我正在使用云转换API来转换视频。当我使用curl_exec（）命中它的purl URL时，它返回json输出
{"id":"F024KteuEliCgA9TLMxh","url":"//hostiorg3y.cloudconvert.com/process/F024KteuEliCgA9TLMxh","percent":100,"message":"Uploaded file to S3 Bucket","step":"finished","starttime":1445239854,"expire":1445283060,"input":{"type":"s3","filename":"newvideo_0.mp4","name":"newvideo_0","ext":"mp4","size":1089552,"url":"//hostiorg3y.cloudconvert.com/download/F024KteuEliCgA9TLMxh/input"},"output":{"url":"//hostiorg3y.cloudconvert.com/download/F024KteuEliCgA9TLMxh","save":true,"ext":"mpg","filename":"newvideo_0.mpg","size":1685504,"type":"s3"},"converter":{"format":"mpg","type":"ffmpeg","options":{"video_codec":"MPEG2VIDEO","video_bitrate":"1024","audio_codec":"MP3","audio_bitrate":"128","audio_frequency":"44100","audio_qscale":"5"},"duration":14.98},"group":"video","endtime":1445239860,"minutes":1}
但是当我使用json_decode（）函数对其进行解码时。它返回NULL。