[FFmpeg-trac] #7303(undetermined:open): h264_nvenc (and hevc_nvenc) with b_ref_mode middle creates invalid video while streaming

[FFmpeg]

#7303: h264_nvenc (and hevc_nvenc) with b_ref_mode middle creates invalid video
while streaming
-------------------------------------+-------------------------------------
             Reporter:               |                    Owner:
  smallishzulu                       |
                 Type:  defect       |                   Status:  open
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  git-master   |               Resolution:
             Keywords:  nvenc        |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by cs9k):

 My apologies if my shotgun-delivery of information was unclear.

 I have not encountered the issue streaming to the internet.  Twitch
 happily ingests and transcodes h264_nvenc output using the "-b_ref_mode
 middle" argument.

 Local recording and transcoding are the only places I've run into the
 DTS/PTS error.

 The error is reproducible using Zeranoe ffmpeg 4.2.2 and the 5/1/20
 nightly on Windows 10, using both the mkv and mp4 containers, regardless
 of whether I use software or nvdec to decode the input.

 I tested the following just now with the Zeranoe 5/1/20 ffmpeg nightly,
 and both threw the DTS/PTS error using "-b_ref_mode middle".

 ffmpeg -loglevel verbose -i input.mkv -c:a copy -c:v h264_nvenc -pix_fmt
 yuv420p -preset:v slow -profile:v high -rc:v cbr -b:v 9M -bf:v 3
 -b_ref_mode:v middle quicktest02.mp4

 ffmpeg -loglevel verbose -i input.mkv -c:a copy -c:v hevc_nvenc -pix_fmt
 yuv420p -preset:v slow -profile:v main -tier:v high -rc:v cbr -b:v 9M
 -bf:v 3 -b_ref_mode:v middle quicktest03.mp4

 I can provide debug logs, or any other logs, or run more tests for you, if
 you'd like.  Please let me know.

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Ticket URL: <https://trac.ffmpeg.org/ticket/7303#comment:15>
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