[MPlayer-users] 2-pass encoding to DVD: how to maximize quality?

[Ergzay]

On 2005/10/30, at 22:44, Rich Felker wrote:

> On Sun, Oct 30, 2005 at 07:10:42PM -0500, Norman Ramsey wrote:
>>> On Sat, Oct 29, 2005 at 10:02:40PM -0400, Norman Ramsey wrote:
>>>> I'm a bit lost in a maze of command-line options.
>>>> I have some HD data streams (720p and 1080i) which
>>>> I wish to transcode for burning onto a DVD...
>>>
>>> I really doubt 720p is 30fps.
>>
>> The ATSC standard says it should be.  Here's what ffplay reports about
>> a saved mpeg-2 transport stream:
>>
>>  Duration: 03:37:56.2, start: 6352.220978, bitrate: 16433 kb/s
>>  Stream #0.0[0x34]: Audio: ac3, 48000 Hz, stereo, 384 kb/s
>>  Stream #0.1[0x31]: Video: mpeg2video, yuv420p, 1280x720, 59.94 fps, 
>> 16800 kb/s
>
> This tells you nothing. It's always nominally 30 fps but it's really
> 60 fields/sec or 24 fps telecined unless you're dealing with ((very
> very rare) real 30 fps content.
>
>>> mp2 audio is not necessarily NTSC DVD players. Use ac3.
>>
>> Interesting.  I've been recoding since some of the audio I capture
>> (from terrestrial broadcast) is quite badly damaged, and I worry about
>> throwing off the hardward DVD player.  But I guess I could recode the
>> ac3 rather than just copy?
>
> Yes.
>
>>>> You'll note the single pass and the hard-coded
>>>> 'vbitrate', which is definitely achieving
>>>> suboptimal results.  Any suggestions would be
>>>> appreciated.
>>>
>>> Worked fine for me.. maybe your video is bad and needs filtering to
>>> correct it..?
>>
>> Sorry, I meant 'suboptimal' in its precise technical sense of 'not as
>> good as possible' rather the more common 'not good'.  Translated into
>> plain language, my video looks OK (not great compared to hi-def, but I
>> suspect it will look fine on a standard TV), but I'm not using all the
>> bits that are available on the DVD.  If I could, I'd rather those bits
>> were carrying video instead of just sitting unused :-)
>
> Then don't set the bitrate so low (4000). DVD can use up to 8000 or
> 9000 kbit/sec, I forget the exact amount. Set the max rate and buffer
> size accordingly for DVD and then set vbitrate to the exact rate that
> will fill the whole DVD, then use 2pass encoding.

Just wanted to say here is a list of possible resolutions and bitrates:
Allowable picture resolutions are:
MPEG-2, 525/60 (NTSC): 720x480, 704x480, 352x480, 352x240
MPEG-2, 625/50 (PAL): 720x576, 704x576, 352x576, 352x288
MPEG-1, 525/60 (NTSC): 352x240
MPEG-1, 625/50 (PAL): 352x288
Maximum bitrate for MPEG-2 is 9.8mbits/s
I got this information from here: 
http://www.dvddemystified.com/dvdfaq.html#3.4 (scroll down a bit)

Ergzay