[FFmpeg-trac] #10062(undetermined:new): av1_qsv produces incorrect output files

[FFmpeg]

#10062: av1_qsv produces incorrect output files
-------------------------------------+-------------------------------------
             Reporter:  oviano       |                    Owner:  (none)
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  qsv          |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
Comment (by oviano):

 Thank you for the information.

 In the meantime and for fun/to try and learn something I have been trying
 to figure out why even with the suggested workaround from James above the
 bitstream was not correct, and I think I can see what is going on.

 ============================================================
 Bitstream produced by FFmpeg (with workaround to overwrite packet.pts
 timestamps)
 ============================================================

 EXTRADATA
 OBU (1)
 SEQ

 PACKET PTS 0

 OBU (1)
 SEQ
 OBU (6)
 FRAME (SHOW)

 PACKET PTS 512

 OBU (6)
 FRAME

 PACKET PTS 1024

 OBU (6)
 FRAME

 PACKET PTS 1536

 OBU (6)
 FRAME

 PACKET PTS 2048

 OBU (6)
 FRAME (SHOW)
 OBU (3)
 FRAME HDR (SHOW FRAME IDX 3)

 PACKET PTS 2560

 OBU (6)
 FRAME (SHOW)
 OBU (3)
 FRAME HDR (SHOW FRAME IDX 2)

 PACKET PTS 3072

 OBU (6)
 FRAME

 PACKET PTS 3584

 OBU (6)
 FRAME (SHOW)
 OBU (3)
 FRAME HDR (SHOW FRAME IDX 0)

 PACKET PTS 4096

 OBU (6)
 FRAME (SHOW)

 ============================================================
 Bitstream produced by QSVEnc (which has its own workaround for this issue)
 ============================================================

 EXTRADATA
 OBU (1)
 SEQ

 PACKET PTS 0

 OBU (1)
 SEQ
 OBU (6)
 FRAME (SHOW)

 PACKET PTS 512

 OBU (6)
 FRAME
 OBU (6)
 FRAME
 OBU (6)
 FRAME
 OBU (6)
 FRAME (SHOW)

 PACKET PTS 1024

 OBU (3)
 FRAME HDR (SHOW FRAME IDX 3)

 PACKET PTS 1536

 OBU (6)
 FRAME (SHOW)

 PACKET PTS 2048

 OBU (3)
 FRAME HDR (SHOW FRAME IDX 2)

 PACKET PTS 2560

 OBU (6)
 FRAME
 OBU (6)
 FRAME (SHOW)

 PACKET PTS 3072

 OBU (3)
 FRAME HDR (SHOW FRAME IDX 0)

 PACKET PTS 3584

 OBU (6)
 FRAME (SHOW)

 ============================================================

 In the FFmpeg bitstream not all packets output by QSV containable a frame
 that can be shown, whereas with QSVEnc a packet always ends with a frame
 that can be shown. This explains the stutter that occurs with FFmpeg-
 produced bitstreams, because at some timestamps there is no frame, whereas
 at other times they're a multiple.

 Hopefully the fixes will resolve this, if not then I guess any FFmpeg
 workaround would involve splitting and merging OBUs across packets.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10062#comment:17>
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