On Tue, Oct 31, 2017 at 08:24:37PM +0000, Derek Buitenhuis wrote: > On 10/31/2017 2:25 AM, Michael Niedermayer wrote: > > (though as said, this fix is not ideal or complete, I would very much > > prefer if this would be fixed by using a single buffer or any other > > solution that avoids the speedloss.) > > Using a single buffer would be marginally faster, but it does not solve > the underlying problem, which is that the NAL "cache" (nals_allocated) > seems to be cumulative, and the size of each buffer in it seems to be > the largest observed size of a NAL in that position. > > Consider I could craft a stream that contains, in order: > > Has 1999 tiny NALs, followed by 1 10MiB NAL, in packet 1. > Has 1998 tiny NALs, followed by 1 10MiB NAL, in packet 2. > . > . > . > Has 500 tiny NALs, followed by 1 10MiB NAL, in packet 1500. > . > . > . > And so forth. > > The result would be that we have 2000 10MiB buffers allocated > in the NAL memory "pool" (nals_allocated == 2000), which will > persist until the decode is deinitialized. > > Am I missing something here?
The idea would be that there would only be one uint8_t buffer and the 2000 entries from te pool would point into that. So as a larger NAL shifts through the 2000 the pointers would get distributed differently but the size would not grow Any variable size buffer the H2645NAL needs would be such a "shared" buffer I dont know if theres anything that would make this non trivial to implement. > > P.S. I see Kieran mailed the same thing as I wrote this. > > - Derek > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel -- Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB The real ebay dictionary, page 2 "100% positive feedback" - "All either got their money back or didnt complain" "Best seller ever, very honest" - "Seller refunded buyer after failed scam"
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