Ffmpeg 将特定（看似有效）GIF转换为mp4时图像高度无效

我在互联网上遇到了一个奇怪的GIF文件，ffmpeg似乎不喜欢它。尝试运行以下命令：

curl http://images6.fanpop.com/image/photos/34300000/Klaus-The-Originals-klaus-34349255-120-113.gif > input.gif
ffmpeg -y -i input.gif -movflags faststart -pix_fmt yuv420p -vf "scale=trunc(iw/2)*2:trunc(ih/2)*2" output.mp4

我使用ffmpeg版本3.4.6和4.1.3获得以下输出：

ffmpeg version 4.1.3-0ubuntu1 Copyright (c) 2000-2019 the FFmpeg developers
  built with gcc 8 (Ubuntu 8.3.0-6ubuntu1)
  configuration: --prefix=/usr --extra-version=0ubuntu1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
Input #0, gif, from 'a.gif':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: gif, bgra, 120x113, 5 fps, 5 tbr, 100 tbn, 100 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (gif (native) -> h264 (libx264))
Press [q] to stop, [?] for help
[libx264 @ 0x5613f5420c80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x5613f5420c80] profile High, level 1.0
[libx264 @ 0x5613f5420c80] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=3 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=5 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to 'o.mp4':
  Metadata:
    encoder         : Lavf58.20.100
    Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 120x112, q=-1--1, 5 fps, 10240 tbn, 5 tbc
    Metadata:
      encoder         : Lavc58.35.100 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[gif @ 0x5613f540edc0] Invalid image height.
Error while decoding stream #0:0: Invalid data found when processing input
[mp4 @ 0x5613f541f380] Starting second pass: moving the moov atom to the beginning of the file
frame=    1 fps=0.0 q=23.0 Lsize=       3kB time=00:00:00.00 bitrate=253795.9kbits/s speed=0.0245x    
video:2kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 34.588745%
[libx264 @ 0x5613f5420c80] frame I:1     Avg QP:21.16  size:  1622
[libx264 @ 0x5613f5420c80] mb I  I16..4: 14.3% 42.9% 42.9%
[libx264 @ 0x5613f5420c80] 8x8 transform intra:42.9%
[libx264 @ 0x5613f5420c80] coded y,uvDC,uvAC intra: 67.9% 41.1% 33.9%
[libx264 @ 0x5613f5420c80] i16 v,h,dc,p: 25% 38% 25% 12%
[libx264 @ 0x5613f5420c80] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu:  8% 58% 18%  2%  3%  3%  1%  4%  2%
[libx264 @ 0x5613f5420c80] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 23% 29% 15%  7%  7%  6%  5%  4%  3%
[libx264 @ 0x5613f5420c80] i8c dc,h,v,p: 77%  5% 16%  2%
[libx264 @ 0x5613f5420c80] kb/s:64.88
Conversion failed!

我是ffmpeg的新手，但据我所知，

-vf“scale=trunc（iw/2）*2:trunc（ih/2）*2”

缩放图像，使其高度和宽度为偶数（mp4文件格式所需），以防止发生此类错误

---

这看起来非常类似于trac.ffmpeg.org上的补丁，它显然已经被修复。

事实证明，尽管它在不久前已经修复，但该补丁只在版本

4.2

中发布。安装最新版本有几个选项：使用PPA、下载

ffmpeg

，或编译它

PPAs 要在Ubuntu19.04上安装4.2版，我遵循以下步骤：

现在它可以很好地处理GIF。对于Ubuntu18.04，为我工作：

sudo add-apt-repository ppa:jonathonf/ffmpeg-4
sudo apt-get update
sudo apt-get install ffmpeg

下载已编译的ffmpeg 或者，您可以选择已编译的。如果您想将其放在

路径中，请将其放在
~/bin
或
/usr/local/bin

编译ffmpeg
或者，您也可以按照一步一步的指南进行操作

sudo add-apt-repository ppa:jonathonf/ffmpeg-4
sudo apt-get update
sudo apt-get install ffmpeg