[MEncoder-users] i-frames only ... two pass?

[Andy Civil]

Reimar Döffinger wrote:

> No, two pass is for determining quantization factors, only setting
> vqscale makes that pointless, keyframes have nothing to do with it
> (though the question is if the default bit allocation strategy works
> well for this, you might have to tune it).

Thank you. I am finding that a video with all i-frames is not very good (I think 
this is not news to someone here). I can't get the bit rate up high enough??? I 
ask for 20,000 kb/s but it still only compresses at 10,000 kb/s. I can see 
macroblocks. Here is my command:

\me\mencoder -oac copy -ovc lavc -of mpeg -mpegopts format=mpeg2:muxrate=20000 
-vf scale=720:480:1,harddup -lavcopts 
vcodec=mpeg2video:vrc_buf_size=1835:vrc_maxrate=20000:vbitrate=20000:keyint=1:aspect=16/9:ildct:ilme:top=1:mbd=2:trell 
-ofps 30000/1001 -o me_test_keyint1_mpeg2.mpg 20080213133737.m2t

and I will paste the output at the end. Also, I am concerned about two things in 
the output. It tells me to use -vf scale, but I already did that. Also,

"The selected video_out device is incompatible with this codec."
"Try appending the scale filter to your filter list,"
"e.g. -vf spp,scale instead of -vf spp."

sounds like an error, did I do something wrong?

Output:

I:\Plan Sony ME>\me\mencoder -oac copy -ovc lavc -of mpeg -mpegopts format=mpeg2
:muxrate=20000 -vf scale=720:480:1,harddup -lavcopts vcodec=mpeg2video:vrc_buf_s
ize=1835:vrc_maxrate=20000:vbitrate=20000:keyint=1:aspect=16/9:ildct:ilme:top=1:
mbd=2:trell -ofps 30000/1001 -o me_test_keyint1_mpeg2.mpg 20080213133737.m2t
MEncoder Sherpya-SVN-r25962-4.2.3 (C) 2000-2008 MPlayer Team
CPU: Intel(R) Pentium(R) 4 CPU 2.40GHz (Family: 15, Model: 2, Stepping: 7)
CPUflags: Type: 15 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled with runtime CPU detection.
success: format: 0  data: 0x0 - 0x41db004
TS file format detected.
VIDEO MPEG2(pid=2064) AUDIO MPA(pid=2068) NO SUBS (yet)!  PROGRAM N. 100
VIDEO:  MPEG2  1440x1080  (aspect 3)  29.970 fps  25000.0 kbps (3125.0 kbyte/s)
[V] filefmt:29  fourcc:0x10000002  size:1440x1080  fps:29.97  ftime:=0.0334
==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
AUDIO: 48000 Hz, 2 ch, s16le, 384.0 kbit/25.00% (ratio: 48000->192000)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
PACKET SIZE: 2048 bytes, deltascr: 22118
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [harddup]
Opening video filter: [scale w=720 h=480 interlaced=1]
==========================================================================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 1440 x 1080 (preferred colorspace: Mpeg PES)
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed :(
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
==========================================================================
audiocodec: framecopy (format=50 chans=2 rate=48000 bits=16 B/s=48000 sample-1)
Limiting audio preload to 0.4s.
Increasing audio density to 4.
VDec: vo config request - 1440 x 1080 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
SwScaler: reducing / aligning filtersize 9 -> 8
SwScaler: reducing / aligning filtersize 9 -> 8
SwScaler: reducing / aligning filtersize 10 -> 9
SwScaler: reducing / aligning filtersize 10 -> 9
[swscaler @ 00D532A0]SwScaler: BICUBIC scaler, from yuv420p to yuv420p using MMX
2
[swscaler @ 00D532A0]SwScaler: using 8-tap MMX scaler for horizontal luminance s
caling
[swscaler @ 00D532A0]SwScaler: using 8-tap MMX scaler for horizontal chrominance
  scaling
[swscaler @ 00D532A0]SwScaler: using n-tap MMX scaler for vertical scaling (YV12
  like)
[swscaler @ 00D532A0]SwScaler: 1440x540 -> 720x240
SwScaler: reducing / aligning filtersize 9 -> 8
SwScaler: reducing / aligning filtersize 9 -> 8
SwScaler: reducing / aligning filtersize 10 -> 9
SwScaler: reducing / aligning filtersize 10 -> 9
[swscaler @ 00D532A0]SwScaler: BICUBIC scaler, from yuv420p to yuv420p using MMX
2
[swscaler @ 00D532A0]SwScaler: using 8-tap MMX scaler for horizontal luminance s
caling
[swscaler @ 00D532A0]SwScaler: using 8-tap MMX scaler for horizontal chrominance
  scaling
[swscaler @ 00D532A0]SwScaler: using n-tap MMX scaler for vertical scaling (YV12
  like)
[swscaler @ 00D532A0]SwScaler: 1440x540 -> 720x240
videocodec: libavcodec (720x480 fourcc=3267706d [mpg2])
[VE_LAVC] High quality encoding selected (non-realtime)!
Writing header...2f ( 3%)  0.00fps Trem:   0min   0mb  A-V:0.003 [0:0]
INITV: 0.200, 0.167, fps: 29.970

1 duplicate frame(s)!
Pos:   0.7s     22f ( 7%) 10.79fps Trem:   0min   8mb  A-V:0.070 [0:384]
Skipping frame!
TS_PARSE: COULDN'T SYNC%) 15.07fps Trem:   0min  26mb  A-V:0.064 [9917:384]
Pos:  20.8s    626f (100%) 15.03fps Trem:   0min  26mb  A-V:0.064 [10009:384]
Flushing video frames.
Writing index...

Overhead: 3.555% (961629 / 27046819)
Writing header...

Video stream: 10009.590 kbit/s  (1251198 B/s)  size: 26050959 bytes  20.821 secs
   626 frames

Audio stream:  384.000 kbit/s  (48000 B/s)  size: 1003392 bytes  20.904 secs

I:\Plan Sony ME>

-- 
Andy