我正在尝试使用 ffmpeg 来确定整体媒体音量。我只使用一次传递：
ffmpeg -i C:\Users\User\Desktop\test.mp4 -af Loudnorm=I=-23:tp=-1:LRA=15:print_format=json -f null -
出去：
C:\Users\User\Desktop\ffmpeg-4.2.1-win64-static\bin>ffmpeg -i C:\Users\User\Desktop\test.mp4 -af loudnorm=I=-23:tp=-1:LRA=15:print_format=json -f null -
ffmpeg version 4.2.1 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 9.1.1 (GCC) 20190807
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --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 --enable-libopenmpt
libavutil 56. 31.100 / 56. 31.100
libavcodec 58. 54.100 / 58. 54.100
libavformat 58. 29.100 / 58. 29.100
libavdevice 58. 8.100 / 58. 8.100
libavfilter 7. 57.100 / 7. 57.100
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Guessed Channel Layout for Input Stream #0.1 : stereo
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'C:\Users\User\Desktop\test.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
creation_time : 2019-01-31T07:52:41.000000Z
encoder : Lavf57.57.100
Duration: 00:00:11.00, start: 0.000000, bitrate: 10459 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 720x576 [SAR 16:15 DAR 4:3], 8918 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
Metadata:
creation_time : 2019-01-31T07:52:41.000000Z
handler_name : VideoHandler
timecode : 00:00:00:00
Stream #0:1(und): Audio: pcm_s16be (twos / 0x736F7774), 48000 Hz, stereo, s16, 1536 kb/s (default)
Metadata:
creation_time : 2019-01-31T07:52:41.000000Z
handler_name : SoundHandler
Stream #0:2(eng): Data: none (tmcd / 0x64636D74), 0 kb/s
Metadata:
creation_time : 2019-01-31T07:52:41.000000Z
handler_name : TimeCodeHandler
timecode : 00:00:00:00
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> wrapped_avframe (native))
Stream #0:1 -> #0:1 (pcm_s16be (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Output #0, null, to 'pipe:':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Stream #0:0(und): Video: wrapped_avframe, yuv420p, 720x576 [SAR 16:15 DAR 4:3], q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc (default)
Metadata:
creation_time : 2019-01-31T07:52:41.000000Z
handler_name : VideoHandler
timecode : 00:00:00:00
encoder : Lavc58.54.100 wrapped_avframe
Stream #0:1(und): Audio: pcm_s16le, 192000 Hz, stereo, s16, 6144 kb/s (default)
Metadata:
creation_time : 2019-01-31T07:52:41.000000Z
handler_name : SoundHandler
encoder : Lavc58.54.100 pcm_s16le
[null @ 00000191eeeb7740] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 274 >= 274
frame= 275 fps=0.0 q=-0.0 Lsize=N/A time=00:00:11.04 bitrate=N/A speed=15.8x
video:144kB audio:8250kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[Parsed_loudnorm_0 @ 00000191eee03500]
{
"input_i" : "-22.39",
"input_tp" : "-11.87",
"input_lra" : "5.20",
"input_thresh" : "-32.54",
"output_i" : "-21.67",
"output_tp" : "-10.61",
"output_lra" : "4.90",
"output_thresh" : "-31.82",
"normalization_type" : "dynamic",
"target_offset" : "-1.33"
}
在短媒体（少于 30 秒）上，ffmpeg 的结果开始与 Adobe Premier Pro 或 Orban 中的类似检查出现显著差异。 在奥尔班检查此文件时。 在 Adobe Premier Pro 中检查此文件时。
为什么会发生这种情况？在这种情况下哪些数据更准确？
答案1
Loudnorm 滤波器可为包含在EBU 响度测试仪. 与其他应用程序中的仪表进行比较。