--- /dev/null
+/*
+ * Copyright (C) 2010 Stefano Sabatini
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Set timebase for the output link.
+ */
+
+#include "libavutil/avstring.h"
+#include "libavutil/eval.h"
+#include "libavutil/rational.h"
+#include "avfilter.h"
+#include "internal.h"
+
+static const char *var_names[] = {
+ "E",
+ "PHI",
+ "PI",
+ "AVTB", /* default timebase 1/AV_TIME_BASE */
+ "intb", /* input timebase */
+ NULL
+};
+
+enum var_name {
+ VAR_E,
+ VAR_PHI,
+ VAR_PI,
+ VAR_AVTB,
+ VAR_INTB,
+ VAR_VARS_NB
+};
+
+typedef struct {
+ char tb_expr[256];
+ double var_values[VAR_VARS_NB];
+} SetTBContext;
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+ SetTBContext *settb = ctx->priv;
+ av_strlcpy(settb->tb_expr, "intb", sizeof(settb->tb_expr));
+
+ if (args)
+ sscanf(args, "%255[^:]", settb->tb_expr);
+
+ return 0;
+}
+
+static int config_output_props(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ SetTBContext *settb = ctx->priv;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVRational time_base;
+ int ret;
+ double res;
+
+ settb->var_values[VAR_E] = M_E;
+ settb->var_values[VAR_PHI] = M_PHI;
+ settb->var_values[VAR_PI] = M_PI;
+ settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
+ settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
+
+ outlink->w = inlink->w;
+ outlink->h = inlink->h;
+
+ if ((ret = av_parse_and_eval_expr(&res, settb->tb_expr, var_names, settb->var_values,
+ NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
+ return ret;
+ }
+ time_base = av_d2q(res, INT_MAX);
+ if (time_base.num <= 0 || time_base.den <= 0) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Invalid non-positive values for the timebase num:%d or den:%d.\n",
+ time_base.num, time_base.den);
+ return AVERROR(EINVAL);
+ }
+
+ outlink->time_base = time_base;
+ av_log(outlink->src, AV_LOG_INFO, "tb:%d/%d -> tb:%d/%d\n",
+ inlink ->time_base.num, inlink ->time_base.den,
+ outlink->time_base.num, outlink->time_base.den);
+
+ return 0;
+}
+
+static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ AVFilterBufferRef *picref2 = picref;
+
+ if (av_cmp_q(inlink->time_base, outlink->time_base)) {
+ picref2 = avfilter_ref_buffer(picref, ~0);
+ picref2->pts = av_rescale_q(picref->pts, inlink->time_base, outlink->time_base);
+ av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
+ inlink ->time_base.num, inlink ->time_base.den, picref ->pts,
+ outlink->time_base.num, outlink->time_base.den, picref2->pts);
+ avfilter_unref_buffer(picref);
+ }
+
+ avfilter_start_frame(outlink, picref2);
+}
+
+AVFilter avfilter_vf_settb = {
+ .name = "settb",
+ .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
+ .init = init,
+
+ .priv_size = sizeof(SetTBContext),
+
+ .inputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .get_video_buffer = avfilter_null_get_video_buffer,
+ .start_frame = start_frame,
+ .end_frame = avfilter_null_end_frame },
+ { .name = NULL }},
+
+ .outputs = (AVFilterPad[]) {{ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output_props, },
+ { .name = NULL}},
+};