我们正在使用Unity生产用于VR耳机的360视频播放器。我们正在努力实现空间音频。最简单的情况是视频和音频位于单独的文件中，但是现在我们决定也支持带有嵌入式音频的视频。我需要在加载视频之前知道音频是否模棱两可。我正在寻找一种简单的方法来确定音频是否模棱两可，以便将其从视频中分离出来并转换为.tbe文件，目前我们的应用程序支持该文件。
我正在尝试使用ffmpeg：
$./ffmpeg.exe -i ~/Videos/video.mp4
并得到：
ffmpeg version 4.1.3 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 8.3.1 (GCC) 20190414
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --enable-libmfx --enable-amf --enable-ffnvcodec --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
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
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 'C:/Users/Medion/Videos/video.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf57.56.101
Duration: 00:11:39.40, start: 0.000000, bitrate: 17290 kb/s
Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 3840x2160 [SAR 1:1 DAR 16:9], 16497 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
handler_name : VideoHandler
Side data:
stereo3d: top and bottom
spherical: equirectangular (0.000000/0.000000/0.000000)
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 4.0, fltp, 778 kb/s (default)
Metadata:
handler_name : SoundHandler
Stream #0:2(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 4.0, fltp, 4 kb/s
Metadata:
handler_name : SoundHandler
Stream #0:3(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 2 kb/s
Metadata:
handler_name : SoundHandler
At least one output file must be specified
但是我看不到任何行可以表明音频是模棱两可的。我看到流＃0：1和＃0：2中有4个频道，但我敢打赌这还不够。
我也尝试过MediaInfo，但这是同一件事：
General
CompleteName : C:\Users\Medion\Videos\video.mp4
Format/String : MPEG-4
Format_Profile : Base Media
CodecID/String : isom (isom/iso2/avc1/mp41)
FileSize/String : 1.41 GiB
Duration/String : 11 min 39 s
OverallBitRate_Mode/String : Variable
OverallBitRate/String : 17.3 Mb/s
Encoded_Application/String : Lavf57.56.101
Video
ID/String : 1
Format/String : AVC
Format/Info : Advanced Video Codec
Format_Profile : High@L5.2
Format_Settings : CABAC / 3 Ref Frames
Format_Settings_CABAC/String : Yes
Format_Settings_RefFrames/String : 3 frames
Format_Settings_GOP : M=3, N=29
CodecID : avc1
CodecID/Info : Advanced Video Coding
Duration/String : 11 min 39 s
BitRate_Mode/String : Variable
BitRate/String : 16.5 Mb/s
BitRate_Maximum/String : 20.0 Mb/s
Width/String : 3 840 pixels
Height/String : 2 160 pixels
DisplayAspectRatio/String : 16:9
FrameRate_Mode/String : Constant
FrameRate/String : 29.970 (30000/1001) FPS
Standard : NTSC
ColorSpace : YUV
ChromaSubsampling/String : 4:2:0
BitDepth/String : 8 bits
ScanType/String : Progressive
Bits-(Pixel*Frame) : 0.066
StreamSize/String : 1.34 GiB (95%)
Language/String : English
Tagged_Date : UTC 2017-06-13 17:37:51
colour_range : Limited
colour_primaries : BT.709
transfer_characteristics : BT.709
matrix_coefficients : BT.709
Codec configuration box : avcC
Audio #1
ID/String : 2
Format/String : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
CodecID : mp4a-40-2
Duration/String : 11 min 39 s
Source_Duration/String : 11 min 39 s
BitRate_Mode/String : Constant
BitRate/String : 779 kb/s
Channel(s)/String : 4 channels
ChannelLayout : C L R Cb
SamplingRate/String : 48.0 kHz
FrameRate/String : 46.875 FPS (1024 SPF)
Compression_Mode/String : Lossy
StreamSize/String : 64.9 MiB (5%)
Source_StreamSize/String : 64.9 MiB (5%)
Default/String : Yes
AlternateGroup/String : 1
Tagged_Date : UTC 2017-06-13 17:37:51
Audio #2
ID/String : 3
Format/String : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
CodecID : mp4a-40-2
Duration/String : 11 min 39 s
Source_Duration/String : 11 min 39 s
BitRate_Mode/String : Variable
BitRate/String : 4 900 b/s
BitRate_Maximum/String : 266 kb/s
Channel(s)/String : 4 channels
ChannelLayout : C L R Cb
SamplingRate/String : 48.0 kHz
FrameRate/String : 46.875 FPS (1024 SPF)
Compression_Mode/String : Lossy
StreamSize/String : 418 KiB (0%)
Source_StreamSize/String : 418 KiB (0%)
Default/String : No
AlternateGroup/String : 1
Tagged_Date : UTC 2017-06-13 17:37:51
Audio #3
ID/String : 4
Format/String : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
CodecID : mp4a-40-2
Duration/String : 11 min 39 s
Source_Duration/String : 11 min 39 s
BitRate_Mode/String : Variable
BitRate/String : 2 275 b/s
BitRate_Maximum/String : 128 kb/s
Channel(s)/String : 2 channels
ChannelLayout : L R
SamplingRate/String : 48.0 kHz
FrameRate/String : 46.875 FPS (1024 SPF)
Compression_Mode/String : Lossy
StreamSize/String : 194 KiB (0%)
Source_StreamSize/String : 194 KiB (0%)
Default/String : No
AlternateGroup/String : 1
Tagged_Date : UTC 2017-06-13 17:37:51
我假设我不知道在这些输出中查找什么。 预先感谢。
答案 0 :(得分：1)
MediaInfo development snapshots（迷你2190520-2）现在支持Spatial Audio RFC (draft)元数据（此类元数据在您作为示例提供的文件中），并通过以下方式显示信息：
Channel layout : Ambisonics (W X Y Z)