From 16134b7c4041406e288c652596acbc872367fae1 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefano.sabatini-lala@poste.it>
Date: Mon, 11 Oct 2010 23:27:33 +0000
Subject: Extend the nullsrc source, make it accept a parameter for specifying
 the timebase. Useful for debugging timebase configuration issues.

Originally committed as revision 25446 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavfilter/vsrc_nullsrc.c | 53 +++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 3 deletions(-)

(limited to 'libavfilter/vsrc_nullsrc.c')

diff --git a/libavfilter/vsrc_nullsrc.c b/libavfilter/vsrc_nullsrc.c
index f319ceb980..76271bbced 100644
--- a/libavfilter/vsrc_nullsrc.c
+++ b/libavfilter/vsrc_nullsrc.c
@@ -21,10 +21,32 @@
  * null video source
  */
 
+#include "libavutil/avstring.h"
+#include "libavutil/eval.h"
+#include "libavcore/parseutils.h"
 #include "avfilter.h"
 
+static const char *var_names[] = {
+    "E",
+    "PHI",
+    "PI",
+    "AVTB",   /* default timebase 1/AV_TIME_BASE */
+    NULL
+};
+
+enum var_name {
+    VAR_E,
+    VAR_PHI,
+    VAR_PI,
+    VAR_AVTB,
+    VAR_INTB,
+    VAR_VARS_NB
+};
+
 typedef struct {
     int w, h;
+    char tb_expr[256];
+    double var_values[VAR_VARS_NB];
 } NullContext;
 
 static int init(AVFilterContext *ctx, const char *args, void *opaque)
@@ -33,9 +55,10 @@ static int init(AVFilterContext *ctx, const char *args, void *opaque)
 
     priv->w = 352;
     priv->h = 288;
+    av_strlcpy(priv->tb_expr, "AVTB", sizeof(priv->tb_expr));
 
     if (args)
-        sscanf(args, "%d:%d", &priv->w, &priv->h);
+        sscanf(args, "%d:%d:%255[^:]", &priv->w, &priv->h, priv->tb_expr);
 
     if (priv->w <= 0 || priv->h <= 0) {
         av_log(ctx, AV_LOG_ERROR, "Non-positive size values are not acceptable.\n");
@@ -47,12 +70,36 @@ static int init(AVFilterContext *ctx, const char *args, void *opaque)
 
 static int config_props(AVFilterLink *outlink)
 {
-    NullContext *priv = outlink->src->priv;
+    AVFilterContext *ctx = outlink->src;
+    NullContext *priv = ctx->priv;
+    AVRational tb;
+    int ret;
+    double res;
+
+    priv->var_values[VAR_E]    = M_E;
+    priv->var_values[VAR_PHI]  = M_PHI;
+    priv->var_values[VAR_PI]   = M_PI;
+    priv->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
+
+    if ((ret = av_parse_and_eval_expr(&res, priv->tb_expr, var_names, priv->var_values,
+                                      NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", priv->tb_expr);
+        return ret;
+    }
+    tb = av_d2q(res, INT_MAX);
+    if (tb.num <= 0 || tb.den <= 0) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid non-positive value for the timebase %d/%d.\n",
+               tb.num, tb.den);
+        return AVERROR(EINVAL);
+    }
 
     outlink->w = priv->w;
     outlink->h = priv->h;
+    outlink->time_base = tb;
 
-    av_log(outlink->src, AV_LOG_INFO, "w:%d h:%d\n", priv->w, priv->h);
+    av_log(outlink->src, AV_LOG_INFO, "w:%d h:%d tb:%d/%d\n", priv->w, priv->h,
+           tb.num, tb.den);
 
     return 0;
 }
-- 
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