FFmpeg: libavfilter/vf_qp.c Source File

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/opt.h"
24 #include "libavutil/video_enc_params.h"
25 
26 #include "avfilter.h"
27 #include "filters.h"
28 #include "video.h"
29 
30  typedef struct QPContext {
31   const AVClass *class;
32   char *qp_expr_str;
33   int8_t lut[257];
34   int h, qstride;
35   int evaluate_per_mb;
36 } QPContext;
37 
38  static const char *const var_names[] = { "known", "qp", "x", "y", "w", "h", NULL };
39 
40  #define OFFSET(x) offsetof(QPContext, x)
41  #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
42 
43  static const AVOption qp_options[] = {
44  { "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
45  { NULL }
46 };
47 
48 AVFILTER_DEFINE_CLASS(qp);
49 
50  static int config_input(AVFilterLink *inlink)
51 {
52  AVFilterContext *ctx = inlink->dst;
53  QPContext *s = ctx->priv;
54  int i;
55  int ret;
56  AVExpr *e = NULL;
57 
58  if (!s->qp_expr_str)
59  return 0;
60 
61  ret = av_expr_parse(&e, s->qp_expr_str, var_names, NULL, NULL, NULL, NULL, 0, ctx);
62  if (ret < 0)
63  return ret;
64 
65  s->h = (inlink->h + 15) >> 4;
66  s->qstride = (inlink->w + 15) >> 4;
67  for (i = -129; i < 128; i++) {
68  double var_values[] = { i != -129, i, NAN, NAN, s->qstride, s->h, 0};
69  double temp_val = av_expr_eval(e, var_values, NULL);
70 
71  if (isnan(temp_val)) {
72  if(strchr(s->qp_expr_str, 'x') || strchr(s->qp_expr_str, 'y'))
73  s->evaluate_per_mb = 1;
74  else {
75  av_expr_free(e);
76  return AVERROR(EINVAL);
77  }
78  }
79 
80  s->lut[i + 129] = lrintf(temp_val);
81  }
82  av_expr_free(e);
83 
84  return 0;
85 }
86 
87  static int filter_frame(AVFilterLink *inlink, AVFrame *in)
88 {
89  AVFilterContext *ctx = inlink->dst;
90  AVFilterLink *outlink = ctx->outputs[0];
91  QPContext *s = ctx->priv;
92  AVFrame *out = NULL;
93  int ret;
94 
95  AVFrameSideData *sd_in;
96  AVVideoEncParams *par_in = NULL;
97  int8_t in_qp_global = 0;
98 
99  AVVideoEncParams *par_out;
100 
101  if (!s->qp_expr_str || ctx->is_disabled)
102  return ff_filter_frame(outlink, in);
103 
104  sd_in = av_frame_get_side_data(in, AV_FRAME_DATA_VIDEO_ENC_PARAMS);
105  if (sd_in && sd_in->size >= sizeof(AVVideoEncParams)) {
106  par_in = (AVVideoEncParams*)sd_in->data;
107 
108  // we accept the input QP table only if it is of the MPEG2 type
109  // and contains either no blocks at all or 16x16 macroblocks
110  if (par_in->type == AV_VIDEO_ENC_PARAMS_MPEG2 &&
111  (par_in->nb_blocks == s->h * s->qstride || !par_in->nb_blocks)) {
112  in_qp_global = par_in->qp;
113  if (!par_in->nb_blocks)
114  par_in = NULL;
115  } else
116  par_in = NULL;
117  }
118 
119  out = av_frame_clone(in);
120  if (!out) {
121  ret = AVERROR(ENOMEM);
122  goto fail;
123  }
124 
125  par_out = av_video_enc_params_create_side_data(out, AV_VIDEO_ENC_PARAMS_MPEG2,
126  (s->evaluate_per_mb || sd_in) ?
127  s->h * s->qstride : 0);
128  if (!par_out) {
129  ret = AVERROR(ENOMEM);
130  goto fail;
131  }
132 
133 #define BLOCK_QP_DELTA(block_idx) \
134  (par_in ? av_video_enc_params_block(par_in, block_idx)->delta_qp : 0)
135 
136  if (s->evaluate_per_mb) {
137  int y, x;
138 
139  for (y = 0; y < s->h; y++)
140  for (x = 0; x < s->qstride; x++) {
141  unsigned int block_idx = y * s->qstride + x;
142  AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
143  double qp = sd_in ? in_qp_global + BLOCK_QP_DELTA(block_idx) : NAN;
144  double var_values[] = { !!sd_in, qp, x, y, s->qstride, s->h, 0};
145  double temp_val;
146 
147  ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
148  var_names, var_values,
149  NULL, NULL, NULL, NULL, 0, 0, ctx);
150  if (ret < 0)
151  goto fail;
152  b->delta_qp = lrintf(temp_val);
153  }
154  } else if (sd_in) {
155  int y, x;
156 
157  for (y = 0; y < s->h; y++)
158  for (x = 0; x < s->qstride; x++) {
159  unsigned int block_idx = y * s->qstride + x;
160  AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
161  b->delta_qp = s->lut[129 + (int8_t)(in_qp_global + BLOCK_QP_DELTA(block_idx))];
162  }
163  } else {
164  par_out->qp = s->lut[0];
165  }
166 
167  ret = ff_filter_frame(outlink, out);
168  out = NULL;
169 fail:
170  av_frame_free(&in);
171  av_frame_free(&out);
172  return ret;
173 }
174 
175  static const AVFilterPad qp_inputs[] = {
176  {
177  .name = "default",
178  .type = AVMEDIA_TYPE_VIDEO,
179  .filter_frame = filter_frame,
180  .config_props = config_input,
181  },
182 };
183 
184  const FFFilter ff_vf_qp = {
185  .p.name = "qp",
186  .p.description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
187  .p.priv_class = &qp_class,
188  .p.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
189  AVFILTER_FLAG_METADATA_ONLY,
190  .priv_size = sizeof(QPContext),
191  FILTER_INPUTS(qp_inputs),
192  FILTER_OUTPUTS(ff_video_default_filterpad),
193 };
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:38
out
FILE * out
Definition: movenc.c:55
av_frame_get_side_data
AVFrameSideData * av_frame_get_side_data(const AVFrame *frame, enum AVFrameSideDataType type)
Definition: frame.c:659
QPContext
Definition: vf_qp.c:30
QPContext::qp_expr_str
char * qp_expr_str
Definition: vf_qp.c:32
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1067
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:64
FILTER_INPUTS
#define FILTER_INPUTS(array)
Definition: filters.h:263
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:427
QPContext::evaluate_per_mb
int evaluate_per_mb
Definition: vf_qp.c:35
AVOption
AVOption.
Definition: opt.h:429
b
#define b
Definition: input.c:42
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:220
video.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:710
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:87
fail
#define fail()
Definition: checkasm.h:207
av_expr_free
void av_expr_free(AVExpr *e)
Free a parsed expression previously created with av_expr_parse().
Definition: eval.c:358
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: filters.h:39
AVFrameSideData::size
size_t size
Definition: frame.h:285
ff_video_default_filterpad
const AVFilterPad ff_video_default_filterpad[1]
An AVFilterPad array whose only entry has name "default" and is of type AVMEDIA_TYPE_VIDEO.
Definition: video.c:37
FFFilter
Definition: filters.h:266
s
#define s(width, name)
Definition: cbs_vp9.c:198
filters.h
ctx
AVFormatContext * ctx
Definition: movenc.c:49
av_expr_eval
double av_expr_eval(AVExpr *e, const double *const_values, void *opaque)
Evaluate a previously parsed expression.
Definition: eval.c:792
av_frame_clone
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:483
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:158
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:264
NAN
#define NAN
Definition: mathematics.h:115
if
if(ret)
Definition: filter_design.txt:179
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:76
NULL
#define NULL
Definition: coverity.c:32
isnan
#define isnan(x)
Definition: libm.h:342
config_input
static int config_input(AVFilterLink *inlink)
Definition: vf_qp.c:50
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:58
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:94
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:805
QPContext::lut
int8_t lut[257]
Definition: vf_qp.c:33
AVFrameSideData::data
uint8_t * data
Definition: frame.h:284
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:41
lrintf
#define lrintf(x)
Definition: libm_mips.h:72
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AVVideoBlockParams
Data structure for storing block-level encoding information.
Definition: video_enc_params.h:120
OFFSET
#define OFFSET(x)
Definition: vf_qp.c:40
AVFilterPad::name
const char * name
Pad name.
Definition: filters.h:45
ret
ret
Definition: filter_design.txt:187
QPContext::h
int h
Definition: vf_qp.c:34
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:170
avfilter.h
AVFILTER_FLAG_METADATA_ONLY
#define AVFILTER_FLAG_METADATA_ONLY
The filter is a "metadata" filter - it does not modify the frame data in any way.
Definition: avfilter.h:183
QPContext::qstride
int qstride
Definition: vf_qp.c:34
AVFilterContext
An instance of a filter.
Definition: avfilter.h:274
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
FFFilter::p
AVFilter p
The public AVFilter.
Definition: filters.h:270
ff_vf_qp
const FFFilter ff_vf_qp
Definition: vf_qp.c:184
AVFrameSideData
Structure to hold side data for an AVFrame.
Definition: frame.h:282
qp_options
static const AVOption qp_options[]
Definition: vf_qp.c:43
qp_inputs
static const AVFilterPad qp_inputs[]
Definition: vf_qp.c:175
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:205
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)
Get the block at the specified.
Definition: video_enc_params.h:143
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Underlying C type is a uint8_t* that is either NULL or points to a C string allocated with the av_mal...
Definition: opt.h:276
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(qp)
video_enc_params.h
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