與FFmpeg的初次邂逅

前面的文章(http://blog.csdn.net/ericbar/article/details/69937295)已經幫助我們搭建好了編譯FFmpeg的環境,接下來,便可以來認識一下FFmpeg的廬山真面目了。

下載FFmpeg源碼

首先登陸FFmpeg的官方網站https://ffmpeg.org/,打開下載地址:https://ffmpeg.org/download.html#get-sources,在頁面的“Releases”段落裏,可以看到多個版本的FFmpeg源代碼。筆者當前的最新Releases版本是 3.2.4 ,代號”Hypatia”(百度了一下,希帕蒂婭出生在埃及,是古希臘著名數學家,天文學家,哲學家。人稱世界上第一位女數學家,這位聰慧的女性以她的才華和貢獻躋身於古代世界最優秀的學者之列,而她慘死在野蠻的教徒手下實爲一千古悲劇)。
下面是此版本的發佈日期以及它從主分支版本分離出來的日期:
FFmpeg 3.2.4 was released on 2017-02-10. It is the latest stable FFmpeg release from the 3.2.4 release branch, which was cut from master on 2016-10-26.

下面是FFmpeg各庫的子版本號:

libavutil      55. 34.100
libavcodec     57. 64.101
libavformat    57. 56.100
libavdevice    57.  1.100
libavfilter     6. 65.100
libavresample   3.  1.  0
libswscale      4.  2.100
libswresample   2.  3.100
libpostproc    54.  1.100

選擇xz擴展名的tarball 包ffmpeg-3.2.4.tar.xz下載,將下載完畢的包放到Ubuntu虛擬機的/home/ffmpeg/work目錄下。

編譯FFmpeg

首先通過命令行(Terminal程序)解壓縮FFmpeg的源代碼,並進入ffmpeg-3.2.4目錄。

tar xvf ffmpeg-3.2.4.tar.xz
cd ffmpeg-3.2.4

編譯前要配置FFmpeg,可以通過如下命令看一下有哪些配置選項,

./configure --help

可配置選項十分豐富,可見FFmpeg功能之強大,

ffmpeg@ubuntu:~/work/ffmpeg-3.2.4$ ./configure --help
Usage: configure [options]
Options: [defaults in brackets after descriptions]

Help options:
  --help                   print this message
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-demuxers          show all available demuxers
  --list-muxers            show all available muxers
  --list-parsers           show all available parsers
  --list-protocols         show all available protocols
  --list-bsfs              show all available bitstream filters
  --list-indevs            show all available input devices
  --list-outdevs           show all available output devices
  --list-filters           show all available filters

Standard options:
  --logfile=FILE           log tests and output to FILE [config.log]
  --disable-logging        do not log configure debug information
  --fatal-warnings         fail if any configure warning is generated
  --prefix=PREFIX          install in PREFIX []
  --bindir=DIR             install binaries in DIR [PREFIX/bin]
  --datadir=DIR            install data files in DIR [PREFIX/share/ffmpeg]
  --docdir=DIR             install documentation in DIR [PREFIX/share/doc/ffmpeg]
  --libdir=DIR             install libs in DIR [PREFIX/lib]
  --shlibdir=DIR           install shared libs in DIR [LIBDIR]
  --incdir=DIR             install includes in DIR [PREFIX/include]
  --mandir=DIR             install man page in DIR [PREFIX/share/man]
  --pkgconfigdir=DIR       install pkg-config files in DIR [LIBDIR/pkgconfig]
  --enable-rpath           use rpath to allow installing libraries in paths
                           not part of the dynamic linker search path
                           use rpath when linking programs [USE WITH CARE]
  --install-name-dir=DIR   Darwin directory name for installed targets

Licensing options:
  --enable-gpl             allow use of GPL code, the resulting libs
                           and binaries will be under GPL [no]
  --enable-version3        upgrade (L)GPL to version 3 [no]
  --enable-nonfree         allow use of nonfree code, the resulting libs
                           and binaries will be unredistributable [no]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-small           optimize for size instead of speed
  --disable-runtime-cpudetect disable detecting cpu capabilities at runtime (smaller binary)
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale
  --disable-all            disable building components, libraries and programs
  --enable-raise-major     increase major version numbers in sonames [no]

Program options:
  --disable-programs       do not build command line programs
  --disable-ffmpeg         disable ffmpeg build
  --disable-ffplay         disable ffplay build
  --disable-ffprobe        disable ffprobe build
  --disable-ffserver       disable ffserver build

Documentation options:
  --disable-doc            do not build documentation
  --disable-htmlpages      do not build HTML documentation pages
  --disable-manpages       do not build man documentation pages
  --disable-podpages       do not build POD documentation pages
  --disable-txtpages       do not build text documentation pages

Component options:
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-swresample     disable libswresample build
  --disable-swscale        disable libswscale build
  --disable-postproc       disable libpostproc build
  --disable-avfilter       disable libavfilter build
  --enable-avresample      enable libavresample build [no]
  --disable-pthreads       disable pthreads [autodetect]
  --disable-w32threads     disable Win32 threads [autodetect]
  --disable-os2threads     disable OS/2 threads [autodetect]
  --disable-network        disable network support [no]
  --disable-dct            disable DCT code
  --disable-dwt            disable DWT code
  --disable-error-resilience disable error resilience code
  --disable-lsp            disable LSP code
  --disable-lzo            disable LZO decoder code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-fft            disable FFT code
  --disable-faan           disable floating point AAN (I)DCT code
  --disable-pixelutils     disable pixel utils in libavutil

Individual component options:
  --disable-everything     disable all components listed below
  --disable-encoder=NAME   disable encoder NAME
  --enable-encoder=NAME    enable encoder NAME
  --disable-encoders       disable all encoders
  --disable-decoder=NAME   disable decoder NAME
  --enable-decoder=NAME    enable decoder NAME
  --disable-decoders       disable all decoders
  --disable-hwaccel=NAME   disable hwaccel NAME
  --enable-hwaccel=NAME    enable hwaccel NAME
  --disable-hwaccels       disable all hwaccels
  --disable-muxer=NAME     disable muxer NAME
  --enable-muxer=NAME      enable muxer NAME
  --disable-muxers         disable all muxers
  --disable-demuxer=NAME   disable demuxer NAME
  --enable-demuxer=NAME    enable demuxer NAME
  --disable-demuxers       disable all demuxers
  --enable-parser=NAME     enable parser NAME
  --disable-parser=NAME    disable parser NAME
  --disable-parsers        disable all parsers
  --enable-bsf=NAME        enable bitstream filter NAME
  --disable-bsf=NAME       disable bitstream filter NAME
  --disable-bsfs           disable all bitstream filters
  --enable-protocol=NAME   enable protocol NAME
  --disable-protocol=NAME  disable protocol NAME
  --disable-protocols      disable all protocols
  --enable-indev=NAME      enable input device NAME
  --disable-indev=NAME     disable input device NAME
  --disable-indevs         disable input devices
  --enable-outdev=NAME     enable output device NAME
  --disable-outdev=NAME    disable output device NAME
  --disable-outdevs        disable output devices
  --disable-devices        disable all devices
  --enable-filter=NAME     enable filter NAME
  --disable-filter=NAME    disable filter NAME
  --disable-filters        disable all filters

External library support:

  Using any of the following switches will allow FFmpeg to link to the
  corresponding external library. All the components depending on that library
  will become enabled, if all their other dependencies are met and they are not
  explicitly disabled. E.g. --enable-libwavpack will enable linking to
  libwavpack and allow the libwavpack encoder to be built, unless it is
  specifically disabled with --disable-encoder=libwavpack.

  Note that only the system libraries are auto-detected. All the other external
  libraries must be explicitly enabled.

  Also note that the following help text describes the purpose of the libraries
  themselves, not all their features will necessarily be usable by FFmpeg.

  --enable-avisynth        enable reading of AviSynth script files [no]
  --disable-bzlib          disable bzlib [autodetect]
  --enable-chromaprint     enable audio fingerprinting with chromaprint [no]
  --enable-frei0r          enable frei0r video filtering [no]
  --enable-gcrypt          enable gcrypt, needed for rtmp(t)e support
                           if openssl, librtmp or gmp is not used [no]
  --enable-gmp             enable gmp, needed for rtmp(t)e support
                           if openssl or librtmp is not used [no]
  --enable-gnutls          enable gnutls, needed for https support
                           if openssl is not used [no]
  --disable-iconv          disable iconv [autodetect]
  --enable-jni             enable JNI support [no]
  --enable-ladspa          enable LADSPA audio filtering [no]
  --enable-libass          enable libass subtitles rendering,
                           needed for subtitles and ass filter [no]
  --enable-libbluray       enable BluRay reading using libbluray [no]
  --enable-libbs2b         enable bs2b DSP library [no]
  --enable-libcaca         enable textual display using libcaca [no]
  --enable-libcelt         enable CELT decoding via libcelt [no]
  --enable-libcdio         enable audio CD grabbing with libcdio [no]
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libebur128      enable libebur128 for EBU R128 measurement,
                           needed for loudnorm filter [no]
  --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
  --enable-libflite        enable flite (voice synthesis) support via libflite [no]
  --enable-libfontconfig   enable libfontconfig, useful for drawtext filter [no]
  --enable-libfreetype     enable libfreetype, needed for drawtext filter [no]
  --enable-libfribidi      enable libfribidi, improves drawtext filter [no]
  --enable-libgme          enable Game Music Emu via libgme [no]
  --enable-libgsm          enable GSM de/encoding via libgsm [no]
  --enable-libiec61883     enable iec61883 via libiec61883 [no]
  --enable-libilbc         enable iLBC de/encoding via libilbc [no]
  --enable-libkvazaar      enable HEVC encoding via libkvazaar [no]
  --enable-libmodplug      enable ModPlug via libmodplug [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libnut          enable NUT (de)muxing via libnut,
                           native (de)muxer exists [no]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libopencv       enable video filtering via libopencv [no]
  --enable-libopenh264     enable H.264 encoding via OpenH264 [no]
  --enable-libopenjpeg     enable JPEG 2000 de/encoding via OpenJPEG [no]
  --enable-libopenmpt      enable decoding tracked files via libopenmpt [no]
  --enable-libopus         enable Opus de/encoding via libopus [no]
  --enable-libpulse        enable Pulseaudio input via libpulse [no]
  --enable-librubberband   enable rubberband needed for rubberband filter [no]
  --enable-librtmp         enable RTMP[E] support via librtmp [no]
  --enable-libschroedinger enable Dirac de/encoding via libschroedinger [no]
  --enable-libshine        enable fixed-point MP3 encoding via libshine [no]
  --enable-libsmbclient    enable Samba protocol via libsmbclient [no]
  --enable-libsnappy       enable Snappy compression, needed for hap encoding [no]
  --enable-libsoxr         enable Include libsoxr resampling [no]
  --enable-libspeex        enable Speex de/encoding via libspeex [no]
  --enable-libssh          enable SFTP protocol via libssh [no]
  --enable-libtesseract    enable Tesseract, needed for ocr filter [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libtwolame      enable MP2 encoding via libtwolame [no]
  --enable-libv4l2         enable libv4l2/v4l-utils [no]
  --enable-libvidstab      enable video stabilization using vid.stab [no]
  --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
  --enable-libvorbis       enable Vorbis en/decoding via libvorbis,
                           native implementation exists [no]
  --enable-libvpx          enable VP8 and VP9 de/encoding via libvpx [no]
  --enable-libwavpack      enable wavpack encoding via libwavpack [no]
  --enable-libwebp         enable WebP encoding via libwebp [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libx265         enable HEVC encoding via x265 [no]
  --enable-libxavs         enable AVS encoding via xavs [no]
  --enable-libxcb          enable X11 grabbing using XCB [autodetect]
  --enable-libxcb-shm      enable X11 grabbing shm communication [autodetect]
  --enable-libxcb-xfixes   enable X11 grabbing mouse rendering [autodetect]
  --enable-libxcb-shape    enable X11 grabbing shape rendering [autodetect]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-libzimg         enable z.lib, needed for zscale filter [no]
  --enable-libzmq          enable message passing via libzmq [no]
  --enable-libzvbi         enable teletext support via libzvbi [no]
  --disable-lzma           disable lzma [autodetect]
  --enable-decklink        enable Blackmagic DeckLink I/O support [no]
  --enable-mediacodec      enable Android MediaCodec support [no]
  --enable-netcdf          enable NetCDF, needed for sofalizer filter [no]
  --enable-openal          enable OpenAL 1.1 capture support [no]
  --enable-opencl          enable OpenCL code
  --enable-opengl          enable OpenGL rendering [no]
  --enable-openssl         enable openssl, needed for https support
                           if gnutls is not used [no]
  --disable-schannel       disable SChannel SSP, needed for TLS support on
                           Windows if openssl and gnutls are not used [autodetect]
  --disable-sdl2           disable sdl2 [autodetect]
  --disable-securetransport disable Secure Transport, needed for TLS support
                           on OSX if openssl and gnutls are not used [autodetect]
  --enable-x11grab         enable X11 grabbing (legacy) [no]
  --disable-xlib           disable xlib [autodetect]
  --disable-zlib           disable zlib [autodetect]

  The following libraries provide various hardware acceleration features:
  --disable-audiotoolbox   disable Apple AudioToolbox code [autodetect]
  --enable-cuda            enable dynamically linked Nvidia CUDA code [no]
  --enable-cuvid           enable Nvidia CUVID support [autodetect]
  --disable-d3d11va        disable Microsoft Direct3D 11 video acceleration code [autodetect]
  --disable-dxva2          disable Microsoft DirectX 9 video acceleration code [autodetect]
  --enable-libmfx          enable Intel MediaSDK (AKA Quick Sync Video) code via libmfx [no]
  --enable-libnpp          enable Nvidia Performance Primitives-based code [no]
  --enable-mmal            enable Broadcom Multi-Media Abstraction Layer (Raspberry Pi) via MMAL [no]
  --disable-nvenc          disable Nvidia video encoding code [autodetect]
  --enable-omx             enable OpenMAX IL code [no]
  --enable-omx-rpi         enable OpenMAX IL code for Raspberry Pi [no]
  --disable-vaapi          disable Video Acceleration API (mainly Unix/Intel) code [autodetect]
  --disable-vda            disable Apple Video Decode Acceleration code [autodetect]
  --disable-vdpau          disable Nvidia Video Decode and Presentation API for Unix code [autodetect]
  --disable-videotoolbox   disable VideoToolbox code [autodetect]

Toolchain options:
  --arch=ARCH              select architecture []
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --cross-prefix=PREFIX    use PREFIX for compilation tools []
  --progs-suffix=SUFFIX    program name suffix []
  --enable-cross-compile   assume a cross-compiler is used
  --sysroot=PATH           root of cross-build tree
  --sysinclude=PATH        location of cross-build system headers
  --target-os=OS           compiler targets OS []
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --target-samples=DIR     path to samples directory on target
  --tempprefix=PATH        force fixed dir/prefix instead of mktemp for checks
  --toolchain=NAME         set tool defaults according to NAME
  --nm=NM                  use nm tool NM [nm -g]
  --ar=AR                  use archive tool AR [ar]
  --as=AS                  use assembler AS []
  --ln_s=LN_S              use symbolic link tool LN_S [ln -s -f]
  --strip=STRIP            use strip tool STRIP [strip]
  --windres=WINDRES        use windows resource compiler WINDRES [windres]
  --yasmexe=EXE            use yasm-compatible assembler EXE [yasm]
  --cc=CC                  use C compiler CC [gcc]
  --cxx=CXX                use C compiler CXX [g++]
  --objcc=OCC              use ObjC compiler OCC [gcc]
  --dep-cc=DEPCC           use dependency generator DEPCC [gcc]
  --ld=LD                  use linker LD []
  --pkg-config=PKGCONFIG   use pkg-config tool PKGCONFIG [pkg-config]
  --pkg-config-flags=FLAGS pass additional flags to pkgconf []
  --ranlib=RANLIB          use ranlib RANLIB [ranlib]
  --doxygen=DOXYGEN        use DOXYGEN to generate API doc [doxygen]
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host
  --host-ld=HOSTLD         use host linker HOSTLD
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --host-os=OS             compiler host OS []
  --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS []
  --extra-cxxflags=ECFLAGS add ECFLAGS to CXXFLAGS []
  --extra-objcflags=FLAGS  add FLAGS to OBJCFLAGS []
  --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS []
  --extra-ldexeflags=ELDFLAGS add ELDFLAGS to LDEXEFLAGS []
  --extra-ldlibflags=ELDFLAGS add ELDFLAGS to LDLIBFLAGS []
  --extra-libs=ELIBS       add ELIBS []
  --extra-version=STRING   version string suffix []
  --optflags=OPTFLAGS      override optimization-related compiler flags
  --build-suffix=SUFFIX    library name suffix []
  --enable-pic             build position-independent code
  --enable-thumb           compile for Thumb instruction set
  --enable-lto             use link-time optimization
  --env="ENV=override"     override the environment variables

Advanced options (experts only):
  --malloc-prefix=PREFIX   prefix malloc and related names with PREFIX
  --custom-allocator=NAME  use a supported custom allocator
  --disable-symver         disable symbol versioning
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --disable-safe-bitstream-reader
                           disable buffer boundary checking in bitreaders
                           (faster, but may crash)
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers
  --sws-max-filter-size=N  the max filter size swscale uses [256]

Optimization options (experts only):
  --disable-asm            disable all assembly optimizations
  --disable-altivec        disable AltiVec optimizations
  --disable-vsx            disable VSX optimizations
  --disable-power8         disable POWER8 optimizations
  --disable-amd3dnow       disable 3DNow! optimizations
  --disable-amd3dnowext    disable 3DNow! extended optimizations
  --disable-mmx            disable MMX optimizations
  --disable-mmxext         disable MMXEXT optimizations
  --disable-sse            disable SSE optimizations
  --disable-sse2           disable SSE2 optimizations
  --disable-sse3           disable SSE3 optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-sse4           disable SSE4 optimizations
  --disable-sse42          disable SSE4.2 optimizations
  --disable-avx            disable AVX optimizations
  --disable-xop            disable XOP optimizations
  --disable-fma3           disable FMA3 optimizations
  --disable-fma4           disable FMA4 optimizations
  --disable-avx2           disable AVX2 optimizations
  --disable-aesni          disable AESNI optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-vfp            disable VFP optimizations
  --disable-neon           disable NEON optimizations
  --disable-inline-asm     disable use of inline assembly
  --disable-yasm           disable use of nasm/yasm assembly
  --disable-mipsdsp        disable MIPS DSP ASE R1 optimizations
  --disable-mipsdspr2      disable MIPS DSP ASE R2 optimizations
  --disable-msa            disable MSA optimizations
  --disable-mipsfpu        disable floating point MIPS optimizations
  --disable-mmi            disable Loongson SIMD optimizations
  --disable-fast-unaligned consider unaligned accesses slow

Developer options (useful when working on FFmpeg itself):
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level []
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --disable-stripping      disable stripping of executables and shared libraries
  --assert-level=level     0(default), 1 or 2, amount of assertion testing,
                           2 causes a slowdown at runtime.
  --enable-memory-poisoning fill heap uninitialized allocated space with arbitrary data
  --valgrind=VALGRIND      run "make fate" tests through valgrind to detect memory
                           leaks and errors, using the specified valgrind binary.
                           Cannot be combined with --target-exec
  --enable-ftrapv          Trap arithmetic overflows
  --samples=PATH           location of test samples for FATE, if not set use
                           $FATE_SAMPLES at make invocation time.
  --enable-neon-clobber-test check NEON registers for clobbering (should be
                           used only for debugging purposes)
  --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                           should be used only for debugging purposes)
  --enable-random          randomly enable/disable components
  --disable-random
  --enable-random=LIST     randomly enable/disable specific components or
  --disable-random=LIST    component groups. LIST is a comma-separated list
                           of NAME[:PROB] entries where NAME is a component
                           (group) and PROB the probability associated with
                           NAME (default 0.5).
  --random-seed=VALUE      seed value for --enable/disable-random
  --disable-valgrind-backtrace do not print a backtrace under Valgrind
                           (only applies to --disable-optimizations builds)

NOTE: Object files are built at the place where configure is launched.

初次編譯FFmpeg,我們先不要關心那麼多配置選項,這裏只設置一個選項,即–prefix,它指定我們編譯後的結果,包括庫文件和可執行程序以及頭文件等放置到的路徑。

./configure --prefix=/home/ffmpeg/work/ffmpeg-3.2.4/out

如果配置遇到如下錯誤,

ffmpeg@ubuntu:~/work/ffmpeg-3.2.4$ ./configure 
yasm/nasm not found or too old. Use --disable-yasm for a crippled build.

則表示缺少yasm包,可以通過–disable-yasm選項關閉或者安裝此包,我們這裏選擇安裝,

ffmpeg@ubuntu:~/work/ffmpeg-3.2.4$ sudo apt-get install yasm
ffmpeg@ubuntu:~/work/ffmpeg-3.2.4$ sudo apt-get install nasm

configure完成後,執行make進行編譯,如果想多線程編譯可以嘗試make -jN,其中N爲多線程數量(過多併發可能會編譯報錯),最後執行make install,將編譯結果拷貝到out目錄下。

make
make install

最後在out目錄下生成的結果如下,

編譯結果

其中,
bin目錄ffmpeg,ffprobe和ffserver是三個可執行程序,可以直接運行;
include下是FFmpeg的頭文件;
lib下是FFmpeg的所有靜態庫,如果想編譯爲動態庫的形式,可以修改configure的配置選項,這個後期我們再介紹。

測試FFmpeg

接下來,我們可以用ffprobe來做一個測試,比如解析一個媒體文件(自己準備哦,這裏採用的是Android CTS測試的一個碼流,bbb_short.ffmpeg.1280x720.mp4.libx264_5000kbps_30fps.libfaac_stereo_192kbps_48000Hz,也可以到這裏下載:http://pan.baidu.com/s/1mieAJFy,),將其音視頻信息打印出來,

ffprobe

bin目錄下的ffmpeg也是一個可執行程序,功能十分強大,可以通過命令行進行轉碼,格式轉換等操作,我們可以通過help命令來查看它的信息,詳細功能本文暫不做介紹。

cd /out/bin
./ffmpeg --help

現在,我們已經順利的完成了FFmpeg編譯和測試了。看起來,初次邂逅FFmpeg顯得十分順利和簡單,這極大的增強了小工繼續深入研究FFmpeg的信心,^_^ 。

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