[FFmpeg-user] HEVC decoding of first frame
christian.herglotz at fau.de
Fri Oct 16 12:23:14 CEST 2015
a) I know that there is some overhead. So I also tested this for
sequences with different resolutions where I could observe the same
Mean decoding times for FFmpeg HM
460*240 1 I-frame: 0.15s 0.18s
460*240 2 I-frames: 0.23s 0.36s
1920*1080 1 I-frame: 2.26s 2.89s
1920*1080 2 I-frames: 3.43s 5.8s
2560*1600 1 I-frame: 4.25s 5.46s
2560*1600 2 I-frames: 6.43s 11s
A constant offset would not scale like this. Furthermore, I'm giving the
corresponding decoding times for the HM-software as a reference where
obviously the decoding time doubles for all cases.
b) The bit streams I am talking about are all-intra coded.
Thanks for your help!
Grüße zurück aus Franken!
Am 16.10.2015 um 11:37 schrieb Moritz Barsnick:
> On Thu, Oct 15, 2015 at 08:22:35 +0200, Christian Herglotz wrote:
>> When timing the process I found that the decoding of the
>> first frame always takes twice as long as the decoding of all the other
> I'm not sure I consider the test you provide as valid.
> a) Initializing a decoder has (some) overhead. That aligns your numbers
> a bit more.
> b) HEVC does not only consist of I-frames (unless you claim the
> opposite of your content). Who says P- or B-frames are easier/faster to
> decode than I-frames?
> That's just the theory from me. Someone who knows the code could help
> more, or someone who is willing to add the benchmarking macros into the
> code and rebuild. :-)
> Gruß nach Franken,
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
Dipl.-Ing. Dipl.-Wirt.Ing. Christian Herglotz
Chair of Multimedia Communications and Signal Processing
Friedrich-Alexander University Erlangen-Nürnberg
Cauerstr. 7, D-91058 Erlangen, Germany
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