[FFmpeg-cvslog] vf_aspect: support variables in evaluating the aspect ratios
Rudolf Polzer
git at videolan.org
Sun Nov 3 12:01:37 CET 2013
ffmpeg | branch: master | Rudolf Polzer <divVerent at xonotic.org> | Sat Nov 2 11:57:24 2013 +0100| [34a0ac41a880039c7fb4b3abce10d8e2ce48fac7] | committer: Anton Khirnov
vf_aspect: support variables in evaluating the aspect ratios
Example: -vf setsar=sar="sar*9/10"
Signed-off-by: Rudolf Polzer <divverent at xonotic.org>
Signed-off-by: Anton Khirnov <anton at khirnov.net>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=34a0ac41a880039c7fb4b3abce10d8e2ce48fac7
---
Changelog | 1 +
doc/filters.texi | 54 +++++++++++++++++++++++++++--
libavfilter/vf_aspect.c | 86 +++++++++++++++++++++++++++++++++++++++++++++--
3 files changed, 137 insertions(+), 4 deletions(-)
diff --git a/Changelog b/Changelog
index d978fe0..540aa08 100644
--- a/Changelog
+++ b/Changelog
@@ -45,6 +45,7 @@ version 10:
- raw HEVC, HEVC in MOV/MP4, HEVC in Matroska, HEVC in MPEG-TS demuxing
- remove avplay -vismv option, which has not worked for a long time
- Live HDS muxer
+- setsar/setdar filters now support variables in ratio expressions
version 9:
diff --git a/doc/filters.texi b/doc/filters.texi
index e4fb57e..afb48b1 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -2049,10 +2049,35 @@ This filter accepts the following options:
@table @option
@item dar
-Output display aspect ratio, as a rational or a decimal number.
+Output display aspect ratio.
@end table
+The parameter @var{dar} is an expression containing
+the following constants:
+
+ at table @option
+ at item E, PI, PHI
+the corresponding mathematical approximated values for e
+(euler number), pi (greek PI), phi (golden ratio)
+
+ at item w, h
+the input width and height
+
+ at item a
+same as @var{w} / @var{h}
+
+ at item sar
+input sample aspect ratio
+
+ at item dar
+input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
+
+ at item hsub, vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+ at end table
+
For example to change the display aspect ratio to 16:9, specify:
@example
setdar=dar=16/9
@@ -2158,10 +2183,35 @@ This filter accepts the following options:
@table @option
@item sar
-Output sample aspect ratio, as a rational or decimal number.
+Output sample aspect ratio.
@end table
+The parameter @var{sar} is an expression containing
+the following constants:
+
+ at table @option
+ at item E, PI, PHI
+the corresponding mathematical approximated values for e
+(euler number), pi (greek PI), phi (golden ratio)
+
+ at item w, h
+the input width and height
+
+ at item a
+same as @var{w} / @var{h}
+
+ at item sar
+input sample aspect ratio
+
+ at item dar
+input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
+
+ at item hsub, vsub
+horizontal and vertical chroma subsample values. For example for the
+pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
+ at end table
+
For example to change the sample aspect ratio to 10:11, specify:
@example
setsar=sar=10/11
diff --git a/libavfilter/vf_aspect.c b/libavfilter/vf_aspect.c
index 51ae27f..bb7f15e 100644
--- a/libavfilter/vf_aspect.c
+++ b/libavfilter/vf_aspect.c
@@ -26,13 +26,42 @@
#include <float.h>
#include "libavutil/common.h"
+#include "libavutil/eval.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/pixdesc.h"
#include "avfilter.h"
#include "internal.h"
#include "video.h"
+static const char *const var_names[] = {
+ "PI",
+ "PHI",
+ "E",
+ "w",
+ "h",
+ "a", "dar",
+ "sar",
+ "hsub",
+ "vsub",
+ NULL
+};
+
+enum var_name {
+ VAR_PI,
+ VAR_PHI,
+ VAR_E,
+ VAR_W,
+ VAR_H,
+ VAR_A, VAR_DAR,
+ VAR_SAR,
+ VAR_HSUB,
+ VAR_VSUB,
+ VARS_NB
+};
+
typedef struct {
const AVClass *class;
AVRational dar;
@@ -40,6 +69,7 @@ typedef struct {
#if FF_API_OLD_FILTER_OPTS
float aspect_num, aspect_den;
#endif
+ char *ratio_expr;
} AspectContext;
#if FF_API_OLD_FILTER_OPTS
@@ -68,12 +98,54 @@ static int filter_frame(AVFilterLink *link, AVFrame *frame)
#define OFFSET(x) offsetof(AspectContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
+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_PI] = M_PI;
+ var_values[VAR_PHI] = M_PHI;
+ var_values[VAR_E] = M_E;
+ 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*/
+ if ((ret = av_expr_parse_and_eval(&res, s->ratio_expr,
+ var_names, var_values,
+ NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
+ av_log(NULL, AV_LOG_ERROR,
+ "Error when evaluating the expression '%s'\n", s->ratio_expr);
+ return ret;
+ }
+ *aspect_ratio = av_d2q(res, INT_MAX);
+ return 0;
+}
+
#if CONFIG_SETDAR_FILTER
/* for setdar filter, convert from frame aspect ratio to pixel aspect ratio */
static int setdar_config_props(AVFilterLink *inlink)
{
AspectContext *s = inlink->dst->priv;
AVRational dar;
+ int ret;
+
+#if FF_API_OLD_FILTER_OPTS
+ if (!(s->aspect_num > 0 && s->aspect_den > 0)) {
+#endif
+ if ((ret = get_aspect_ratio(inlink, &s->dar)))
+ return ret;
+#if FF_API_OLD_FILTER_OPTS
+ }
+#endif
if (s->dar.num && s->dar.den) {
av_reduce(&s->sar.num, &s->sar.den,
@@ -98,7 +170,7 @@ static const AVOption setdar_options[] = {
{ "dar_num", NULL, OFFSET(aspect_num), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
{ "dar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
#endif
- { "dar", "display aspect ratio", OFFSET(dar), AV_OPT_TYPE_RATIONAL, { .dbl = 0 }, 0, INT_MAX, FLAGS },
+ { "dar", "display aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "1" }, .flags = FLAGS },
{ NULL },
};
@@ -150,6 +222,16 @@ AVFilter ff_vf_setdar = {
static int setsar_config_props(AVFilterLink *inlink)
{
AspectContext *s = inlink->dst->priv;
+ int ret;
+
+#if FF_API_OLD_FILTER_OPTS
+ if (!(s->aspect_num > 0 && s->aspect_den > 0)) {
+#endif
+ if ((ret = get_aspect_ratio(inlink, &s->sar)))
+ return ret;
+#if FF_API_OLD_FILTER_OPTS
+ }
+#endif
inlink->sample_aspect_ratio = s->sar;
@@ -161,7 +243,7 @@ static const AVOption setsar_options[] = {
{ "sar_num", NULL, OFFSET(aspect_num), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
{ "sar_den", NULL, OFFSET(aspect_den), AV_OPT_TYPE_FLOAT, { .dbl = 0 }, 0, FLT_MAX, FLAGS },
#endif
- { "sar", "sample (pixel) aspect ratio", OFFSET(sar), AV_OPT_TYPE_RATIONAL, { .dbl = 1 }, 0, INT_MAX, FLAGS },
+ { "sar", "sample (pixel) aspect ratio", OFFSET(ratio_expr), AV_OPT_TYPE_STRING, { .str = "1" }, .flags = FLAGS },
{ NULL },
};
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