int avfilter_config_links(AVFilterContext *filter) { int (*config_link)(AVFilterLink *); unsigned i; int ret; for (i = 0; i < filter->nb_inputs; i ++) { AVFilterLink *link = filter->inputs[i]; AVFilterLink *inlink = link->src->nb_inputs ? link->src->inputs[0] : NULL; if (!link) continue; link->current_pts = AV_NOPTS_VALUE; switch (link->init_state) { case AVLINK_INIT: continue; case AVLINK_STARTINIT: av_log(filter, AV_LOG_INFO, "circular filter chain detected\n"); return 0; case AVLINK_UNINIT: link->init_state = AVLINK_STARTINIT; if ((ret = avfilter_config_links(link->src)) < 0) return ret; if (!(config_link = link->srcpad->config_props)) { if (link->src->nb_inputs != 1) { av_log(link->src, AV_LOG_ERROR, "Source filters and filters " "with more than one input " "must set config_props() " "callbacks on all outputs\n"); return AVERROR(EINVAL); } } else if ((ret = config_link(link)) < 0) { av_log(link->src, AV_LOG_ERROR, "Failed to configure output pad on %s\n", link->src->name); return ret; } switch (link->type) { case AVMEDIA_TYPE_VIDEO: if (!link->time_base.num && !link->time_base.den) link->time_base = inlink ? inlink->time_base : AV_TIME_BASE_Q; if (!link->sample_aspect_ratio.num && !link->sample_aspect_ratio.den) link->sample_aspect_ratio = inlink ? inlink->sample_aspect_ratio : (AVRational){1,1}; if (inlink && !link->frame_rate.num && !link->frame_rate.den) link->frame_rate = inlink->frame_rate; if (inlink) { if (!link->w) link->w = inlink->w; if (!link->h) link->h = inlink->h; } else if (!link->w || !link->h) { av_log(link->src, AV_LOG_ERROR, "Video source filters must set their output link's " "width and height\n"); return AVERROR(EINVAL); } break; case AVMEDIA_TYPE_AUDIO: if (inlink) { if (!link->sample_rate) link->sample_rate = inlink->sample_rate; if (!link->time_base.num && !link->time_base.den) link->time_base = inlink->time_base; if (!link->channel_layout) link->channel_layout = inlink->channel_layout; } else if (!link->sample_rate) { av_log(link->src, AV_LOG_ERROR, "Audio source filters must set their output link's " "sample_rate\n"); return AVERROR(EINVAL); } if (!link->time_base.num && !link->time_base.den) link->time_base = (AVRational) {1, link->sample_rate}; } if ((config_link = link->dstpad->config_props)) if ((ret = config_link(link)) < 0) { av_log(link->src, AV_LOG_ERROR, "Failed to configure input pad on %s\n", link->dst->name); return ret; } link->init_state = AVLINK_INIT; } } return 0; }