H264 vs DV compression

[richard p. t.]

Can someone here confirm my belief that in principal H264 is a higher level of compression (as in more compression - more loss) than DV codec. Obviously H264 is more normally associated with HD video rather than the SD that DV is. But I suggest if I took a 4 Gig SD file and compressed it to DV codec it would be about 700 or 800 Meg in size, whereas the same file compressed in H264 would be smaller again. I suggest that in SD, DV codec is a better format than H264.

On this note, anyone have an idea how much prores compresses? If for instance I start with a 20 gig HD uncompressed file, how big would the file be compressed in prores (for which I would have to buy a mac and fcp)?
richard

[ekoe]

In my experience, yes... H.264 is a greater degree of compression than DV. For some things such as HD footage with little grain, H.264 works ok... if you don't look too closely at it. For other things, like grainy super8, H.264 is absolute mud.
With ProRes... it depends on what ProRes you mean. There's ProResLT, ProResHQ, ProRes422, ProRes444, etc. In general, ProRes compression is minimal and for most things the loss in the quality of your image is barely noticeable, if at all. I'm not sure what the resulting file size would be with a 20gig HD file, but I'd venture to guess somewhere in the range of 10 or 15gigs. Someone here will probably straighten me out for daring to guess.

[Uppsala BildTeknik]

If you´d tell me what resolution and framerate the file is in I can calculate the filesize for you.

ProRes is by the way a fantastic codec. ProRes HQ is what we use for all our captures and intermediate files.

And yes, H.264 is more compressed.

[MovieStuff]

.... I suggest that in SD, DV codec is a better format than H264.

Haven't compared the two at the SD image size but I would say that is entirely possible. Codecs that seem to work really efficiently at higher frame sizes sometimes don't look as good on smaller frames. JPEG, in general, is a good example. Small JPEGs at around 2x3 inches can often look quite blocky and unattractive while 8x10 jpegs of even higher compression will look much better. The same can be said of MJPEG, in general. MJPEG for SD will often look pretty awful while MJPEG in HD can look quite stunning. So it would not surprise me if DV "looked" better for SD than h.264.

Roger

[Uppsala BildTeknik]

Furthermore, DV is all I-frames and H-264 is not.

1 hour of DV in NTSC is 13.64 GB, and in ProRes HQ that would be 32.51 GB. Should give an idea about the difference in compression, but I you cannot just look at the filesize either. It depends on how efficient the codec is.

If you want to read more about ProRes this could be interesting, although it is a few years old I guess (it has no info about the latest ProRes versions): http://provideocoalition.com/index.php/ ... r_look/P0/

[mattias]

you can use h.264 with i frames only, or you can use a high enough bitrate that the interframe encoding doesn't mess with the grain. either way it's a better codec than dv when it comes to quality per bit. just make sure you use the power to get better quality, not fewer bits as recording devices tend to these days. dv is more compatible though, and prores is probably the best of both worlds.

[Uppsala BildTeknik]

Ah, I didn´t know about the I-frames only H.264... But as you say, the recording devices usually boast about how many hours they can fit in a 8 GB CF-card (or whatever). With more hours as "a good feature"... :roll: