Encode real-time dvb-s stream using mencoder

Question

My satellite receiver can stream MPEG-2 video/audio output through the LAN.

Using mencoder, I'm trying to build a script to encode and save the stream in real time with my Core 2 Duo 1.8 GHz.

Right now, I'm using a single pass; it produces good quality for a video rate of 800Kb/s, but takes more then 95% of CPU power, thus making a lot of frameskips if the computer is used while encoding.

mencoder <input> -o <output> -vf lavcdeint -oac mp3lame -lameopts abr:q=2:aq=2 -ovc x264 -ffourcc avc1 -x264encopts crf=25:me=hex:subq=9:frameref=2:nocabac:threads=auto -mc 3  

I'm considering using 2-pass encoding to alleviate the processor and record 100% of the stream. However I have no idea how to start.

Further information:

• Standard Stream: MPEG-2 720*576 25fps
• HD Stream: 1920*1080 50fps (this is not my goal to record it, but it will be super cool if I could)

Answer 1

It seems that it is not possible to use a 2-pass encoding with a stream. (at least with mencoder)
Probably the best solution for that is to dump the stream to the harddrive, then encode it later.

Answer 2

you may be avoid transcoding, or use mencoder + ffmpeg-mt (multi thread) for better performance...