Reproduction steps:
First, clone this repo locally and install deps with npm install.
Then run:
node --require ./required.js --experimental-wasm-threads .
Below is the output. Notice that we get the log from required.js the first
time as expected, but then we get it several other times while ffmpeg is
running. This is a problem.
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
[info] use ffmpeg.wasm v0.10.1
[info] load ffmpeg-core
[info] loading ffmpeg-core
[info] fetch ffmpeg.wasm-core script from @ffmpeg/core
[info] ffmpeg-core loaded
[info] run FS.writeFile test.avi <92440 bytes binary file>
[info] run ffmpeg command: -i test.avi test.mp4
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
[fferr] ffmpeg version v0.9.0-2-gb11e5c1495 Copyright (c) 2000-2020 the FFmpeg developers
[fferr] built with emcc (Emscripten gcc/clang-like replacement) 2.0.8 (d059fd603d0b45b584f634dc2365bc9e9a6ec1dd)
[fferr] configuration: --target-os=none --arch=x86_32 --enable-cross-compile --disable-x86asm --disable-inline-asm --disable-stripping --disable-programs --disable-doc --disable-debug --disable-runtime-cpudetect --disable-autodetect --extra-cflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1' --extra-cxxflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1' --extra-ldflags='-s USE_PTHREADS=1 -I/src/build/include -O3 --closure 1 -L/src/build/lib' --pkg-config-flags=--static --nm=llvm-nm --ar=emar --ranlib=emranlib --cc=emcc --cxx=em++ --objcc=emcc --dep-cc=emcc --enable-gpl --enable-nonfree --enable-zlib --enable-libx264 --enable-libx265 --enable-libvpx --enable-libwavpack --enable-libmp3lame --enable-libfdk-aac --enable-libtheora --enable-libvorbis --enable-libfreetype --enable-libopus --enable-libwebp --enable-libass --enable-libfribidi
[fferr] libavutil 56. 51.100 / 56. 51.100
[fferr] libavcodec 58. 91.100 / 58. 91.100
[fferr] libavformat 58. 45.100 / 58. 45.100
[fferr] libavdevice 58. 10.100 / 58. 10.100
[fferr] libavfilter 7. 85.100 / 7. 85.100
[fferr] libswscale 5. 7.100 / 5. 7.100
[fferr] libswresample 3. 7.100 / 3. 7.100
[fferr] libpostproc 55. 7.100 / 55. 7.100
[fferr] Input #0, avi, from 'test.avi':
[fferr] Metadata:
[fferr] encoder : Lavf58.45.100
[fferr] Duration: 00:00:01.00, start: 0.000000, bitrate: 739 kb/s
[fferr] Stream #0:0: Video: indeo4 (IV41 / 0x31345649), yuv410p, 256x240, 707 kb/s, 35 fps, 35 tbr, 35 tbn, 35 tbc
[fferr] Stream mapping:
[fferr] Stream #0:0 -> #0:0 (indeo4 (native) -> h264 (libx264))
[fferr] [libx264 @ 0x1a6bcc0] using cpu capabilities: none!
[fferr] [libx264 @ 0x1a6bcc0] profile High, level 1.3, 4:2:0, 8-bit
[fferr] [libx264 @ 0x1a6bcc0] 264 - core 160 - H.264/MPEG-4 AVC codec - Copyleft 2003-2020 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
[fferr] Output #0, mp4, to 'test.mp4':
[fferr] Metadata:
[fferr] encoder : Lavf58.45.100
[fferr] Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 256x240, q=-1--1, 35 fps, 17920 tbn, 35 tbc
[fferr] Metadata:
[fferr] encoder : Lavc58.91.100 libx264
[fferr] Side data:
[fferr] cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
**************************************************************************
**************************************************************************
**************************************************************************
**************************************************************************
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
**************************************************************************
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
THIS WAS REQUIRED!!!
**************************************************************************
[fferr] frame= 35 fps=0.0 q=-1.0 Lsize= 37kB time=00:00:00.91 bitrate= 335.7kbits/s speed= 2.1x
[fferr] video:36kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 3.345004%
[fferr] [libx264 @ 0x1a6bcc0] frame I:1 Avg QP:23.21 size: 1433
[fferr] [libx264 @ 0x1a6bcc0] frame P:11 Avg QP:24.26 size: 1517
[fferr] [libx264 @ 0x1a6bcc0] frame B:23 Avg QP:26.38 size: 797
[fferr] [libx264 @ 0x1a6bcc0] consecutive B-frames: 8.6% 11.4% 0.0% 80.0%
[fferr] [libx264 @ 0x1a6bcc0] mb I I16..4: 14.6% 85.4% 0.0%
[fferr] [libx264 @ 0x1a6bcc0] mb P I16..4: 5.7% 55.2% 2.0% P16..4: 8.4% 4.1% 2.2% 0.0% 0.0% skip:22.5%
[fferr] [libx264 @ 0x1a6bcc0] mb B I16..4: 1.9% 15.9% 1.0% B16..8: 18.9% 6.7% 1.7% direct: 2.7% skip:51.2% L0:49.7% L1:41.1% BI: 9.2%
[fferr] [libx264 @ 0x1a6bcc0] 8x8 transform intra:86.6% inter:76.6%
[fferr] [libx264 @ 0x1a6bcc0] coded y,uvDC,uvAC intra: 69.5% 0.0% 0.0% inter: 11.9% 0.0% 0.0%
[fferr] [libx264 @ 0x1a6bcc0] i16 v,h,dc,p: 26% 44% 27% 3%
[fferr] [libx264 @ 0x1a6bcc0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 15% 27% 51% 2% 1% 1% 1% 1% 3%
[fferr] [libx264 @ 0x1a6bcc0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 23% 18% 20% 6% 6% 7% 5% 8% 6%
[fferr] [libx264 @ 0x1a6bcc0] i8c dc,h,v,p: 100% 0% 0% 0%
[fferr] [libx264 @ 0x1a6bcc0] Weighted P-Frames: Y:0.0% UV:0.0%
[fferr] [libx264 @ 0x1a6bcc0] ref P L0: 55.4% 10.6% 20.9% 13.0%
[fferr] [libx264 @ 0x1a6bcc0] ref B L0: 78.5% 16.6% 5.0%
[fferr] [libx264 @ 0x1a6bcc0] ref B L1: 90.8% 9.2%
[fferr] [libx264 @ 0x1a6bcc0] kb/s:291.64
[ffout] FFMPEG_END
[info] run FS.readFile test.mp4