[FFmpeg-cvslog] lavfi/scale: implement clever/insane parsing heuristic, and add a size option
Stefano Sabatini
git at videolan.org
Mon Oct 29 17:45:27 CET 2012
ffmpeg | branch: master | Stefano Sabatini <stefasab at gmail.com> | Mon Oct 29 11:48:53 2012 +0100| [19add3224f1ea6ea8e78a9bf79340edd3e924e04] | committer: Stefano Sabatini
lavfi/scale: implement clever/insane parsing heuristic, and add a size option
If the first argument can be read as a video size, set that output size
in the scale. This allows to specify in a filtergraph scale=qcif or
scale=320x240.
This is not completely safe, for example in case of a typo in the video
size string the first argument will be read as the input width
expression, giving rise to a confusing comment.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=19add3224f1ea6ea8e78a9bf79340edd3e924e04
---
doc/filters.texi | 27 ++++++++++++++++++++++++---
libavfilter/version.h | 2 +-
libavfilter/vf_scale.c | 44 ++++++++++++++++++++++++++++++++++++++++----
3 files changed, 65 insertions(+), 8 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 7807b45..b9ad187 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -3017,7 +3017,9 @@ of the input, by changing the output sample aspect ratio.
This filter accepts a list of named options in the form of
@var{key}=@var{value} pairs separated by ":". If the key for the first
two options is not specified, the assumed keys for the first two
-values are @code{w} and @code{h}.
+values are @code{w} and @code{h}. If the first option has no key and
+can be interpreted like a video size specification, it will be used
+to set the video size.
A description of the accepted options follows.
@@ -3050,6 +3052,10 @@ Default value is @code{0}.
@item flags
Set libswscale scaling flags. If not explictly specified the filter
applies a bilinear scaling algorithm.
+
+ at item size, s
+Set the video size, the value must be a valid abbreviation or in the
+form @var{width}x at var{height}.
@end table
The values of the @var{w} and @var{h} options are expressions
@@ -3102,12 +3108,27 @@ Scale the input video to a size of 200x100:
scale=200:100
@end example
- at item
-The above example is the same as:
+This is equivalent to:
@example
scale=w=200:h=100
@end example
+or:
+ at example
+scale=200x100
+ at end example
+
+ at item
+Specify a size abbreviation for the output size:
+ at example
+scale=qcif
+ at end example
+
+which can also be written as:
+ at example
+scale=size=qcif
+ at end example
+
@item
Scale the input to 2x:
@example
diff --git a/libavfilter/version.h b/libavfilter/version.h
index 3ce13c1..e6c10e5 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -30,7 +30,7 @@
#define LIBAVFILTER_VERSION_MAJOR 3
#define LIBAVFILTER_VERSION_MINOR 20
-#define LIBAVFILTER_VERSION_MICRO 107
+#define LIBAVFILTER_VERSION_MICRO 108
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
index 5c6751b..82a777c 100644
--- a/libavfilter/vf_scale.c
+++ b/libavfilter/vf_scale.c
@@ -35,6 +35,7 @@
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/avassert.h"
@@ -78,6 +79,7 @@ typedef struct {
*/
int w, h;
char *flags_str; ///sws flags string
+ char *size_str;
unsigned int flags; ///sws flags
int hsub, vsub; ///< chroma subsampling
@@ -94,12 +96,14 @@ typedef struct {
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption scale_options[] = {
- { "w", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, FLAGS },
- { "width", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = "iw"}, 0, 0, FLAGS },
- { "h", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, FLAGS },
- { "height", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = "ih"}, 0, 0, FLAGS },
+ { "w", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
+ { "width", "set width expression", OFFSET(w_expr), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
+ { "h", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
+ { "height", "set height expression", OFFSET(h_expr), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, FLAGS },
{ "flags", "set libswscale flags", OFFSET(flags_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, INT_MAX, FLAGS },
{ "interl", "set interlacing", OFFSET(interlaced), AV_OPT_TYPE_INT, {.i64 = 0 }, -1, 1, FLAGS },
+ { "size", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
+ { "s", "set video size", OFFSET(size_str), AV_OPT_TYPE_STRING, {.str = NULL}, 0, FLAGS },
{ NULL },
};
@@ -110,13 +114,45 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
ScaleContext *scale = ctx->priv;
static const char *shorthand[] = { "w", "h", NULL };
int ret;
+ const char *args0 = args;
scale->class = &scale_class;
av_opt_set_defaults(scale);
+ if (args && (scale->size_str = av_get_token(&args, ":"))) {
+ if (av_parse_video_size(&scale->w, &scale->h, scale->size_str) < 0) {
+ av_freep(&scale->size_str);
+ args = args0;
+ } else if (*args)
+ args++;
+ }
+
if ((ret = av_opt_set_from_string(scale, args, shorthand, "=", ":")) < 0)
return ret;
+ if (scale->size_str && (scale->w_expr || scale->h_expr)) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Size and width/height expressions cannot be set at the same time.\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (scale->size_str) {
+ char buf[32];
+ if ((ret = av_parse_video_size(&scale->w, &scale->h, scale->size_str)) < 0) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Invalid size '%s'\n", scale->size_str);
+ return ret;
+ }
+ snprintf(buf, sizeof(buf)-1, "%d", scale->w);
+ av_opt_set(scale, "w", buf, 0);
+ snprintf(buf, sizeof(buf)-1, "%d", scale->h);
+ av_opt_set(scale, "h", buf, 0);
+ }
+ if (!scale->w_expr)
+ av_opt_set(scale, "w", "iw", 0);
+ if (!scale->h_expr)
+ av_opt_set(scale, "h", "ih", 0);
+
av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s flags:%s interl:%d\n",
scale->w_expr, scale->h_expr, scale->flags_str, scale->interlaced);
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