Respect my wild-honkin' bitrate homie!

[devo]

What a best way to start off a help thread: humorous tile ensues lot's of laughter and most importantly attention.. that's all I want in these days of self expression and individuality!

So! my problem includes many versions of ffmpeg past present and hopefully not future. It also has to do with divx with the most competent library there is MENCODER and finally a good dose of .vob files.

I've been discussing this matter with a couple of fellow dvd encoder/rippers for a couple of weeks now and seeing we can't come up with a good answer I said to myself why not resort to the great ffmpeg forum.. after all the most active user is major himself.. talking about a competent and attentive developper. (ok enough with the shameless butt-licking)

Here it is.. when encoding a .vob file extracted with OSEx no matter what version of ffmpeg it never respects the bitrate setting we so meticulously calculated for example I wanted to encode a 121 minute video file to make it a double cd rip fine, I set the bitrate to 1403kbps (as ffmpeg bitrate calc so kindly suggested) let it encode overnight with 2pass setting some cropping a nice dimension etc.. the whole shabang actually and what is my surprise to wake up to a 767mb file encoded at 500kbps with 192kbps mp3 audio... I was a bit mad I must say but I cooled down contacted some fellow rippers they told me to use 3-pass encoding.. well that sounds great.. try it the next night.. same exact thing happens.

I started to get a little deeper into the problem and noticed that after using a way old version that proved to be working (0.0.6 to be exact) it did the same thing as earlier with the brand spanking new version. I started to wonder if the actual OS X system could be the problem here... that's where, major i'm asking your help and thoughts on this pressing issue of mine.

regards.

D

[major]

I suppose you're encoding to mencoder mpeg-4. You should also specify which image size you are using. The bitrate may vary automatically in respect to the value you have choosen, when the encoder decides that it would lead to a waste of bits in respect to image size, quantizers and movie complexity.

[devo]

Yes i'm using mencoder mpeg4 but I tried it with xvid too. The Image width dimension varies from 608 to 576 when in 4:3 ratio and mostly 640 when in 16:9.

what I wonder is.. that before I could select any bitrate and it would keep it until the end of the encoding.. basically how can we tell mencoder to not judge wether or not he thinks it's a waste of bits?

[major]

A bitrate of 1400kbps is unnecessarily high for mencoder mpeg-4 to encode an image width of 640. When the encoder runs at minimum quantizer, it has no means to fit more water in an already filled bath-tub.

[devo]

Ok I see the analogy.. but I noticed that before I could fill the already full bathtub and the picture was accordinly better looking.

I don't understand how this changed overnight..? Keeping in mind that i'm using the exact same settings as before.

[major]

Let suppose your target filesize was 1340MB for a 121 min video. The way to go is to click the "Auto" button, so as the video size should be set to 720x400, and it should be indeed better looking.

[devo]

ok so it has to do with the image size.. i've been told earlier that the bitrate has no influence on the image dimensions and vice versa, it seems I was wrong.

gladly i'm finding some answers, I wonder if there's any other settings I should adjust to get a top class rip you the ones the mpaa so heartily wants out of the misled kids hands. so here's a run down of my settings:

-I usually crop because not many dvds are pretty out of the box
-I sometime de-interlace when the source is video
-Dering and Deblock when needed (usually not on dvds)
-I use high-quality and 2-pass
-I use the normal bi-linear method
- 2 to 10 adaptative quantizers too

seeing this, is there any other setting I should use to get a sharp image we all lust on when we get this rip the mpaa has been telling you about?

[devo]

I'm trying what you suggested, with a little twist. I pressed the bitrate button first for a 2cd file then I pressed the IMG button which gave me a width of 800px (fine I have a large screen) and I pressed the encode button after setting the crop and all that yip yap!

Encoding started on Fri Apr 8 04:46:05 EDT 2005
MEncoder dev-CVS-050123-19:55-3.3 (C) 2000-2005 MPlayer Team
Mac OSX static build for ffmpegX
AltiVec found
CPU: PowerPC
File not found: 'frameno.avi'
Failed to open frameno.avi
success: format: 0 data: 0x0 - 0xf8ab2800
MPEG-PS file format detected.
VIDEO: MPEG2 720x480 (aspect 3) 29.970 fps 9801.6 kbps (1225.2 kbyte/s)
[V] filefmt:2 fourcc:0x10000002 size:720x480 fps:29.97 ftime:=0.0334
================================================== ========================
Opening audio decoder: [liba52] AC3 decoding with liba52
Using AltiVec optimized IMDCT transform
AC3: 5.1 (3f+2r+lfe) 48000 Hz 448.0 kbit/s
Checking for AltiVec resampler : 0x0000000a, 2
Using AltiVec optimized resampler
AUDIO: 48000 Hz, 2 ch, 16 bit (0x8), ratio: 56000->192000 (448.0 kbit)
Selected audio codec: [a52] afm:liba52 (AC3-liba52)
================================================== ========================
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1 (-1=autodetect) osd: 1
Opening video filter: [scale w=800 h=336]
Opening video filter: [crop w=720 h=368 x=0 y=54]
Crop: 720 x 368, 0 ; 54
================================================== ========================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 480 (preferred csp: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
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))
================================================== ========================
MP3 audio selected
Building audio filter chain for 48000Hz/2ch/16bit -> 48000Hz/2ch/16bit...
Writing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.
VDec: vo config request - 720 x 480 (preferred csp: 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 21 -> 16
SwScaler: reducing / aligning filtersize 21 -> 16
SwScaler: reducing / aligning filtersize 23 -> 16
SwScaler: reducing / aligning filtersize 23 -> 16

SwScaler: Bicubic spline scaler, from Planar YV12 to Planar YV12 using AltiVec
videocodec: libavcodec (800x336 fourcc=58564944 [XVID])
High quality encoding selected (non real time)!
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.

1 duplicate frame(s)!
Pos: 0.6s 16f ( 0%) 8fps Trem: 0min 0mb A-V:0.050 [0:127]
demux_mpg: 24fps progressive NTSC content detected, switching framerate.
Pos: 1.0s 25f ( 0%) 8fps Trem: 0min 0mb A-V:0.087 [1296:128]
Skipping frame!
Pos: 1.4s 35f ( 0%) 8fps Trem: 0min 0mb A-V:0.086 [1271:128]
Skipping frame!
Pos: 10.0s 243f ( 0%) 6fps Trem: 637min 1238mb A-V:0.084 [1043:128]
Skipping frame!
Pos: 108.2s 2599f ( 2%) 5fps Trem: 392min 914mb A-V:0.075 [1424:128]]

I'll post the result when the encoding will be done with a smily according to how it went.

[devo]

end of first pass

Pos:6931.3s 166220f (94%) 39fps Trem: 3min 932mb A-V:0.084 [938:128]
Skipping frame!
Pos:7154.9s 171582f (98%) 40fps Trem: 1min 952mb A-V:0.084 [965:128]
Skipping frame!
Pos:7231.2s 173413f (100%) 40fps Trem: 0min 965mb A-V:0.001 [988:128]
Flushing video frames


CBR audio: 16000 bytes/sec, 384 bytes/block

Writing AVI index...
Fixing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.

Video stream: 988.260 kbit/s (123532 bps) size: 893286727 bytes 7231.189 secs 173413 frames

Audio stream: 128.000 kbit/s (16000 bps) size: 115707264 bytes 7231.704 secs

doesn't look to good.
beginning of the second pass

MEncoder dev-CVS-050123-19:55-3.3 (C) 2000-2005 MPlayer Team
Mac OSX static build for ffmpegX
AltiVec found
CPU: PowerPC
File not found: 'frameno.avi'
Failed to open frameno.avi
success: format: 0 data: 0x0 - 0xf8ab2800
MPEG-PS file format detected.
VIDEO: MPEG2 720x480 (aspect 3) 29.970 fps 9801.6 kbps (1225.2 kbyte/s)
[V] filefmt:2 fourcc:0x10000002 size:720x480 fps:29.97 ftime:=0.0334
================================================== ========================
Opening audio decoder: [liba52] AC3 decoding with liba52
Using AltiVec optimized IMDCT transform
AC3: 5.1 (3f+2r+lfe) 48000 Hz 448.0 kbit/s
Checking for AltiVec resampler : 0x0000000a, 2
Using AltiVec optimized resampler
AUDIO: 48000 Hz, 2 ch, 16 bit (0x8), ratio: 56000->192000 (448.0 kbit)
Selected audio codec: [a52] afm:liba52 (AC3-liba52)
================================================== ========================
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1 (-1=autodetect) osd: 1
Opening video filter: [scale w=800 h=336]
Opening video filter: [crop w=720 h=368 x=0 y=54]
Crop: 720 x 368, 0 ; 54
================================================== ========================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 720 x 480 (preferred csp: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
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))
================================================== ========================
MP3 audio selected
Building audio filter chain for 48000Hz/2ch/16bit -> 48000Hz/2ch/16bit...
Writing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.
VDec: vo config request - 720 x 480 (preferred csp: 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 21 -> 16
SwScaler: reducing / aligning filtersize 21 -> 16
SwScaler: reducing / aligning filtersize 23 -> 16
SwScaler: reducing / aligning filtersize 23 -> 16

SwScaler: Bicubic spline scaler, from Planar YV12 to Planar YV12 using AltiVec
videocodec: libavcodec (800x336 fourcc=58564944 [XVID])
High quality encoding selected (non real time)!
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.

1 duplicate frame(s)!
Pos: 0.6s 16f ( 0%) 0fps Trem: 0min 0mb A-V:0.050 [0:127]
demux_mpg: 24fps progressive NTSC content detected, switching framerate.
Pos: 1.0s 25f ( 0%) 0fps Trem: 0min 0mb A-V:0.087 [1763:128]
Skipping frame!
Pos: 1.4s 35f ( 0%) 0fps Trem: 0min 0mb A-V:0.086 [1817:128]
Skipping frame!
Pos: 10.0s 243f ( 0%) 3fps Trem:1372min 1567mb A-V:0.084 [1358:128]
Skipping frame!
Pos: 108.9s 2617f ( 2%) 6fps Trem: 310min 1081mb A-V:0.085 [1705:128]
Skipping frame!
Pos: 171.5s 4118f ( 3%) 6fps Trem: 323min 1215mb A-V:0.041 [1909:128]

looks abit better.. if the bitrate goes on from there I might actually have a chance to get the 1468 bitrate I set at the beginning

[major]

However you should never set the image size larger than the source size. So, before encoding this file, you should set width to 720 (source size), define aspect ratio, and click "Best" to determine the bitrate for that new image size.

[devo]

but will I ever be able to fill 2 cds?

and why not bigger than the source? there's a scaling method just for that?

[major]

Because if you upscale in respect to source, the quality can only decrease in respect to the bitrate, as you're encoding information which does not exist in the source image.

[devo]

ok I get why the upscaling is a no go.

end of second pass

Pos: 340.5s 8170f ( 6%) 5fps Trem: 377min 1324mb A-V:0.085 [1975:128]
Skipping frame!
Pos: 955.0s 22905f (15%) 5fps Trem: 393min 1197mb A-V:0.086 [1487:127]]
Skipping frame!
Pos:1476.4s 35407f (23%) 8fps Trem: 236min 1232mb A-V:0.084 [1496:128]
Skipping frame!
Pos:1649.6s 39563f (26%) 9fps Trem: 201min 1282mb A-V:0.085 [1575:128]
Skipping frame!
Pos:1798.2s 43126f (28%) 10fps Trem: 181min 1257mb A-V:0.084 [1529:128]
Skipping frame!
Pos:2499.4s 59940f (36%) 14fps Trem: 126min 1136mb A-V:0.084 [1246:128]
Skipping frame!
Pos:3125.0s 74942f (43%) 17fps Trem: 94min 1062mb A-V:0.072 [1099:128]
demux_mpg: 30fps NTSC content detected, switching framerate.
Warning! FPS changed 23.976 -> 29.970 (-5.994000) [4] V:0.075 [1099:128]
Pos:3125.3s 74947f (43%) 17fps Trem: 94min 1061mb A-V:0.085 [1099:128]
Skipping frame!
Pos:3125.5s 74956f (43%) 17fps Trem: 94min 1061mb A-V:0.063 [1099:128]
Skipping frame!
Pos:3126.0s 74969f (43%) 17fps Trem: 94min 1061mb A-V:0.053 [1099:128]
demux_mpg: 24fps progressive NTSC content detected, switching framerate.
Pos:3126.7s 74986f (43%) 17fps Trem: 93min 1061mb A-V:0.084 [1099:128]
Skipping frame!
Pos:3554.3s 85241f (48%) 20fps Trem: 76min 1026mb A-V:0.084 [1039:128]]
Skipping frame!
Pos:3790.8s 90912f (52%) 21fps Trem: 65min 1040mb A-V:0.083 [1069:128]
Skipping frame!
Pos:3997.7s 95873f (55%) 22fps Trem: 58min 1045mb A-V:0.084 [1078:128]
Skipping frame!
Pos:4433.7s 106329f (60%) 25fps Trem: 46min 1012mb A-V:0.085 [1029:128]]
Skipping frame!
Pos:4876.5s 116946f (67%) 27fps Trem: 34min 997mb A-V:0.085 [1022:128]]
Skipping frame!
Pos:5399.5s 129486f (74%) 30fps Trem: 24min 985mb A-V:0.085 [1011:128]
Skipping frame!
Pos:5804.3s 139195f (80%) 32fps Trem: 17min 981mb A-V:0.084 [1008:128]]
Skipping frame!
Pos:5986.4s 143562f (82%) 33fps Trem: 14min 979mb A-V:0.084 [1006:128]
Skipping frame!
Pos:6409.6s 153710f (88%) 36fps Trem: 8min 976mb A-V:0.084 [1003:128]]
Skipping frame!
Pos:6644.1s 159335f (91%) 37fps Trem: 6min 968mb A-V:0.083 [987:128]]]
Skipping frame!
Pos:6644.1s 159337f (91%) 37fps Trem: 6min 968mb A-V:0.039 [987:128]
1 duplicate frame(s)!
Pos:6931.3s 166220f (94%) 39fps Trem: 3min 965mb A-V:0.084 [975:128]
Skipping frame!
Pos:7154.9s 171582f (98%) 40fps Trem: 1min 983mb A-V:0.084 [1000:128]
Skipping frame!
Pos:7231.2s 173413f (100%) 40fps Trem: 0min 996mb A-V:0.001 [1023:128]
Flushing video frames


CBR audio: 16000 bytes/sec, 384 bytes/block

Writing AVI index...
Fixing AVI header...
ODML: Aspect information not (yet?) available or unspecified, not writing vprp header.

Video stream: 1023.735 kbit/s (127966 bps) size: 925352710 bytes 7231.189 secs 173413 frames

Audio stream: 128.000 kbit/s (16000 bps) size: 115707264 bytes 7231.704 secs
Encoding completed on Fri Apr 8 19:33:25 EDT 2005

what I don't get though is why I was perfectly able to do a 2cd rip before

[devo]

so it's a no go? no wise solution for me?

no special yip yap either?

that's too bad

[major]

You could try the "Best" button after selecting DVD size (with proper aspect), and then use 2-pass encoding.