[FFmpeg-devel] AVCodec struct fields (encode function prototype)

[Dang Le]

Hi all,
I'm writing my own codec for ffmpeg.
I have completed the decoder and it works well thanks to nice 
explanations about the parameters of decode frame function from here:

http://wiki.multimedia.cx/index.php?title=FFmpeg_codec_HOWTO#libavcodec.2Fcook.c_Decode

Unfortunately, there's no documentation on the encode frame function 
(parameters & return value) out there.
Could someone please help me to understand those params?

The function prototype is:
int (*encode)(AVCodecContext *, uint8_t *buf, int buf_size, void *data);

Particularly: buf, buf_size and data. which is the input, which is the 
output?
Do I have to av_malloc memory for the output or not?

Thank you very much!

Le Hong Dang.