【赛昉科技昉·星光RISC-V单板计算机试用体验】FFmpeg环境测试

背景

背景

因为我本人是做音视频处理基础技术的，所以通常拿到一块板子后首先想到的是尝试把视频能力用起来，例如视频的编码，视频的解码，看一看编码的画质如何，解码性能如何，然后再进行下一步。

既然要尝试使用，那么首先就考虑装一个操作系统吧，第一件事是参考说明文档，去下载一个Fedora，然后刷到sd卡里面。

尝试使用

根据说明文档看，我下载的Fedora不可以直接刷到sd里面，因为他的格式是这样的：

Fedora-riscv64-jh7100-developer-xfce-Rawhide-20211226-214100.n.0-sda.raw.zst

要先安装一下zstd，然后

zstd Fedora-riscv64-jh7100-developer-xfce-Rawhide-20211226-214100.n.0-sda.raw.zst -o Fedora-riscv64-jh7100-developer-xfce-Rawhide-20211226-214100.n.0-sda.raw

然后用dd将Fedora-riscv64-jh7100-developer-xfce-Rawhide-20211226-214100.n.0-sda.raw写到SD卡即可

插入sd卡以后，用USB type-c接口的电源线插到板子上上电，插入HDMI链接到显示器，稍等一会就能够看到Fedora的启动界面，登录提示页面，按照手册中写的用户名密码输入后即可进入系统。

看一下系统的cpu信息

[riscv@fedora-starfive ~]$ cat //proc/cpuinfo
processor	: 0
hart		: 1
isa		: rv64imafdc
mmu		: sv39
uarch		: sifive,u74-mc

processor	: 1
hart		: 0
isa		: rv64imafdc
mmu		: sv39
uarch		: sifive,u74-mc```

还是个双核。看板子的介绍是支持视频编码的

尝试使用FFmpeg自动识别环境

但是手册里面并未说明该如何跑起来，于是我尝试用ffmpeg来跑一下。

[riscv@fedora-starfive ~]$ git clone git://source.ffmpeg.org/ffmpeg.git
正克隆到 'ffmpeg'...
remote: Enumerating objects: 666444, done.
remote: Counting objects: 100% (666444/666444), done.
remote: Compressing objects: 100% (130415/130415), done.
remote: Total 666444 (delta 539474), reused 661607 (delta 534726)
接收对象中: 100% (666444/666444), 131.55 MiB | 58.00 KiB/s, 完成.
处理 delta 中: 100% (539474/539474), 完成.
正在更新文件: 100% (7781/7781), 完成.
[riscv@fedora-starfive ~]$ cd ffmpeg/
[riscv@fedora-starfive ffmpeg]$ ls
Changelog  CONTRIBUTING.md  COPYING.LGPLv2.1  doc      INSTALL.md   libavfilter  libpostproc    LICENSE.md   presets    tests
compat     COPYING.GPLv2    COPYING.LGPLv3    ffbuild  libavcodec   libavformat  libswresample  MAINTAINERS  README.md  tools
configure  COPYING.GPLv3    CREDITS           fftools  libavdevice  libavutil    libswscale     Makefile     RELEASE
[riscv@fedora-starfive ffmpeg]$ cd ..
[riscv@fedora-starfive ~]$ mkdir build_ffmpeg
[riscv@fedora-starfive ~]$ cd build_ffmpeg/
[riscv@fedora-starfive build_ffmpeg]$ ../ffmpeg/configure --disable-everything --enable-ffmpeg --enable-decoder=h264,mpeg4 --enable-hwaccels
install prefix            /usr/local
source path               src
C compiler                gcc
C library                 glibc
ARCH                      riscv (generic)
big-endian                no
runtime cpu detection     yes
debug symbols             yes
strip symbols             yes
optimize for size         no
optimizations             yes
static                    yes
shared                    no
postprocessing support    no
network support           yes
threading support         pthreads
safe bitstream reader     yes
texi2html enabled         no
perl enabled              yes
pod2man enabled           yes
makeinfo enabled          yes
makeinfo supports HTML    yes
xmllint enabled           yes

External libraries:
alsa                    iconv                   libxcb_shape            libxcb_xfixes           zlib
bzlib                   libxcb                  libxcb_shm              lzma

External libraries providing hardware acceleration:
cuda_llvm               v4l2_m2m

Libraries:
avcodec                 avdevice                avfilter                avformat                avutil                  swresample              swscale

Programs:
ffmpeg                  ffprobe

Enabled decoders:
h263                    h264                    mpeg4

Enabled encoders:

Enabled hwaccels:

Enabled parsers:
h263                    mpeg4video

Enabled demuxers:

Enabled muxers:

Enabled protocols:

Enabled filters:
aformat                 atrim                   hflip                   transpose               vflip
anull                   format                  null                    trim

Enabled bsfs:

Enabled indevs:

Enabled outdevs:

License: LGPL version 2.1 or later
config_components.h is unchanged
libavutil/avconfig.h is unchanged
libavfilter/filter_list.c is unchanged
libavcodec/codec_list.c is unchanged
libavcodec/parser_list.c is unchanged
libavcodec/bsf_list.c is unchanged
libavformat/demuxer_list.c is unchanged
libavformat/muxer_list.c is unchanged
libavdevice/indev_list.c is unchanged
libavdevice/outdev_list.c is unchanged
libavformat/protocol_list.c is unchanged
ffbuild/config.sh is unchanged