Recommendations for high quality encoding (HC)

[zilog jones]

I'm converting some old home videos to DVD (PAL, keeping them interlaced) and was wondering if there's any improvements I could make to the MPEG2 encoding. They're quite short (20-30 minutes) and I'm using PCM audio so I can go up to 8Mb/s. I heard CBR should be fine at this bitrate so I tried QuEnc at first but had trouble with it keeping under the specified bitrate (max. set to same) with some videos, so I'm using HC instead (average bitrate 2-pass).

This is what I'm using so far:

*BITRATE 8000
*MAXBITRATE 8000
*PROFILE best
*ASPECT 4:3
*AUTOGOP 15
*AQ 1
*DC_PREC 10
*INTERLACED
*BIAS 100
*MATRIX mpeg

However, there's a few options I'm not sure about. Would there be much point in using higher AQ or luminance gain at this bitrate? Also, I don't know much about matrices - are there any aimed particularly at high bitrate/quality?

Also, I take it 1.0 mono PCM would not be DVD compliant? IIRC the audio needs at least 2 channels, right?

[blutach]

Depending on source quality, I can't see what is wrong with using VBR. Say BIAS of 20-30 and max BR of 8500 with a BR of 6,000. Lumgain of 2 might adjust better for darker scenes. High BR matrix would be Fox 1.

08 08 09 11 13 13 14 17
08 08 11 12 13 14 17 18
09 11 13 13 14 17 17 19
11 11 13 13 14 17 18 20
11 13 13 14 16 17 20 24
13 13 14 16 17 20 24 29
13 13 14 17 19 23 28 34
13 14 17 19 23 28 34 41

08 08 08 09 09 09 09 10
08 08 09 09 09 09 10 10
08 09 09 09 09 10 10 10
09 09 09 09 10 10 10 10
09 09 09 10 10 10 10 11
09 09 10 10 10 10 11 11
09 10 10 10 10 11 11 11
10 10 10 10 11 11 11 11
AFAIK, there is no issues with having only 1 channel LPCM.

Discs containing 525/60 (NTSC) video must use PCM or Dolby Digital on at least one track. Discs containing 625/50 (PAL/SECAM) video must use PCM or MPEG audio or Dolby Digital on at least one track. Additional tracks may be in any format. So, you are OK with 1 channel PCM.

Regards

[zilog jones]

Thanks for the advice, however using that matrix I noticed rather persistant blocking (not sure of correct terminology) on B-frames in dark noisy scenes. This issue was not as apparent using the MPEG matrix with the same settings for everything else.

Also, I interpret that quote regarding audio as "at least one track" refering to audio tracks or streams, not the amount of channels in a stream or track or whatever you want to call it, as he is talking about the mandatory minimum requirements for audio streams in a compliant DVD (e.g. you can't have just a DTS track, or just an MP2 track on an NTSC DVD). Wikipedia says only MP2 and AC3 can be 1-channel (LPCM or DTS need 2), but it doesn't seem to site a source for this info and I always thought it was at least 2 for any type of audio.

[Blue_MiSfit]

heck - why not just mp2 or ac3 compress it? save a little bitrate for video ;)

~MiSfit

[blutach]

Thanks for the advice, however using that matrix I noticed rather persistant blocking (not sure of correct terminology) on B-frames in dark noisy scenes. This issue was not as apparent using the MPEG matrix with the same settings for everything else.
And to fix this, use Lumgain=2 (or even 3).

Regards

[EpheMeroN]

What exactly does this Lumgain increase do? I've wondered about it, and I see you guys saying to use it sometimes for high bitrate encodes in HC.

[blutach]

Read the help file (PDF)!

This command adapts the quantization matrices on dark scenes so the bitrate will be raised.
• 0 no change
• 1 mild change
• 2 moderate change
• 3 heavy change
• 4 hit dark scenes real hard

Regards

[zilog jones]

And to fix this, use Lumgain=2 (or even 3).

Regards

I was using Lumgain=2 like you said in your first reply. :confused:
I compared it to the same video encoded using the "mpeg" matrix and exact same settings for everything else and there was very little blocking in comparison.

heck - why not just mp2 or ac3 compress it? save a little bitrate for video
The videos are less than an hour long, so I have 8Mb/s for video as it is :)

[Blue_MiSfit]

Gotcha :)

Have fun!

[blutach]

Well, it sounds as if you're satisfied, and if that's the case, there's no more to be done. :)

Regards