Hendrik Leppkes wrote:
On Wed, Jan 20, 2016 at 12:13 PM, Andy Furniss <adf.li...@gmail.com> wrote:
wm4 wrote:
On Wed, 20 Jan 2016 09:59:12 +0000 Andy Furniss <adf.li...@gmail.com>
wrote:
wm4 wrote:
On Wed, 20 Jan 2016 00:42:18 +0000 Andy Furniss
<adf.li...@gmail.com> wrote:
Hendrik Leppkes wrote:
I do not agree that it should be a warning. As outlined
in the commit message and this thread, there are serious
flaws with frame threading and hwaccel.
I'm fine with it being an error, but since it is an API
change, it should follow the usual deprecation period to
allow downstream users time to fix it. Meanwhile it can be
a warning so that people notice the problem.
Its fundamentally broken, and making it a warning would
re-introduce known crashes. So no.
So are the flaws in ffmpeg or particular drivers?
It does seem a shame perf wise, I've been testing my AMD UVD
decode recently and for 500 UHD frames in a really high
bitrate h264 file it's like -
ffmpeg threaded = 16 sec.
ffmpeg single thread = 20 sec.
With or without hwaccel?
Both are with hwaccel. ffmpeg 2.8.4 cli
Admittedly a very concocted benchmark with a very high bitrate
sample.
I know on normal x264 stuff my CPU could beat GPU anyway as the
copy back seems to hurt quite a lot/UVD is for playing.
For future GPUs that will do hevc I guess it could be more
relevant.
gstreamer vaapi 14 sec.
gstreamer omx 10 sec.
the omx is a faster as the others do nv12 -> I420 on cpu
(AFAICT)
Maybe -threads 1 hurts perf by limiting the format conversion
as well?
Is there a way to get whatever the h/w spits out (nv12)
directly? Trying to ask for nv12 seemed to get a double
conversion.
Both vdpau and vaapi can retrieve image data as nv12.
With ffmpeg cli?
ffmpeg cli doesn't support vaapi.
I know, but it does do vdpau: so to restate my question in a clearer way -
Is it possible with ffmpeg cli -hwaccel vdpau to avoid nv12 -> I420
conversion?
With what hardware was this? What were the command lines you used?
GPU is AMD R9285 TONGA (drivers are still new/experemental) but results
for this test seem consistent.
Rest of system is older Phenom II x4 3.4GHz (cpufreq forced for tests).
Mobo is PCIE 2.0 *Gig ram @ 1333.
Here's a paste I made a few days ago - includes s/w test (which by
chance for this sample comes out the same as multithread h/w) You can
see from the time cpu use output I really do get h/w decode as requested.
If you would run with verbose logging (-loglevel verbose), you would
get information which format the vdpau code uses to retrieve the data,
as well as clear confirmation that it uses hwaccel.
Thanks, I don't see input format, but I guess the graph 0 ... line is
saying that something is being converted to yuv420p.
So back to one of my questions - how to avoid this?
If I specify -pix_fmt nv12 I just get a double conversion.
ffmpeg -loglevel verbose -threads 1 -hwaccel vdpau -i
/mnt/ramdisk/x264-otc-2160p60-220M.mkv -f rawvideo /mnt/ramdisk/raw
ffmpeg version N-77817-gd3fe2e0 Copyright (c) 2000-2016 the FFmpeg
developers
built with gcc 5.3.0 (GCC)
configuration: --prefix=/usr --disable-doc --enable-gpl
--enable-libvpx --enable-libx265 --enable-libdcadec --enable-libmp3lame
--enable-libx264
libavutil 55. 13.100 / 55. 13.100
libavcodec 57. 22.100 / 57. 22.100
libavformat 57. 21.101 / 57. 21.101
libavdevice 57. 0.100 / 57. 0.100
libavfilter 6. 23.100 / 6. 23.100
libswscale 4. 0.100 / 4. 0.100
libswresample 2. 0.101 / 2. 0.101
libpostproc 54. 0.100 / 54. 0.100
Input #0, matroska,webm, from '/mnt/ramdisk/x264-otc-2160p60-220M.mkv':
Metadata:
ENCODER : Lavf57.19.100
Duration: 00:00:08.33, start: 0.000000, bitrate: 218593 kb/s
Stream #0:0: Video: h264 (High), 5 reference frames, yuv420p,
3840x2160 [SAR 1:1 DAR 16:9], 60 fps, 60 tbr, 1k tbn, 120 tbc (default)
Metadata:
ENCODER : Lavc57.16.101 libx264
DURATION : 00:00:08.334000000
[graph 0 input from stream 0:0 @ 0x347b100] w:3840 h:2160 pixfmt:yuv420p
tb:1/1000 fr:60/1 sar:1/1 sws_param:flags=2
Output #0, rawvideo, to '/mnt/ramdisk/raw':
Metadata:
encoder : Lavf57.21.101
Stream #0:0: Video: rawvideo, 1 reference frame (I420 /
0x30323449), yuv420p, 3840x2160 [SAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 60
fps, 60 tbn, 60 tbc (default)
Metadata:
DURATION : 00:00:08.334000000
encoder : Lavc57.22.100 rawvideo
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Using VDPAU -- G3DVL VDPAU Driver Shared Library version 1.0 -- on X11
display :0.0, to decode input stream #0:0.
_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
