[MPlayer-dev-eng] VFW Encoding VP6 - Ignored bit rate

[Tom Shaw]

Hi All,

Two pass encoding using the VFW VP62 vp6vfw.dll codec seems to be a
little bit broken.

Im not sure if this is a mencoder issue or something with the dll but
no matter what bitrate you set in the settings file it is never
achieved when it comes to encoding - its not even close.

Heres a list of my tests  encoding a series of 555 jpgs into a video
file (no audio).  Max frames between key frames was set to 12 (12fps
so a key frame every second):

46.250 secs qty:555 768x768 frames (auto keyframe on/off seems to make
little difference)

Two pass HQ 100kbit/s (auto keyframe OFF) - result 327.677 kbit/s
Two pass HQ 200kbit/s (auto keyframe OFF) - result 327.925 kbit/s

Two pass HQ 800kbit/s (auto keyframe OFF) - result 382.129 kbit/s

Two pass HQ 1120kbit/s (auto keyframe OFF) - result 486.535 kbit/s
Two pass HQ 1200kbit/s (auto keyframe OFF) - result 515.477 kbit/s

Two pass HQ 1600kbit/s (auto keyframe OFF) - result 671.637 kbit/s

Two pass HQ 2000kbit/s (auto keyframe OFF) - result 833.478 kbit/s
Two pass HQ 2000kbit/s (auto keyframe ON) - result 833.478 kbit/s

I did the tests so I would have a reference so I could achieve some
known targets.

Perhaps a kind dev could take a look and see what is causing the
problem.  I can supply all the log/setting files if needed.

Cheers,
Tom