OT MPEG2LowestBitrateQuestion

B.Verlik wrote on 4/7/2006, 10:55 PM
I'm trying to cram a large amount of music onto a single 4.7 Gig DVD-R. (AC3s)
I would like to make some very simple, white lettering on black background, text that explains the artist and title of song etc. Very much like it's done on Satellite TV, on the music stations, where the white lettering moves up and down. I can do the pan & crop and movement, but I'd like to know if anyone has figured out a very good but very low Mpeg2 bitrate that would still look nice and crisp when done. (or good enough)
What is the lowest bitrate that can be used on a normal set-top player? I'm rushing a project and am not quite to this stage yet but would like to move as fast as I can, when I get there.
Thanks in advance...........

Comments

johnmeyer wrote on 4/8/2006, 12:10 AM
There is no lower limit (other than zero). If you're looking for some "rule" as to where the video really starts to look "yucky," there isn't one. It all depends on your video. Faster motion will require higher bitrates. Little motion, and you can use really low bitrates. Lots of detail, high bitrates required. Noisy video requires much higher bitrate, because a lot of bits are "wasted" encoding the noise.

I'm waiting for an encode of today's Masters TV coverage (captured from DirecTV via analog capture through my DV camcorder) that I'm doing for my next door neighbor who has lifetime tickets and is in Augusta right now. Golf is 90% no movement, and then a little excitement. Last year, I did the same thing for him and on the final round (with playoff holes) I managed to fit over 3 hours on one 4.7 GB DVD and it looked pretty good. I used an external MPEG encoder and did a lot of tweaks, but the bitrate was really low. Normally, I don't like to encode more than about 85 minutes on one DVD, so this was WAY beyond what I would normally recommend.
farss wrote on 4/8/2006, 1:49 AM
For what you're doing as most of the frame is black and there's no noise the motion vector thingy should have no problems so I'd say you could go to maybe 1 MB/sec, I'd try a short segment first.

You could add the song title as a subtitle, they use very little bandwidth. They are static though. Howvere you can just have them jump to different positions on the screen.

Bob.
riredale wrote on 4/8/2006, 1:16 PM
Everybody has different experiences and techniques. I've put as much as 2:15 on a single-layer DVD-R (including Dolby audio and a second Dolby commentary track) and the video looked amazingly good, with only a few rare hints that things could be better. I used CinemaCraft as the encoder, which some say is one of the best MPEG2 engines out there. VBR encoding of course, and multiple encoding passes to ensure that the encoder can allocate bits as precisely as it can.

EDIT: The video bitrate in this instance was 600/135=4.4Mb/sec minus .2 for audio minus .2 for commentary = 4Mb/sec.

min=0
avg=4
max=9
fldave wrote on 4/8/2006, 7:29 PM
I've thought of doing this, also. Dish Network has Sirius sat radio channels, and I wanted a few discs of different music than what I normally listen to.

My set-top DVD recorder has a 10-hour option, so do the math to get a bit-rate. That's a long time on one disc.
johnmeyer wrote on 4/8/2006, 9:02 PM
I'm doing some this weekend that have close to three hours of NTSC 29.97 video. I have some very special settings for the MainConcept external encoder that took me several days to perfect. If anyone wants the template, I'd be happy to post (it is ASCII text, so I can even post it here).

MichaelS wrote on 4/8/2006, 10:15 PM
John,

I'd love to see what you've come up with!
johnmeyer wrote on 4/9/2006, 1:26 AM
This post isn't going to mean anything unless you have the MainConcept external MPEG-2 encoder. If you do, copy this information to Notepad, save as a file with the extension "mef" and put it in your "MCMPEGEnc" folder, which you'll find in the Application Data folder under your user name in the "Documents and Settings" section.

When you start the external Mainconcept encoder (this is a product separate from Vegas or DVDA) after copying this file, you will see a new template. Select this, change the average bitrate to whatever you want, and try an encode. This template is designed for really low bitrates, under 4,000 kbps.
=======================
[MAIN]
StreamType=5
MpegType=4
VideoMode=0
AudioMode=4
Width=720
Height=480
DestStartX=0
DestStartY=0
DestWidth=720
DestHeight=480
SrcStartX=0
SrcStartY=0
SrcWidth=720
SrcHeight=480
FlipVertical=0
SampleRate=48000
LineFiltering=0
Deinterlacing=0
Passes=2
ID=mep-profile
Name=JHM
[WaveAudio]
Channels=9216
Bits=5888
[basic]
settingsVersion=2
online=0
perfLevel=16
motionSearchType=23
mpegType=4
deinterlacing_mode=0
relaxed_standards=0
[video]
videoPulldownFlag=0
rateControlMode=1
aspectRatio=2
frameRateCode=4
iFramesInGOP=15
ipFrameDistance=3
bitrateFlag=0
mquantValue=10
constBitrate=6000000
maxBitrate=8324000
avgBitrate=5000000
minBitrate=192000
timeCode0=0
dropFrameTC=0
constrParms=0
closedGOPs=0
[audio]
audioLayer=4
audioMode=1
deEmphasis=0
audioBitrate=0
privateBit=128
copyrightBit=0
originalBit=0
errorProtection=0
psychModel=0
[multiplex]
programStreamType=4
vbrMultiplex=1
padVCDAudio=0
writeProgramEndCode=1
muxSVCDScanOffsets=0
alignSequenceHeaders=1
usePrivateStream2=1
useComputedBitrate=0
frameTimestamps=2
muxPulldownFlag=3
userMuxRate=25200
sectorSize=2048
packetsPerPack=1
videoBufferSize=232
audioBufferSize=4
audio1BufferSize=4
sectorDelay=0
videoDelay=180
audioDelay=180
audio1Delay=180
alwaysWriteSysHeader=0
maxFileSize=0
muxStartTime=0
muxStopTime=0
resetClocks=0
setBrokenLink=0
writeEndCodes=0
[advVideo]
profile=4
level=8
chromaFormat=1
colorPrimaries=4
transferCharacteristics=4
matrixCoefficients=5
videoFormat=2
intraDCPrec=2
vbvBufferSize=112
forceVBVDelay=1
displayHorizontalSize=720
displayVerticalSize=480
progressiveSequence=0
progressiveFrame=0
fieldPictures=0
topFieldFirst=0
repeatFirstField=0
intraVLCFormatI=1
intraVLCFormatP=1
intraVLCFormatB=1
framePredDCTI=0
framePredDCTP=0
framePredDCTB=0
quantizationScaleI=1
quantizationScaleP=1
quantizationScaleB=1
alternateScanI=1
alternateScanP=1
alternateScanB=1
writeSequenceDisplayExt=0
writeSequenceEveryGOP=1
writeSequenceEndCode=1
embedSVCDUserBlocks=0
writePictureDisplayExt=0
frameCentreHorizontalOffset=0
frameCentreVerticalOffset=0
qtNoiseSensitivity=5
featureFlags=544
reactionParameter=0
initialAverageActivity=0
initialIComplexity=0
initialPComplexity=0
initialBComplexity=0
initialIFullness=0
initialPFullness=0
initialBFullness=0
minFramePercentage=25
padFramePercentage=0
autoVectorLengths=1
horzPelMovement=16
vertPelMovement=14
forwHorzFCodeP=4
forwVertFCodeP=4
forwHorzSearchP=48
forwVertSearchP=42
forwHorzFCodeB1=3
forwVertFCodeB1=2
forwHorzSearchB1=16
forwVertSearchB1=14
backHorzFCodeB1=4
backVertFCodeB1=3
backHorzSearchB1=32
backVertSearchB1=28
forwHorzFCodeB2=4
forwVertFCodeB2=3
forwHorzSearchB2=32
forwVertSearchB2=28
backHorzFCodeB2=3
backVertFCodeB2=2
backHorzSearchB2=16
backVertSearchB2=14
forwHorzFCodeB3=0
forwVertFCodeB3=0
forwHorzSearchB3=0
forwVertSearchB3=0
backHorzFCodeB3=0
backVertFCodeB3=0
backHorzSearchB3=0
backVertSearchB3=0
forwHorzFCodeB4=0
forwVertFCodeB4=0
forwHorzSearchB4=0
forwVertSearchB4=0
backHorzFCodeB4=0
backVertFCodeB4=0
backHorzSearchB4=0
backVertSearchB4=0
forwHorzFCodeB5=0
forwVertFCodeB5=0
forwHorzSearchB5=0
forwVertSearchB5=0
backHorzFCodeB5=0
backVertFCodeB5=0
backHorzSearchB5=0
backVertSearchB5=0
forwHorzFCodeB6=0
forwVertFCodeB6=0
forwHorzSearchB6=0
forwVertSearchB6=0
backHorzFCodeB6=0
backVertFCodeB6=0
backHorzSearchB6=0
backVertSearchB6=0
forwHorzFCodeB7=0
forwVertFCodeB7=0
forwHorzSearchB7=0
forwVertSearchB7=0
backHorzFCodeB7=0
backVertFCodeB7=0
backHorzSearchB7=0
backVertSearchB7=0
ignore_frame_interval=0
user_iquant=1
intra_q[0]=8
intra_q[1]=13
intra_q[2]=13
intra_q[3]=17
intra_q[4]=17
intra_q[5]=21
intra_q[6]=21
intra_q[7]=28
intra_q[8]=13
intra_q[9]=13
intra_q[10]=17
intra_q[11]=17
intra_q[12]=19
intra_q[13]=21
intra_q[14]=23
intra_q[15]=30
intra_q[16]=13
intra_q[17]=17
intra_q[18]=19
intra_q[19]=19
intra_q[20]=21
intra_q[21]=23
intra_q[22]=28
intra_q[23]=34
intra_q[24]=13
intra_q[25]=17
intra_q[26]=19
intra_q[27]=19
intra_q[28]=21
intra_q[29]=23
intra_q[30]=28
intra_q[31]=48
intra_q[32]=17
intra_q[33]=19
intra_q[34]=19
intra_q[35]=19
intra_q[36]=23
intra_q[37]=28
intra_q[38]=34
intra_q[39]=48
intra_q[40]=19
intra_q[41]=19
intra_q[42]=23
intra_q[43]=25
intra_q[44]=28
intra_q[45]=32
intra_q[46]=34
intra_q[47]=48
intra_q[48]=19
intra_q[49]=21
intra_q[50]=23
intra_q[51]=25
intra_q[52]=28
intra_q[53]=32
intra_q[54]=34
intra_q[55]=48
intra_q[56]=21
intra_q[57]=21
intra_q[58]=25
intra_q[59]=25
intra_q[60]=28
intra_q[61]=32
intra_q[62]=34
intra_q[63]=48
user_niquant=1
inter_q[0]=8
inter_q[1]=11
inter_q[2]=11
inter_q[3]=15
inter_q[4]=15
inter_q[5]=17
inter_q[6]=17
inter_q[7]=24
inter_q[8]=11
inter_q[9]=11
inter_q[10]=15
inter_q[11]=15
inter_q[12]=17
inter_q[13]=17
inter_q[14]=21
inter_q[15]=24
inter_q[16]=13
inter_q[17]=15
inter_q[18]=15
inter_q[19]=17
inter_q[20]=21
inter_q[21]=21
inter_q[22]=26
inter_q[23]=34
inter_q[24]=13
inter_q[25]=17
inter_q[26]=15
inter_q[27]=17
inter_q[28]=21
inter_q[29]=21
inter_q[30]=26
inter_q[31]=48
inter_q[32]=17
inter_q[33]=21
inter_q[34]=21
inter_q[35]=23
inter_q[36]=21
inter_q[37]=30
inter_q[38]=34
inter_q[39]=48
inter_q[40]=17
inter_q[41]=21
inter_q[42]=21
inter_q[43]=23
inter_q[44]=28
inter_q[45]=30
inter_q[46]=34
inter_q[47]=48
inter_q[48]=19
inter_q[49]=19
inter_q[50]=25
inter_q[51]=26
inter_q[52]=28
inter_q[53]=30
inter_q[54]=48
inter_q[55]=48
inter_q[56]=19
inter_q[57]=19
inter_q[58]=25
inter_q[59]=26
inter_q[60]=28
inter_q[61]=30
inter_q[62]=48
inter_q[63]=48
B.Verlik wrote on 4/9/2006, 2:55 AM
I think you misspelled one word in the middle of that.
Just kidding.
Okay, I did a couple of experiments and I started with 192,000 bps and CBR, since it was a handy figure to start with. It didn't look very good. Then I moved up to 500,000 bps and CBR. This is actually passable for my needs. Remember, I only needed a small, moving, white letters on black background, text, about the size of a typical MTV ID. I did see some very slight artifacting at the start of it, but for the most part, it looked okay a few seconds after it settled in. 750,000 bps with CBR looked pretty good. (using a 27" Toshiba CRT for all)
I had it set to pan from top to bottom (or vice versa) in 2 minutes time, so a very slow moving text.
I haven't tried VBR yet.
Only 12 Mbs for 3 minutes at 500,000 bps CBR. Not counting audio, that should be good for nearly 6 hours.
Thanks for the answers, they saved me some time.
fldave wrote on 4/9/2006, 5:48 AM
Also, if you have DVDA ver 3, it now supports 352x240 MPEG-2 for DVD. So that size should be smaller still than a 720x480 full size frame.
B.Verlik wrote on 4/9/2006, 1:48 PM
I don't have DVDA3. I'm wondering...I got the lettering about as small as I'd want it, so is the memory used, only for the lettering, or is much memory used because the lettering is scrolling a longer distance?
In other words, if I'd made the lettering scroll within the dimensions of the 352x240 window, would I save some memory space? What if I just scrolled back and forth over a two inch section?
The black seems to be there, no matter what the size.
I should say, 5 or 6 hours will be enough for this project. I'm just asking out of curiosity.
fldave wrote on 4/9/2006, 4:25 PM
352x240 MPG2 is a DVD standard, DVDA just didn't support it until recently. Other DVD authoring programs did, though.

Dish Network's music channels, if I remember correctly, have the words stationery for a few seconds, then jump to another location, instead of smoothly moving around. I would think the "jumping" would result in better compression overall. Probably minor.

I think the moving prevents "burn-in" of your expensive plasma TVs and CRTs.

More lettering hints: use a Text track that is double the size of your final output with larger fonts. The final output appears to be better when shrunk down. And avoid harsh contrasts such as White on Black. Lots of "Title" hints if you search this forum.