2 * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
4 * This file is part of FFmpeg.
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/eval.h"
23 #include "libavutil/imgutils.h"
24 #include "libavutil/pixdesc.h"
25 #include "libavutil/opt.h"
31 typedef struct QPContext {
38 #define OFFSET(x) offsetof(QPContext, x)
39 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
41 static const AVOption qp_options[] = {
42 { "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
46 AVFILTER_DEFINE_CLASS(qp);
48 static int config_input(AVFilterLink *inlink)
50 AVFilterContext *ctx = inlink->dst;
51 QPContext *s = ctx->priv;
57 s->h = (inlink->h + 15) >> 4;
58 s->qstride = (inlink->w + 15) >> 4;
59 for (i = -129; i < 128; i++) {
60 double var_values[] = { i != -129, i, 0 };
61 static const char *var_names[] = { "known", "qp", NULL };
65 ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
66 var_names, var_values,
67 NULL, NULL, NULL, NULL, 0, 0, ctx);
71 s->lut[i + 129] = lrintf(temp_val);
77 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
79 AVFilterContext *ctx = inlink->dst;
80 AVFilterLink *outlink = ctx->outputs[0];
81 QPContext *s = ctx->priv;
82 AVBufferRef *out_qp_table_buf;
84 const int8_t *in_qp_table;
85 int type, stride, ret;
87 if (!s->qp_expr_str || ctx->is_disabled)
88 return ff_filter_frame(outlink, in);
90 out_qp_table_buf = av_buffer_alloc(s->h * s->qstride);
91 if (!out_qp_table_buf) {
92 ret = AVERROR(ENOMEM);
96 out = av_frame_clone(in);
98 av_buffer_unref(&out_qp_table_buf);
99 ret = AVERROR(ENOMEM);
103 in_qp_table = av_frame_get_qp_table(in, &stride, &type);
104 av_frame_set_qp_table(out, out_qp_table_buf, s->qstride, type);
109 for (y = 0; y < s->h; y++)
110 for (x = 0; x < s->qstride; x++)
111 out_qp_table_buf->data[x + s->qstride * y] = s->lut[129 +
112 ((int8_t)in_qp_table[x + stride * y])];
114 int y, x, qp = s->lut[0];
116 for (y = 0; y < s->h; y++)
117 for (x = 0; x < s->qstride; x++)
118 out_qp_table_buf->data[x + s->qstride * y] = qp;
121 ret = ff_filter_frame(outlink, out);
127 static const AVFilterPad qp_inputs[] = {
130 .type = AVMEDIA_TYPE_VIDEO,
131 .filter_frame = filter_frame,
132 .config_props = config_input,
137 static const AVFilterPad qp_outputs[] = {
140 .type = AVMEDIA_TYPE_VIDEO,
145 AVFilter ff_vf_qp = {
147 .description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
148 .priv_size = sizeof(QPContext),
150 .outputs = qp_outputs,
151 .priv_class = &qp_class,
152 .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL,