亞洲篇
中國(guó)
先畫(huà)個(gè)五角星
- 在100x100的畫(huà)布P1中，先畫(huà)一個(gè)三角形M
ffplay -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)' - 此三角形M水平鏡像后得到M1， M1與M水平方向并列排布，得到200x100的畫(huà)布P2，內(nèi)部為等腰三角形，三角形包含了向上方向的三角形
ffplay -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2 - 針對(duì)200x100的畫(huà)布P2，底部再填充200x100的白色，變?yōu)?200x200的畫(huà)布P3，此時(shí)等腰三角形在畫(huà)布上半部，注意使用colorkey filter將背景白色摳圖為透明色
ffplay -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white - 畫(huà)布P3，一分為五，分布旋轉(zhuǎn)0/72/144/216/288度，得到五個(gè)方向的三角形，overly排布后即可.
ffplay -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay - 由于三角形的邊緣的顏色，旋轉(zhuǎn)之后會(huì)導(dǎo)致一些邊緣出現(xiàn)在五角星內(nèi)部，故要除去此邊緣,
ffplay -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)'
畫(huà)圖命令為：ffmpeg -f lavfi -i color=ffffff00:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0) -frames:v 1 -y five_pointed_star.png
OK，再來(lái)看下維基百科上中國(guó)國(guó)旗的繪畫(huà)方法
其中紅色色號(hào)為 #ee1c25, 黃色色號(hào)為 #ffff00,其中的尺寸特征
- 寬高為3000x2000,
- 大五角星的外圓半徑為300，疊加坐標(biāo)為（200， 200），小五角星的外圓半徑為100，疊加坐標(biāo)分別為(900, 100), (1100, 300) (1100, 600),(900, 800)
- 四顆小五角星的旋轉(zhuǎn)角度分別為逆時(shí)針 90+arctan(3/5), 90+arctan(1/7), 90+arctan(7/2), 90+arctan(5/4)
- OK, 開(kāi)始繪畫(huà)
- 繪制透明的大五角星
ffmpeg -f lavfi -i color=white:300x300[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:white[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=white[R2];[T3]rotate=a=(144*PI/180):c=white[R3];[T4]rotate=a=(216*PI/180):c=white[R4];[T5]rotate=a=(288*PI/180):c=white[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)'[s1];[s1]colorkey=white:0.35 -frames:v 1 -y big_star.png
- 繪制小的五角星，無(wú)須透明
ffmpeg -f lavfi -i color=white:100x100[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:white[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=white[R2];[T3]rotate=a=(144*PI/180):c=white[R3];[T4]rotate=a=(216*PI/180):c=white[R4];[T5]rotate=a=(288*PI/180):c=white[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0) -frames:v 1 -y small_star.png
分別對(duì)小五角星旋轉(zhuǎn)處理對(duì)應(yīng)的角度，并透明化背景得到1,2, 3,4 小五角星ffmpeg -i small_star.png -vf rotate=a=(3*PI/2-atan(3/5)):fillcolor=white[s1];[s1]colorkey=white:0.35 -frames:v 1 -y small_star_1.pngffmpeg -i small_star.png -vf rotate=a=(3*PI/2-atan(1/7)):fillcolor=white[s1];[s1]colorkey=white:0.35 -frames:v 1 -y small_star_2.pngffmpeg -i small_star.png -vf rotate=a=(-atan(7/2)):fillcolor=white[s1];[s1]colorkey=white:0.35 -frames:v 1 -y small_star_3.pngffmpeg -i small_star.png -vf rotate=a=(-atan(5/4)):fillcolor=white[s1];[s1]colorkey=white:0.35 -frames:v 1 -y small_star_4.png
OK,至此完成了準(zhǔn)備工作，接下來(lái)創(chuàng)建背景圖像，并將大五角星和四顆小五角星分別overlay疊加到紅色背景的指定位置即可ffmpeg -i big_star.png -i small_star_1.png -i small_star_2.png -i small_star_3.png -i small_star_4.png -filter_complex color=ee1c25:3000x2000[bg];[bg][0:v]overlay=200:200[bg1];[bg1][1:v]overlay=900:100[bg2];[bg2][2:v]overlay=1100:300[bg3];[bg3][3:v]overlay=1100:600[bg4];[bg4][4:v]overlay=900:800 -frames:v 1 -y China_Flag.png
大功告成，China_Flag.png 如下圖所示
朝鮮
參考中國(guó)國(guó)旗章節(jié)，先畫(huà)一個(gè)半徑為155的白底紅色五角星ffmpeg -f lavfi -i color=white:155x155[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),0)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),0)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)' -frames:v 1 -y star.png
再畫(huà)對(duì)應(yīng)的背景圖案ffmpeg -f lavfi -i color=red:1440x440[red];color=blue:1440x120[blue];[blue]split=2[b1][b2];color=white:1440x20[w0];[w0]split=2[w1][w2];[red]geq=r='if(gt((X-W/3)*(X-W/3)+(Y-H/2)*(Y-H/2),W*W/81),r(X,Y),255)':g='if(gt((X-W/3)*(X-W/3)+(Y-H/2)*(Y-H/2),W*W/81),g(X,Y),255)':b='if(gt((X-W/3)*(X-W/3)+(Y-H/2)*(Y-H/2),W*W/81),b(X,Y),255)'[r1];[b1][w1][r1][w2][b2]vstack=5 -frames:v 1 -y bg.png
再將五角星透明化，并和背景圖案overlay疊加，可得朝鮮國(guó)旗ffmpeg -i star.png -i bg.png -filter_complex [0:v]colorkey=white:0.3[star2];[1:v][star2]overlay=W*325/1440:H*205/720 -frames:v 1 -y north_Korea_flag.png
維基百科草圖與north_Korea_flag.png 如下：
由于此命令過(guò)長(zhǎng)，無(wú)法將五角星等命令放置于一條命令中，可能我當(dāng)前ffmpeg的版本無(wú)法解析過(guò)長(zhǎng)的filter命令，故此國(guó)旗的制作方法拆成了三條命令
韓國(guó)
維基百科草圖如下
其中白色為 #FFFFFF, 紅色為 #CD2E3A, 藍(lán)色為#0047A0, 黑色為#000000
基本思路為先在水平位置上繪制 乾卦(左上角)和坤卦(右下角),以及中心圓，隨后順時(shí)針旋轉(zhuǎn) atan(2/3)度即可
再水平方向上畫(huà)出離卦(左下角)和坎卦(右上角)，隨后逆時(shí)針旋轉(zhuǎn)atan(2/3),
最后二者疊加即可
先做乾坤離坎四卦和中心圓(未旋轉(zhuǎn))ffmpeg -f lavfi -i color=black:20x120[black];[black]split=3[b1][b2][b3];color=white:10x120[white];[white]split=2[w1][w2];[b1][w1][b2][w2][b3]hstack=5 -frames:v 1 -y Qian.pngffmpeg -i Qian.png -vf color=white:80x10[white_strip];[0:v][white_strip]overlay=0:(11*H/24) -frames:v 1 -y Kun.pngffmpeg -i Qian.png -vf color=white:20x10[white_strip];[0:v][white_strip]overlay=(3*W/8):(11*H/24) -frames:v 1 -y Li.pngffmpeg -i Kun.png -vf color=black:20x10[black_strip];[0:v][black_strip]overlay=(3*W/8):(11*H/24) -frames:v 1 -y Kai.pngffmpeg -f lavfi -i color=white:720x480[bg];[bg]geq=r='if(lt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),H*H/16),if(lt(Y,H/2),0xcd,0),r(X,Y))':g='if(lt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),H*H/16),if(lt(Y,H/2),0x2e,0x47),g(X,Y))':b='if(lt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),H*H/16),if(lt(Y,H/2),0x3a,0xa0),b(X,Y))'[c1];[c1]geq=r='if(lt((X-5*W/12)*(X-5*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0xcd,r(X,Y))':g='if(lt((X-5*W/12)*(X-5*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0x2e,g(X,Y))':b='if(lt((X-5*W/12)*(X-5*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0x3a,b(X,Y))'[c2];[c2]geq=r='if(lt((X-7*W/12)*(X-7*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0,r(X,Y))':g='if(lt((X-7*W/12)*(X-7*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0x47,g(X,Y))':b='if(lt((X-7*W/12)*(X-7*W/12)+(Y-H/2)*(Y-H/2),H*H/64),0xa0,b(X,Y))' -frames:v 1 -y circle.png
之后將中心圓與乾坤卦疊加，并順時(shí)針旋轉(zhuǎn)atan(2/3)度ffmpeg -i circle.png -i Qian.png -i Kun.png -filter_complex [0:v][1:v]overlay=(10*W/72):(3*H/8)[bg1];[bg1][2:v]overlay=(54*W/72):(3*H/8)[bg2];[bg2]rotate=a=atan(2/3):fillcolor=white -frames:v 1 -y base_1.png
之后將離坎卦疊加到一起并逆時(shí)針旋轉(zhuǎn)atan(2/3)度,并透明后ffmpeg -i Li.png -i Kai.png -filter_complex color=white:720x480[bg];[bg][0:v]overlay=(10*W/72):(3*H/8)[bg1];[bg1][1:v]overlay=(54*W/72):(3*H/8)[bg2];[bg2]rotate=a=(2*PI-atan(2/3)):fillcolor=white[bg3];[bg3]colorkey=white:0.35 -frames:v 1 -y base_2.png
最后將base_1.png與base_2.png疊加到一塊即可ffmpeg -i base_1.png -i base_2.png -filter_complex [0:v][1:v]overlay -frames:v 1 -y South_Korea_Flag.png
最終South_Korea_Flag.png的效果如下：
蒙古~待補(bǔ)充
日本
預(yù)覽ffplay -f lavfi -i color=white:900x600[white];[white]geq=g='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*3/10)*(H*3/10)),0,255)':b='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*3/10)*(H*3/10)),0,255)'
生成ffmpeg -f lavfi -i color=white:900x600[white];[white]geq=g='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*3/10)*(H*3/10)),0,255)':b='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*3/10)*(H*3/10)),0,255)' -frames:v 1 Japan_flag.jpg
僅供技術(shù)交流，不代表任何意識(shí)形態(tài)
說(shuō)明日本國(guó)旗寬高比為3:2，中心圓的直徑為高的3/5
越南
參考中國(guó)國(guó)旗的五角星一節(jié)，先畫(huà)一個(gè)外圓半徑為 600 的五角星(只需改color filter內(nèi)部的寬高參數(shù)即可)ffplay -f lavfi -i color=ffffff00:600x600[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)'
將此五角星的非五角星的位置透明化后，與一3000x2000的矩形疊加即可ffplay -f lavfi -i color=ffffff00:600x600[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)'[s2];[s2]colorkey=white:0.3[star2];color=DA251D:3000x2000[bg];[bg][star2]overlay=3*W/10:H/5
整體轉(zhuǎn)換命令為ffmpeg -f lavfi -i color=ffffff00:600x600[white];[white]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),0)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:ffffff00[T];[T]colorkey=white[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=ffffff00[R2];[T3]rotate=a=(144*PI/180):c=ffffff00[R3];[T4]rotate=a=(216*PI/180):c=ffffff00[R4];[T5]rotate=a=(288*PI/180):c=ffffff00[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),0)'[s2];[s2]colorkey=white:0.3[star2];color=DA251D:3000x2000[bg];[bg][star2]overlay=3*W/10:H/5 -frames:v 1 -y Vietnam_Flag.png
維基百科的國(guó)旗草圖與最終生成的Vietnam_Flag.png如下：
老撾
預(yù)覽ffplay -f lavfi -i color=red:1500x250[red];[red]split=2[R1][R2];color=white:1500x500[white];[white]geq=r='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*2/5)*(H*2/5)),255,0)':g='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*2/5)*(H*2/5)),255,0)'[middle];[R1][middle][R2]vstack=3
生成ffmpeg -f lavfi -i color=red:1500x250[red];[red]split=2[R1][R2];color=white:1500x500[white];[white]geq=r='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*2/5)*(H*2/5)),255,0)':g='if(lte((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),(H*2/5)*(H*2/5)),255,0)'[middle];[R1][middle][R2]vstack=3 -frames:v 1 Laos.jpg
柬埔寨~待補(bǔ)充
緬甸
參考中國(guó)國(guó)旗一節(jié)，先繪制外圓半徑為422的黑底白色的五角星ffplay -f lavfi -i color=black:442x442[black];[black]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),255)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:black[T];[T]colorkey=black[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=black[R2];[T3]rotate=a=(144*PI/180):c=black[R3];[T4]rotate=a=(216*PI/180):c=black[R4];[T5]rotate=a=(288*PI/180):c=black[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),255)'
再繪制三個(gè)條紋的顏色，并與透明化后的五角星疊加，注意疊加的相對(duì)位置ffplay -f lavfi -i color=black:442x442[black];[black]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),255)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:black[T];[T]colorkey=black[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=black[R2];[T3]rotate=a=(144*PI/180):c=black[R3];[T4]rotate=a=(216*PI/180):c=black[R4];[T5]rotate=a=(288*PI/180):c=black[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),255)'[s2];[s2]colorkey=black:0.3[star2];color=FECB00:1800x400[Y];color=34B233:1800x400[G];color=EA2839:1800x400[R];[Y][G][R]vstack=3[bg];[bg][star2]overlay=458*W/1800:2002*H/12000
其生成命令為ffmpeg -f lavfi -i color=black:442x442[black];[black]geq=r='if(gt(X*tan(72*PI/180),Y),r(X,Y),255)':g='if(gt(X*tan(72*PI/180),Y),g(X,Y),255)':b='if(gt(X*tan(72*PI/180),Y),b(X,Y),255)'[triangle];[triangle]split=2[T1][T2];[T2]hflip[T22];[T22][T1]hstack=2[UP];[UP]pad=iw:ih*2:0:0:black[T];[T]colorkey=black[RAW];[RAW]split=5[T1][T2][T3][T4][T5];[T2]rotate=a=(72*PI/180):c=black[R2];[T3]rotate=a=(144*PI/180):c=black[R3];[T4]rotate=a=(216*PI/180):c=black[R4];[T5]rotate=a=(288*PI/180):c=black[R5];[R2][R3]overlay[U1];[R4][R5]overlay[U2];[U1][U2]overlay[V1];[V1][T1]overlay[star];[star]geq=r='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),r(X,Y),255)':g='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),g(X,Y),255)':b='if(gt((X-W/2)*(X-W/2)+(Y-H/2)*(Y-H/2),1468*H*H/(200*200)),b(X,Y),255)'[s2];[s2]colorkey=black:0.3[star2];color=FECB00:1800x400[Y];color=34B233:1800x400[G];color=EA2839:1800x400[R];[Y][G][R]vstack=3[bg];[bg][star2]overlay=458*W/1800:2002*H/12000 -frames:v 1 -y Myanmar_Flag.png
其維基百科的草圖以及Myanmar_Flag.png如下：
注意由于浮點(diǎn)數(shù)的存在，五角星與背景的疊加位置只能做到相對(duì)準(zhǔn)確
泰國(guó)
ffmpeg -f lavfi -i color=A51931:900x100[R1];color=F4F5F8:900x100[W1];color=2D2A4A:900x100[B1];[R1][W1][B1]vstack=3[up];[up]split=2[up1][up2];[up2]vflip[bottom];[up1][bottom]vstack -frames:v 1 -y Thailand_Flag.png
說(shuō)明：實(shí)際轉(zhuǎn)碼出來(lái)發(fā)現(xiàn) Thailand_Flag.png 中的顏色有色差，如要求的紅色是 A51931，實(shí)際轉(zhuǎn)碼出來(lái)的是 A41730，目前還未找到解決的辦法，可能與BT709這些轉(zhuǎn)換矩陣有關(guān)
馬來(lái)西亞
ffmpeg -f lavfi -i color=00803A:480x240[bt];[bt]geq=r='if(gt((X-27*W/48)*(X-27*W/48)+(Y-H/2)*(Y-H/2),H*H/9),r(X,Y),255)':g='if(gt((X-27*W/48)*(X-27*W/48)+(Y-H/2)*(Y-H/2),H*H/9),g(X,Y),255)':b='if(gt((X-27*W/48)*(X-27*W/48)+(Y-H/2)*(Y-H/2),H*H/9),b(X,Y),255)'[bt2];[bt2]geq=r='if(gt((X-30*W/48)*(X-30*W/48)+(Y-H/2)*(Y-H/2),H*H/9),r(X,Y),0)':g='if(gt((X-30*W/48)*(X-30*W/48)+(Y-H/2)*(Y-H/2),H*H/9),g(X,Y),128)':b='if(gt((X-30*W/48)*(X-30*W/48)+(Y-H/2)*(Y-H/2),H*H/9),b(X,Y),0x3A)'[fg];color=D21034:720x480[bg];[bg][fg]overlay=120:120 -frames:v 1 -y Maldives_Flag.png
先畫(huà)內(nèi)部的綠色矩形，然后特定圓內(nèi)置為白色，再設(shè)置特定園內(nèi)為綠色，隨后再畫(huà)外部的紅色矩形，二者overlay疊加即可。
參考草圖與生成的Maldives_Flag.png
歐洲篇
挪威~待補(bǔ)充
瑞典~待補(bǔ)充
芬蘭~待補(bǔ)充
冰島~待補(bǔ)充
丹麥~待補(bǔ)充
愛(ài)沙尼亞
預(yù)覽ffplay -f lavfi -i color=0072CE:990x210[blue];color=black:990x210[black];color=white:990x210[white];[blue][black][white]vstack=3
生成ffmpeg -f lavfi -i color=0072CE:990x210[blue];color=black:990x210[black];color=white:990x210[white];[blue][black][white]vstack=3 -frames:v 1 Estonia_flag.jpg
說(shuō)明
愛(ài)沙尼亞共和國(guó)國(guó)旗（英語(yǔ)：The National Flag of the Republic of Estonia，愛(ài)沙尼亞語(yǔ)：Eesti Vabariik Riigilipp），是愛(ài)沙尼亞共和國(guó)的國(guó)旗，呈長(zhǎng)方形，長(zhǎng)寬比為11∶7，旗面由自上而下的藍(lán)、黑、白三色平行且面積相等的橫長(zhǎng)方形相連組成，在愛(ài)沙尼亞語(yǔ)中，國(guó)旗通常叫作“sinimustvalge”（意為“藍(lán)色-黑色-白色”）.Link:參考鏈接
拉脫維亞
預(yù)覽ffplay -f lavfi -i color=9D2235:1000x200[crimson];[crimson]split=2[crimson1][crimson2];color=white:1000x100[white];[crimson1][white][crimson2]vstack=3
生成ffmpeg -f lavfi -i color=9D2235:1000x200[crimson];[crimson]split=2[crimson1][crimson2];color=white:1000x100[white];[crimson1][white][crimson2]vstack=3 -frames:v 1 Latvia_flag.jpg
說(shuō)明拉脫維亞共和國(guó)國(guó)旗（英語(yǔ)：The National Flag of the Republic of Latvia，拉脫維亞語(yǔ)：Latvijas Republikas nacionālā karogs），是拉脫維亞共和國(guó)的國(guó)旗，呈長(zhǎng)方形，長(zhǎng)寬比為2∶1，旗面由三個(gè)自上而下的橫長(zhǎng)方形相連組成，顏色依次是深紅、白色、深紅，顏色分布比例為2∶1∶2，國(guó)旗上的深紅色一般被稱之為“拉脫維亞紅”。Link:參考鏈接
立陶宛
預(yù)覽ffplay -f lavfi -i color=yellow:1000x200[yellow];color=green:1000x200[green];color=red:1000x200[red];[yellow][green][red]vstack=3
白俄羅斯~待補(bǔ)充
待補(bǔ)充
烏克蘭
ffplay -f lavfi -i color=0057b7:900x300[blue];color=ffd700:900x300[yellow];[blue][yellow]vstack=2
Link:參考鏈接
摩爾多瓦~待補(bǔ)充
待補(bǔ)充
俄羅斯
預(yù)覽ffplay -f lavfi -i color=white:900x200[white];color=0051BA:900x200[blue];color=D81E05:900x200[red];[white][blue][red]vstack=3
生成ffmpeg -f lavfi -i color=white:900x200[white];color=0051BA:900x200[blue];color=D81E05:900x200[red];[white][blue][red]vstack=3 -frames:v 1 Russian_flag.jpg
說(shuō)明
俄羅斯聯(lián)邦的國(guó)旗是橫長(zhǎng)方形的，其長(zhǎng)和寬的比值大約為3:2 。國(guó)旗的表面由3個(gè)長(zhǎng)方形并排組成的，主要以白色、藍(lán)色和紅色三種顏色為主。
Link:色號(hào)參考鏈接文章來(lái)源：http://www.zghlxwxcb.cn/news/detail-798542.html
德國(guó)
ffplay -f lavfi -i color=0A0A0D:900x200[C1];color=C1121C:900x200[C2];color=EEC900:900x200[C3];[C1][C2][C3]vstack=3 
Link:參考鏈接文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-798542.html
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