好吧，我只是尝试按照http://mikebrinkerink.com/2018/04/05/preparing-a-video-with-alpha-channel-for-unity/和其他教程在Unity和Im中播放透明视频。
我尝试使用alpha和Webm VP8导出为ProRes 444，并使用终端ffmpeg命令。但是，当我将视频放到Unity中时，它会无限期加载，因此我不得不强行退出。
我的文件是这样的：https://drive.google.com/file/d/1RhOvYfeaK1rEaKdlTNcJB9EBpz4xxjvw/view?usp=sharing
我下载的这个文件运行良好：https://simpl.info/videoalpha/video/dancer1.webm
有什么区别/如何让我工作？
日志：
ffmpeg -i my_clip_with_alpha.avi -vcodec vp8 -acodec libvorbis -pix_fmt yuva420p -metadata:s:v:0 alpha_mode=”1″ -auto-alt-ref 0 my_vp8_clip_with_alpha.webm
作为命令（带有我的剪辑名称）
然后
built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/openjdk-11.0.2.jdk/Contents/Home/include/darwin' --host-ldflags= --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libbluray --enable-libmp3lame --enable-libopus --enable-librubberband --enable-libsnappy --enable-libtesseract --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-librtmp --enable-libspeex --enable-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
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, mov,mp4,m4a,3gp,3g2,mj2, from '/Users/skylarthomas/Desktop/INSTRUCTIONS1_00000.mov':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
creation_time : 2019-03-27T00:19:30.000000Z
Duration: 00:00:17.05, start: 0.000000, bitrate: 40959 kb/s
Stream #0:0(eng): Video: prores (ap4h / 0x68347061), yuva444p10le(tv, bt709, progressive), 2215x1773, 40467 kb/s, SAR 1:1 DAR 2215:1773, 29.97 fps, 29.97 tbr, 30k tbn, 30k tbc (default)
Metadata:
creation_time : 2019-03-27T00:19:30.000000Z
handler_name : Apple Video Media Handler
encoder : Apple ProRes 4444
timecode : 00:00:00:00
Stream #0:1(eng): Data: none (tmcd / 0x64636D74), 0 kb/s (default)
Metadata:
creation_time : 2019-03-27T00:19:30.000000Z
handler_name : Time Code Media Handler
timecode : 00:00:00:00
Stream mapping:
Stream #0:0 -> #0:0 (prores (native) -> vp8 (libvpx))
Press [q] to stop, [?] for help
[libvpx @ 0x7fe11701d600] v1.8.0
Output #0, webm, to 'my_vp8_clip_with_alpha.webm':
Metadata:
major_brand : qt
minor_version : 537199360
compatible_brands: qt
encoder : Lavf58.20.100
Stream #0:0(eng): Video: vp8 (libvpx), yuva420p, 2215x1773 [SAR 1:1 DAR 2215:1773], q=-1--1, 200 kb/s, 29.97 fps, 1k tbn, 29.97 tbc (default)
Metadata:
creation_time : 2019-03-27T00:19:30.000000Z
handler_name : Apple Video Media Handler
timecode : 00:00:00:00
alpha_mode : ”1″
encoder : Lavc58.35.100 libvpx
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
frame= 2 fps=2.0 q=0.0 size= 1kB time=00:00:00.03 bitrate= 200.7kbits/sframe= 6 fps=3.7 q=0.0 size= 1kB time=00:00:00.16 bitrate= 40.6kbits/sframe= 10 fps=4.5 q=0.0 size= 1kB time=00:00:00.30 bitrate= 22.7kbits/s speedframe= 35 fps=2.9 q=0.0 size= 1kB time=00:00:01.13 bitrate= 6.0kbits/s speed=0.0934x