[FFmpeg-trac] #7030(avcodec:open): qsv in ffmpeg

[FFmpeg]

#7030: qsv in ffmpeg
-------------------------------------+-------------------------------------
             Reporter:  palich2000   |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  important    |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  qsv          |               Blocked By:
  regression                         |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by fulinjie):

 Before commit
 http://git.videolan.org/?p=ffmpeg.git;a=commitdiff;h=b0cd14fb1dab4b044f7fe6b53ac635409849de77#patch3,


 {{{
 -        if (ist->hwaccel_id != HWACCEL_NONE)
 -            type = hw_device_match_type_by_hwaccel(ist->hwaccel_id);
 -        else
 -            type = hw_device_match_type_in_name(ist->dec->name);
 -        if (type != AV_HWDEVICE_TYPE_NONE) {
              dev = hw_device_get_by_type(type);
 }}}
 dev could be got through dec->name and then calls
 '''ff_qsv_init_session_device''' to CreateCORE/SetHandle and make sure the
 decoder works well.

 However, after this commit, dev could not be got in
 hw_device_match_by_codec
 {{{
 dev = hw_device_match_by_codec(ist->dec);
 }}}

 because AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX is not configured as a
 method in ff_qsv_hw_configs.

 {{{
 +    for (i = 0;; i++) {
 +        config = avcodec_get_hw_config(codec, i);
 +        if (!config)
 +            return NULL;
 +        if (!(config->methods & AV_CODEC_HW_CONFIG_METHOD_HW_DEVICE_CTX))
 +            continue;
 +        dev = hw_device_get_by_type(config->device_type);
 +        if (dev)
 +            return dev;
      }
 }}}

 As a consequence, '''ff_qsv_init_internal_session''' was called to
 CreateCORE only without SetHandle.
 And it leads to the decode failure.

 Also as Zhong has mentioned, the removal of ff_qsv_set_display_handle() in
 ff_qsv_init_internal_session is one of the reasons as well.

--
Ticket URL: <https://trac.ffmpeg.org/ticket/7030#comment:23>
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