[Stage3D]The ATF compress texture quality loss in some phone.

Left picture is original. On the right is to use the ATF compress texture.
I used the command png2atf.exe -c e -q 0 -n 0,0 -r -4 -i "in.png" -o "out.atf"
The phone use android system 4.2.2 and CPU model is MT6592(GPU is "Mali 450 MP4").

it's really a big problem in our project
without -r , the atf ByteArray memory will be 10 times larger
I have a test on a 2048x2048 atf
use -c -r will takes about 6M gpu memory and  350K normal memory on ByteArray
use -c only, still 6M on gpu but 4M normal memory on ByteArray
if it's a bug on atftool hope abobe will fix it soon
or anyone could tell me a good way to use atf without memory waste

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    So unless you are visibly seeing image degradation I wouldn't worry about the file size reduction, especially in iPhoto as it's compressed only once no matter how many edits are made and saved. Apple uses a compression algorithm that gives the best image quality for the amount of compression it uses.
    The following is from the Usernet FAQ site article "JPEG image compression FAQ, part 1/2':
    Subject: [4] How well does JPEG compress images?
    Very well indeed, when working with its intended type of image (photographs and suchlike). For full-color images, the uncompressed data is normally 24 bits/pixel. The best known lossless compression methods can compress such data about 2:1 on average. JPEG can typically achieve 10:1 to 20:1 compression without visible loss, bringing the effective storage requirement down to 1 to 2 bits/pixel. 30:1 to 50:1 compression is possible with small to moderate defects, while for very-low-quality purposes such as previews or archive indexes, 100:1 compression is quite feasible. An image compressed 100:1 with JPEG takes up the same space as a full-color one-tenth-scale thumbnail image, yet it retains much more detail than such a thumbnail.
    Read more: http://www.faqs.org/faqs/jpeg-faq/part1/#ixzz0UKB59gND
    Message was edited by: Old Toad

  • Exporting a movie on a G4 without quality loss

    I do not have idvd on my PowerMac G4. Can someone explain how to export a movie without quality loss? I tried the various options in the dropdown menu but they seem to cause distortion.
    ~Thanks

    Without quality loss ... what format did you start with? What format or delivery media do you need to output? If you're going to DVD-Video, there will be a quality loss due to the amount of compression needed.
    You can output a QT movie (self-contained, using current settings, do NOT recompress!) that should be an exact duplicate of your sequence.
    -DH

  • Compression Rate = Quality...  Rule of Thmb?

    Are there any rules of thumb for compression rates and resulting quality? For instance, I've heard 5Mbps is the bottom end for "as good as commercial movie DVDs". I guess measures that describe "quality" are subjective or varied... but terms that are significant to me are things like "Movie DVD's" "Betacam" "VHS" "no perceptable loss, even in motion scenes".
    I often need to decide if a client will need one or two disks, based on the proposed amount of footage, before production. I make a rough bit-budget ahead of time. So, if the bit-budget calls for a 4.2 bit rate and that is too ugly for what I think my client needs, then I'll need to go to 2 disks. So, knowing in advance the bit rate -to- quality relationship would be very helpful.
    Let's say the constants are:
    Decent DV footage, let's say "average" screen action
    Edited on FCP
    Compressed with Compressor-2, Constant Bit Rate, to Mpeg-2
    Thanks, Ralph
    Desktop G4 / 1.5 G / Mac OS X (10.3.6)
    Desktop G4 / 1.5 G / Mac OS X (10.3.6)

    Not really. A lot comes down to what you see on screen when you try a few test encodes. Higher data rates don't always equate to higher quality - particularly at the upper end of the scale... can you see a difference between 8MBPS and 9.4MBPS, for example?
    The fact is that it is only through experience that you get to know what tends to look good for the material you have got... therefore encode lots of things and see how it turns out!
    Quite often the client will demand a single disc set, for example. Your experience will tell you that their 4 hour sport video won't look very good and so you have to have that conversation with them. No matter how good the source footage is, when you reduce the bitrate too far to get a file that fits the disc they want the quality will suffer - but you can turn to MPEG1, half D1, etc to help get them to replication, of course.
    In general, the middle of the bit rate scale will be a good enough place to start. If you have really clean source footage then a software encoder like Compressor might do the job alright, but a better encoder, such as BitVice, MegaPEG.X, Canopus Procoder will do a better job with the same bit rates. A hardware encoder like the sonic SD2000 might give a different result again, whilst Cinemacraft could be set up to run a multi-pass VBR encode over a period of several days and squeeze every last drop of quality out of the footage.
    There are simply too many variables involved, and I'd be sceptical of a 'one size fits all' approach, I'm afraid.
    5MBPS for 'as good as commercial DVDs' is nonsense in this context. 5MBPS on really clean betacam source footage run through an SD2000 is a dream compared to 5MBPS on noisy, poorly lit mini-DV put through Compressor... it's unwise to make generalisations, IMO.

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