Possible to pipe image stream?

[hbar-digital]

I'm trying to do something like the following:

cat *.jpg | ffmpeg -f image2pipe -i - video.mp4

Is there some way to do something similar with ffmpeg.js?

I was looking into recording with canvas.captureStream, however, I want to ensure all frames get recorded (no skipping) and ideally as fast as I can generate the frames.

[iamrototo]

What I am doing right now is:

• Every 30ms, store the canvas image in memory
• send this image directly with MEMFS as explained in the README

Please see this code in this issues to help you:
#20 (comment)

[hbar-digital]

Thanks for your response. I took a look at the code and here's my attempt at simply generating a video from an array of jpgs (ultimate goal being streaming the jpgs).

const ffmpeg = require('ffmpeg.js/ffmpeg-mp4.js');
const svg2img = require('svg2img');
const leftPad = require('left-pad');
const fs = require('fs');

let promises = [];

for(let i = 0; i < 30; i++) {
  let svg =
  `<svg xmlns="http://www.w3.org/2000/svg" version="1.1" width="512" height="512" viewBox="0 0 512 512">
    <rect width="512" height="512" style="fill:rgb(200,200,255)" />
    <text x="100" y="100" font-size="35">Frame ${i}</text>
  </svg>`;

  promises.push(new Promise(resolve => svg2img(svg, (err, buff) => resolve(buff))));
}

Promise.all(promises)
  .then(blobs => {
    // blobs.forEach((d, i) => fs.writeFile(`tmp/image-${leftPad(i, 3, '0')}.jpg`, d))

    let result = ffmpeg({
      MEMFS: blobs.map((data, i) => ({ name: `frame-${leftPad(i, 3, '0')}.jpg`, data })),
      arguments: ["-i", "frame-%03d.jpg", "-c:v", "libx264", "-pix_fmt", "yuv420p", "out.mp4"],
      stdin: () => {},
    });

    console.log(result.MEMFS[0].data); // empty
  });

I get an empty result as well as the following output. Am I doing something wrong? The jpg data should be correct as writing them to files seems to work as intended. Any help is appreciated!

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 --disable-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=mpeg2video --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 --enable-filter=scale --enable-filter=crop --enable-filter=overlay --disable-bzlib --disable-iconv --disable-libxcb --disable-lzma --disable-sdl --disable-securetransport --disable-xlib --disable-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
[mjpeg @ 0x80a630] Warning: not compiled with thread support, using thread emulation
[mjpeg @ 0x80a630] bits 107 is invalid
[mjpeg @ 0x80a630] bits 71 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
    Last message repeated 1 times
[mjpeg @ 0x80a630] bits 137 is invalid
[mjpeg @ 0x80a630] bits 0 is invalid
[mjpeg @ 0x80a630] JPEG-LS support not enabled.
[mjpeg @ 0x80a630] No JPEG data found in image
    Last message repeated 1 times
[mjpeg @ 0x80a630] JPEG-LS support not enabled.
[mjpeg @ 0x80a630] No JPEG data found in image
    Last message repeated 1 times
[mjpeg @ 0x80a630] JPEG-LS support not enabled.
    Last message repeated 1 times
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] bits 62 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] [IMGUTILS @ 0x309948] Picture size 56504x56161 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] JPEG-LS support not enabled.
[mjpeg @ 0x80a630] bits 155 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] bits 251 is invalid
[mjpeg @ 0x80a630] bits 242 is invalid
[mjpeg @ 0x80a630] bits 0 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] bits 110 is invalid
[mjpeg @ 0x80a630] Changing bps from 6 to 7
[mjpeg @ 0x80a630] [IMGUTILS @ 0x309948] Picture size 48788x48673 is invalid
[mjpeg @ 0x80a630] No JPEG data found in image
[mjpeg @ 0x80a630] Changing bps from 7 to 11
[mjpeg @ 0x80a630] [IMGUTILS @ 0x309948] Picture size 26301x54195 is invalid
[image2 @ 0x809290] decoding for stream 0 failed
[image2 @ 0x809290] Could not find codec parameters for stream 0 (Video: mjpeg, none(bt470bg/unknown/unknown)): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Input #0, image2, from 'frame-%03d.jpg':
  Duration: 00:00:01.20, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mjpeg, none(bt470bg/unknown/unknown), 25 fps, 25 tbr, 25 tbn, 25 tbc
[buffer @ 0x824010] Unable to parse option value "0x0" as image size
[buffer @ 0x824010] Unable to parse option value "-1" as pixel format
[buffer @ 0x824010] Unable to parse option value "0x0" as image size
[buffer @ 0x824010] Error setting option video_size to value 0x0.
[graph 0 input from stream 0:0 @ 0x824360] Error applying options to the filter.
Error opening filters!
Uint8Array [  ]

[CodeFetch]

Yes, that looks wrong to me. MEMFS can't parse Blobs, but only ArrayBuffers.
Either create a file reader from the Blob first or use WORKERFS:

mounts: [{
		type: "WORKERFS",
		mountpoint: "/test",
		opts: {
			blobs: [{
					name: "example.mp4",
					data: **blob**
				}]
			}
		}],

[Kagami]

@CodeFetch is right, thanks.