ffmpeg将流转换为jpg缓冲区而不保存磁盘

Question

I have a webrtc video stream coming from the client to the server. I want to convert the stream into jpg images, but not save any image to disk (work from memory only). Currently I'm using this command line function (called from node js):

var ops = [
'-i', '-',
'-f', 'image2',
'-vcodec', 'mjpeg',
'-b:v', '1000k',
'-q:v', '2',
'-s', '640x480',
'-updatefirst', '1',
'-',
];

ffmpeg_process = cp.spawn('ffmpeg', ops);

ffmpeg_process.stdout.on('data', function(chunk) {
var size = chunk.length
data += chunk
if (((chunk[size - 2] << 8) + chunk[size - 1]) === 65497)  //EOF 
{
   if (data) 
  {
lib.addFrame(Buffer(data).toString('base64')) //full jpg data
  }
  data = ''
}
};

However, some of the output jpg images are corrupt. this is because sometimes the buffer contains only part of a jpg image data.

What are the correct params needed to be passed to ffmpeg for correctly creating the jpg images?

Answer 1

I don't remember well but shinobiCE has some code about this situation. You can have a look. It's a huge project so good luck!