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00026 #include "libavutil/avstring.h"
00027 #include "libavutil/eval.h"
00028 #include "libavutil/mathematics.h"
00029 #include "libavutil/rational.h"
00030 #include "avfilter.h"
00031 #include "internal.h"
00032
00033 static const char *var_names[] = {
00034 "E",
00035 "PHI",
00036 "PI",
00037 "AVTB",
00038 "intb",
00039 NULL
00040 };
00041
00042 enum var_name {
00043 VAR_E,
00044 VAR_PHI,
00045 VAR_PI,
00046 VAR_AVTB,
00047 VAR_INTB,
00048 VAR_VARS_NB
00049 };
00050
00051 typedef struct {
00052 char tb_expr[256];
00053 double var_values[VAR_VARS_NB];
00054 } SetTBContext;
00055
00056 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
00057 {
00058 SetTBContext *settb = ctx->priv;
00059 av_strlcpy(settb->tb_expr, "intb", sizeof(settb->tb_expr));
00060
00061 if (args)
00062 sscanf(args, "%255[^:]", settb->tb_expr);
00063
00064 return 0;
00065 }
00066
00067 static int config_output_props(AVFilterLink *outlink)
00068 {
00069 AVFilterContext *ctx = outlink->src;
00070 SetTBContext *settb = ctx->priv;
00071 AVFilterLink *inlink = ctx->inputs[0];
00072 AVRational time_base;
00073 int ret;
00074 double res;
00075
00076 settb->var_values[VAR_E] = M_E;
00077 settb->var_values[VAR_PHI] = M_PHI;
00078 settb->var_values[VAR_PI] = M_PI;
00079 settb->var_values[VAR_AVTB] = av_q2d(AV_TIME_BASE_Q);
00080 settb->var_values[VAR_INTB] = av_q2d(inlink->time_base);
00081
00082 outlink->w = inlink->w;
00083 outlink->h = inlink->h;
00084
00085 if ((ret = av_expr_parse_and_eval(&res, settb->tb_expr, var_names, settb->var_values,
00086 NULL, NULL, NULL, NULL, NULL, 0, NULL)) < 0) {
00087 av_log(ctx, AV_LOG_ERROR, "Invalid expression '%s' for timebase.\n", settb->tb_expr);
00088 return ret;
00089 }
00090 time_base = av_d2q(res, INT_MAX);
00091 if (time_base.num <= 0 || time_base.den <= 0) {
00092 av_log(ctx, AV_LOG_ERROR,
00093 "Invalid non-positive values for the timebase num:%d or den:%d.\n",
00094 time_base.num, time_base.den);
00095 return AVERROR(EINVAL);
00096 }
00097
00098 outlink->time_base = time_base;
00099 av_log(outlink->src, AV_LOG_INFO, "tb:%d/%d -> tb:%d/%d\n",
00100 inlink ->time_base.num, inlink ->time_base.den,
00101 outlink->time_base.num, outlink->time_base.den);
00102
00103 return 0;
00104 }
00105
00106 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
00107 {
00108 AVFilterContext *ctx = inlink->dst;
00109 AVFilterLink *outlink = ctx->outputs[0];
00110 AVFilterBufferRef *picref2 = picref;
00111
00112 if (av_cmp_q(inlink->time_base, outlink->time_base)) {
00113 picref2 = avfilter_ref_buffer(picref, ~0);
00114 picref2->pts = av_rescale_q(picref->pts, inlink->time_base, outlink->time_base);
00115 av_log(ctx, AV_LOG_DEBUG, "tb:%d/%d pts:%"PRId64" -> tb:%d/%d pts:%"PRId64"\n",
00116 inlink ->time_base.num, inlink ->time_base.den, picref ->pts,
00117 outlink->time_base.num, outlink->time_base.den, picref2->pts);
00118 avfilter_unref_buffer(picref);
00119 }
00120
00121 avfilter_start_frame(outlink, picref2);
00122 }
00123
00124 AVFilter avfilter_vf_settb = {
00125 .name = "settb",
00126 .description = NULL_IF_CONFIG_SMALL("Set timebase for the output link."),
00127 .init = init,
00128
00129 .priv_size = sizeof(SetTBContext),
00130
00131 .inputs = (AVFilterPad[]) {{ .name = "default",
00132 .type = AVMEDIA_TYPE_VIDEO,
00133 .get_video_buffer = avfilter_null_get_video_buffer,
00134 .start_frame = start_frame,
00135 .end_frame = avfilter_null_end_frame },
00136 { .name = NULL }},
00137
00138 .outputs = (AVFilterPad[]) {{ .name = "default",
00139 .type = AVMEDIA_TYPE_VIDEO,
00140 .config_props = config_output_props, },
00141 { .name = NULL}},
00142 };