AVOutputStream   1056 ffmpeg.c           AVOutputStream *ost;
AVOutputStream   1181 ffmpeg.c           AVOutputStream *ost;
AVOutputStream   1557 ffmpeg.c           AVOutputStream *ost, **ost_table = NULL;
AVOutputStream   1639 ffmpeg.c           ost_table = av_mallocz(sizeof(AVOutputStream *) * nb_ostreams);
AVOutputStream   1643 ffmpeg.c               ost = av_mallocz(sizeof(AVOutputStream));