1.环境
ubuntu 16.04.1 64位
编解码使用nvidia的硬件加速接口
调用方式ffmpeg api
2.多filters研究
2.1.filter_spec描述
char *video_filter_spec = "drawtext=fontfile=FreeSerif.ttf:\
fontsize=36: \
fontcolor=yellow@1.0: \
x='if(gte(t,5), (main_w-mod(t*30,main_w+text_w)), NAN)':\
y=500:\
text='Hello, this is drawtext function,any more questsion can concat su.gao(sugao_cn@163.com)!' [text]; \
movie=/root/mscore/extern/source/logo/test.png [wm]; \
[text] [wm] overlay=0:0 [out]";
2.2.filter_spec描述解读
1].从左到右滚动播出Hello, this is drawtext function,any more questsion can concat su.gao(sugao_cn@163.com)!的内容，字体颜色为黄色，字体透明度100%，字体大小为36，字体FreeSerif。且将视频输出管道打上标签text；
drawtext=fontfile=FreeSerif.ttf:\
fontsize=36: \
fontcolor=yellow@1.0: \
x='if(gte(t,5), (main_w-mod(t*30,main_w+text_w)), NAN)':\
y=500:\
text='Hello, this is drawtext function,any more questsion can concat su.gao(sugao_cn@163.com)!' [text];
2].将图片test.png叠加到标签为text的视频上，位置为左上角；
movie=/root/mscore/extern/source/logo/test.png [wm]; \
[text] [wm] overlay=0:0 [out]";
2.3.filters使用情况
nb_filters:5
----------------------
filters:in(buffer)
filters outputs:default(0)
----------------------
----------------------
filters：out(buffersink)
filters inputs:default(0)
----------------------
----------------------
filtersarsed_drawtext_0(drawtext)
filters inputs:default(0)
filters outputs:default(0)
----------------------
----------------------
filtersarsed_movie_1(movie)
----------------------
----------------------
filtersarsed_overlay_2(overlay)
filters inputs:main(0)
filters outputs:default(0)
----------------------
3.效果图
4.参考