FFMPEG - 如何在不生成不需要的元数据的情况下传输 RMS_level 和 pts_time 元数据
FFMPEG - How to pipe RMS_level and pts_time metadata without generating unwanted metadata
我试图在音频文件中找到最响亮（最高 rms_level）的时刻，但我需要通过管道传输元数据而不是写入文件。
我转换了在这里找到的答案：[https://superuser.com/questions/1183663/determining-audio-level-peaks-with-ffmpeg][1]
通过删除写入文件命令并添加管道。
这就是我所拥有的。
ffmpeg -i loudSoft.mp3 -af astats=metadata=1:reset=1,ametadata=print:key=lavfi.astats.Overall.RMS_level -f null - 2> result.txt
唯一的问题是，现在我在 RMS_level 和 pts_time 数据以及每行打印的 [Parsed_ametadata_1 @ 0x7f9d42c37500] 前后有很多不需要的元数据。 None 当我写入文件而不是管道时正在写入。 （我只需要时间和有效值。）
这是我写入文件时得到的缩略版：
frame:0 pts:0 pts_time:0
lavfi.astats.Overall.RMS_level=-inf
frame:1 pts:47 pts_time:0.00106576
lavfi.astats.Overall.RMS_level=-165.163347
frame:2 pts:1199 pts_time:0.0271882
lavfi.astats.Overall.RMS_level=-99.736394
frame:3 pts:2351 pts_time:0.0533107
lavfi.astats.Overall.RMS_level=-88.112282
frame:4 pts:3503 pts_time:0.0794331
lavfi.astats.Overall.RMS_level=-86.554314
frame:5 pts:4655 pts_time:0.105556
lavfi.astats.Overall.RMS_level=-82.977501
frame:6 pts:5807 pts_time:0.131678
lavfi.astats.Overall.RMS_level=-79.698739
frame:7 pts:6959 pts_time:0.1578
lavfi.astats.Overall.RMS_level=-76.629393
frame:8 pts:8111 pts_time:0.183923
lavfi.astats.Overall.RMS_level=-71.581211
frame:9 pts:9263 pts_time:0.210045
lavfi.astats.Overall.RMS_level=-75.038503
frame:10 pts:10415 pts_time:0.236168
这是我正在查看的内容：
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple clang version 11.0.0 (clang-1100.0.33.16)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_1 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include/darwin -fno-stack-check' --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-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --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-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
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
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mp3, from 'loudSoft2.mp3':
Metadata:
encoder : Lavf58.29.100
Duration: 00:00:09.85, start: 0.025057, bitrate: 128 kb/s
Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
Metadata:
encoder : Lavc58.54
Stream mapping:
Stream #0:0 -> #0:0 (mp3 (mp3float) -> pcm_s16le (native))
Press [q] to stop, [?] for help
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:0 pts:0 pts_time:0
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-inf
Output #0, null, to 'pipe:':
Metadata:
encoder : Lavf58.29.100
Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
Metadata:
encoder : Lavc58.54.100 pcm_s16le
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:1 pts:47 pts_time:0.00106576
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-165.163347
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:2 pts:1199 pts_time:0.0271882
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-99.736394
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:3 pts:2351 pts_time:0.0533107
*** MIDDLE OMITTED FOR BREVITY ***
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.532185
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:375 pts:430895 pts_time:9.77086
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.594276
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:376 pts:432047 pts_time:9.79698
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.654138
size=N/A time=00:00:09.82 bitrate=N/A speed=82.6x
video:0kB audio:1692kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 1
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 2
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Overall
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Number of samples: 1105
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0.000000
ffmpeg 将其消息的 所有 记录到 stderr。通过省略 file 选项，ametadata 过滤器会将其输出发送到记录器，在那里它将与其他日志一起打印。
相反，设置 file=- 并捕获标准输出。
我试图在音频文件中找到最响亮（最高 rms_level）的时刻，但我需要通过管道传输元数据而不是写入文件。
我转换了在这里找到的答案：[https://superuser.com/questions/1183663/determining-audio-level-peaks-with-ffmpeg][1]
通过删除写入文件命令并添加管道。 这就是我所拥有的。
ffmpeg -i loudSoft.mp3 -af astats=metadata=1:reset=1,ametadata=print:key=lavfi.astats.Overall.RMS_level -f null - 2> result.txt
唯一的问题是，现在我在 RMS_level 和 pts_time 数据以及每行打印的 [Parsed_ametadata_1 @ 0x7f9d42c37500] 前后有很多不需要的元数据。 None 当我写入文件而不是管道时正在写入。 （我只需要时间和有效值。）
这是我写入文件时得到的缩略版：
frame:0 pts:0 pts_time:0
lavfi.astats.Overall.RMS_level=-inf
frame:1 pts:47 pts_time:0.00106576
lavfi.astats.Overall.RMS_level=-165.163347
frame:2 pts:1199 pts_time:0.0271882
lavfi.astats.Overall.RMS_level=-99.736394
frame:3 pts:2351 pts_time:0.0533107
lavfi.astats.Overall.RMS_level=-88.112282
frame:4 pts:3503 pts_time:0.0794331
lavfi.astats.Overall.RMS_level=-86.554314
frame:5 pts:4655 pts_time:0.105556
lavfi.astats.Overall.RMS_level=-82.977501
frame:6 pts:5807 pts_time:0.131678
lavfi.astats.Overall.RMS_level=-79.698739
frame:7 pts:6959 pts_time:0.1578
lavfi.astats.Overall.RMS_level=-76.629393
frame:8 pts:8111 pts_time:0.183923
lavfi.astats.Overall.RMS_level=-71.581211
frame:9 pts:9263 pts_time:0.210045
lavfi.astats.Overall.RMS_level=-75.038503
frame:10 pts:10415 pts_time:0.236168
这是我正在查看的内容：
ffmpeg version 4.2.2 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple clang version 11.0.0 (clang-1100.0.33.16)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.2.2_1 --enable-shared --enable-pthreads --enable-version3 --enable-avresample --cc=clang --host-cflags='-I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include -I/Library/Java/JavaVirtualMachines/adoptopenjdk-13.0.1.jdk/Contents/Home/include/darwin -fno-stack-check' --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-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --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-libsoxr --enable-videotoolbox --disable-libjack --disable-indev=jack
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
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mp3, from 'loudSoft2.mp3':
Metadata:
encoder : Lavf58.29.100
Duration: 00:00:09.85, start: 0.025057, bitrate: 128 kb/s
Stream #0:0: Audio: mp3, 44100 Hz, stereo, fltp, 128 kb/s
Metadata:
encoder : Lavc58.54
Stream mapping:
Stream #0:0 -> #0:0 (mp3 (mp3float) -> pcm_s16le (native))
Press [q] to stop, [?] for help
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:0 pts:0 pts_time:0
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-inf
Output #0, null, to 'pipe:':
Metadata:
encoder : Lavf58.29.100
Stream #0:0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
Metadata:
encoder : Lavc58.54.100 pcm_s16le
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:1 pts:47 pts_time:0.00106576
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-165.163347
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:2 pts:1199 pts_time:0.0271882
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-99.736394
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:3 pts:2351 pts_time:0.0533107
*** MIDDLE OMITTED FOR BREVITY ***
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.532185
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:375 pts:430895 pts_time:9.77086
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.594276
[Parsed_ametadata_1 @ 0x7f9d42c37500] frame:376 pts:432047 pts_time:9.79698
[Parsed_ametadata_1 @ 0x7f9d42c37500] lavfi.astats.Overall.RMS_level=-88.654138
size=N/A time=00:00:09.82 bitrate=N/A speed=82.6x
video:0kB audio:1692kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 1
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Channel: 2
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Crest factor: 3.126627
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Dynamic range: 76.274252
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings: 246
[Parsed_astats_0 @ 0x7f9d42c37280] Zero crossings rate: 0.222624
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0
[Parsed_astats_0 @ 0x7f9d42c37280] Overall
[Parsed_astats_0 @ 0x7f9d42c37280] DC offset: 0.000001
[Parsed_astats_0 @ 0x7f9d42c37280] Min level: -0.000106
[Parsed_astats_0 @ 0x7f9d42c37280] Max level: 0.000115
[Parsed_astats_0 @ 0x7f9d42c37280] Min difference: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Max difference: 0.000077
[Parsed_astats_0 @ 0x7f9d42c37280] Mean difference: 0.000017
[Parsed_astats_0 @ 0x7f9d42c37280] RMS difference: 0.000022
[Parsed_astats_0 @ 0x7f9d42c37280] Peak level dB: -78.752617
[Parsed_astats_0 @ 0x7f9d42c37280] RMS level dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS peak dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] RMS trough dB: -88.654138
[Parsed_astats_0 @ 0x7f9d42c37280] Flat factor: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Peak count: 2.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Bit depth: 32/32
[Parsed_astats_0 @ 0x7f9d42c37280] Number of samples: 1105
[Parsed_astats_0 @ 0x7f9d42c37280] Number of NaNs: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Number of Infs: 0.000000
[Parsed_astats_0 @ 0x7f9d42c37280] Number of denormals: 0.000000
ffmpeg 将其消息的 所有 记录到 stderr。通过省略 file 选项，ametadata 过滤器会将其输出发送到记录器，在那里它将与其他日志一起打印。
相反，设置 file=- 并捕获标准输出。