i'm trying to overlap two video clips using FFMpeg. I'm using the following command:
ffmpeg -i a.mp4 -i b.mp4 -filter_complex "blend=all_mode='multiply'" c.mp4
I was expecting to get something like in a bitmap editor. Instead, I get a green overlay on top of the resulting video.
Could you explain that and help me fix my command-line? I'm also open to other alternative programs.
Thanks
Edit:
Here if the full log
ffmpeg version n4.2.1 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 9.1.0 (GCC)
configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
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
libswscale 5. 5.100 / 5. 5.100
libswresample 3. 5.100 / 3. 5.100
libpostproc 55. 5.100 / 55. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'contrast.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Duration: 00:00:02.67, start: 0.000000, bitrate: 1071 kb/s
Stream #0:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p, 1920x1080, 985 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 86 kb/s (default)
Metadata:
handler_name : Core Media Audio
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'contrast.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Duration: 00:00:02.67, start: 0.000000, bitrate: 1071 kb/s
Stream #1:0(und): Video: h264 (High 4:4:4 Predictive) (avc1 / 0x31637661), yuv444p, 1920x1080, 985 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
handler_name : VideoHandler
Stream #1:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 86 kb/s (default)
Metadata:
handler_name : Core Media Audio
File 'combined.mp4' already exists. Overwrite ? [y/N] y
Stream mapping:
Stream #0:0 (h264) -> blend:top (graph 0)
Stream #1:0 (h264) -> blend:bottom (graph 0)
blend (graph 0) -> Stream #0:0 (libx264)
Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x558fa4a84680] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
[libx264 @ 0x558fa4a84680] profile High 4:4:4 Predictive, level 4.0, 4:4:4, 8-bit
[libx264 @ 0x558fa4a84680] 264 - core 157 r2945 72db437 - 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=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=4 threads=6 lookahead_threads=1 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_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 'combined.mp4':
Metadata:
major_brand : isom
minor_version : 512
compatible_brands: isomiso2avc1mp41
encoder : Lavf58.29.100
Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuv444p, 1920x1080, q=-1--1, 29.97 fps, 30k tbn, 29.97 tbc (default)
Metadata:
encoder : Lavc58.54.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s (default)
Metadata:
handler_name : Core Media Audio
encoder : Lavc58.54.100 aac
frame= 79 fps= 19 q=-1.0 Lsize= 329kB time=00:00:02.64 bitrate=1018.5kbits/s speed=0.639x
video:297kB audio:28kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.255968%
[libx264 @ 0x558fa4a84680] frame I:2 Avg QP:11.42 size: 9143
[libx264 @ 0x558fa4a84680] frame P:27 Avg QP:20.64 size: 4721
[libx264 @ 0x558fa4a84680] frame B:50 Avg QP:22.19 size: 3150
[libx264 @ 0x558fa4a84680] consecutive B-frames: 12.7% 7.6% 3.8% 75.9%
[libx264 @ 0x558fa4a84680] mb I I16..4: 97.7% 0.0% 2.3%
[libx264 @ 0x558fa4a84680] mb P I16..4: 9.0% 0.0% 1.0% P16..4: 4.9% 1.1% 0.3% 0.0% 0.0% skip:83.7%
[libx264 @ 0x558fa4a84680] mb B I16..4: 2.1% 0.0% 0.2% B16..8: 9.6% 1.2% 0.0% direct: 0.6% skip:86.2% L0:52.2% L1:46.4% BI: 1.4%
[libx264 @ 0x558fa4a84680] coded y,u,v intra: 4.5% 0.3% 1.0% inter: 0.9% 0.1% 0.5%
[libx264 @ 0x558fa4a84680] i16 v,h,dc,p: 68% 18% 9% 4%
[libx264 @ 0x558fa4a84680] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 32% 10% 28% 4% 7% 9% 4% 6% 1%
[libx264 @ 0x558fa4a84680] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x558fa4a84680] ref P L0: 52.8% 6.5% 24.4% 16.3%
[libx264 @ 0x558fa4a84680] ref B L0: 70.8% 23.2% 6.0%
[libx264 @ 0x558fa4a84680] ref B L1: 88.5% 11.5%
[libx264 @ 0x558fa4a84680] kb/s:920.37
[aac @ 0x558fa4b1ea00] Qavg: 1424.024
