I'm using Fluent-FFmpeg with Node.JS to create videos with text overlaid on them and I'm wanting to change the color of the text as the video progresses.
My filters follow this pattern:
drawtext=enable='between(t,18.93,20.28)':fontfile=fonts/cousine-bold.ttf:fontsize=144:fontcolor_expr=%{expr\\\: if(between(t\\, 0\\, 20)\\, 888888\\, 111111)}:x=82:y=288:text='PROGRAMMING'
And it prints out this stuff:
ffmpeg version 3.3.2 Copyright (c) 2000-2017 the FFmpeg developers
built with Apple LLVM version 8.1.0 (clang-802.0.42)
configuration: --prefix=/usr/local/Cellar/ffmpeg/3.3.2 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-libfreetype --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --disable-lzma --enable-vda
libavutil 55. 58.100 / 55. 58.100
libavcodec 57. 89.100 / 57. 89.100
libavformat 57. 71.100 / 57. 71.100
libavdevice 57. 6.100 / 57. 6.100
libavfilter 6. 82.100 / 6. 82.100
libavresample 3. 5. 0 / 3. 5. 0
libswscale 4. 6.100 / 4. 6.100
libswresample 2. 7.100 / 2. 7.100
libpostproc 54. 5.100 / 54. 5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'uploads/0c719e39820366bc62c8fd66a6327828':
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
creation_time : 2017-06-23T00:19:46.000000Z
com.apple.quicktime.make: Apple
com.apple.quicktime.model: MacBookPro9,2
com.apple.quicktime.software: Mac OS X 10.12.5 (16F73)
com.apple.quicktime.creationdate: 2017-06-22T17:18:42-0700
Duration: 00:00:22.00, start: 0.000000, bitrate: 3408 kb/s
Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 1280x720 [SAR 1:1 DAR 16:9], 3091 kb/s, 15 fps, 15 tbr, 30k tbn, 50 tbc (default)
Metadata:
creation_time : 2017-06-23T00:19:46.000000Z
handler_name : Core Media Data Handler
encoder : H.264
Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 316 kb/s (default)
Metadata:
creation_time : 2017-06-23T00:19:46.000000Z
handler_name : Core Media Data Handler
Stream mapping:
Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
Stream #0:1 -> #0:1 (aac (native) -> aac (native))
Press [q] to stop, [?] for help
[libx264 @ 0x7ff72e810a00] using SAR=1/1
[libx264 @ 0x7ff72e810a00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x7ff72e810a00] profile High, level 3.1
[libx264 @ 0x7ff72e810a00] 264 - core 148 r2748 97eaef2 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - 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=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=15 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 './outputFile.mp4':
Metadata:
major_brand : qt
minor_version : 0
compatible_brands: qt
com.apple.quicktime.creationdate: 2017-06-22T17:18:42-0700
com.apple.quicktime.make: Apple
com.apple.quicktime.model: MacBookPro9,2
com.apple.quicktime.software: Mac OS X 10.12.5 (16F73)
encoder : Lavf57.71.100
Stream #0:0(und): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 15 fps, 15360 tbn, 15 tbc (default)
Metadata:
creation_time : 2017-06-23T00:19:46.000000Z
handler_name : Core Media Data Handler
encoder : Lavc57.89.100 libx264
Side data:
cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
Stream #0:1(und): Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s (default)
Metadata:
creation_time : 2017-06-23T00:19:46.000000Z
handler_name : Core Media Data Handler
encoder : Lavc57.89.100 aac
frame= 52 fps=0.0 q=27.0 size= 37kB time=00:00:04.66 bitrate= 65.7kbits/s speed=8.74x
frame= 72 fps= 70 q=27.0 size= 187kB time=00:00:06.03 bitrate= 253.4kbits/s speed=5.83x
frame= 95 fps= 61 q=27.0 size= 358kB time=00:00:07.52 bitrate= 390.4kbits/s speed=4.82x
frame= 117 fps= 57 q=27.0 size= 569kB time=00:00:08.98 bitrate= 518.9kbits/s speed=4.35x
frame= 137 fps= 53 q=27.0 size= 732kB time=00:00:10.32 bitrate= 580.2kbits/s speed=4.03x
frame= 159 fps= 52 q=27.0 size= 942kB time=00:00:11.79 bitrate= 654.7kbits/s speed=3.84x
frame= 180 fps= 50 q=27.0 size= 1110kB time=00:00:13.18 bitrate= 689.5kbits/s speed=3.67x
frame= 204 fps= 50 q=27.0 size= 1331kB time=00:00:14.78 bitrate= 737.2kbits/s speed= 3.6x
frame= 223 fps= 48 q=27.0 size= 1486kB time=00:00:16.06 bitrate= 757.9kbits/s speed=3.49x
frame= 248 fps= 48 q=27.0 size= 1708kB time=00:00:17.71 bitrate= 789.7kbits/s speed=3.46x
frame= 266 fps= 47 q=27.0 size= 1859kB time=00:00:18.92 bitrate= 805.0kbits/s speed=3.35x
frame= 285 fps= 46 q=27.0 size= 2013kB time=00:00:20.19 bitrate= 816.4kbits/s speed=3.28x
[drawtext @ 0x7ff72d84bc00] Cannot find color '888888.000000'
Last message repeated 9 times
frame= 308 fps= 46 q=27.0 size= 2224kB time=00:00:21.75 bitrate= 837.5kbits/s speed=3.27x
frame= 330 fps= 46 q=27.0 size= 2401kB time=00:00:21.96 bitrate= 895.5kbits/s speed=3.06x
frame= 330 fps= 41 q=-1.0 Lsize= 2834kB time=00:00:22.00 bitrate=1055.0kbits/s speed=2.73x
video:2484kB audio:338kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.441003%
[libx264 @ 0x7ff72e810a00] frame I:22 Avg QP:13.64 size: 47604
[libx264 @ 0x7ff72e810a00] frame P:154 Avg QP:16.76 size: 8574
[libx264 @ 0x7ff72e810a00] frame B:154 Avg QP:19.42 size: 1138
[libx264 @ 0x7ff72e810a00] consecutive B-frames: 6.7% 93.3% 0.0% 0.0%
[libx264 @ 0x7ff72e810a00] mb I I16..4: 85.1% 13.3% 1.6%
[libx264 @ 0x7ff72e810a00] mb P I16..4: 5.5% 3.1% 0.0% P16..4: 41.5% 4.0% 5.5% 0.0% 0.0% skip:40.4%
[libx264 @ 0x7ff72e810a00] mb B I16..4: 0.0% 0.0% 0.0% B16..8: 14.7% 0.1% 0.0% direct: 4.7% skip:80.4% L0:28.0% L1:71.4% BI: 0.7%
[libx264 @ 0x7ff72e810a00] 8x8 transform intra:21.7% inter:84.8%
[libx264 @ 0x7ff72e810a00] coded y,uvDC,uvAC intra: 60.5% 98.6% 92.9% inter: 6.0% 24.3% 3.1%
[libx264 @ 0x7ff72e810a00] i16 v,h,dc,p: 35% 19% 43% 3%
[libx264 @ 0x7ff72e810a00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 10% 7% 80% 1% 1% 1% 1% 0% 0%
[libx264 @ 0x7ff72e810a00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 33% 20% 45% 0% 0% 0% 0% 0% 0%
[libx264 @ 0x7ff72e810a00] i8c dc,h,v,p: 77% 9% 10% 4%
[libx264 @ 0x7ff72e810a00] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x7ff72e810a00] ref P L0: 75.3% 0.3% 17.1% 7.3%
[libx264 @ 0x7ff72e810a00] ref B L0: 80.0% 20.0%
[libx264 @ 0x7ff72e810a00] kb/s:924.66
[aac @ 0x7ff72e812200] Qavg: 2159.960
In particular this annoying bit:
[drawtext @ 0x7ff72d84bc00] Cannot find color '888888.000000'
However, it would be really nice to do something like this:
fontcolor_expr=%{expr\\\\: if(between(t\\, 0\\, 20)\\, pink\\, white)}
Which prints out this error:
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
frame= 287 fps= 46 q=27.0 size= 2023kB time=00:00:20.31 bitrate= 815.9kbits/s speed=3.27x
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Undefined constant or missing '(' in 'pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] [Eval @ 0x7fff5f7760c0] Missing ')' or too many args in 'if(between(t,0,20),pink,white)'
[Parsed_drawtext_0 @ 0x7ff3cf523300] Expression 'if(between(t, 0, 20), pink, white)' for the expr text expansion function is not valid
There aren't a lot of examples of fontcolor_expr, so I wanted to see if anyone had experience with this. Any tips on changing fonrcolors dynamically without creating multiple filters?
Please note that fontcolor_expr=white and fontcolor_expr=888888 are valid and create videos with a fixed font color.
I've figured it out enough for what I need it for:
drawtext=enable='between(t,18.93,20.28)':fontfile=fonts/cousine-bold.ttf:fontsize=144:fontcolor_expr=%{eif\\: if(between(t\, 18.93\, 19.02)\, 0xFFFFFF\, 0xFFB6C1) \\: x}:x=82:y=288:text='PROGRAMMING'
Specifically:
fontcolor_expr=%{eif\\: if(between(t\, 18.93\, 19.02)\, 0xFFFFFF\, 0xFFB6C1) \\: x}
From what I can tell eif :expression :format :decimal[optional] allows for an expression to be run and returned in a specific format. By running the if statement in eif and specifying x at the end, it returns the result of the expression as a hexidecimal value.
Just to save someone in the future some trouble, everything has to be properly escaped. In Node.JS, I use string interpolation and my code looks like this:
`drawtext=enable='between(t,${groupStart},${groupEnd})':fontfile=${fontFile}:fontsize=${fontSize}:fontcolor_expr=%{eif\\\\: if(between(t\\, ${groupStart}\\, ${wordStart})\\, 0xFFFFFF\\, 0xFFB6C1) \\\\: x}:x=${Math.floor((fontSize / 1.75) * xDistance)}:y=${Math.floor(fontSize * (lineCount + 1))}:text='${elem[0]}'`
expr_int_format, eif
Evaluate the expression's value and output as formatted integer. The first argument is the expression to be evaluated, just as for the expr function. The second argument specifies the output format. Allowed values are x, X, d and u. They are treated exactly as in the "printf" function. The third parameter is optional and sets the number of positions taken by the output. It can be used to add padding with zeros from the left.