我有两个不同长度的视频，每个视频都有立体声音频，我使用 ffmpeg 将它们叠加在一起。我已将两个视频的音频分别分配到输出视频的左声道和右声道。
这是我正在使用的命令：
ffmpeg -i v1.mp4 -i v2.mp4 -filter_complex "amerge=inputs=2,pan=stereo|c0<c0+c1|c1<c2+c3;blend=all_expr='A*0.5+B*0.5'" output.mp4
问题是，一旦较短的视频停止播放，它就会切断两个输入视频的音频，这是过滤器的记录行为amerge。它还会吐出很多这样的错误——
Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory
——尽管它确实完成了处理。我试过简单地省略 amerge 过滤器
ffmpeg -i v1.mp4 -i v2.mp4 -filter_complex "pan=stereo|c0<c0+c1|c1<c2+c3;blend=all_expr='A*0.5+B*0.5'" output.mp4
但输出结果不包括第二个视频的音频。如何正确完成此操作？抱歉，这个问题比较菜鸟，我本周才开始使用 ffmpeg。
谢谢您的任何建议。
[编辑] 这是上述命令的错误消息输出：
C:\Users\admin\Downloads\ffmpeg-20170110-f48b6b8-win64-static\ffmpeg-20170110-f4 8b6b8-win64-static\bin>ffmpeg -i v01.mp4 -i v02.mp4 -filter_complex "amerge=inpu ts=2,pan=stereo|c1<c0+c1|c0<c2+c3;blend=all_expr='A*0.5+B*0.5'" out1.mp4 > outpu t.txt ffmpeg version N-83034-gf48b6b8 Copyright (c) 2000-2017 the FFmpeg developers built with gcc 5.4.0 (GCC) configuration: --enable-gpl --enable-version3 --enable-dxva2 --enable-libmfx - -enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei 0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-li bbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --en able-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-li bopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --e nable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable -libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --e nable-lzma --enable-decklink --enable-zlib libavutil 55. 43.100 / 55. 43.100 libavcodec 57. 71.100 / 57. 71.100 libavformat 57. 62.100 / 57. 62.100 libavdevice 57. 2.100 / 57. 2.100 libavfilter 6. 68.100 / 6. 68.100 libswscale 4. 3.101 / 4. 3.101 libswresample 2. 4.100 / 2. 4.100 libpostproc 54. 2.100 / 54. 2.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'v01.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.62.100 location-eng : +37.3789-005.9891/ location : +37.3789-005.9891/ Duration: 00:00:05.02, start: 0.000000, bitrate: 4760 kb/s Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 , 4642 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default) Metadata: handler_name : VideoHandler Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, flt p, 122 kb/s (default) Metadata: handler_name : SoundHandler Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'v02.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.62.100 Duration: 00:00:15.02, start: 0.000000, bitrate: 3766 kb/s Stream #1:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 , 3632 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default) Metadata: handler_name : VideoHandler Stream #1:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, flt p, 126 kb/s (default) Metadata: handler_name : SoundHandler File 'out1.mp4' already exists. Overwrite ? [y/N] y [Parsed_amerge_0 @ 0000000002325e80] No channel layout for input 1 [Parsed_amerge_0 @ 0000000002325e80] Input channel layouts overlap: output layou t will be determined by the number of distinct input channels [libx264 @ 0000000001bff560] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 AVX2 LZCNT BMI2 [libx264 @ 0000000001bff560] profile High, level 4.0 [libx264 @ 0000000001bff560] 264 - core 148 r2744 b97ae06 - H.264/MPEG-4 AVC cod ec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=1 r ef=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_pski p=1 chroma_qp_offset=-2 threads=6 lookahead_threads=1 sliced_threads=0 nr=0 deci mate=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=2 5 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.6 0 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00 Output #0, mp4, to 'out1.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2avc1mp41 encoder : Lavf57.62.100 Stream #0:0: Audio: aac (LC) ([64][0][0][0] / 0x0040), 48000 Hz, stereo, flt p, 128 kb/s (default) Metadata: encoder : Lavc57.71.100 aac Stream #0:1: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1920x1 080, q=-1--1, 29.97 fps, 30k tbn, 29.97 tbc (default) Metadata: encoder : Lavc57.71.100 libx264 Side data: cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1 Stream mapping: Stream #0:0 (h264) -> blend:top Stream #0:1 (aac) -> amerge:in0 Stream #1:0 (h264) -> blend:bottom Stream #1:1 (aac) -> amerge:in1 pan -> Stream #0:0 (aac) blend -> Stream #0:1 (libx264) Press [q] to stop, [?] for help frame= 5 fps=0.0 q=0.0 size= 0kB time=00:00:00.23 bitrate= 0.0kbits/s frame= 10 fps=9.5 q=0.0 size= 0kB time=00:00:00.38 bitrate= 0.0kbits/s frame= 16 fps=9.7 q=0.0 size= 0kB time=00:00:00.60 bitrate= 0.0kbits/s frame= 22 fps=9.8 q=0.0 size= 0kB time=00:00:00.79 bitrate= 0.0kbits/s frame= 28 fps=9.9 q=0.0 size= 0kB time=00:00:00.98 bitrate= 0.0kbits/s frame= 34 fps= 10 q=0.0 size= 0kB time=00:00:01.19 bitrate= 0.0kbits/s frame= 39 fps= 10 q=0.0 size= 0kB time=00:00:01.36 bitrate= 0.0kbits/s frame= 44 fps= 10 q=0.0 size= 0kB time=00:00:01.51 bitrate= 0.0kbits/s frame= 46 fps=9.0 q=0.0 size= 0kB time=00:00:01.60 bitrate= 0.0kbits/s frame= 51 fps=9.0 q=29.0 size= 42kB time=00:00:01.75 bitrate= 197.4kbits/ frame= 55 fps=8.8 q=29.0 size= 147kB time=00:00:01.90 bitrate= 633.2kbits/ frame= 59 fps=8.7 q=29.0 size= 220kB time=00:00:02.02 bitrate= 888.5kbits/ frame= 63 fps=8.5 q=29.0 size= 288kB time=00:00:02.15 bitrate=1092.1kbits/ frame= 67 fps=8.4 q=29.0 size= 360kB time=00:00:02.28 bitrate=1289.4kbits/ frame= 71 fps=8.3 q=29.0 size= 435kB time=00:00:02.43 bitrate=1465.1kbits/ frame= 75 fps=8.2 q=29.0 size= 514kB time=00:00:02.56 bitrate=1642.1kbits/ frame= 79 fps=8.1 q=29.0 size= 577kB time=00:00:02.69 bitrate=1757.4kbits/ frame= 83 fps=8.1 q=29.0 size= 630kB time=00:00:02.81 bitrate=1831.7kbits/ frame= 87 fps=8.0 q=29.0 size= 695kB time=00:00:02.96 bitrate=1917.5kbits/ frame= 91 fps=8.0 q=29.0 size= 760kB time=00:00:03.09 bitrate=2011.4kbits/ frame= 95 fps=8.0 q=29.0 size= 822kB time=00:00:03.22 bitrate=2088.1kbits/ frame= 99 fps=7.9 q=29.0 size= 890kB time=00:00:03.37 bitrate=2161.8kbits/ frame= 103 fps=7.9 q=29.0 size= 968kB time=00:00:03.50 bitrate=2264.7kbits/ frame= 107 fps=7.8 q=29.0 size= 1053kB time=00:00:03.62 bitrate=2376.7kbits/ frame= 111 fps=7.8 q=29.0 size= 1124kB time=00:00:03.75 bitrate=2450.1kbits/ frame= 115 fps=7.8 q=29.0 size= 1192kB time=00:00:03.90 bitrate=2499.5kbits/ frame= 119 fps=7.8 q=29.0 size= 1251kB time=00:00:04.03 bitrate=2540.7kbits/ frame= 123 fps=7.8 q=29.0 size= 1308kB time=00:00:04.16 bitrate=2573.6kbits/ frame= 127 fps=7.8 q=29.0 size= 1365kB time=00:00:04.29 bitrate=2606.3kbits/ frame= 131 fps=7.7 q=29.0 size= 1432kB time=00:00:04.44 bitrate=2642.3kbits/ frame= 135 fps=7.7 q=29.0 size= 1488kB time=00:00:04.56 bitrate=2667.8kbits/ frame= 139 fps=7.7 q=29.0 size= 1542kB time=00:00:04.69 bitrate=2690.3kbits/ frame= 143 fps=7.7 q=29.0 size= 1595kB time=00:00:04.82 bitrate=2708.7kbits/ frame= 147 fps=7.7 q=29.0 size= 1645kB time=00:00:04.97 bitrate=2709.7kbits/ frame= 151 fps=7.7 q=29.0 size= 1698kB time=00:00:04.97 bitrate=2797.2kbits/ frame= 155 fps=7.7 q=29.0 size= 1756kB time=00:00:04.97 bitrate=2892.4kbits/ frame= 160 fps=7.6 q=29.0 size= 1833kB time=00:00:04.97 bitrate=3019.7kbits/ frame= 165 fps=7.7 q=29.0 size= 1902kB time=00:00:04.97 bitrate=3132.8kbits/ frame= 169 fps=7.7 q=29.0 size= 1954kB time=00:00:04.97 bitrate=3219.1kbits/ frame= 173 fps=7.7 q=29.0 size= 2006kB time=00:00:04.97 bitrate=3303.5kbits/ frame= 178 fps=7.7 q=29.0 size= 2066kB time=00:00:04.97 bitrate=3402.7kbits/ frame= 182 fps=7.7 q=29.0 size= 2121kB time=00:00:04.97 bitrate=3493.2kbits/ frame= 187 fps=7.7 q=29.0 size= 2187kB time=00:00:04.97 bitrate=3601.8kbits/ Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory frame= 191 fps=7.7 q=29.0 size= 2262kB time=00:00:04.97 bitrate=3725.2kbits/ Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory frame= 195 fps=7.6 q=29.0 size= 2344kB time=00:00:04.97 bitrate=3860.9kbits/ Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory ..... Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory frame= 436 fps=7.9 q=29.0 size= 2466kB time=00:00:12.77 bitrate=1580.9kbits/ Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory frame= 440 fps=7.9 q=29.0 size= 2466kB time=00:00:12.91 bitrate=1564.5kbits/ Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory Failed to inject frame into filter network: Cannot allocate memory Error while decoding stream #1:1: Cannot allocate memory frame= 446 fps=8.0 q=29.0 size= 2466kB time=00:00:13.11 bitrate=1540.7kbits/ frame= 450 fps=8.0 q=29.0 size= 2466kB time=00:00:13.24 bitrate=1525.1kbits/ frame= 450 fps=7.7 q=-1.0 Lsize= 5298kB time=00:00:14.91 bitrate=2910.2kbits /s speed=0.255x video:5213kB audio:76kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.194365% [aac @ 0000000001f5bb20] Qavg: 5159.816 [libx264 @ 0000000001cd03e0] frame I:2 Avg QP:20.68 size: 76647 [libx264 @ 0000000001cd03e0] frame P:113 Avg QP:21.48 size: 25608 [libx264 @ 0000000001cd03e0] frame B:335 Avg QP:24.65 size: 6836 [libx264 @ 0000000001cd03e0] consecutive B-frames: 0.7% 0.0% 0.7% 98.7% [libx264 @ 0000000001cd03e0] mb I I16..4: 21.3% 66.8% 11.9% [libx264 @ 0000000001cd03e0] mb P I16..4: 4.0% 5.3% 0.5% P16..4: 45.0% 11.2 % 5.0% 0.0% 0.0% skip:29.1% [libx264 @ 0000000001cd03e0] mb B I16..4: 0.6% 0.6% 0.0% B16..8: 35.6% 2.3 % 0.2% direct: 1.9% skip:58.7% L0:44.8% L1:52.0% BI: 3.2% [libx264 @ 0000000001cd03e0] 8x8 transform intra:54.6% inter:85.5% [libx264 @ 0000000001cd03e0] coded y,uvDC,uvAC intra: 30.3% 42.6% 4.6% inter: 7. 5% 12.1% 0.0% [libx264 @ 0000000001cd03e0] i16 v,h,dc,p: 32% 49% 8% 11% [libx264 @ 0000000001cd03e0] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 29% 23% 33% 3% 2% 2% 2% 3% 4% [libx264 @ 0000000001cd03e0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 34% 29% 14% 3% 4% 4% 4% 3% 4% [libx264 @ 0000000001cd03e0] i8c dc,h,v,p: 48% 31% 18% 3% [libx264 @ 0000000001cd03e0] Weighted P-Frames: Y:0.0% UV:0.0% [libx264 @ 0000000001cd03e0] ref P L0: 54.3% 9.2% 25.5% 11.0% [libx264 @ 0000000001cd03e0] ref B L0: 80.4% 15.0% 4.6% [libx264 @ 0000000001cd03e0] ref B L1: 91.3% 8.7% [libx264 @ 0000000001cd03e0] kb/s:2843.59
答案1
尝试使用amix过滤器，其默认以最长持续时间结束：
ffmpeg -i v1.mp4 -i v2.mp4 -filter_complex "amix;blend=all_expr='A*0.5+B*0.5'" output.mp4
如果使用当前命令，您还可以填充较短的音频。假设 v1 是较短的视频：
ffmpeg -i v1.mp4 -i v2.mp4 -filter_complex "[0]apad[a];[a][1]amerge=inputs=2,pan=stereo|c0<c0+c1|c1<c2+c3;blend=all_expr='A*0.5+B*0.5'" output.mp4