我输入FFmpeg的来源是一个AVI文件或其中的concat。无论哪种方式，我生成的游戏中时光倒流文件都具有较长的帧尾，这些帧是单个帧的重复。这就像在我的输出文件末尾产生了一个很长的冻结帧。
我使用的是较旧的Mac Pro，因此无法更新FFmpeg。我有一台具有较新版本的笔记本电脑，在那我也得到了相同的版本。我不确定是否是因为我的源文件是否为AVI。
ffmpeg version 4.1.1 Copyright (c) 2000-2019 the FFmpeg developers
built with Apple LLVM version 8.0.0 (clang-800.0.42.1)
configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1.1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags=-I/System/Library/Frameworks/JavaVM.framework/Versions/Current/Headers/ --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-libvorbis --enable-libvpx --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-videotoolbox --disable-libjack --disable-indev=jack --enable-libaom --enable-libsoxr
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
libavresample 4. 0. 0 / 4. 0. 0
libswscale 5. 3.100 / 5. 3.100
libswresample 3. 3.100 / 3. 3.100
libpostproc 55. 3.100 / 55. 3.100
[avi @ 0x7fa82080c800] sample size (1) != block align (2)
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, avi, from 'concat:16460001.AVI|16460002.AVI|16460003.AVI|16460004.AVI|16460005.AVI|16460006.AVI|16460007.AVI|16460008.AVI|16460009.AVI|16460010.AVI|16460011.AVI|16460012.AVI|16460013.AVI|16460014.AVI|16460015.AVI|16460016.AVI|16460017.AVI|16460018.AVI|16460019.AVI|16460020.AVI|16460021.AVI':
Duration: 00:10:02.00, start: 0.000000, bitrate: 365923 kb/s
Stream #0:0: Video: mjpeg (MJPG / 0x47504A4D), yuvj420p(pc, bt470bg/unknown/unknown), 1280x720, 30 fps, 30 tbr, 30 tbn, 30 tbc
Stream #0:1: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 32000 Hz, mono, s16, 512 kb/s
Stream mapping:
Stream #0:0 -> #0:0 (mjpeg (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (pcm_s16le (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x7fa82082cc00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.1 Cache64
[libx264 @ 0x7fa82082cc00] profile High, level 3.1
[libx264 @ 0x7fa82082cc00] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - http://www.videolan.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=12 lookahead_threads=2 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=16 scenecut=40 intra_refresh=0 rc_lookahead=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 'out.mp4':
Metadata:
encoder : Lavf58.20.100
Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuvj420p(pc, progressive), 1280x720, q=-1--1, 16 fps, 16384 tbn, 16 tbc
Metadata:
encoder : Lavc58.35.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 32000 Hz, mono, fltp, 69 kb/s
Metadata:
encoder : Lavc58.35.100 aac
frame= 1962 fps=1.2 q=-1.0 Lsize= 136725kB time=03:24:07.00 bitrate= 91.5kbits/s dup=0 drop=365448 speed=7.41x
video:31548kB audio:103624kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.149437%
[libx264 @ 0x7fa82082cc00] frame I:10 Avg QP:18.74 size: 62176
[libx264 @ 0x7fa82082cc00] frame P:514 Avg QP:21.24 size: 30528
[libx264 @ 0x7fa82082cc00] frame B:1438 Avg QP:22.74 size: 11121
[libx264 @ 0x7fa82082cc00] consecutive B-frames: 1.4% 2.0% 2.0% 94.6%
[libx264 @ 0x7fa82082cc00] mb I I16..4: 2.1% 97.2% 0.7%
[libx264 @ 0x7fa82082cc00] mb P I16..4: 2.0% 33.3% 0.1% P16..4: 37.7% 12.0% 10.4% 0.0% 0.0% skip: 4.5%
[libx264 @ 0x7fa82082cc00] mb B I16..4: 0.7% 11.5% 0.0% B16..8: 29.1% 4.8% 1.3% direct:12.0% skip:40.6% L0:47.5% L1:42.9% BI: 9.6%
[libx264 @ 0x7fa82082cc00] 8x8 transform intra:94.3% inter:83.0%
[libx264 @ 0x7fa82082cc00] coded y,uvDC,uvAC intra: 73.4% 66.7% 8.5% inter: 25.9% 46.8% 2.2%
[libx264 @ 0x7fa82082cc00] i16 v,h,dc,p: 17% 33% 26% 24%
[libx264 @ 0x7fa82082cc00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 13% 23% 51% 1% 2% 1% 4% 1% 2%
[libx264 @ 0x7fa82082cc00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 17% 21% 19% 5% 8% 7% 13% 5% 5%
[libx264 @ 0x7fa82082cc00] i8c dc,h,v,p: 46% 29% 23% 2%
[libx264 @ 0x7fa82082cc00] Weighted P-Frames: Y:47.5% UV:19.3%
[libx264 @ 0x7fa82082cc00] ref P L0: 45.0% 13.8% 20.6% 15.7% 5.0%
[libx264 @ 0x7fa82082cc00] ref B L0: 61.1% 30.4% 8.5%
[libx264 @ 0x7fa82082cc00] ref B L1: 85.8% 14.2%
[libx264 @ 0x7fa82082cc00] kb/s:2107.54
[aac @ 0x7fa82081ea00] Qavg: 130.084
我已阅读此线程并尝试遵循它：
Create time lapse video from other video
以下是我尝试过的一些试验，所有试验都具有相同的输出：
# ffmpeg -y -i $mov -vf framestep=10,setpts=N/FRAME_RATE/TB,fps=2 -r 30 $out
# ffmpeg -y -i $mov -vf framestep=10,setpts=.01*PTS -r 30 $out
# ffmpeg -y -i $mov -vf framestep=10,setpts=.1*PTS -r 30 $out
# ffmpeg -y -i "concat:16460001.AVI|16460002.AVI|16460003.AVI|16460004.AVI|16460005.AVI|16460006.AVI|16460007.AVI|16460008.AVI|16460009.AVI|16460010.AVI|16460011.AVI|16460012.AVI|16460013.AVI|16460014.AVI|16460015.AVI|16460016.AVI|16460017.AVI|16460018.AVI|16460019.AVI|16460020.AVI|16460021.AVI" -vf framestep=10,setpts=.05*PTS -r 30 $out
ffmpeg -y -i "concat:16460001.AVI|16460002.AVI|16460003.AVI|16460004.AVI|16460005.AVI|16460006.AVI|16460007.AVI|16460008.AVI|16460009.AVI|16460010.AVI|16460011.AVI|16460012.AVI|16460013.AVI|16460014.AVI|16460015.AVI|16460016.AVI|16460017.AVI|16460018.AVI|16460019.AVI|16460020.AVI|16460021.AVI" -r 16 -filter:v "setpts=0.01*PTS" out.mp4
我在俯视什么吗？我正在尝试将输入加速到单个文件中，以快速查看传入的安全录像。我如何做到这一点而又没有超长无用的尾巴呢？
答案 0 :(得分：1)
使用
ffmpeg -i 16460021.AVI -vf framestep=15,setpts=N/30/TB -r 30 -an out.mp4
我得到的输出是原始长度的1/15。使用framestep = X时，如果要避免帧重复，则setpts的格式应为N/X/TB。压缩视频时长时请勿使用fps，因为它会使用压缩前的旧视频流时长（错误）。跳过音频，因为这会导致原始长度。