static int atrim_filter_frame(AVFilterLink *inlink, AVFrame *frame) { AVFilterContext *ctx = inlink->dst; TrimContext *s = ctx->priv; int64_t start_sample, end_sample = frame->nb_samples; int64_t pts; int drop; /* drop everything if EOF has already been returned */ if (s->eof) { av_frame_free(&frame); return 0; } if (frame->pts != AV_NOPTS_VALUE) pts = av_rescale_q(frame->pts, inlink->time_base, (AVRational){ 1, inlink->sample_rate }); else pts = s->next_pts; s->next_pts = pts + frame->nb_samples; /* check if at least a part of the frame is after the start time */ if (s->start_sample < 0 && s->start_pts == AV_NOPTS_VALUE) { start_sample = 0; } else { drop = 1; start_sample = frame->nb_samples; if (s->start_sample >= 0 && s->nb_samples + frame->nb_samples > s->start_sample) { drop = 0; start_sample = FFMIN(start_sample, s->start_sample - s->nb_samples); } if (s->start_pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && pts + frame->nb_samples > s->start_pts) { drop = 0; start_sample = FFMIN(start_sample, s->start_pts - pts); } if (drop) goto drop; } if (s->first_pts == AV_NOPTS_VALUE) s->first_pts = pts + start_sample; /* check if at least a part of the frame is before the end time */ if (s->end_sample == INT64_MAX && s->end_pts == AV_NOPTS_VALUE && !s->duration_tb) { end_sample = frame->nb_samples; } else { drop = 1; end_sample = 0; if (s->end_sample != INT64_MAX && s->nb_samples < s->end_sample) { drop = 0; end_sample = FFMAX(end_sample, s->end_sample - s->nb_samples); } if (s->end_pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE && pts < s->end_pts) { drop = 0; end_sample = FFMAX(end_sample, s->end_pts - pts); } if (s->duration_tb && pts - s->first_pts < s->duration_tb) { drop = 0; end_sample = FFMAX(end_sample, s->first_pts + s->duration_tb - pts); } if (drop) { s->eof = 1; goto drop; } } s->nb_samples += frame->nb_samples; start_sample = FFMAX(0, start_sample); end_sample = FFMIN(frame->nb_samples, end_sample); av_assert0(start_sample < end_sample); if (start_sample) { AVFrame *out = ff_get_audio_buffer(ctx->outputs[0], end_sample - start_sample); if (!out) { av_frame_free(&frame); return AVERROR(ENOMEM); } av_frame_copy_props(out, frame); av_samples_copy(out->extended_data, frame->extended_data, 0, start_sample, out->nb_samples, av_get_channel_layout_nb_channels(frame->channel_layout), frame->format); if (out->pts != AV_NOPTS_VALUE) out->pts += av_rescale_q(start_sample, (AVRational){ 1, out->sample_rate }, inlink->time_base); av_frame_free(&frame); frame = out; } else frame->nb_samples = end_sample; s->got_output = 1; return ff_filter_frame(ctx->outputs[0], frame); drop: s->nb_samples += frame->nb_samples; av_frame_free(&frame); return 0; }