[Spice-devel] playbin can't detect vaapi decoder correctly when playing a video stream.

[Qiu Wenbo]

Thank you for the reply. I am pretty sure I have a working vaapih264dec 
element since I can setup a pipeline manually to play a H.264 video. 
Also, the output of remote-viewer with --spice-debug is almost the same 
as yours(vaapidecodebin, vaapih264dec).

 >> Couldn't set vaapidecodebin0 to PAUSEDElement vaapidecode_h264-0 
does not accept caps

The last line of the log says vaapidecode_h264 dose not accept caps. Is 
there any possibility that my hardware(intel i5-6500) can't decode some 
H.264 stream with certain parameter (as the default x264enc setup 
generate) since I can confirm playbin is using vaapih264dec when I 
manually change the encoder of spice-server from x264 to vaapih264enc 
(still has a jamed pipeline). Can you provides some hardware known to 
work?


On Fri, Aug 3, 2018 at 5:03 PM, Victor Toso <victortoso at redhat.com> 
wrote:
> Hi,
> 
> On Fri, Aug 03, 2018 at 11:20:52AM +0800, Qiu Wenbo wrote:
>>  I'm trying to turn on streaming video with H.264 codec
>>  manually. I have noticed spice-gtk will use playbin to decode
>>  the video stream with recent gstreamer.
> 
> Yes
> 
>>  However,  playbin tends to use software decoder (avdec_h264) on
>>  my box (latest Archlinux running on an Intel i5-6500 PC with
>>  gstreamer-vaapi). When I remove gstreamer-libav, gstreamer
>>  complains like this and refuse to setup pipeline:
> 
> What is the output of
> $ gst-inspect-1.0 | grep -i vaapi
> 
> Note that with --spice-debug enabled you should be seeing
> something like
> 
>  | Spice-DEBUG: 10:52:22.453: channel-display-gst.c:696:
>  | gstvideo_debug_available_decoders: From  15 video decoder elements,
>  | 1 can handle caps image/jpeg: jpegdec
> 
>  | Spice-DEBUG: 10:52:22.453: channel-display-gst.c:696:
>  | gstvideo_debug_available_decoders: From  15 video decoder elements,
>  | 2 can handle caps video/x-vp8: vaapidecodebin, vp8dec
> 
>  | Spice-DEBUG: 10:52:22.453: channel-display-gst.c:696:
>  | gstvideo_debug_available_decoders: From  15 video decoder elements,
>  | 1 can handle caps video/x-h264: vaapidecodebin
> 
>  | Spice-DEBUG: 10:52:22.453: channel-display-gst.c:696:
>  | gstvideo_debug_available_decoders: From  15 video decoder elements,
>  | 2 can handle caps video/x-vp9: vaapidecodebin, vp9dec
> 
> This debug info is similar to running gst-inspect-1.0 and finding
> the decoder elements per codec supported in spice-protocol
> 
>>  0:00:00.221423602 4816 0x7f24e40454a0 ERROR h264parse
>>  gsth264parse.c:2588:gst_h264_parse_set_caps: video/x-h264 caps 
>> without
>>  codec_data or stream-format
>>  0:00:00.221548091 4816 0x7f24e40454a0 ERROR h264parse
>>  gsth264parse.c:2588:gst_h264_parse_set_caps: video/x-h264 caps 
>> without
>>  codec_data or stream-format
> 
> stream-format is not needed to play the stream and we lack a
> way to set this info reliably in the procotol (the host is
> hardcded to stream with byte-stream but could change, etc)
> 
> See 
> https://gitlab.freedesktop.org/spice/spice-gtk/commit/c9129ed202b00f4
> 
>>  0:00:00.517686292 4816 0x7f24e40454a0 WARN decodebin
>>  gstdecodebin2.c:2514:connect_pad:<decodebin0> Couldn't set 
>> vaapidecodebin0
>>  to PAUSED
>>  0:00:00.518742010 4816 0x7f24e40454a0 WARN decodebin
>>  gstdecodebin2.c:2339:connect_pad:<decodebin0> Element 
>> vaapidecode_h264-0
>>  does not accept caps
>>  0:00:00.518908940 4816 0x7f24e40454a0 WARN uridecodebin
>>  gsturidecodebin.c:921:unknown_type_cb:<uridecodebin0> warning: No 
>> decoder
>>  available for type 'video/x-h264, pixel-aspect-ratio=(fraction)1/1,
>>  width=(int)1920, height=(int)1080, framerate=(fraction)30/1,
>>  interlace-mode=(string)progressive, chroma-format=(string)4:4:4,
>>  bit-depth-luma=(uint)8, bit-depth-chroma=(uint)8, 
>> parsed=(boolean)true,
>>  stream-format=(string)avc, alignment=(string)au, 
>> profile=(string)high-4:4:4,
>>  level=(string)5, 
>> codec_data=(buffer)01f40032ffe1001e67f400329184680780227e27016a02020280000003008000001e478c195001000468ce3192'.
>>  0:00:00.518933285 4816 0x7f24e40454a0 WARN decodebin
>>  gstdecodebin2.c:4640:gst_decode_bin_expose:<decodebin0> error: no 
>> suitable
>>  plugins found:
>>  Couldn't set vaapidecodebin0 to PAUSEDElement vaapidecode_h264-0 
>> does not
>>  accept caps
> 
> "No decoder available" and "No plugins found", that's why I asked
> above questions. Besides having gstreamer1-vaapi, you need
> suitable drivers to make vaapi work
> 
>>  0:00:00.518951522 4816 0x7f24e40454a0 WARN uridecodebin
>>  gsturidecodebin.c:988:no_more_pads_full:<uridecodebin0> error: no 
>> suitable
>>  plugins found:
>>  gstdecodebin2.c(4640): gst_decode_bin_expose ():
>>  
>> /GstPlayBin:playbin/GstURIDecodeBin:uridecodebin0/GstDecodeBin:decodebin0:
>>  no suitable plugins found:
>>  Couldn't set vaapidecodebin0 to PAUSEDElement vaapidecode_h264-0 
>> does not
>>  accept caps
>> 
>>  However, after install gstreamer-libav, the log shows playbin is 
>> using
>>  avdec_h264. Also, I can confirm playbin is using vaapih264dec when I
>>  manually change the encoder of spice-server from x264 to 
>> vaapih264enc.
> 
> Cheers,
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/spice-devel/attachments/20180804/6f8d0d59/attachment.html>