aha - ok. Thanks
- Piotr ________________________________ From: Halfdan Ingvarsson [half...@sidefx.com] Sent: 18 June 2013 09:49 To: Piotr Stanczyk Cc: Juri Abramov; openexr-u...@nongnu.org; openexr-devel@nongnu.org Subject: Re: [Openexr-devel] Optimisation code path for reading images Actually, I should clarify. The corruption occurs on *read*, not *write*. Attached is a tiff file converted from a PIZ compressed exr, also attached. It's most noticeable in the alpha channel, although there's a definite glitch in the red channel just above the plane. - ½ On 13-06-18 12:44 PM, Piotr Stanczyk wrote: Thanks. Let me see if I can repro this. I presume that simply writing out PIZ files should flare up. Were you also seeing test failures? - Piotr ________________________________ From: Juri Abramov [gabra...@nvidia.com<mailto:gabra...@nvidia.com>] Sent: 18 June 2013 09:26 To: Piotr Stanczyk; Halfdan Ingvarsson Cc: openexr-u...@nongnu.org<mailto:openexr-u...@nongnu.org>; openexr-devel@nongnu.org<mailto:openexr-devel@nongnu.org> Subject: RE: [Openexr-devel] Optimisation code path for reading images I’m afraid mine are under customer’s NDA. It is rather common though, the corruption was reported for alpha. Juri From: Piotr Stanczyk [mailto:pstanc...@ilm.com] Sent: 18 June, 2013 18:16 To: Juri Abramov; Halfdan Ingvarsson Cc: openexr-u...@nongnu.org<mailto:openexr-u...@nongnu.org>; openexr-devel@nongnu.org<mailto:openexr-devel@nongnu.org> Subject: RE: [Openexr-devel] Optimisation code path for reading images Is this something that was quite deterministic in behaviour? (Does anyone have an example of a corrupted image?) - Piotr ________________________________ From: Juri Abramov [gabra...@nvidia.com<mailto:gabra...@nvidia.com>] Sent: 18 June 2013 09:13 To: Halfdan Ingvarsson; Piotr Stanczyk Cc: openexr-u...@nongnu.org<mailto:openexr-u...@nongnu.org>; openexr-devel@nongnu.org<mailto:openexr-devel@nongnu.org> Subject: RE: [Openexr-devel] Optimisation code path for reading images Hi Halfdan, Yep, we ran into this one too. Was already the case for OpenEXR 1.6/1.7. Would be good to know if it is fixed in 4.5. Juri From: openexr-devel-bounces+gabramov=nvidia....@nongnu.org<mailto:openexr-devel-bounces+gabramov=nvidia....@nongnu.org> [mailto:openexr-devel-bounces+gabramov=nvidia....@nongnu.org] On Behalf Of Halfdan Ingvarsson Sent: 18 June, 2013 18:06 To: Piotr Stanczyk Cc: openexr-u...@nongnu.org<mailto:openexr-u...@nongnu.org>; openexr-devel@nongnu.org<mailto:openexr-devel@nongnu.org> Subject: Re: [Openexr-devel] Optimisation code path for reading images Also, compiling the EXR2.0 library using gcc 4.2/4.3/4.4 with -O3 results in the PIZ compression code producing occasional garbage data (-O3 is the default for cmake release builds). The workaround was to build with -O2. gcc 4.6 and up seem ok. I didn't test with gcc 4.5. Unfortunately, I didn't have time to dig any deeper as to whether this was an actual optimizer bug, or whether there are some spurious assumptions in the code leading to it. Just something to keep in mind. - ½ On 13-06-17 09:35 PM, Piotr Stanczyk wrote: Hi, There have been a few usage cases reported that exercised parts of the optimised reading code path which unfortunately revealed erroneous assumptions in the source. We have a fix for handling these, which also extents to handling more general cases, in a separate branch and will be releasing that once we have built up more usage cycles. In the meantime, however, a v2.0.1 release will be available shortly, which disables the optimisation. - Piotr _______________________________________________ Openexr-devel mailing list Openexr-devel@nongnu.org<mailto:Openexr-devel@nongnu.org> https://lists.nongnu.org/mailman/listinfo/openexr-devel ________________________________ This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message. ________________________________
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