[Libav-user] Fwd: Re: the difference between mjpeg in ffmpeg and libjpeg

[Carl Eugen Hoyos]

On Thursday 03 December 2015 05:51:42 am qw wrote:
> JPEG has adopted many standards. There are several jpeg codec in ffmpeg,
> such as mjpeg, mjpegb, ljpeg, jpegls. libjpeg is another open source of
> jpeg codec.

> what's difference between mjpeg in ffmpeg and libjpeg? 

It's like the difference between Porsche and Ferrari. They do not share 
any parts, both produce cars.

> Does libjpeg support all JPEG standards/algorithms?

To the best of my knowledge: No, but I am not a libjpeg developer.

> In libjpeg, jpeg encoder accepts quality level as input parameter, while 
> mjpeg uses bit rate as input parameter in ffmpeg.

FFmpeg's jpeg encoder allows both bitrate and quantizer as input parameter.

Carl Eugen