Re: [Mjpeg-users] workaround (PPC) for mpeg2enc's buggyness

[Mark H. <mj...@si...>]

On 17/01/2008, at 3:34 PM, Steven M. Schultz wrote:

>
> On Wed, 16 Jan 2008, Christian Ebert wrote:
>
>> I get buffer underflows for longer stuff when encoding from dv to
>> mpeg2 for dvd with ffmpeg, and i really played around a lot with
>
> 	That's the rate control issue(s) I had in mind.

I found that ffmpeg had trouble with DV files.

When I did direct conversions from DV to mpeg2 dvd constrained files, =20=

I found some strangeness that caused the frame rate of the dv file to =20=

increase, or drop frames, and therefore reduce the duration of the =20
movie.  Due to the non-contiguous nature of the resulting dv file, =20
the bitrate of the mpeg file would increase and couldn't be controlled.

I would always need to go via another tool before making the mpeg2 =20
file with ffmpeg.

>
>> the ever changing options...
>
> 	Yep - hard to keep up sometimes.
> =09
>> But I'd like to decode with lav2yuv, but it segfaults here on dv movs
>
> 	Works fine here - BUT I have seen the problem you mentioned =
earlier
> 	(symptom is that 'twos' audio isn't recognized as valid).


I have some hacky code which uses libav to do decoding (really wanted =20=

it after WMV3 support was added) to yuv4mpeg

check out: http://silicontrip.net/~mark/lavtools/

http://silicontrip.net/~mark/lavtools/libav2yuv.c

Maybe someone could make it a little more compiler friendly.  I think =20=

that it doesn't compile with the latest version of libav, and needs =20
some libav_open calls changes (and structs made into pointers)  and I =20=

need a cvs system at home!


>> There's an Apple compressor for mpeg2?
> =09
> 	And 3gpp, H.264, AC3, MPEG-1, AAC, MPEG-4 and a bunch of others =
I'd
> 	have to lookup.  "Compressor" (I'm only at Compressor2, not =
having
> 	upgraded to 3) is Apple's compression engine frontend.  It's not
> 	sold separately but only as part of the Final Cut Studio bundle
> 	(a bit pricey but a fair value for the amount of software and
> 	documentation you get).


Although doesn't come with mpeg2 encoding (or decoding, unless the =20
quicktime component is installed) have a look at MPEG Streamclip
http://www.squared5.com/

Mark

=93What if Microsoft had designed Windows Vista.=94