Hello, a) I know that there is some overhead. So I also tested this for sequences with different resolutions where I could observe the same behavior: 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! Christian 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 frames. 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. :-)
Cheers, Gruß nach Franken, Moritz _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user
-- 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