-callback.h:153:50 :&#xA;warning : static_assert with no message is a C++17 extension&#xA;[-Wc++17-extensions]&#xA;kIsolateIndex - kReturnValueIndex) ;&#xA;^&#xA;, "" ./src/util/macros.lzz:157:21 : error : no member named&#xA;'AccessorSignature' in namespace 'v8'&#xA;v8::AccessorSignature::New(isolate, recv)&#xA; ^ ./src/util/binder.lzz:37:51 : error : no member named 'CreationContext' in 'v8::Object'&#xA;v8::Local ctx = obj->CreationContext() ;&#xA; ^ 22 warnings and 6 errors generated. make : ***&#xA;[Release/obj.target/better_sqlite3/src/better_sqlite3.o] Error 1 rm&#xA;ba23eeee118cd63e16015df367567cb043fed872.intermediate gyp ERR ! build&#xA;error gyp ERR ! stack Error : make failed with exit code : 2 gyp ERR !&#xA;stack at ChildProcess.onExit&#xA;(/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/electron-rebuild/node_modules/node-gyp/lib/build.js:203:23)&#xA;gyp ERR ! stack at ChildProcess.emit (node:events:514:28) gyp ERR !&#xA;stack at ChildProcess._handle.onexit&#xA;(node:internal/child_process:294:12) gyp ERR ! System Darwin 18.7.0 gyp&#xA;ERR ! command "/usr/local/bin/node"&#xA;"/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/.bin/node-gyp"&#xA;"rebuild" "—release" gyp ERR ! cwd&#xA;/Users/administrator/Desktop/Stage-Whisper/electron/node_modules/better-sqlite3

    &#xA;

    &#xA;

    Same goes for the the "poetry install" command in the backend folder :

    &#xA;

    8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/build/onig_sys-3a9a2f947b5ad744/outwarning: variable does not need to be mutable --> tokenizers-lib/src/models/unigram/model.rs:265:21 | 265 |                 let mut target_node = &amp;mut best_path_ends_at[key_pos]; |                     ----^^^^^^^^^^^ |                     | |                     help: remove thismut| = note:#[warn(unused_mut)]` on by default

    &#xA;

    warning : variable does not need to be mutable&#xA;—> tokenizers-lib/src/models/unigram/model.rs:282:21&#xA;|&#xA;282 | let mut target_node = &mut best_path_ends_at[starts_at + mblen] ;&#xA;| ----^^^^^^^^^^^&#xA;| |&#xA;| help : remove this mut

    &#xA;

    warning : variable does not need to be mutable&#xA;—> tokenizers-lib/src/pre_tokenizers/byte_level.rs:200:59&#xA;|&#xA;200 | encoding.process_tokens_with_offsets_mut(|(i, (token, mut offsets))| &#xA;| ----^^^^^^^&#xA;| |&#xA;| help : remove this mut

    &#xA;

    error : casting &amp;T to &amp;mut T is undefined behavior, even if the reference is unused, consider instead using an UnsafeCell&#xA;—> tokenizers-lib/src/models/bpe/trainer.rs:526:47&#xA;|&#xA;522 | let w = &words[*i] as *const _ as *mut _ ;&#xA;| -------------------------------- casting happend here&#xA;...&#xA;526 | let word : &mut Word = &mut (*w) ;&#xA;| ^^^^^^^^^&#xA;|&#xA;= note : #[deny(invalid_reference_casting)] on by default

    &#xA;

    warning : tokenizers (lib) generated 3 warnings&#xA;error : could not compile tokenizers (lib) due to previous error ; 3 warnings emitted

    &#xA;

    Caused by :&#xA;process didn't exit successfully : /Users/administrator/.rustup/toolchains/stable-x86_64-apple-darwin/bin/rustc --crate-name tokenizers --edition=2018 tokenizers-lib/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no --cfg &#x27;feature="cached-path"&#x27; --cfg &#x27;feature="clap"&#x27; --cfg &#x27;feature="cli"&#x27; --cfg &#x27;feature="default"&#x27; --cfg &#x27;feature="http"&#x27; --cfg &#x27;feature="indicatif"&#x27; --cfg &#x27;feature="progressbar"&#x27; --cfg &#x27;feature="reqwest"&#x27; -C metadata=cb36f9861d265e60 -C extra-filename=-cb36f9861d265e60 --out-dir /private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps -L dependency=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps --extern aho_corasick=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libaho_corasick-021885281f13d108.rmeta --extern cached_path=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libcached_path-767095c4d4a77107.rmeta --extern clap=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libclap-c92d2593d8a75e62.rmeta --extern derive_builder=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libderive_builder-833217c2af636976.dylib --extern dirs=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libdirs-f12e99ecd3a76eae.rmeta --extern esaxx_rs=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libesaxx_rs-b694f04df571686b.rmeta --extern indicatif=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libindicatif-39491a3282a24810.rmeta --extern itertools=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libitertools-b322e49e83853c17.rmeta --extern lazy_static=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/liblazy_static-28a96417d88df3c9.rmeta --extern log=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/liblog-937f94f366843d8a.rmeta --extern macro_rules_attribute=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libmacro_rules_attribute-d4d77bee9330e675.rmeta --extern onig=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libonig-7f9dab4334743bdf.rmeta --extern paste=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libpaste-a36a4a0dbc2ac63f.dylib --extern rand=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/librand-4b1adc86e35ea892.rmeta --extern rayon=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/librayon-d134e48f83d52e6e.rmeta --extern rayon_cond=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/librayon_cond-5715a923c66c54a9.rmeta --extern regex=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libregex-a5c54f2d0034ab98.rmeta --extern regex_syntax=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libregex_syntax-58c405f62323b6ed.rmeta --extern reqwest=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libreqwest-1551c89d20e17f58.rmeta --extern serde=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libserde-f4748cc953dd1338.rmeta --extern serde_json=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libserde_json-5fba404e8440399e.rmeta --extern spm_precompiled=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libspm_precompiled-6bd24072bd3c9d31.rmeta --extern thiserror=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libthiserror-bcbb2769006ee534.rmeta --extern unicode_normalization_alignments=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libunicode_normalization_alignments-658520cf6a5461dc.rmeta --extern unicode_segmentation=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libunicode_segmentation-fffd829ab6256bb0.rmeta --extern unicode_categories=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/deps/libunicode_categories-e3815c3d18c1086b.rmeta -L native=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/build/bzip2-sys-d2cb72d65b178690/out/lib -L native=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/build/zstd-sys-ddff0154a55a136c/out -L native=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/build/esaxx-rs-69d9e34a40d41449/out -L native=/private/var/folders/zc/c2qvlcjd5cgcg5l84484t8vh0000gt/T/tmp2yohvwu_/tokenizers-0.12.1/target/release/build/onig_sys-3a9a2f947b5ad744/out (exit status : 1)&#xA;error : cargo rustc --lib --message-format=json-render-diagnostics --manifest-path Cargo.toml --release -v --features pyo3/extension-module --crate-type cdylib -- -C &#x27;link-args=-undefined dynamic_lookup -Wl,-install_name,@rpath/tokenizers.cpython-311-darwin.so&#x27; failed with code 101

    &#xA;

    at /usr/local/lib/python3.11/site-packages/poetry/installation/chef.py:166 in _prepare&#xA;162│&#xA;163│ error = ChefBuildError("\n\n".join(message_parts))&#xA;164│&#xA;165│ if error is not None :&#xA;→ 166│ raise error from None&#xA;167│&#xA;168│ return path&#xA;169│&#xA;170│ def _prepare_sdist(self, archive : Path, destination : Path | None = None) -> Path :

    &#xA;

    Note : This error originates from the build backend, and is likely not a problem with poetry but with tokenizers (0.12.1) not supporting PEP 517 builds. You can verify this by running 'pip wheel —no-cache-dir —use-pep517 "tokenizers (==0.12.1)"'.

    &#xA;

    UPDATE (SOLVED) :

    &#xA;

      &#xA;
    • i found a solution and this worked for me :

      • &#xA;

    &#xA;

    "I had the same problem and nothing mentioned here worked for me. Here is what worked for me :

    &#xA;

    **("Didnt do this Part")"Require all dependencies you need in the main.js file that is run by electron."**    &#xA;

    &#xA;

    What i did was :&#xA;Run npm i -D electron-rebuild to add the electron-rebuild package&#xA;Remove the node-modules folder, as well as the packages-lock.json file.&#xA;Run npm i to install all modules.&#xA;Run ./node_modules/.bin/electron-rebuild (.\node_modules.bin\electron-rebuild.cmd for Windows) to rebuild everything

    &#xA;

    It is very important to run ./node_modules/.bin/electron-rebuild directly after npm i otherwise it did not work on my mac."

    &#xA;

    But now i get following Error, when i upload and transcribe the file :

    &#xA;

    > [ELECTRON] NewEntry: Creating new entry with UUID: XY...&#xA;[ELECTRON] NewEntry: Copying audio file to store...&#xA;[ELECTRON] NewEntry: Audio file copied to store.&#xA;[ELECTRON] NewEntry: Entry added to database!&#xA;[ELECTRON] RunWhisper: Running model with args [&#xA;[ELECTRON]   &#x27;--verbose&#x27;,&#xA;[ELECTRON]   &#x27;true&#x27;,&#xA;[ELECTRON]   &#x27;--output_dir&#x27;,&#xA;[ELECTRON]   &#x27;/Users/administrator/Library/Application Support/stagewhisper/store/whisper/2a07203b-ad88-438c-babf-b600cb76aa1d&#x27;,&#xA;[ELECTRON]   &#x27;--task&#x27;,&#xA;[ELECTRON]   &#x27;translate&#x27;,&#xA;[ELECTRON]   &#x27;--model&#x27;,&#xA;[ELECTRON]   &#x27;base&#x27;,&#xA;[ELECTRON]   &#x27;--device&#x27;,&#xA;[ELECTRON]   &#x27;cpu&#x27;,&#xA;[ELECTRON]   &#x27;--input&#x27;,&#xA;[ELECTRON]   &#x27;/Users/administrator/Library/Application Support/stagewhisper/store/audio/harvard.mp3&#x27;&#xA;[ELECTRON] ]&#xA;[ELECTRON] RunWhisper: Child process closed with code 1&#xA;[ELECTRON] RunWhisper: Error running whisper script!&#xA;[ELECTRON] Error occurred in handler for &#x27;run-whisper&#x27;: Error: Error running whisper script!&#xA;[ELECTRON]     at ChildProcess.<anonymous> (/Users/administrator/Desktop/Stage-Whisper/electron/main/handlers/runWhisper/runWhisper.js:234:31)&#xA;[ELECTRON]     at ChildProcess.emit (node:events:390:28)&#xA;[ELECTRON]     at maybeClose (node:internal/child_process:1064:16)&#xA;[ELECTRON]     at Socket.<anonymous> (node:internal/child_process:450:11)&#xA;[ELECTRON]     at Socket.emit (node:events:390:28)&#xA;[ELECTRON]     at Pipe.<anonymous> (node:net:687:12)&#xA;&#xA; &#xA;</anonymous></anonymous></anonymous>

    &#xA;

  • Things I Have Learned About Emscripten

    1er septembre 2015, par Multimedia Mike — Cirrus Retro

    3 years ago, I released my Game Music Appreciation project, a website with a ludicrously uninspired title which allowed users a relatively frictionless method to experience a range of specialized music files related to old video games. However, the site required use of a special Chrome plugin. Ever since that initial release, my #1 most requested feature has been for a pure JavaScript version of the music player.

    “Impossible !” I exclaimed. “There’s no way JS could ever run fast enough to run these CPU emulators and audio synthesizers in real time, and allow for the visualization that I demand !” Well, I’m pleased to report that I have proved me wrong. I recently quietly launched a new site with what I hope is a catchier title, meant to evoke a cloud-based retro-music-as-a-service product : Cirrus Retro. Right now, it’s basically the same as the old site, but without the wonky Chrome-specific technology.

    Along the way, I’ve learned a few things about using Emscripten that I thought might be useful to share with other people who wish to embark on a similar journey. This is geared more towards someone who has a stronger low-level background (such as C/C++) vs. high-level (like JavaScript).

    General Goals
    Do you want to cross-compile an entire desktop application, one that relies on an extensive GUI toolkit ? That might be difficult (though I believe there is a path for porting qt code directly with Emscripten). Your better wager might be to abstract out the core logic and processes of the program and then create a new web UI to access them.

    Do you want to compile a game that basically just paints stuff to a 2D canvas ? You’re in luck ! Emscripten has a porting path for SDL. Make a version of your C/C++ software that targets SDL (generally not a tall order) and then compile that with Emscripten.

    Do you just want to cross-compile some functionality that lives in a library ? That’s what I’ve done with the Cirrus Retro project. For this, plan to compile the library into a JS file that exports some public functions that other, higher-level, native JS (i.e., JS written by a human and not a computer) will invoke.

    Memory Levels
    When porting C/C++ software to JavaScript using Emscripten, you have to think on 2 different levels. Or perhaps you need to force JavaScript into a low level C lens, especially if you want to write native JS code that will interact with Emscripten-compiled code. This often means somehow allocating chunks of memory via JS and passing them to the Emscripten-compiled functions. And you wouldn’t believe the type of gymnastics you need to execute to get native JS and Emscripten-compiled JS to cooperate.

    “Emscripten : Pointers and Pointers” is the best (and, really, ONLY) explanation I could find for understanding the basic mechanics of this process, at least when I started this journey. However, there’s a mistake in the explanation that left me confused for a little while, and I’m at a loss to contact the author (doesn’t anyone post a simple email address anymore ?).

    Per the best of my understanding, Emscripten allocates a large JS array and calls that the memory space that the compiled C/C++ code is allowed to operate in. A pointer in C/C++ code will just be an index into that mighty array. Really, that’s not too far off from how a low-level program process is supposed to view memory– as a flat array.

    Eventually, I just learned to cargo-cult my way through the memory allocation process. Here’s the JS code for allocating an Emscripten-compatible byte buffer, taken from my test harness (more on that later) :

    var musicBuffer = fs.readFileSync(testSpec[’filename’]) ;
var musicBufferBytes = new Uint8Array(musicBuffer) ;
var bytesMalloc = player._malloc(musicBufferBytes.length) ;
var bytes = new Uint8Array(player.HEAPU8.buffer, bytesMalloc, musicBufferBytes.length) ;
bytes.set(new Uint8Array(musicBufferBytes.buffer)) ;

    So, read the array of bytes from some input source, create a Uint8Array from the bytes, use the Emscripten _malloc() function to allocate enough bytes from the Emscripten memory array for the input bytes, then create a new array… then copy the bytes…

    You know what ? It’s late and I can’t remember how it works exactly, but it does. It has been a few months since I touched that code (been fighting with front-end website tech since then). You write that memory allocation code enough times and it begins to make sense, and then you hope you don’t have to write it too many more times.

    Multithreading
    You can’t port multithreaded code to JS via Emscripten. JavaScript has no notion of threads ! If you don’t understand the computer science behind this limitation, a more thorough explanation is beyond the scope of this post. But trust me, I’ve thought about it a lot. In fact, the official Emscripten literature states that you should be able to port most any C/C++ code as long as 1) none of the code is proprietary (i.e., all the raw source is available) ; and 2) there are no threads.

    Yes, I read about the experimental pthreads support added to Emscripten recently. Don’t get too excited ; that won’t be ready and widespread for a long time to come as it relies on a new browser API. In the meantime, figure out how to make your multithreaded C/C++ code run in a single thread if you want it to run in a browser.

    Printing Facility
    Eventually, getting software to work boils down to debugging, and the most primitive tool in many a programmer’s toolbox is the humble print statement. A print statement allows you to inspect a piece of a program’s state at key junctures. Eventually, when you try to cross-compile C/C++ code to JS using Emscripten, something is not going to work correctly in the generated JS “object code” and you need to understand what. You’ll be pleading for a method of just inspecting one variable deep in the original C/C++ code.

    I came up with this simple printf-workalike called emprintf() :

    #ifndef EMPRINTF_H
#define EMPRINTF_H

    #include <stdio .h>
    
#include <stdarg .h>
    
#include <emscripten .h>
    

    #define MAX_MSG_LEN 1000
    

    /* NOTE : Don’t pass format strings that contain single quote (’) or newline
    
* characters. */
    
static void emprintf(const char *format, ...)
    

    
    char msg[MAX_MSG_LEN] ;
    
    char consoleMsg[MAX_MSG_LEN + 16] ;
    
    va_list args ;
    

        /* create the string */
    
    va_start(args, format) ;
    
    vsnprintf(msg, MAX_MSG_LEN, format, args) ;
    
    va_end(args) ;
    

        /* wrap the string in a console.log(’’) statement */
    
    snprintf(consoleMsg, MAX_MSG_LEN + 16, "console.log(’%s’)", msg) ;
    

        /* send the final string to the JavaScript console */
    
    emscripten_run_script(consoleMsg) ;
    

    

    #endif  /* EMPRINTF_H */

    Put it in a file called “emprint.h”. Include it into any C/C++ file where you need debugging visibility, use emprintf() as a replacement for printf() and the output will magically show up on the browser’s JavaScript debug console. Heed the comments and don’t put any single quotes or newlines in strings, and keep it under 1000 characters. I didn’t say it was perfect, but it has helped me a lot in my Emscripten adventures.

    Optimization Levels
    Remember to turn on optimization when compiling. I have empirically found that optimizing for size (-Os) leads to the best performance all around, in addition to having the smallest size. Just be sure to specify some optimization level. If you don’t, the default is -O0 which offers horrible performance when running in JS.

    Static Compression For HTTP Delivery
    JavaScript code compresses pretty efficiently, even after it has been optimized for size using -Os. I routinely see compression ratios between 3.5:1 and 5:1 using gzip.

    Web servers in this day and age are supposed to be smart enough to detect when a requesting web browser can accept gzip-compressed data and do the compression on the fly. They’re even supposed to be smart enough to cache compressed output so the same content is not recompressed for each request. I would have to set up a series of tests to establish whether either of the foregoing assertions are correct and I can’t be bothered. Instead, I took it into my own hands. The trick is to pre-compress the JS files and then instruct the webserver to serve these files with a ‘Content-Type’ of ‘application/javascript’ and a ‘Content-Encoding’ of ‘gzip’.

    1. Compress your large Emscripten-build JS files with ‘gzip’ : ‘gzip compiled-code.js’
    2. Rename them from extension .js.gz to .jsgz
    3. Tell the webserver to deliver .jsgz files with the correct Content-Type and Content-Encoding headers

    To do that last step with Apache, specify these lines :

    AddType application/javascript jsgz
AddEncoding gzip jsgz

    They belong in either a directory’s .htaccess file or in the sitewide configuration (/etc/apache2/mods-available/mime.conf works on my setup).

    Build System and Build Time Optimization
    Oh goodie, build systems ! I had a very specific manner in which I wanted to build my JS modules using Emscripten. Can I possibly coerce any of the many popular build systems to do this ? It has been a few months since I worked on this problem specifically but I seem to recall that the build systems I tried to used would freak out at the prospect of compiling stuff to a final binary target of .js.

    I had high hopes for Bazel, which Google released while I was developing Cirrus Retro. Surely, this is software that has been battle-tested in the harshest conditions of one of the most prominent software-developing companies in the world, needing to take into account the most bizarre corner cases and still build efficiently and correctly every time. And I have little doubt that it fulfills the order. Similarly, I’m confident that Google also has a team of no fewer than 100 or so people dedicated to developing and supporting the project within the organization. When you only have, at best, 1-2 hours per night to work on projects like this, you prefer not to fight with such cutting edge technology and after losing 2 or 3 nights trying to make a go of Bazel, I eventually put it aside.

    I also tried to use Autotools. It failed horribly for me, mostly for my own carelessness and lack of early-project source control.

    After that, it was strictly vanilla makefiles with no real dependency management. But you know what helps in these cases ? ccache ! Or at least, it would if it didn’t fail with Emscripten.

    Quick tip : ccache has trouble with LLVM unless you set the CCACHE_CPP2 environment variable (e.g. : “export CCACHE_CPP2=1”). I don’t remember the specifics, but it magically fixes things. Then, the lazy build process becomes “make clean && make”.

    Testing
    If you have never used Node.js, testing Emscripten-compiled JS code might be a good opportunity to start. I was able to use Node.js to great effect for testing the individually-compiled music player modules, wiring up a series of invocations using Python for a broader test suite (wouldn’t want to go too deep down the JS rabbit hole, after all).

    Be advised that Node.js doesn’t enjoy the same kind of JIT optimizations that the browser engines leverage. Thus, in the case of time critical code like, say, an audio synthesis library, the code might not run in real time. But as long as it produces the correct bitwise waveform, that’s good enough for continuous integration.

    Also, if you have largely been a low-level programmer for your whole career and are generally unfamiliar with the world of single-threaded, event-driven, callback-oriented programming, you might be in for a bit of a shock. When I wanted to learn how to read the contents of a file in Node.js, this is the first tutorial I found on the matter. I thought the code presented was a parody of bad coding style :

    var fs = require("fs") ;
var fileName = "foo.txt" ;

    fs.exists(fileName, function(exists) 
    
  if (exists) 
    
    fs.stat(fileName, function(error, stats) 
    
      fs.open(fileName, "r", function(error, fd) 
    
        var buffer = new Buffer(stats.size) ;
    

            fs.read(fd, buffer, 0, buffer.length, null, function(error, bytesRead, buffer) 
    
          var data = buffer.toString("utf8", 0, buffer.length) ;
    

              console.log(data) ;
    
          fs.close(fd) ;
    
            ) ;
    
          ) ;
    
        ) ;
    
  ) ;

    Apparently, this kind of thing doesn’t raise an eyebrow in the JS world.

    Now, I understand and respect the JS programming model. But this was seriously frustrating when I first encountered it because a simple script like the one I was trying to write just has an ordered list of tasks to complete. When it asks for bytes from a file, it really has nothing better to do than to wait for the answer.

    Thankfully, it turns out that Node’s fs module includes synchronous versions of the various file access functions. So it’s all good.

    Conclusion
    I’m sure I missed or underexplained some things. But if other brave souls are interested in dipping their toes in the waters of Emscripten, I hope these tips will come in handy.

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