我知道在这个平台上已经有无数次类似的问题被问到了，但似乎都没有帮助到我。有一段时间，我可以在我的系统上使用 mpv 媒体播放器播放 x265 10 位视频，但在更新到 Ubuntu 20.04 后，视频又恢复到了以前的播放状态，延迟非常严重，字幕/视频不同步，有时视频甚至不会显示而音频继续播放。我以前也遇到过这些问题，但在获得软件包后gstreamer1.0-libde265，问题得到了解决，至少在 mpv 上是这样。所有 x265 视频播放都很流畅。但自从更新以来，我再也无法在 mpv 上流畅播放 x265 视频了，事实上在任何媒体播放器上都无法流畅播放。不过在 Windows 上我仍然可以流畅播放它们。我猜是因为我用来添加上述包的 ppa 在升级到 20.04 时被禁用了。
如果有人需要信息，这里是 vainfo 的输出：
libva info: VA-API version 1.7.0
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so
libva info: Found init function __vaDriverInit_1_7
libva error: /usr/lib/x86_64-linux-gnu/dri/iHD_drv_video.so init failed
libva info: va_openDriver() returns 1
libva info: Trying to open /usr/lib/x86_64-linux-gnu/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_1_6
libva info: va_openDriver() returns 0
vainfo: VA-API version: 1.7 (libva 2.6.0)
vainfo: Driver version: Intel i965 driver for Intel(R) CherryView - 2.4.0
vainfo: Supported profile and entrypoints
VAProfileMPEG2Simple : VAEntrypointVLD
VAProfileMPEG2Simple : VAEntrypointEncSlice
VAProfileMPEG2Main : VAEntrypointVLD
VAProfileMPEG2Main : VAEntrypointEncSlice
VAProfileH264ConstrainedBaseline: VAEntrypointVLD
VAProfileH264ConstrainedBaseline: VAEntrypointEncSlice
VAProfileH264Main : VAEntrypointVLD
VAProfileH264Main : VAEntrypointEncSlice
VAProfileH264High : VAEntrypointVLD
VAProfileH264High : VAEntrypointEncSlice
VAProfileH264MultiviewHigh : VAEntrypointVLD
VAProfileH264MultiviewHigh : VAEntrypointEncSlice
VAProfileH264StereoHigh : VAEntrypointVLD
VAProfileH264StereoHigh : VAEntrypointEncSlice
VAProfileVC1Simple : VAEntrypointVLD
VAProfileVC1Main : VAEntrypointVLD
VAProfileVC1Advanced : VAEntrypointVLD
VAProfileNone : VAEntrypointVideoProc
VAProfileJPEGBaseline : VAEntrypointVLD
VAProfileJPEGBaseline : VAEntrypointEncPicture
VAProfileVP8Version0_3 : VAEntrypointVLD
VAProfileVP8Version0_3 : VAEntrypointEncSlice
VAProfileHEVCMain : VAEntrypointVLD
以下是 lscpu 的输出：
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian
Address sizes: 36 bits physical, 48 bits virtual
CPU(s): 2
On-line CPU(s) list: 0,1
Thread(s) per core: 1
Core(s) per socket: 2
Socket(s): 1
NUMA node(s): 1
Vendor ID: GenuineIntel
CPU family: 6
Model: 76
Model name: Intel(R) Celeron(R) CPU N3060 @ 1.60GHz
Stepping: 4
CPU MHz: 1968.194
CPU max MHz: 2480.0000
CPU min MHz: 480.0000
BogoMIPS: 3200.00
Virtualization: VT-x
L1d cache: 48 KiB
L1i cache: 64 KiB
L2 cache: 2 MiB
NUMA node0 CPU(s): 0,1
Vulnerability Itlb multihit: Not affected
Vulnerability L1tf: Not affected
Vulnerability Mds: Mitigation; Clear CPU buffers; SMT disabled
Vulnerability Meltdown: Mitigation; PTI
Vulnerability Spec store bypass: Not affected
Vulnerability Spectre v1: Mitigation; usercopy/swapgs barriers and __user
pointer sanitization
Vulnerability Spectre v2: Mitigation; Full generic retpoline, IBPB condit
ional, IBRS_FW, STIBP disabled, RSB filling
Vulnerability Srbds: Not affected
Vulnerability Tsx async abort: Not affected
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtr
r pge mca cmov pat pse36 clflush dts acpi mmx f
xsr sse sse2 ss ht tm pbe syscall nx rdtscp lm
constant_tsc arch_perfmon pebs bts rep_good nop
l xtopology tsc_reliable nonstop_tsc cpuid aper
fmperf tsc_known_freq pni pclmulqdq dtes64 moni
tor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm sse
4_1 sse4_2 movbe popcnt tsc_deadline_timer aes
rdrand lahf_lm 3dnowprefetch epb pti ibrs ibpb
stibp tpr_shadow vnmi flexpriority ept vpid tsc
_adjust smep erms dtherm ida arat md_clear
PS：抱歉，我发了这么多牢骚，我是个菜鸟，所以如果能给我一个低级的解释就更好了。
答案1
答案2
我通过安装错误报告底部提到的缺失驱动程序来改进https://bugs.launchpad.net/ubuntu/+source/libva-utils/+bug/1890815
使用 18.04 LTS 中的软件包进行修复，如下所示：
cd ~/Downloads
wget -c http://archive.ubuntu.com/ubuntu/pool/universe/v/vdpau-video/vdpau-va-driver_0.7.4-6ubuntu1_amd64.deb
sudo apt-get install ./vdpau-va-driver_0.7.4-6ubuntu1_amd64.deb