> 在 2019年8月27日，23:29，Limin Wang <lance.lmw...@gmail.com> 写道：
>
> On Tue, Aug 27, 2019 at 03:17:09PM +0800, Steven Liu wrote:
>> Signed-off-by: Steven Liu <l...@chinaffmpeg.org>
>> ---
>> libavfilter/vf_delogo.c | 72 ++++++++++++++++++++++++++++++++++++++---
>> 1 file changed, 68 insertions(+), 4 deletions(-)
>>
>> diff --git a/libavfilter/vf_delogo.c b/libavfilter/vf_delogo.c
>> index 065d093641..cbc7e87a1c 100644
>> --- a/libavfilter/vf_delogo.c
>> +++ b/libavfilter/vf_delogo.c
>> @@ -31,10 +31,52 @@
>> #include "libavutil/imgutils.h"
>> #include "libavutil/opt.h"
>> #include "libavutil/pixdesc.h"
>> +#include "libavutil/eval.h"
>> #include "avfilter.h"
>> #include "formats.h"
>> #include "internal.h"
>> #include "video.h"
>> +static const char * const var_names[] = {
>> + "x",
>> + "y",
>> + "w",
>> + "h",
>> + "n", ///< number of frame
>> + "t", ///< timestamp expressed in seconds
>> + NULL
>> +};
>> +
>> +enum var_name {
>> + VAR_X,
>> + VAR_Y,
>> + VAR_W,
>> + VAR_H,
>> + VAR_N,
>> + VAR_T,
>> + VAR_VARS_NB
>> +};
>> +#define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts) *
>> av_q2d(tb))
>> +
>> +static int set_expr(AVExpr **pexpr, const char *expr, const char *option,
>> void *log_ctx)
>> +{
>> + int ret;
>> + AVExpr *old = NULL;
>> +
>> + if (*pexpr)
>> + old = *pexpr;
>> + ret = av_expr_parse(pexpr, expr, var_names, NULL, NULL, NULL, NULL, 0,
>> log_ctx);
>> + if (ret < 0) {
>> + av_log(log_ctx, AV_LOG_ERROR,
>> + "Error when parsing the expression '%s' for %s\n",
>> + expr, option);
>> + *pexpr = old;
>> + return ret;
>> + }
>> +
>> + av_expr_free(old);
>> + return 0;
>> +}
>> +
>>
>> /**
>> * Apply a simple delogo algorithm to the image in src and put the
>> @@ -156,16 +198,19 @@ static void apply_delogo(uint8_t *dst, int
>> dst_linesize,
>> typedef struct DelogoContext {
>> const AVClass *class;
>> int x, y, w, h, band, show;
>> + char *x_expr, *y_expr, *w_expr, *h_expr;
>> + AVExpr *x_pexpr, *y_pexpr, *w_pexpr, *h_pexpr;
>> + double var_values[VAR_VARS_NB];
>> } DelogoContext;
>>
>> #define OFFSET(x) offsetof(DelogoContext, x)
>> #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
>>
>> static const AVOption delogo_options[]= {
>> - { "x", "set logo x position", OFFSET(x), AV_OPT_TYPE_INT, {
>> .i64 = -1 }, -1, INT_MAX, FLAGS },
>> - { "y", "set logo y position", OFFSET(y), AV_OPT_TYPE_INT, {
>> .i64 = -1 }, -1, INT_MAX, FLAGS },
>> - { "w", "set logo width", OFFSET(w), AV_OPT_TYPE_INT, {
>> .i64 = -1 }, -1, INT_MAX, FLAGS },
>> - { "h", "set logo height", OFFSET(h), AV_OPT_TYPE_INT, {
>> .i64 = -1 }, -1, INT_MAX, FLAGS },
>> + { "x", "set logo x position", OFFSET(x_expr),
>> AV_OPT_TYPE_STRING, { .str = "-1" }, CHAR_MIN, CHAR_MAX, FLAGS },
>> + { "y", "set logo y position", OFFSET(y_expr),
>> AV_OPT_TYPE_STRING, { .str = "-1" }, CHAR_MIN, CHAR_MAX, FLAGS },
>> + { "w", "set logo width", OFFSET(w_expr),
>> AV_OPT_TYPE_STRING, { .str = "-1" }, CHAR_MIN, CHAR_MAX, FLAGS },
>> + { "h", "set logo height", OFFSET(h_expr),
>> AV_OPT_TYPE_STRING, { .str = "-1" }, CHAR_MIN, CHAR_MAX, FLAGS },
>> #if LIBAVFILTER_VERSION_MAJOR < 7
>> /* Actual default value for band/t is 1, set in init */
>> { "band", "set delogo area band size", OFFSET(band), AV_OPT_TYPE_INT, {
>> .i64 = 0 }, 0, INT_MAX, FLAGS },
>> @@ -194,6 +239,18 @@ static int query_formats(AVFilterContext *ctx)
>> static av_cold int init(AVFilterContext *ctx)
>> {
>> DelogoContext *s = ctx->priv;
>> + int ret = 0;
>> +
>> + if ((ret = set_expr(&s->x_pexpr, s->x_expr, "x", ctx)) < 0 ||
>> + (ret = set_expr(&s->y_pexpr, s->y_expr, "y", ctx)) < 0 ||
>> + (ret = set_expr(&s->w_pexpr, s->w_expr, "w", ctx)) < 0 ||
>> + (ret = set_expr(&s->h_pexpr, s->h_expr, "h", ctx)) < 0 )
>> + return ret;
>> +
>> + s->x = av_expr_eval(s->x_pexpr, s->var_values, s);
>> + s->y = av_expr_eval(s->y_pexpr, s->var_values, s);
>> + s->w = av_expr_eval(s->w_pexpr, s->var_values, s);
>> + s->h = av_expr_eval(s->h_pexpr, s->var_values, s);
>
> it'll memory leak if not to use av_expr_free after uninit I think.
okay, will submit new version patch.
>
>>
>> #define CHECK_UNSET_OPT(opt) \
>> if (s->opt == -1) { \
>> @@ -252,6 +309,13 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
>> *in)
>> int plane;
>> AVRational sar;
>>
>> + s->var_values[VAR_N] = inlink->frame_count_out;
>> + s->var_values[VAR_T] = TS2T(in->pts, inlink->time_base);
>> + s->x = av_expr_eval(s->x_pexpr, s->var_values, s);
>> + s->y = av_expr_eval(s->y_pexpr, s->var_values, s);
>> + s->w = av_expr_eval(s->w_pexpr, s->var_values, s);
>> + s->h = av_expr_eval(s->h_pexpr, s->var_values, s);
>> +
>> if (av_frame_is_writable(in)) {
>> direct = 1;
>> out = in;
>> --
>> 2.17.2 (Apple Git-113)
>>
>>
>>
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Thanks
Steven
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