int ff_parse_time_base(AVRational *ret, const char *arg, void *log_ctx)
{
AVRational r;
if(av_parse_ratio(&r, arg, INT_MAX, 0, log_ctx) < 0 ||r.num<=0 ||r.den<=0) {
av_log(log_ctx, AV_LOG_ERROR, "Invalid time base '%s'\n", arg);
return AVERROR(EINVAL);
}
*ret = r;
return 0;
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
AspectContext *aspect = ctx->priv;
aspect->ratio = (AVRational) {0, 1};
if (args) {
if (av_parse_ratio(&aspect->ratio, args, 100, 0, ctx) < 0 ||
aspect->ratio.num < 0 || aspect->ratio.den <= 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid string '%s' for aspect ratio.\n", args);
return AVERROR(EINVAL);
}
}
av_log(ctx, AV_LOG_INFO, "a:%d/%d\n", aspect->ratio.num, aspect->ratio.den);
return 0;
}
static int get_aspect_ratio(AVFilterLink *inlink, AVRational *aspect_ratio)
{
AVFilterContext *ctx = inlink->dst;
AspectContext *s = inlink->dst->priv;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
double var_values[VARS_NB], res;
int ret;
var_values[VAR_W] = inlink->w;
var_values[VAR_H] = inlink->h;
var_values[VAR_A] = (double) inlink->w / inlink->h;
var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
(double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
/* evaluate new aspect ratio*/
ret = av_expr_parse_and_eval(&res, s->ratio_expr,
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0) {
ret = av_parse_ratio(aspect_ratio, s->ratio_expr, s->max, 0, ctx);
} else
*aspect_ratio = av_d2q(res, s->max);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR,
"Error when evaluating the expression '%s'\n", s->ratio_expr);
return ret;
}
if (aspect_ratio->num < 0 || aspect_ratio->den <= 0) {
av_log(ctx, AV_LOG_ERROR,
"Invalid string '%s' for aspect ratio\n", s->ratio_expr);
return AVERROR(EINVAL);
}
return 0;
}
