Xvid MSP=0 - MJPEG relation ?

[Poutnik]

Hi,

isnt XviD encoding with motion search precision roughly
equivalent to MJPEG ?

[Sulik]

MJPEG is pretty much equivalent to I-frame only MPEG.

[Poutnik]

So does XviD MSP 0. I frames only. No P, no B....

[Tommy Carrot]

Originally posted by Sulik
MJPEG is pretty much equivalent to I-frame only MPEG.

I wouldn't say 'equivalent', mpeg4 keyframes has got some improvements on plain jpeg, so it should be a little bit more efficient. I suppose Syskin can explain the exact differences.

[*.mp4 guy]

it might be slower then an mjpeg codec though, another plus to xvid with all I frames is u can use custom quants and modulated quants, along with 2pass(why anyone would make a two pass all i frames i have no clue, but you could if you wanted to).

[Poutnik]

I asked, because in capture FAQ is mentioned capturing
to huffyuv, or mjpeg, if size matter.

I have not mjpeg, and not sure about being free, but I have XviD..

I use MSP0 ( or MSPx with I frame distance 10-15 ) as a first stage
of my "3-pass" TV capture encoding, because of disk space.
( used B frames also, but it is said not recommended here )

I know huffyuv would be better,
but still have not more then 4GB free
and have not enough money for buying new HD yet.

[Neo Neko]

Originally posted by Poutnik
I asked, because in capture FAQ is mentioned capturing
to huffyuv, or mjpeg, if size matter.

I have not mjpeg, and not sure about being free, but I have XviD..

Xvid and MJPEG are gonna be quite different. And no most MJPEG codecs are not free. Although FFdshow/FFvfw has free MJPEG and Huffyuv built in. You can find recent compiles -> http://athos.leffe.dnsalias.com/

Quick warning though. I have had issues with ffvfw's Huffyuv mode. It seems chroma planes are getting swapped in the output. But that can be easily fixed.

[Poutnik]

Originally posted by Neo Neko
Xvid and MJPEG are gonna be quite different. And no most MJPEG codecs are not free.


Thanks for reply.

What is the difference ?
AFAIK MJPEG is, roughly said, a sequence of static JPEG images.

XviD with MSP=0 contains I frames only,
that are also a kind of a static JPEG.

There can be, of coarse, the difference in quantization policy
and settings.....

[Poutnik]

My TV PVR application use its own, unconfigurable MJPEG codec.

By bitrate cca 10000kb/s it seems cca equivalent to
XviD I-VOPs only ( Motion search precision = 0)
with MPEG Quantization with quantisizer=2.

XviD seems to run slightly faster ( according to CPU time ).