[FFmpeg-cvslog] avfilter: port qp filter from libmpcodecs
Paul B Mahol
git at videolan.org
Wed Jan 14 21:05:04 CET 2015
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Wed Sep 18 23:57:55 2013 +0000| [baea14d86021d04901171ff2430da3f93898636b] | committer: Michael Niedermayer
avfilter: port qp filter from libmpcodecs
Signed-off-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=baea14d86021d04901171ff2430da3f93898636b
---
doc/filters.texi | 32 ++++++++++
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/vf_qp.c | 152 ++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 186 insertions(+)
diff --git a/doc/filters.texi b/doc/filters.texi
index 42f69ea..154508c 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -7351,6 +7351,38 @@ telecine NTSC input:
ffmpeg -i input -vf pullup -r 24000/1001 ...
@end example
+ at section qp
+
+Change video quantization parameters (QP).
+
+The filter accepts the following option:
+
+ at table @option
+ at item qp
+Set expression for quantization parameter.
+ at end table
+
+The expression is evaluated through the eval API and can contain, among others,
+the following constants:
+
+ at table @var
+ at item known
+1 if index is not 129, 0 otherwise.
+
+ at item qp
+Sequentional index starting from -129 to 128.
+ at end table
+
+ at subsection Examples
+
+ at itemize
+ at item
+Some equation like:
+ at example
+qp=2+2*sin(PI*qp)
+ at end example
+ at end itemize
+
@section removelogo
Suppress a TV station logo, using an image file to determine which
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index a2bac38..37f5a65 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -167,6 +167,7 @@ OBJS-$(CONFIG_PP_FILTER) += vf_pp.o
OBJS-$(CONFIG_PP7_FILTER) += vf_pp7.o
OBJS-$(CONFIG_PSNR_FILTER) += vf_psnr.o dualinput.o framesync.o
OBJS-$(CONFIG_PULLUP_FILTER) += vf_pullup.o
+OBJS-$(CONFIG_QP_FILTER) += vf_qp.o
OBJS-$(CONFIG_REMOVELOGO_FILTER) += bbox.o lswsutils.o lavfutils.o vf_removelogo.o
OBJS-$(CONFIG_ROTATE_FILTER) += vf_rotate.o
OBJS-$(CONFIG_SEPARATEFIELDS_FILTER) += vf_separatefields.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index a330eb9..b19da61 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -182,6 +182,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(PP7, pp7, vf);
REGISTER_FILTER(PSNR, psnr, vf);
REGISTER_FILTER(PULLUP, pullup, vf);
+ REGISTER_FILTER(QP, qp, vf);
REGISTER_FILTER(REMOVELOGO, removelogo, vf);
REGISTER_FILTER(ROTATE, rotate, vf);
REGISTER_FILTER(SAB, sab, vf);
diff --git a/libavfilter/vf_qp.c b/libavfilter/vf_qp.c
new file mode 100644
index 0000000..9c0679a
--- /dev/null
+++ b/libavfilter/vf_qp.c
@@ -0,0 +1,152 @@
+/*
+ * Copyright (C) 2004 Michael Niedermayer <michaelni at gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <math.h>
+#include "libavutil/eval.h"
+#include "libavutil/imgutils.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct QPContext {
+ const AVClass *class;
+ char *qp_expr_str;
+ int8_t lut[257];
+ int h, qstride;
+} QPContext;
+
+#define OFFSET(x) offsetof(QPContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption qp_options[] = {
+ { "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(qp);
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ QPContext *s = ctx->priv;
+ int i;
+
+ if (!s->qp_expr_str)
+ return 0;
+
+ s->h = (inlink->h + 15) >> 4;
+ s->qstride = (inlink->w + 15) >> 4;
+ for (i = -129; i < 128; i++) {
+ double var_values[] = { i != -129, i, 0 };
+ static const char *var_names[] = { "known", "qp", NULL };
+ double temp_val;
+ int ret;
+
+ ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
+ var_names, var_values,
+ NULL, NULL, NULL, NULL, 0, 0, ctx);
+ if (ret < 0)
+ return ret;
+
+ s->lut[i + 129] = lrintf(temp_val);
+ }
+
+ return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ QPContext *s = ctx->priv;
+ AVBufferRef *out_qp_table_buf;
+ AVFrame *out;
+ const int8_t *in_qp_table;
+ int type, stride, ret;
+
+ if (!s->qp_expr_str || ctx->is_disabled)
+ return ff_filter_frame(outlink, in);
+
+ out_qp_table_buf = av_buffer_alloc(s->h * s->qstride);
+ if (!out_qp_table_buf) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ out = av_frame_clone(in);
+ if (!out) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ in_qp_table = av_frame_get_qp_table(in, &stride, &type);
+ av_frame_set_qp_table(out, out_qp_table_buf, s->qstride, type);
+
+ if (in_qp_table) {
+ int y, x;
+
+ for (y = 0; y < s->h; y++)
+ for (x = 0; x < s->qstride; x++)
+ out_qp_table_buf->data[x + s->qstride * y] = s->lut[129 +
+ ((int8_t)in_qp_table[x + stride * y])];
+ } else {
+ int y, x, qp = s->lut[0];
+
+ for (y = 0; y < s->h; y++)
+ for (x = 0; x < s->qstride; x++)
+ out_qp_table_buf->data[x + s->qstride * y] = qp;
+ }
+
+ ret = ff_filter_frame(outlink, out);
+fail:
+ av_frame_free(&in);
+ return ret;
+}
+
+static const AVFilterPad qp_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .filter_frame = filter_frame,
+ .config_props = config_input,
+ },
+ { NULL }
+};
+
+static const AVFilterPad qp_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ },
+ { NULL }
+};
+
+AVFilter ff_vf_qp = {
+ .name = "qp",
+ .description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
+ .priv_size = sizeof(QPContext),
+ .inputs = qp_inputs,
+ .outputs = qp_outputs,
+ .priv_class = &qp_class,
+ .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,
+};
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