FFmpeg.js Extract images (jpeg/png) from MP4 file

Question

I'm trying to extract images/frames from a mp4 on client side with the help of ffmpeg.js.

Equivalent Ffmpeg command:

ffmpeg -i Sample.mp4 -r 1 output%d.png

However i could try to create webm file from jpeg files but i couldn't do the reverse and ends up with following error message

Unable to find a suitable output format for 'output%d.png'

Here is the code i'm trying to use.

var ffmpeg = require("ffmpeg.js/ffmpeg-mp4");
var fs = require("fs");
var stdout = "";
var stderr = "";

var testData = new Uint8Array(fs.readFileSync("Sample.mp4"));

var result = ffmpeg({
  MEMFS: [{name: "Sample.mp4", data: testData}],
  stdin: function() {},
  arguments: ["-i", "Sample.mp4","-r","1", "output%d.png"],
});

console.log(result.MEMFS.length)
if(result.MEMFS.length>0){
    var out = result.MEMFS[0].data;
    fs.writeFileSync("test.jpg", Buffer(out.data));
    }

Console Output

ffmpeg version n3.1.2 Copyright (c) 2000-2016 the FFmpeg developers
  built with emcc (Emscripten gcc/clang-like replacement) 1.36.7 ()
  configuration: --cc=emcc --enable-cross-compile --target-os=none --arch=x86 --disable-runtime-cpudetect --disable-asm --disable-fast-unaligned --disable-pthreads --disable-w32threads --di
sable-os2threads --disable-debug --disable-stripping --disable-all --enable-ffmpeg --enable-avcodec --enable-avformat --enable-avutil --enable-swresample --enable-swscale --enable-avfilter
--disable-network --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --enable-decoder=vp8 --enable-decoder=vp9 --enable-decoder=theora --enable-decoder=mpeg2vid
eo --enable-decoder=mpeg4 --enable-decoder=h264 --enable-decoder=hevc --enable-decoder=png --enable-decoder=mjpeg --enable-decoder=vorbis --enable-decoder=opus --enable-decoder=mp3 --enable
-decoder=ac3 --enable-decoder=aac --enable-decoder=ass --enable-decoder=ssa --enable-decoder=srt --enable-decoder=webvtt --enable-demuxer=matroska --enable-demuxer=ogg --enable-demuxer=avi
--enable-demuxer=mov --enable-demuxer=flv --enable-demuxer=mpegps --enable-demuxer=image2 --enable-demuxer=mp3 --enable-demuxer=concat --enable-protocol=file --enable-filter=aresample --ena
ble-filter=scale --enable-filter=crop --enable-filter=overlay --disable-bzlib --disable-iconv --disable-libxcb --disable-lzma --disable-sdl --disable-securetransport --disable-xlib --disabl
e-zlib --enable-encoder=libx264 --enable-encoder=libmp3lame --enable-encoder=aac --enable-muxer=mp4 --enable-muxer=mp3 --enable-muxer=null --enable-gpl --enable-libmp3lame --enable-libx264
--extra-cflags=-I../lame/dist/include --extra-ldflags=-L../lame/dist/lib
  libavutil      55. 28.100 / 55. 28.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 41.100 / 57. 41.100
  libavfilter     6. 47.100 /  6. 47.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
[h264 @ 0x809d50] Warning: not compiled with thread support, using thread emulation
[aac @ 0x80e640] Warning: not compiled with thread support, using thread emulation
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Sample.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.56.100
  Duration: 00:01:00.00, start: 0.000000, bitrate: 137 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 360x214, 113 kb/s, 1 fps, 1 tbr, 16384 tbn, 32768 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 22050 Hz, mono, fltp, 23 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
[NULL @ 0x810d00] Unable to find a suitable output format for 'output%d.png'
output%d.png: Invalid argument

Answer 1

You have --disable-all to "disable building components, libraries and programs", but you didn't include --enable-muxer=image2 (and possibly some other components).

I don't recommend using --disable-all unless you want to --enable-headaches due to the requirement of re-compiling to enable forgotten components.

Also, avoid using --disable-asm: it will make things unnecessarily slow.