[FFmpeg-trac] #11292(avcodec:open): AMD Hardware Encoding is Broken in versions >= 7.1

[FFmpeg]

#11292: AMD Hardware Encoding is Broken in versions >= 7.1
------------------------------------+-----------------------------------
             Reporter:  TanMan      |                    Owner:  (none)
                 Type:  defect      |                   Status:  open
             Priority:  important   |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+-----------------------------------
Comment (by TanMan):

 @Roman, thank you so much for the great explanation. In particular, the
 need to set the video bitrate (-b:v) and how the -maxrate is calculated
 when not specified (1.5x). Using your new information, I reencoded the
 target video using:

 `ffmpeg -i input -c:v hevc_amf -b:v 1M output`

 This encoding resulted in a reasonable bitrate of 1651bps which looks
 fine. The 2:08:48 1920x800 movie I encoded is now a reasonable 1.5GB, and
 that includes 590MB for the DD 5.1 audio. And yes, it threw the
 rc_max_rate error since I didn't set -maxrate.

 Now that I have properly thanked you for fixing my issue, I have 3
 additional comments:

 1. The change in the amf encoder defaults is not documented in the
 changelog. Something major like this needs to be highlighted in something
 other than a github diff list.

 2. This change eliminates the parity with the libx265 encoder. libx265
 appears to still use a lower default bitrate - the encode of this same
 movie using libx265 (CPU only) was much, much slower, but resulted in a
 tiny file (under 1GB) and a bitrate under 1kbps.

 3. I agree with @Gyan that 20M is excessive for x265. There seems to be no
 reason for this change as x265 gives great results with much lower
 bitrates.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/11292#comment:8>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker