我正在尝试对《寂静之地》进行编码...我知道确实有强制字幕，但是当尝试将其从 4K（原生）编码为 4K（x265）或 1080（x264）时，强制字幕不会刻录在生成的文件中。
同一命令在刻录另一部电影的强制字幕时效果很好。当我使用 Handbrake 时，它确实刻录了强制字幕。
这是我正在使用的命令：
ffmpeg -y -probesize 2048M -analyzeduration 2048M -forced_subs_only 1 -i ../in/A Quiet Place.mkv -map 0:0 -map 0:1 -map 0:1 -c:v libx264 -preset slower -profile:v high -level 5.1 -crf:v 22 -vf scale=1920:-1 -x264-params ref=5:bframes=5:b_adapt=2:direct=auto:analyse=all:me=umh:merange=24:subme=10:trellis=2:vbv-bufsize=512000:vbv-maxrate=512000:rc-lookahead=60:colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc -c:a:0 aac -ac 6 -c:a:1 ac3 -ac 6 -disposition:a:0 default -disposition:a:1 none ../temp/A Quiet Place - 1080p.mp4
这是我的 mkv 文件：
General
Unique ID : 23590760640855359557197555294735710745 (0x11BF6A4CB436978F1FFA81AF8C2C3A19)
Complete name : ../in/A Quiet Place (2018).mkv
Format : Matroska
Format version : Version 2
File size : 45.1 GiB
Duration : 1 h 30 min
Overall bit rate mode : Variable
Overall bit rate : 71.5 Mb/s
Movie name : A Quiet Place
Encoded date : UTC 2018-08-03 16:35:34
Writing application : MakeMKV v1.12.3 win(x64-release)
Writing library : libmakemkv v1.12.3 (1.3.5/1.4.7) win(x64-release)
Video
ID : 1
ID in the original source medium : 4113 (0x1011)
Format : HEVC
Format/Info : High Efficiency Video Coding
Format profile : Main [email protected]@High
Codec ID : V_MPEGH/ISO/HEVC
Duration : 1 h 30 min
Bit rate : 66.3 Mb/s
Width : 3 840 pixels
Height : 2 160 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0 (Type 2)
Bit depth : 10 bits
Bits/(Pixel*Frame) : 0.333
Stream size : 41.8 GiB (93%)
Language : English
Default : No
Forced : No
Color range : Limited
Color primaries : BT.2020
Transfer characteristics : PQ
Matrix coefficients : BT.2020 non-constant
Original source medium : Blu-ray
Mastering display color primaries : Display P3
Mastering display luminance : min: 0.0001 cd/m2, max: 1000 cd/m2
Audio #1
ID : 2
ID in the original source medium : 4352 (0x1100)
Format : TrueHD
Format profile : TrueHD+Atmos / TrueHD
Codec ID : A_TRUEHD
Duration : 1 h 30 min
Bit rate mode : Variable
Bit rate : 3 890 kb/s
Maximum bit rate : 8 064 kb/s
Channel(s) : Object Based / 8 channels
Channel positions : Object Based / Front: L C R, Side: L R, Back: L R, LFE
Sampling rate : / 48.0 kHz
Frame rate : 1 200.000 FPS (40 SPF)
Bit depth : 24 bits
Compression mode : Lossless
Stream size : 2.45 GiB (5%)
Title : Surround 7.1
Language : English
Default : Yes
Forced : No
Original source medium : Blu-ray
Audio #2
ID : 3
ID in the original source medium : 4352 (0x1100)
Format : AC-3
Format/Info : Audio Coding 3
Codec ID : A_AC3
Duration : 1 h 30 min
Bit rate mode : Constant
Bit rate : 640 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 413 MiB (1%)
Title : Surround 5.1
Language : English
Service kind : Complete Main
Default : No
Forced : No
Original source medium : Blu-ray
Audio #3
ID : 4
ID in the original source medium : 4353 (0x1101)
Format : AC-3
Format/Info : Audio Coding 3
Codec ID : A_AC3
Duration : 1 h 30 min
Bit rate mode : Constant
Bit rate : 640 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)
Bit depth : 16 bits
Compression mode : Lossy
Stream size : 413 MiB (1%)
Title : Surround 5.1
Language : English
Service kind : Complete Main
Default : No
Forced : No
Original source medium : Blu-ray
Text #1
ID : 5
ID in the original source medium : 4768 (0x12A0)
Format : PGS
Codec ID : S_HDMV/PGS
Codec ID/Info : Picture based subtitle format used on BDs/HD-DVDs
Duration : 1 h 11 min
Bit rate : 1 932 b/s
Count of elements : 302
Stream size : 1 016 KiB (0%)
Language : English
Default : No
Forced : No
Original source medium : Blu-ray
Text #2
ID : 6
ID in the original source medium : 4768 (0x12A0)
Format : PGS
Codec ID : S_HDMV/PGS
Codec ID/Info : Picture based subtitle format used on BDs/HD-DVDs
Duration : 1 h 11 min
Bit rate : 1 252 b/s
Count of elements : 200
Stream size : 658 KiB (0%)
Language : English
Default : Yes
Forced : No
Original source medium : Blu-ray
Text #3
ID : 7
ID in the original source medium : 4769 (0x12A1)
Format : PGS
Codec ID : S_HDMV/PGS
Codec ID/Info : Picture based subtitle format used on BDs/HD-DVDs
Duration : 1 h 22 min
Bit rate : 3 951 b/s
Count of elements : 652
Stream size : 2.32 MiB (0%)
Language : English
Default : No
Forced : No
Original source medium : Blu-ray
Menu
00:00:00.000 : en:Chapter 01
00:10:19.118 : en:Chapter 02
00:14:38.002 : en:Chapter 03
00:21:52.894 : en:Chapter 04
00:25:09.674 : en:Chapter 05
00:31:05.029 : en:Chapter 06
00:36:23.389 : en:Chapter 07
00:43:47.124 : en:Chapter 08
00:47:42.526 : en:Chapter 09
00:53:48.058 : en:Chapter 10
01:00:31.377 : en:Chapter 11
01:05:55.326 : en:Chapter 12
01:10:57.836 : en:Chapter 13
01:15:29.066 : en:Chapter 14
01:23:47.147 : en:Chapter 15
答案1
它-forced_subs_only的作用是告诉 PGS 解码器只解码标记为强制的字幕。您需要叠加这些基于图像的字幕，才能在输出视频中看到它们。因此，
ffmpeg -y -probesize 2048M -analyzeduration 2048M -forced_subs_only 1 -i ../in/A Quiet Place.mkv -map 0:0 -map 0:1 -map 0:1 -c:v libx264 -preset slower -profile:v high -level 5.1 -crf:v 22 -filter_complex [0:v]scale=1920:-1[v];[v][0:s:0]overlay -x264-params ref=5:bframes=5:b_adapt=2:direct=auto:analyse=all:me=umh:merange=24:subme=10:trellis=2:vbv-bufsize=512000:vbv-maxrate=512000:rc-lookahead=60:colorprim=bt2020:transfer=smpte2084:colormatrix=bt2020nc -c:a:0 aac -ac 6 -c:a:1 ac3 -ac 6 -disposition:a:0 default -disposition:a:1 none ../temp/A Quiet Place - 1080p.mp4
叠加滤镜会将第一个字幕流中的强制字幕刻录到视频中。根据字幕帧大小，您可能需要在叠加之前缩放该流。