我正在对视频文件进行转码，其中包含2条音轨--波兰语和英语。不幸的是，我的转码器在元数据方面出了问题，在输出时，当我用MediaInfo检查视频文件时，我看到两个音轨都被描述为英语。我想把第一条音轨的描述改成波兰语，所以按照ffmpeg文档的规定。
To set the language of the first audio stream:
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
不幸的是，运行命令：
ffmpeg -i INPUTPATH -metadata:s:a:0 language=pol OUTPUTPATH
覆盖输入文件的结果是保存了一个大小为63KB的文件，但它被描述为波兰语音频（没有第二条音轨--英语音轨不知为何被删除了）。
当我使用这个命令时，要把输出文件保存为另一个文件，以避免在漏掉什么东西的情况下被覆盖（这是目前的情况），但用参数 -metadata:s:a:4 因为我想也许我从ffmpeg中读取的元数据不正确，导致输出文件保存为800Mb，只有英语（没有波兰语轨道）。
我不知道我应该在这个命令中改变什么才能让它如我所愿地运行--只是将第一个音轨语言的元数据改为波兰语。
这里是完整的 ffmpeg 输出。
C:\Users\user>ffmpeg -i F:\Path\33244813_6000_1_trailer.mp4 -metadata:s:a:4 language=pol F:\Path\testtest.mp4
ffmpeg version N-91931-gb69ea742ab Copyright (c) 2000-2018 the FFmpeg developers
built with gcc 8.2.1 (GCC) 20180813
configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enabl
e-libass --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amr
wb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libtheora --enab
le-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 --e
nable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth
libavutil 56. 19.101 / 56. 19.101
libavcodec 58. 30.100 / 58. 30.100
libavformat 58. 18.100 / 58. 18.100
libavdevice 58. 4.103 / 58. 4.103
libavfilter 7. 29.100 / 7. 29.100
libswscale 5. 2.100 / 5. 2.100
libswresample 3. 2.100 / 3. 2.100
libpostproc 55. 2.100 / 55. 2.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'F:\Path\33244813_6000_1_trailer.mp4':
Metadata:
major_brand : isom
minor_version : 1
compatible_brands: isom
creation_time : 2020-04-22T16:18:04.000000Z
Duration: 00:40:39.12, start: 0.000000, bitrate: 8848 kb/s
Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], Closed C
aptions, 5068 kb/s, 25 fps, 25 tbr, 120k tbn, 50 tbc (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Video
Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1920x1080 [SAR 1:1 DAR 16:9], Closed C
aptions, 1857 kb/s, 25 fps, 25 tbr, 120k tbn, 50 tbc (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Video
Stream #0:2(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 1280x720 [SAR 1:1 DAR 16:9], Closed Ca
ptions, 902 kb/s, 25 fps, 25 tbr, 120k tbn, 50 tbc (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Video
Stream #0:3(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 640x480 [SAR 4:3 DAR 16:9], Closed Cap
tions, 628 kb/s, 25 fps, 25 tbr, 120k tbn, 50 tbc (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Video
Stream #0:4(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 125 kb/s (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Sound
Stream #0:5(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 253 kb/s (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Sound
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Stream #0:5 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 00000012bef91f80] using SAR=1/1
[libx264 @ 00000012bef91f80] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 00000012bef91f80] profile High, level 4.0, 4:2:0, 8-bit
[libx264 @ 00000012bef91f80] 264 - core 157 r2932 303c484 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.vid
eolan.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=34 looka
head_threads=5 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=25 scenecut=40 intra_refresh=0 rc_lookah
ead=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 'F:\Path\testtest.mp4'
:
Metadata:
major_brand : isom
minor_version : 1
compatible_brands: isom
encoder : Lavf58.18.100
Stream #0:0(und): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], q=-1--1, 25 fps,
12800 tbn, 25 tbc (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Video
encoder : Lavc58.30.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 341 kb/s (default)
Metadata:
creation_time : 2020-04-22T16:18:04.000000Z
handler_name : Sound
encoder : Lavc58.30.100 aac
frame=60981 fps= 84 q=-1.0 Lsize= 816313kB time=00:40:39.12 bitrate=2741.7kbits/s dup=3 drop=0 speed=3.36x
video:713292kB audio:101322kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.208512%
[libx264 @ 00000012bef91f80] frame I:769 Avg QP:16.36 size: 46713
[libx264 @ 00000012bef91f80] frame P:37125 Avg QP:19.81 size: 15059
[libx264 @ 00000012bef91f80] frame B:23087 Avg QP:21.11 size: 5866
[libx264 @ 00000012bef91f80] consecutive B-frames: 40.4% 24.0% 10.2% 25.5%
[libx264 @ 00000012bef91f80] mb I I16..4: 40.3% 58.0% 1.7%
[libx264 @ 00000012bef91f80] mb P I16..4: 6.2% 12.5% 0.1% P16..4: 29.8% 3.7% 2.7% 0.0% 0.0% skip:45.0%
[libx264 @ 00000012bef91f80] mb B I16..4: 1.0% 1.7% 0.0% B16..8: 27.9% 1.1% 0.1% direct: 2.0% skip:66.2% L0:49
.4% L1:49.3% BI: 1.3%
[libx264 @ 00000012bef91f80] 8x8 transform intra:65.3% inter:95.1%
[libx264 @ 00000012bef91f80] coded y,uvDC,uvAC intra: 24.7% 39.7% 3.2% inter: 7.0% 14.6% 0.0%
[libx264 @ 00000012bef91f80] i16 v,h,dc,p: 34% 26% 13% 28%
[libx264 @ 00000012bef91f80] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 25% 15% 41% 3% 3% 4% 3% 3% 2%
[libx264 @ 00000012bef91f80] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 32% 25% 20% 3% 6% 5% 4% 3% 2%
[libx264 @ 00000012bef91f80] i8c dc,h,v,p: 58% 19% 20% 3%
[libx264 @ 00000012bef91f80] Weighted P-Frames: Y:0.1% UV:0.0%
[libx264 @ 00000012bef91f80] ref P L0: 72.2% 6.3% 15.8% 5.7% 0.0%
[libx264 @ 00000012bef91f80] ref B L0: 86.6% 11.5% 1.9%
[libx264 @ 00000012bef91f80] ref B L1: 97.6% 2.4%
[libx264 @ 00000012bef91f80] kb/s:2395.53
[aac @ 00000012bef93b00] Qavg: 471.415
你需要一些更多的选项。
ffmpeg -i input.mp4 -map 0 -c copy -metadata:s:a:0 language=pol output.mp4
-map 0 包括所有的流。默认没有 -map 每个类型只包括1个流。参见 FFmpeg Wiki: 地图 的更多内容。-c copy 到 抄写 而不是重新编码。