[FFmpeg-user] Clarification for decoding AV1 input on the GPU
Mario Roy
marioeroy at gmail.com
Wed Jul 20 16:19:03 EEST 2022
Should -hwaccel nvdec without -c:v take the av1_cuvid path if available for
decoding AV1? I observed 100% video engine utilization.
$ ffmpeg -y -hwaccel nvdec -i input_av1.mp4 -f null - # fps=900
$ ffmpeg -y -hwaccel nvdec -c:v av1 -i input_av1.mp4 -f null - # fps=899
$ ffmpeg -y -hwaccel nvdec -c:v av1_cuvid -i input_av1.mp4 -f null - #
fps=1642
$ ffmpeg -y -hwaccel nvdec -i input_vp9.webm -f null - # fps=1441
$ ffmpeg -y -hwaccel nvdec -c:v vp9 -i input_vp9.webm -f null - # 1428
$ ffmpeg -y -hwaccel nvdec -c:v vp9_cuvid -i input_vp9.webm -f null - #
fps=1432
Thanks,
Mario
On Wed, Jul 20, 2022 at 8:02 AM Mario Roy <marioeroy at gmail.com> wrote:
> Thank you Haihao, for the URL to patchset.
>
> Previously, I applied only the patch contained in the email thread. This
> time, I applied both patches to FFmpeg master and confirmed that
> av1(native) is used for nvdec, vaapi, and vdpau. I observed 100% and 50% ~
> 68% video engine utilization for VP9 and AV1 respectively. Unix time is
> captured for output.ts.
>
> Video Engine Utilization: 100%
>
> $ ffmpeg -y -hwaccel nvdec -i input_vp9.webm -f null - # GPU fps=1441
> $ ffmpeg -y -hwaccel vaapi -i input_vp9.webm -f null - # GPU fps=1320
> $ ffmpeg -y -hwaccel vdpau -i input_vp9.webm -f null - # GPU fps=1308
>
> Video Engine Utilization: 50% ~ 68%
>
> $ ffmpeg -y -hwaccel nvdec -i input_av1.mp4 -f null - # GPU fps=900
> $ ffmpeg -y -hwaccel vaapi -i input_av1.mp4 -f null - # GPU fps=760
> $ ffmpeg -y -hwaccel vdpau -i input_av1.mp4 -f null - # GPU fps=799
>
> Unix Time output.ts:
> -hwaccel vdpau is unexpectedly slow for av1
>
> $ time ffmpeg -y -hwaccel nvdec -i input_vp9.webm output.ts # GPU 6.176s
> $ time ffmpeg -y -hwaccel vaapi -i input_vp9.webm output.ts # GPU 7.754s
> $ time ffmpeg -y -hwaccel vdpau -i input_vp9.webm output.ts # GPU 7.213s
>
> $ time ffmpeg -y -hwaccel nvdec -i input_av1.mp4 output.ts # GPU 8.709s
> $ time ffmpeg -y -hwaccel vaapi -i input_av1.mp4 output.ts # GPU 10.816s
> $ time ffmpeg -y -hwaccel vdpau -i input_av1.mp4 output.ts # GPU 15.162s
>
> The next two commands core dumps using FFmpeg master, ditto for FFmpeg 5.1.
>
> $ ffmpeg -y -hwaccel vdpau -c:v vp9_cuvid -i input_vp9.webm -f null - #
> core dumped
> $ ffmpeg -y -hwaccel vdpau -c:v av1_cuvid -i input_av1.mp4 -f null - #
> core dumped
>
> No issues for nvdec. Passing -c:v av1_cuvid is swift, compared to 900 fps
> above without -c:v av1_cuvid.
>
> $ ffmpeg -y -hwaccel nvdec -c:v vp9_cuvid -i input_vp9.webm -f null - #
> fps=1435
> $ ffmpeg -y -hwaccel nvdec -c:v av1_cuvid -i input_av1.mp4 -f null - #
> fps=1642
>
>
> Thanks,
> Mario
>
>
> On Wed, Jul 20, 2022 at 4:30 AM Xiang, Haihao <
> haihao.xiang-at-intel.com at ffmpeg.org> wrote:
>
>>
>> > Thank you, Haihao. I applied the patchset to FFmpeg 5.1 branch. Passing
>> > -hwaccel {nvdec|vdpau} without -c:v av1 still decoded on the CPU. I
>> double
>> > checked to be sure the patchset was applied.
>> >
>>
>> libdav1d is still used for format probing but av1(native) should be used
>> for
>> decoding when -hwaccel xxx is specified.
>>
>> I rebased the patches on the master(
>> https://github.com/xhaihao/FFmpeg/tree/ffmpeg-choose-dec) however I
>> don't have
>> the environment to verify nvdec/vdpau. I verified it with vaapi
>>
>> $ ffmpeg -hwaccel vaapi -i av1.ivf -f null -
>>
>> [...]
>> Stream mapping:
>> Stream #0:0 -> #0:0 (av1 (native) -> wrapped_avframe (native))
>>
>> $ ffmpeg -i av1.ivf -f null -
>>
>> [...]
>> Stream mapping:
>> Stream #0:0 -> #0:0 (av1 (libdav1d) -> wrapped_avframe (native))
>>
>> Thanks
>> Haihao
>>
>>
>> > I obtained AV1 and VP9 samples via yt-dlp: 1920x1080 resolution.
>> >
>> > $ yt-dlp -F https://youtu.be/mIAfxj7nd9k
>> > $ yt-dlp -f 399 https://youtu.be/mIAfxj7nd9k -o input_av1.mp4
>> > $ yt-dlp -f 248 https://youtu.be/mIAfxj7nd9k -o input_vp9.webm
>> >
>> > Hardware: GeForce RTX 3070 FE
>> >
>> > AV1 Observations.
>> >
>> > $ ffmpeg -y -hwaccel nvdec -c:v av1_cuvid -i input_av1.mp4 output.ts #
>> > GPU fps=653
>> > $ ffmpeg -y -hwaccel vdpau -c:v av1_cuvid -i input_av1.mp4 output.ts #
>> > Core Dumps
>> > $ ffmpeg -y -hwaccel nvdec -c:v av1 -i input_av1.mp4 output.ts #
>> > GPU fps=454
>> > $ ffmpeg -y -hwaccel vdpau -c:v av1 -i input_av1.mp4 output.ts #
>> > GPU fps=246
>> > $ ffmpeg -y -hwaccel nvdec -i input_av1.mp4 output.ts #
>> > CPU libdav1d
>> > $ ffmpeg -y -hwaccel vdpau -i input_av1.mp4 output.ts #
>> > CPU libdav1d
>> >
>> > VP9 Observations.
>> >
>> > $ ffmpeg -y -hwaccel nvdec -c:v vp9_cuvid -i input_vp9.webm output.ts #
>> > GPU fps=669
>> > $ ffmpeg -y -hwaccel vdpau -c:v vp9_cuvid -i input_vp9.webm output.ts #
>> > Core Dumps
>> > $ ffmpeg -y -hwaccel nvdec -c:v vp9 -i input_vp9.webm output.ts #
>> > GPU fps=662
>> > $ ffmpeg -y -hwaccel vdpau -c:v vp9 -i input_vp9.webm output.ts #
>> > GPU fps=529
>> > $ ffmpeg -y -hwaccel nvdec -i input_vp9.webm output.ts #
>> > GPU fps=655
>> > $ ffmpeg -y -hwaccel vdpau -i input_vp9.webm output.ts #
>> > GPU fps=533
>> >
>> > Looking at the AV1 results, -hwaccel vdpau -c:v av1 is nearly 2x slower
>> > than -hwaccel nvdec -c:v av1.
>> >
>> > Should FFmpeg exit gracefully if passing unsupported options for
>> -hwaccel
>> > vdpau? Or is this a bug?
>> > -hwaccel vdpau -c:v av1_cuvid # Crashes
>> > -hwaccel vdpau -c:v vp9_cuvid # Crashes
>> >
>> > Thanks,
>> > Mario
>> >
>> > On Tue, Jul 19, 2022 at 8:42 PM Xiang, Haihao <
>> > haihao.xiang-at-intel.com at ffmpeg.org> wrote:
>> >
>> > > On Tue, 2022-07-19 at 16:54 -0500, Mario Roy wrote:
>> > > > Greetings,
>> > > >
>> > > > With the recent FFmpeg 5.1 supporting AV1 using VDPAU, should
>> decoding
>> > >
>> > > AV1
>> > > > occur on the GPU automatically (NVIDIA 3000 series), similarly to
>> > >
>> > > decoding
>> > > > VP9?
>> > > >
>> > > > ffmpeg -y -hwaccel vdpau -i input_av1.mp4 output.ts # decodes on
>> the
>> > >
>> > > CPU
>> > >
>> > >
>> > > libdav1d has higher priority than the the native av1 decoder in
>> FFmpeg, you
>> > > should specify the native av1 in your command line if you want to use
>> > > vdpau.
>> > >
>> > > $ ffmpeg -y -hwaccel vdpau -c:v av1 -i input_av1.mp4 output.ts
>> > >
>> > > Or you may try
>> > >
>> > >
>>
>> https://patchwork.ffmpeg.org/project/ffmpeg/patch/20210922074207.19451-2-haihao.xiang@intel.com/
>> > > which can decode AV1 on the GPU automatically when -hwaccel xxx is
>> > > specified in
>> > > the command line. (You need to rebase the patchset).
>> > >
>> > > Thanks
>> > > Haihao
>> > >
>> > >
>> > > > ffmpeg -y -hwaccel vdpau -i input_vp9.webm output.ts # decodes on
>> the
>> > >
>> > > GPU
>> > > >
>> > > > Are the following incorrect usage? Both segfaults.
>> > > >
>> > > > ffmpeg -y -hwaccel vdpau -c:v av1_cuvid -i input_av1.mp4 output.ts
>> #
>> > > > segfaults
>> > > > ffmpeg -y -hwaccel vdpau -c:v vp9_cuvid -i input_vp9.webm
>> output.ts #
>> > > > segfaults
>> > > >
>> > > > Thanks,
>> > > > Mario
>> > > >
>> > > > On Wed, Jul 13, 2022 at 9:44 AM Mario Roy <marioeroy at gmail.com>
>> wrote:
>> > > >
>> > > > > Hi,
>> > > > >
>> > > > > What are the recommended arguments for folks using NVIDIA 3000
>> series
>> > > > > graphics and decoding AV1 media? I tried the same with VP9 media.
>> > > > >
>> > > > > The following was done using FFmpeg 5.1.
>> > > > >
>> > > > > ffmpeg -y -hwaccel vdpau -c:v av1_cuvid -i input_av1.mp4
>> > > > > output.ts segfaults
>> > > > > ffmpeg -y -hwaccel vdpau -c:v vp9_cuvid -i input_vp9.webm
>> > > > > output.ts segfaults
>> > > > >
>> > > > > ffmpeg -y -hwaccel vdpau -i input_av1.mp4 output.ts decodes on
>> the
>> > >
>> > > CPU
>> > > > > ffmpeg -y -hwaccel vdpau -i input_vp9.webm output.ts decodes on
>> the
>> > >
>> > > GPU
>> > > > >
>> > > > > ffmpeg -y -hwaccel nvdec -c:v av1_cuvid -i input_av1.mp4 output.ts
>> > > > > ffmpeg -y -hwaccel nvdec -c:v vp9_cuvid -i input_vp9.webm
>> output.ts
>> > > > >
>> > > > > ffmpeg -y -c:v av1_cuvid -i input_av1.mp4 output.ts
>> > > > > ffmpeg -y -c:v vp9_cuvid -i input_vp9.webm output.ts
>> > > > >
>> > > > > Best,
>> > > > > Mario
>> > > > >
>> > > > >
>> > > >
>> > > > _______________________________________________
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