Node.JS: FFmpeg管道视频编码没有创建缩略图

Node.JS: FFmpeg piped video encoding no thumbnail created

本文关键字：创建 略图 编码 视频 JS FFmpeg 管道 Node      更新时间：2023-09-26

我想在上传视频到ffmpeg期间管道实时缩略图创建。一切正常，但没有创建thumbnail.jpg，并且ffmpeg标准错误在库版本显示后挂起。

更新:我更新了我的代码，但它也没有创建一个有效的缩略图。

var formidable = require('formidable'),
        http = require('http'),
        sys = require('sys'),
        spawn = require('child_process').spawn;
function spawnFfmpeg(exitCallback) {
    var args = ['-i', 'pipe:0', '-c:v', 'mjpeg', '-ss', '00:00:13', '-vframes', '1', '-s', '100x80', 'thumbnail.jpg']
    var ffmpeg = spawn('ffmpeg', args);
    console.log('Spawning ffmpeg ' + args.join(' '));
    ffmpeg.on('exit', exitCallback);
    ffmpeg.stderr.on('data', function(data) {
        console.log('grep stderr: ' + data);
    });
    return ffmpeg;
}
http.createServer(function(req, res) {
    if (req.url == '/' && req.method.toLowerCase() == 'get') {
        // show a file upload form
        res.writeHead(200, {'content-type': 'text/html'});
        res.end
                ('<form action="/upload" enctype="multipart/form-data" method="post">'
                        + '<input type="text" name="title"><br>'
                        + '<input type="file" name="upload" multiple="multiple"><br>'
                        + '<input type="submit" value="Upload">'
                        + '</form>'
                        );
    } else if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
        // parse a file upload
        var form = new formidable.IncomingForm();
        form.maxFieldsSize = 29 * 1024 * 1024;
        // Handle each part of the multi-part post
        var ffmpeg = spawnFfmpeg(function(code) {
            console.log('child process exited with code ' + code);
            res.end();
        });
        var form = new formidable.IncomingForm();
        // Handle each part of the multi-part post
        form.onPart = function(part) {
            // Handle each data chunk as data streams in
            part.addListener('data', function(data) {
                ffmpeg.stdout.pipe(res);
                res.pipe(ffmpeg.stdin);
                // Write each chunk to disk
                //savedFile.write(data);
            });
        };
        // Do it
        form.parse(req);
        return;
    }
}).listen(80, "127.0.0.1");
process.on('uncaughtException', function(err) {
});

经过一番研究和几个小时的测试，我找到了正确的解决方案^_^

var formidable = require('formidable'),
        http = require('http'),
        sys = require('sys'),
        spawn = require('child_process').spawn;
function spawnFfmpeg(exitCallback) {
    var args = ['-i', 'pipe:0', '-c:v', 'mjpeg', '-ss', '00:00:13', '-vframes', '1', '-s', '100x80', 'thumbnail.jpg']
    var ffmpeg = spawn('ffmpeg', args);
    console.log('Spawning ffmpeg ' + args.join(' '));
    ffmpeg.on('exit', exitCallback);
    ffmpeg.stderr.on('data', function(data) {
        console.log('grep stderr: ' + data);
    });
    return ffmpeg;
}
http.createServer(function(req, res) {
    if (req.url == '/' && req.method.toLowerCase() == 'get') {
        // show a file upload form
        res.writeHead(200, {'content-type': 'text/html'});
        res.end
                ('<form action="/upload" enctype="multipart/form-data" method="post">'
                        + '<input type="text" name="title"><br>'
                        + '<input type="file" name="upload" multiple="multiple"><br>'
                        + '<input type="submit" value="Upload">'
                        + '</form>'
                        );
    } else if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
        // parse a file upload
        var form = new formidable.IncomingForm();
        form.maxFieldsSize = 29 * 1024 * 1024;
        // Handle each part of the multi-part post
        var ffmpeg = spawnFfmpeg(function(code) {
            console.log('child process exited with code ' + code);
            res.end();
        });
        var form = new formidable.IncomingForm();
        // Handle each part of the multi-part post
        form.onPart = function(part) {
            // Handle each data chunk as data streams in
            part.addListener('data', function(data) {
                /*
                 * This only one line was the solution of my problem now all works really fast !! 500mbit like transloadit it does
                 */
                ffmpeg.stdin.write(data);
            });
        };
        // Do it
        form.parse(req);
        return;
    }
}).listen(80, "127.0.0.1");
process.on('uncaughtException', function(err) {
});

您的代码看起来像是在管道设置之前启动ffmpeg。

以下内容未经过验证，但听起来像是您需要的:

http://nodejs.org/api/child_process.html child_process_child_process_spawn_command_args_options

child_process.spawn()的'stdio'选项是一个数组，其中每个索引对应子进程中的fd。取值为以下任意一种:

'pipe' -在子进程和父进程之间创建一个管道。管道的父端作为child_process对象的ChildProcess.stdio[fd]的属性公开给父端。为fds 0 - 2创建的管道也可以作为ChildProcess使用。ChildProcess stdin。stdout和ChildProcess。分别stderr。

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