Hello, thanks for the quick answer! I upgraded my ffmpeg to version 2.8 and still observe the same problem as stated before: 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. Output of stream 1: root@herglotz-panda:/ramcache# time -p taskset -c 0 ./ffmpeg -i PeopleOnStreet_intra_1frames_QP10.bin -f rawvideo -y /dev/null ffmpeg version 2.8 Copyright (c) 2000-2015 the FFmpeg developers built with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration: libavutil 54. 31.100 / 54. 31.100 libavcodec 56. 60.100 / 56. 60.100 libavformat 56. 40.101 / 56. 40.101 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 40.101 / 5. 40.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.101 / 1. 2.101 Input #0, hevc, from 'PeopleOnStreet_intra_1frames_QP10.bin': Duration: N/A, bitrate: N/A Stream #0:0: Video: hevc (Main), yuv420p(tv), 2560x1600, 25 tbr, 1200k tbn, 25 tbc Output #0, rawvideo, to '/dev/null': Metadata: encoder : Lavf56.40.101 Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 2560x1600, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc Metadata: encoder : Lavc56.60.100 rawvideo Stream mapping: Stream #0:0 -> #0:0 (hevc (native) -> rawvideo (native)) Press [q] to stop, [?] for help frame= 1 fps=0.5 q=-0.0 size= 6000kB time=00:00:00.04 bitrate=1228800.0kbiframe= 1 fps=0.5 q=-0.0 Lsize= 6000kB time=00:00:00.04 bitrate=1228800.0kbits/s video:6000kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000% real 4.39 user 4.28 sys 0.10 Output of stream 2: root@herglotz-panda:/ramcache# time -p taskset -c 0 ./ffmpeg -i PeopleOnStreet_intra_2frames_QP10.bin -f rawvideo -y /dev/null ffmpeg version 2.8 Copyright (c) 2000-2015 the FFmpeg developers built with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) configuration: libavutil 54. 31.100 / 54. 31.100 libavcodec 56. 60.100 / 56. 60.100 libavformat 56. 40.101 / 56. 40.101 libavdevice 56. 4.100 / 56. 4.100 libavfilter 5. 40.101 / 5. 40.101 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 2.101 / 1. 2.101 Input #0, hevc, from 'PeopleOnStreet_intra_2frames_QP10.bin': Duration: N/A, bitrate: N/A Stream #0:0: Video: hevc (Main), yuv420p(tv), 2560x1600, 25 tbr, 1200k tbn, 25 tbc Output #0, rawvideo, to '/dev/null': Metadata: encoder : Lavf56.40.101 Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 2560x1600, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc Metadata: encoder : Lavc56.60.100 rawvideo Stream mapping: Stream #0:0 -> #0:0 (hevc (native) -> rawvideo (native)) Press [q] to stop, [?] for help frame= 2 fps=0.9 q=-0.0 size= 12000kB time=00:00:00.08 bitrate=1228800.0kbiframe= 2 fps=0.5 q=-0.0 size= 12000kB time=00:00:00.08 bitrate=1228800.0kbiframe= 2 fps=0.5 q=-0.0 Lsize= 12000kB time=00:00:00.08 bitrate=1228800.0kbits/s video:12000kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000000% real 6.62 user 6.40 sys 0.21 This observation is also holds for sequences with a lower resolution. Thanks for your help! Christian Am 18.09.2015 um 09:39 schrieb Moritz Barsnick:
Hallo Christian,
On Thu, Sep 17, 2015 at 10:48:16 +0200, Christian Herglotz wrote:
I've got a question regarding the decoding process for HEVC-coded sequences. 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. While I'm happy to try to reproduce your problem and ask smart questions, let me please point out:
ffmpeg version 2.1.git Copyright (c) 2000-2014 the FFmpeg developers built on Feb 20 2014 16:27:13 with gcc 4.6 (Ubuntu/Linaro 4.6.3-1ubuntu5) This version of ffmpeg is extremely old, considering the amount of development happening. Especially with such a "new" codec as HEVC, you can expect many improvements over 18 months. And if ffmpeg happens/happened to have a bug, it may very well have been fixed in the meantime. Nobody here will help trying to identify a bug in such an old version.
Please repeat your tests with a very recent version of ffmpeg, best is if you build if from git HEAD.
Thanks, Gruß, 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