FFmpeg
vf_qp.c
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1 /*
2  * Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
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.
10  *
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.
15  *
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
19  */
20 
21 #include <math.h>
22 #include "libavutil/eval.h"
23 #include "libavutil/imgutils.h"
24 #include "libavutil/pixdesc.h"
25 #include "libavutil/opt.h"
27 
28 #include "avfilter.h"
29 #include "formats.h"
30 #include "internal.h"
31 #include "video.h"
32 
33 typedef struct QPContext {
34  const AVClass *class;
35  char *qp_expr_str;
36  int8_t lut[257];
37  int h, qstride;
39 } QPContext;
40 
41 static const char *const var_names[] = { "known", "qp", "x", "y", "w", "h", NULL };
42 
43 #define OFFSET(x) offsetof(QPContext, x)
44 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
45 
46 static const AVOption qp_options[] = {
47  { "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
48  { NULL }
49 };
50 
52 
54 {
55  AVFilterContext *ctx = inlink->dst;
56  QPContext *s = ctx->priv;
57  int i;
58  int ret;
59  AVExpr *e = NULL;
60 
61  if (!s->qp_expr_str)
62  return 0;
63 
64  ret = av_expr_parse(&e, s->qp_expr_str, var_names, NULL, NULL, NULL, NULL, 0, ctx);
65  if (ret < 0)
66  return ret;
67 
68  s->h = (inlink->h + 15) >> 4;
69  s->qstride = (inlink->w + 15) >> 4;
70  for (i = -129; i < 128; i++) {
71  double var_values[] = { i != -129, i, NAN, NAN, s->qstride, s->h, 0};
72  double temp_val = av_expr_eval(e, var_values, NULL);
73 
74  if (isnan(temp_val)) {
75  if(strchr(s->qp_expr_str, 'x') || strchr(s->qp_expr_str, 'y'))
76  s->evaluate_per_mb = 1;
77  else {
78  av_expr_free(e);
79  return AVERROR(EINVAL);
80  }
81  }
82 
83  s->lut[i + 129] = lrintf(temp_val);
84  }
85  av_expr_free(e);
86 
87  return 0;
88 }
89 
91 {
92  AVFilterContext *ctx = inlink->dst;
93  AVFilterLink *outlink = ctx->outputs[0];
94  QPContext *s = ctx->priv;
95  AVFrame *out = NULL;
96  int ret;
97 
98  AVFrameSideData *sd_in;
99  AVVideoEncParams *par_in = NULL;
100  int8_t in_qp_global = 0;
101 
102  AVVideoEncParams *par_out;
103 
104  if (!s->qp_expr_str || ctx->is_disabled)
105  return ff_filter_frame(outlink, in);
106 
108  if (sd_in && sd_in->size >= sizeof(AVVideoEncParams)) {
109  par_in = (AVVideoEncParams*)sd_in->data;
110 
111  // we accept the input QP table only if it is of the MPEG2 type
112  // and contains either no blocks at all or 16x16 macroblocks
113  if (par_in->type == AV_VIDEO_ENC_PARAMS_MPEG2 &&
114  (par_in->nb_blocks == s->h * s->qstride || !par_in->nb_blocks)) {
115  in_qp_global = par_in->qp;
116  if (!par_in->nb_blocks)
117  par_in = NULL;
118  } else
119  par_in = NULL;
120  }
121 
122  out = av_frame_clone(in);
123  if (!out) {
124  ret = AVERROR(ENOMEM);
125  goto fail;
126  }
127 
129  (s->evaluate_per_mb || sd_in) ?
130  s->h * s->qstride : 0);
131  if (!par_out) {
132  ret = AVERROR(ENOMEM);
133  goto fail;
134  }
135 
136 #define BLOCK_QP_DELTA(block_idx) \
137  (par_in ? av_video_enc_params_block(par_in, block_idx)->delta_qp : 0)
138 
139  if (s->evaluate_per_mb) {
140  int y, x;
141 
142  for (y = 0; y < s->h; y++)
143  for (x = 0; x < s->qstride; x++) {
144  unsigned int block_idx = y * s->qstride + x;
145  AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
146  int qp = sd_in ? in_qp_global + BLOCK_QP_DELTA(block_idx) : NAN;
147  double var_values[] = { !!sd_in, qp, x, y, s->qstride, s->h, 0};
148  double temp_val;
149 
150  ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
151  var_names, var_values,
152  NULL, NULL, NULL, NULL, 0, 0, ctx);
153  if (ret < 0)
154  goto fail;
155  b->delta_qp = lrintf(temp_val);
156  }
157  } else if (sd_in) {
158  int y, x;
159 
160  for (y = 0; y < s->h; y++)
161  for (x = 0; x < s->qstride; x++) {
162  unsigned int block_idx = y * s->qstride + x;
163  AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
164  b->delta_qp = s->lut[129 + (int8_t)(in_qp_global + BLOCK_QP_DELTA(block_idx))];
165  }
166  } else {
167  par_out->qp = s->lut[0];
168  }
169 
170  ret = ff_filter_frame(outlink, out);
171  out = NULL;
172 fail:
173  av_frame_free(&in);
174  av_frame_free(&out);
175  return ret;
176 }
177 
178 static const AVFilterPad qp_inputs[] = {
179  {
180  .name = "default",
181  .type = AVMEDIA_TYPE_VIDEO,
182  .filter_frame = filter_frame,
183  .config_props = config_input,
184  },
185 };
186 
187 static const AVFilterPad qp_outputs[] = {
188  {
189  .name = "default",
190  .type = AVMEDIA_TYPE_VIDEO,
191  },
192 };
193 
195  .name = "qp",
196  .description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
197  .priv_size = sizeof(QPContext),
200  .priv_class = &qp_class,
202 };
AVVideoEncParams::qp
int32_t qp
Base quantisation parameter for the frame.
Definition: video_enc_params.h:103
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
var_names
static const char *const var_names[]
Definition: vf_qp.c:41
out
FILE * out
Definition: movenc.c:54
av_frame_get_side_data
AVFrameSideData * av_frame_get_side_data(const AVFrame *frame, enum AVFrameSideDataType type)
Definition: frame.c:617
QPContext
Definition: vf_qp.c:33
QPContext::qp_expr_str
char * qp_expr_str
Definition: vf_qp.c:35
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1018
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
pixdesc.h
QPContext::evaluate_per_mb
int evaluate_per_mb
Definition: vf_qp.c:38
AVOption
AVOption.
Definition: opt.h:247
b
#define b
Definition: input.c:40
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:153
video.h
formats.h
av_expr_parse
int av_expr_parse(AVExpr **expr, const char *s, const char *const *const_names, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), int log_offset, void *log_ctx)
Parse an expression.
Definition: eval.c:685
AV_VIDEO_ENC_PARAMS_MPEG2
@ AV_VIDEO_ENC_PARAMS_MPEG2
Definition: video_enc_params.h:65
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_qp.c:90
fail
#define fail()
Definition: checkasm.h:127
av_expr_free
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:336
AVVideoEncParams
Video encoding parameters for a given frame.
Definition: video_enc_params.h:73
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:50
AVFrameSideData::size
size_t size
Definition: frame.h:212
ff_vf_qp
const AVFilter ff_vf_qp
Definition: vf_qp.c:194
s
#define s(width, name)
Definition: cbs_vp9.c:257
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_expr_eval
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:766
av_frame_clone
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:424
AVVideoEncParams::type
enum AVVideoEncParamsType type
Type of the parameters (the codec they are used with).
Definition: video_enc_params.h:95
AVExpr
Definition: eval.c:157
NAN
#define NAN
Definition: mathematics.h:64
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: internal.h:191
if
if(ret)
Definition: filter_design.txt:179
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
isnan
#define isnan(x)
Definition: libm.h:340
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_qp.c:53
av_video_enc_params_create_side_data
AVVideoEncParams * av_video_enc_params_create_side_data(AVFrame *frame, enum AVVideoEncParamsType type, unsigned int nb_blocks)
Allocates memory for AVEncodeInfoFrame plus an array of.
Definition: video_enc_params.c:60
eval.h
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
av_expr_parse_and_eval
int av_expr_parse_and_eval(double *d, const char *s, const char *const *const_names, const double *const_values, const char *const *func1_names, double(*const *funcs1)(void *, double), const char *const *func2_names, double(*const *funcs2)(void *, double, double), void *opaque, int log_offset, void *log_ctx)
Parse and evaluate an expression.
Definition: eval.c:776
QPContext::lut
int8_t lut[257]
Definition: vf_qp.c:36
AVFrameSideData::data
uint8_t * data
Definition: frame.h:211
AVVideoEncParams::nb_blocks
unsigned int nb_blocks
Number of blocks in the array.
Definition: video_enc_params.h:81
FLAGS
#define FLAGS
Definition: vf_qp.c:44
internal.h
lrintf
#define lrintf(x)
Definition: libm_mips.h:72
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
qp_outputs
static const AVFilterPad qp_outputs[]
Definition: vf_qp.c:187
AVVideoBlockParams
Data structure for storing block-level encoding information.
Definition: video_enc_params.h:120
OFFSET
#define OFFSET(x)
Definition: vf_qp.c:43
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:56
AVFilter
Filter definition.
Definition: avfilter.h:149
ret
ret
Definition: filter_design.txt:187
QPContext::h
int h
Definition: vf_qp.c:37
AV_FRAME_DATA_VIDEO_ENC_PARAMS
@ AV_FRAME_DATA_VIDEO_ENC_PARAMS
Encoding parameters for a video frame, as described by AVVideoEncParams.
Definition: frame.h:169
avfilter.h
QPContext::qstride
int qstride
Definition: vf_qp.c:37
AVFilterContext
An instance of a filter.
Definition: avfilter.h:386
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVFrameSideData
Structure to hold side data for an AVFrame.
Definition: frame.h:209
qp_options
static const AVOption qp_options[]
Definition: vf_qp.c:46
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: internal.h:192
qp_inputs
static const AVFilterPad qp_inputs[]
Definition: vf_qp.c:178
AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL
#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL
Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will have its filter_frame() c...
Definition: avfilter.h:138
imgutils.h
BLOCK_QP_DELTA
#define BLOCK_QP_DELTA(block_idx)
av_video_enc_params_block
static av_always_inline AVVideoBlockParams * av_video_enc_params_block(AVVideoEncParams *par, unsigned int idx)
Definition: video_enc_params.h:143
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:228
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(qp)
video_enc_params.h