ffmpeg：使用NodeJS从stdin渲染webm [英] ffmpeg: Render webm from stdin using NodeJS
问题描述
我在尝试将动态创建的一些jpeg帧转储到ffmpeg和NodeJS以便创建webm视频时遇到问题。
I'm having an issue trying to dump some jpeg frames created on the fly to ffmpeg and NodeJS in order to create a webm video.
脚本试图做这些事情：
- 在初始化时分叉新的ffmpeg进程
- 渲染画布
- 更新画布中的数据后，从中获取JPEG数据。
- 将JPEG数据插入ffmpeg stdin中。
- ffmpeg负责将其附加到webm视频文件上。
- 这种情况永远存在，并且ffmpeg永不停止
- Fork a new ffmpeg process on initialization
- Render a canvas
- Once the data in canvas is updated, grab JPEG data from it.
- Pipe the JPEG data into the ffmpeg stdin.
- ffmpeg takes care of appending it on a webm video file.
- and this goes forever and ffmpeg should never stop
应该是一个不断增长的视频，可以向所有连接的客户端进行实时广播，但是我得到的结果只是一个单幅webm。
It should be an always growing video to be broadcast live to all connected clients, but the result that I get is just a single frame webm.
这是ffmpeg分支
var args = '-f image2pipe -r 15 -vcodec mjpeg -s 160x144 -i - -f webm -r 15 test.webm'.split(' ');
var encoder = spawn('ffmpeg', args);
encoder.stderr.pipe(process.stdout);
这是画布更新和管道
theCanvas.on('draw', function () {
var readStream = self.canvas.jpegStream();
readStream.pipe(self.encoder.stdin);
});
ffmpeg输出
ffmpeg version 1.2.6-7:1.2.6-1~trusty1 Copyright (c) 2000-2014 the FFmpeg developers
built on Apr 26 2014 18:52:58 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
configuration: --arch=amd64 --disable-stripping --enable-avresample --enable-pthreads --enable-runtime-cpudetect --extra-version='7:1.2.6-1~trusty1' --libdir=/usr/lib/x86_64-linux-gnu --prefix=/usr --enable-bzlib --enable-libdc1394 --enable-libfreetype --enable-frei0r --enable-gnutls --enable-libgsm --enable-libmp3lame --enable-librtmp --enable-libopencv --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-vaapi --enable-vdpau --enable-libvorbis --enable-libvpx --enable-zlib --enable-gpl --enable-postproc --enable-libcdio --enable-x11grab --enable-libx264 --shlibdir=/usr/lib/x86_64-linux-gnu --enable-shared --disable-static
libavutil 52. 18.100 / 52. 18.100
libavcodec 54. 92.100 / 54. 92.100
libavformat 54. 63.104 / 54. 63.104
libavdevice 53. 5.103 / 53. 5.103
libavfilter 3. 42.103 / 3. 42.103
libswscale 2. 2.100 / 2. 2.100
libswresample 0. 17.102 / 0. 17.102
libpostproc 52. 2.100 / 52. 2.100
[image2pipe @ 0xee0740] Estimating duration from bitrate, this may be inaccurate
Input #0, image2pipe, from 'pipe:':
Duration: N/A, bitrate: N/A
Stream #0:0: Video: mjpeg, yuvj420p, 160x144 [SAR 1:1 DAR 10:9], 15 tbr, 15 tbn, 15 tbc
[libvpx @ 0xec5d00] v1.3.0
Output #0, webm, to 'test.webm':
Metadata:
encoder : Lavf54.63.104
Stream #0:0: Video: vp8, yuv420p, 160x144 [SAR 1:1 DAR 10:9], q=-1--1, 200 kb/s, 1k tbn, 15 tbc
Stream mapping:
Stream #0:0 -> #0:0 (mjpeg -> libvpx)
pipe:: Input/output error
frame= 1 fps=0.0 q=0.0 Lsize= 12kB time=00:00:00.06 bitrate=1441.1kbits/s
video:11kB audio:0kB subtitle:0 global headers:0kB muxing overhead 4.195804%
我该怎么办？
谢谢，
Vinicius
Thanks, Vinicius
推荐答案
发送第一帧数据后，管道将关闭。我遇到了类似的问题，这使我得以部分解决。希望这会有所帮助，并且我还不算太晚。
The pipe is being closed after the first frame of data is sent. I have been having a similar problem and this got me part way to fixing it. Hope this helps and that I'm not too late.
theCanvas.on('draw', function () {
var readStream = self.canvas.jpegStream();
readStream.pipe(self.encoder.stdin, {end:false});
});
这篇关于ffmpeg：使用NodeJS从stdin渲染webm的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
