切片生成的ts文件只有一片的问题

一般切片生成一片都是文件本身有问题，比如这个音频文件, 切片的时候可以指定参数/vn/1可修复，vn/1表示的是忽略视频流的信息。

比如这个mp3文件:

http://dn-odum9helk.qbox.me/wjw/48min-66mb.mp3

这样切片生成的文件是只有一片的:

avthumb/m3u8/segtime/10/ab/48k/ar/44100/acodec/libfaac/noDomain/1

加一个vn/1参数再次切片是正常的:

avthumb/m3u8/segtime/10/ab/48k/ar/44100/acodec/libfaac/noDomain/1/vn/1

原因如下:

Frame rate very high for a muxer not efficiently supporting it. 导致结果不符合预期

因为此音频实际含有视频流
index":1,"codec_name":"mjpeg","codec_type":"video","start_time":"0.025056","duration":"2884.075100","bit_rate":"","nb_frames":"","width":420,"height":420,"pix_fmt":"yuvj444p","r_frame_rate":"90000/1","avg_frame_rate":"0/0","sample_aspect_ratio":"1:1","display_aspect_ratio":"1:1","tags":{},"Disposition":

{"attached_pic":1}