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vf_normalize.c
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1 /*
2  * Copyright (c) 2017 Richard Ling
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 /*
22  * Normalize RGB video (aka histogram stretching, contrast stretching).
23  * See: https://en.wikipedia.org/wiki/Normalization_(image_processing)
24  *
25  * For each channel of each frame, the filter computes the input range and maps
26  * it linearly to the user-specified output range. The output range defaults
27  * to the full dynamic range from pure black to pure white.
28  *
29  * Naively maximising the dynamic range of each frame of video in isolation
30  * may cause flickering (rapid changes in brightness of static objects in the
31  * scene) when small dark or bright objects enter or leave the scene. This
32  * filter can apply temporal smoothing to the input range to reduce flickering.
33  * Temporal smoothing is similar to the auto-exposure (automatic gain control)
34  * on a video camera, which performs the same function; and, like a video
35  * camera, it may cause a period of over- or under-exposure of the video.
36  *
37  * The filter can normalize the R,G,B channels independently, which may cause
38  * color shifting, or link them together as a single channel, which prevents
39  * color shifting. More precisely, linked normalization preserves hue (as it's
40  * defined in HSV/HSL color spaces) while independent normalization does not.
41  * Independent normalization can be used to remove color casts, such as the
42  * blue cast from underwater video, restoring more natural colors. The filter
43  * can also combine independent and linked normalization in any ratio.
44  *
45  * Finally the overall strength of the filter can be adjusted, from no effect
46  * to full normalization.
47  *
48  * The 5 AVOptions are:
49  * blackpt, Colors which define the output range. The minimum input value
50  * whitept is mapped to the blackpt. The maximum input value is mapped to
51  * the whitept. The defaults are black and white respectively.
52  * Specifying white for blackpt and black for whitept will give
53  * color-inverted, normalized video. Shades of grey can be used
54  * to reduce the dynamic range (contrast). Specifying saturated
55  * colors here can create some interesting effects.
56  *
57  * smoothing The amount of temporal smoothing, expressed in frames (>=0).
58  * the minimum and maximum input values of each channel are
59  * smoothed using a rolling average over the current frame and
60  * that many previous frames of video. Defaults to 0 (no temporal
61  * smoothing).
62  *
63  * independence
64  * Controls the ratio of independent (color shifting) channel
65  * normalization to linked (color preserving) normalization. 0.0
66  * is fully linked, 1.0 is fully independent. Defaults to fully
67  * independent.
68  *
69  * strength Overall strength of the filter. 1.0 is full strength. 0.0 is
70  * a rather expensive no-op. Values in between can give a gentle
71  * boost to low-contrast video without creating an artificial
72  * over-processed look. The default is full strength.
73  */
74 
75 #include "libavutil/imgutils.h"
76 #include "libavutil/opt.h"
77 #include "libavutil/pixdesc.h"
78 #include "avfilter.h"
79 #include "formats.h"
80 #include "internal.h"
81 #include "video.h"
82 
83 typedef struct NormalizeContext {
84  const AVClass *class;
85 
86  // Storage for the corresponding AVOptions
89  int smoothing;
90  float independence;
91  float strength;
92 
93  int co[4]; // Offsets to R,G,B,A bytes respectively in each pixel
94  int num_components; // Number of components in the pixel format
95  int history_len; // Number of frames to average; based on smoothing factor
96  int frame_num; // Increments on each frame, starting from 0.
97 
98  // Per-extremum, per-channel history, for temporal smoothing.
99  struct {
100  uint8_t *history; // History entries.
101  uint32_t history_sum; // Sum of history entries.
102  } min[3], max[3]; // Min and max for each channel in {R,G,B}.
103  uint8_t *history_mem; // Single allocation for above history entries
104 
106 
107 #define OFFSET(x) offsetof(NormalizeContext, x)
108 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
109 
110 static const AVOption normalize_options[] = {
111  { "blackpt", "output color to which darkest input color is mapped", OFFSET(blackpt), AV_OPT_TYPE_COLOR, { .str = "black" }, CHAR_MIN, CHAR_MAX, FLAGS },
112  { "whitept", "output color to which brightest input color is mapped", OFFSET(whitept), AV_OPT_TYPE_COLOR, { .str = "white" }, CHAR_MIN, CHAR_MAX, FLAGS },
113  { "smoothing", "amount of temporal smoothing of the input range, to reduce flicker", OFFSET(smoothing), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX/8, FLAGS },
114  { "independence", "proportion of independent to linked channel normalization", OFFSET(independence), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, 0.0, 1.0, FLAGS },
115  { "strength", "strength of filter, from no effect to full normalization", OFFSET(strength), AV_OPT_TYPE_FLOAT, {.dbl=1.0}, 0.0, 1.0, FLAGS },
116  { NULL }
117 };
118 
120 
121 // This function is the main guts of the filter. Normalizes the input frame
122 // into the output frame. The frames are known to have the same dimensions
123 // and pixel format.
125 {
126  // Per-extremum, per-channel local variables.
127  struct {
128  uint8_t in; // Original input byte value for this frame.
129  float smoothed; // Smoothed input value [0,255].
130  float out; // Output value [0,255].
131  } min[3], max[3]; // Min and max for each channel in {R,G,B}.
132 
133  float rgb_min_smoothed; // Min input range for linked normalization
134  float rgb_max_smoothed; // Max input range for linked normalization
135  uint8_t lut[3][256]; // Lookup table
136  int x, y, c;
137 
138  // First, scan the input frame to find, for each channel, the minimum
139  // (min.in) and maximum (max.in) values present in the channel.
140  for (c = 0; c < 3; c++)
141  min[c].in = max[c].in = in->data[0][s->co[c]];
142  for (y = 0; y < in->height; y++) {
143  uint8_t *inp = in->data[0] + y * in->linesize[0];
144  uint8_t *outp = out->data[0] + y * out->linesize[0];
145  for (x = 0; x < in->width; x++) {
146  for (c = 0; c < 3; c++) {
147  min[c].in = FFMIN(min[c].in, inp[s->co[c]]);
148  max[c].in = FFMAX(max[c].in, inp[s->co[c]]);
149  }
150  inp += s->num_components;
151  outp += s->num_components;
152  }
153  }
154 
155  // Next, for each channel, push min.in and max.in into their respective
156  // histories, to determine the min.smoothed and max.smoothed for this frame.
157  {
158  int history_idx = s->frame_num % s->history_len;
159  // Assume the history is not yet full; num_history_vals is the number
160  // of frames received so far including the current frame.
161  int num_history_vals = s->frame_num + 1;
162  if (s->frame_num >= s->history_len) {
163  //The history is full; drop oldest value and cap num_history_vals.
164  for (c = 0; c < 3; c++) {
165  s->min[c].history_sum -= s->min[c].history[history_idx];
166  s->max[c].history_sum -= s->max[c].history[history_idx];
167  }
168  num_history_vals = s->history_len;
169  }
170  // For each extremum, update history_sum and calculate smoothed value
171  // as the rolling average of the history entries.
172  for (c = 0; c < 3; c++) {
173  s->min[c].history_sum += (s->min[c].history[history_idx] = min[c].in);
174  min[c].smoothed = s->min[c].history_sum / (float)num_history_vals;
175  s->max[c].history_sum += (s->max[c].history[history_idx] = max[c].in);
176  max[c].smoothed = s->max[c].history_sum / (float)num_history_vals;
177  }
178  }
179 
180  // Determine the input range for linked normalization. This is simply the
181  // minimum of the per-channel minimums, and the maximum of the per-channel
182  // maximums.
183  rgb_min_smoothed = FFMIN3(min[0].smoothed, min[1].smoothed, min[2].smoothed);
184  rgb_max_smoothed = FFMAX3(max[0].smoothed, max[1].smoothed, max[2].smoothed);
185 
186  // Now, process each channel to determine the input and output range and
187  // build the lookup tables.
188  for (c = 0; c < 3; c++) {
189  int in_val;
190  // Adjust the input range for this channel [min.smoothed,max.smoothed]
191  // by mixing in the correct proportion of the linked normalization
192  // input range [rgb_min_smoothed,rgb_max_smoothed].
193  min[c].smoothed = (min[c].smoothed * s->independence)
194  + (rgb_min_smoothed * (1.0f - s->independence));
195  max[c].smoothed = (max[c].smoothed * s->independence)
196  + (rgb_max_smoothed * (1.0f - s->independence));
197 
198  // Calculate the output range [min.out,max.out] as a ratio of the full-
199  // strength output range [blackpt,whitept] and the original input range
200  // [min.in,max.in], based on the user-specified filter strength.
201  min[c].out = (s->blackpt[c] * s->strength)
202  + (min[c].in * (1.0f - s->strength));
203  max[c].out = (s->whitept[c] * s->strength)
204  + (max[c].in * (1.0f - s->strength));
205 
206  // Now, build a lookup table which linearly maps the adjusted input range
207  // [min.smoothed,max.smoothed] to the output range [min.out,max.out].
208  // Perform the linear interpolation for each x:
209  // lut[x] = (int)(float(x - min.smoothed) * scale + max.out + 0.5)
210  // where scale = (max.out - min.out) / (max.smoothed - min.smoothed)
211  if (min[c].smoothed == max[c].smoothed) {
212  // There is no dynamic range to expand. No mapping for this channel.
213  for (in_val = min[c].in; in_val <= max[c].in; in_val++)
214  lut[c][in_val] = min[c].out;
215  } else {
216  // We must set lookup values for all values in the original input
217  // range [min.in,max.in]. Since the original input range may be
218  // larger than [min.smoothed,max.smoothed], some output values may
219  // fall outside the [0,255] dynamic range. We need to clamp them.
220  float scale = (max[c].out - min[c].out) / (max[c].smoothed - min[c].smoothed);
221  for (in_val = min[c].in; in_val <= max[c].in; in_val++) {
222  int out_val = (in_val - min[c].smoothed) * scale + min[c].out + 0.5f;
223  out_val = FFMAX(out_val, 0);
224  out_val = FFMIN(out_val, 255);
225  lut[c][in_val] = out_val;
226  }
227  }
228  }
229 
230  // Finally, process the pixels of the input frame using the lookup tables.
231  for (y = 0; y < in->height; y++) {
232  uint8_t *inp = in->data[0] + y * in->linesize[0];
233  uint8_t *outp = out->data[0] + y * out->linesize[0];
234  for (x = 0; x < in->width; x++) {
235  for (c = 0; c < 3; c++)
236  outp[s->co[c]] = lut[c][inp[s->co[c]]];
237  if (s->num_components == 4)
238  // Copy alpha as-is.
239  outp[s->co[3]] = inp[s->co[3]];
240  inp += s->num_components;
241  outp += s->num_components;
242  }
243  }
244 
245  s->frame_num++;
246 }
247 
248 // Now we define all the functions accessible from the ff_vf_normalize class,
249 // which is ffmpeg's interface to our filter. See doc/filter_design.txt and
250 // doc/writing_filters.txt for descriptions of what these interface functions
251 // are expected to do.
252 
253 // Set the pixel formats that our filter supports. We should be able to process
254 // any 8-bit RGB formats. 16-bit support might be useful one day.
256 {
257  static const enum AVPixelFormat pixel_fmts[] = {
269  };
270  // According to filter_design.txt, using ff_set_common_formats() this way
271  // ensures the pixel formats of the input and output will be the same. That
272  // saves a bit of effort possibly needing to handle format conversions.
274  if (!formats)
275  return AVERROR(ENOMEM);
276  return ff_set_common_formats(ctx, formats);
277 }
278 
279 // At this point we know the pixel format used for both input and output. We
280 // can also access the frame rate of the input video and allocate some memory
281 // appropriately
282 static int config_input(AVFilterLink *inlink)
283 {
284  NormalizeContext *s = inlink->dst->priv;
285  // Store offsets to R,G,B,A bytes respectively in each pixel
287  int c;
288 
289  for (c = 0; c < 4; ++c)
290  s->co[c] = desc->comp[c].offset;
291  s->num_components = desc->nb_components;
292  // Convert smoothing value to history_len (a count of frames to average,
293  // must be at least 1). Currently this is a direct assignment, but the
294  // smoothing value was originally envisaged as a number of seconds. In
295  // future it would be nice to set history_len using a number of seconds,
296  // but VFR video is currently an obstacle to doing so.
297  s->history_len = s->smoothing + 1;
298  // Allocate the history buffers -- there are 6 -- one for each extrema.
299  // s->smoothing is limited to INT_MAX/8, so that (s->history_len * 6)
300  // can't overflow on 32bit causing a too-small allocation.
301  s->history_mem = av_malloc(s->history_len * 6);
302  if (s->history_mem == NULL)
303  return AVERROR(ENOMEM);
304 
305  for (c = 0; c < 3; c++) {
306  s->min[c].history = s->history_mem + (c*2) * s->history_len;
307  s->max[c].history = s->history_mem + (c*2+1) * s->history_len;
308  }
309  return 0;
310 }
311 
312 // Free any memory allocations here
314 {
315  NormalizeContext *s = ctx->priv;
316 
317  av_freep(&s->history_mem);
318 }
319 
320 // This function is pretty much standard from doc/writing_filters.txt. It
321 // tries to do in-place filtering where possible, only allocating a new output
322 // frame when absolutely necessary.
323 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
324 {
325  AVFilterContext *ctx = inlink->dst;
326  AVFilterLink *outlink = ctx->outputs[0];
327  NormalizeContext *s = ctx->priv;
328  AVFrame *out;
329  // Set 'direct' if we can modify the input frame in-place. Otherwise we
330  // need to retrieve a new frame from the output link.
331  int direct = av_frame_is_writable(in) && !ctx->is_disabled;
332 
333  if (direct) {
334  out = in;
335  } else {
336  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
337  if (!out) {
338  av_frame_free(&in);
339  return AVERROR(ENOMEM);
340  }
341  av_frame_copy_props(out, in);
342  }
343 
344  // Now we've got the input and output frames (which may be the same frame)
345  // perform the filtering with our custom function.
346  normalize(s, in, out);
347 
348  if (ctx->is_disabled) {
349  av_frame_free(&out);
350  return ff_filter_frame(outlink, in);
351  }
352 
353  if (!direct)
354  av_frame_free(&in);
355 
356  return ff_filter_frame(outlink, out);
357 }
358 
359 static const AVFilterPad inputs[] = {
360  {
361  .name = "default",
362  .type = AVMEDIA_TYPE_VIDEO,
363  .filter_frame = filter_frame,
364  .config_props = config_input,
365  },
366  { NULL }
367 };
368 
369 static const AVFilterPad outputs[] = {
370  {
371  .name = "default",
372  .type = AVMEDIA_TYPE_VIDEO,
373  },
374  { NULL }
375 };
376 
378  .name = "normalize",
379  .description = NULL_IF_CONFIG_SMALL("Normalize RGB video."),
380  .priv_size = sizeof(NormalizeContext),
381  .priv_class = &normalize_class,
382  .uninit = uninit,
384  .inputs = inputs,
385  .outputs = outputs,
386 };
#define NULL
Definition: coverity.c:32
AVFILTER_DEFINE_CLASS(normalize)
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2446
This structure describes decoded (raw) audio or video data.
Definition: frame.h:226
uint8_t * history
Definition: vf_normalize.c:100
AVOption.
Definition: opt.h:246
misc image utilities
uint8_t whitept[4]
Definition: vf_normalize.c:88
Main libavfilter public API header.
packed RGB 8:8:8, 24bpp, RGBRGB...
Definition: pixfmt.h:68
const char * desc
Definition: nvenc.c:65
static const AVOption normalize_options[]
Definition: vf_normalize.c:110
packed BGR 8:8:8, 32bpp, XBGRXBGR... X=unused/undefined
Definition: pixfmt.h:239
AVFrame * ff_get_video_buffer(AVFilterLink *link, int w, int h)
Request a picture buffer with a specific set of permissions.
Definition: video.c:99
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:385
struct NormalizeContext::@228 max[3]
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1080
AVComponentDescriptor comp[4]
Parameters that describe how pixels are packed.
Definition: pixdesc.h:117
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
packed RGB 8:8:8, 32bpp, RGBXRGBX... X=unused/undefined
Definition: pixfmt.h:238
AVOptions.
#define f(width, name)
Definition: cbs_vp9.c:255
packed ABGR 8:8:8:8, 32bpp, ABGRABGR...
Definition: pixfmt.h:94
AVFilter ff_vf_normalize
Definition: vf_normalize.c:377
#define FFMIN3(a, b, c)
Definition: common.h:97
uint8_t * history_mem
Definition: vf_normalize.c:103
uint32_t history_sum
Definition: vf_normalize.c:101
static int query_formats(AVFilterContext *ctx)
Definition: vf_normalize.c:255
A filter pad used for either input or output.
Definition: internal.h:54
int width
Definition: frame.h:284
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:568
#define AVERROR(e)
Definition: error.h:43
static const AVFilterPad outputs[]
Definition: vf_normalize.c:369
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
packed BGRA 8:8:8:8, 32bpp, BGRABGRA...
Definition: pixfmt.h:95
void * priv
private data for use by the filter
Definition: avfilter.h:353
static const AVFilterPad inputs[]
Definition: vf_normalize.c:359
#define FFMAX(a, b)
Definition: common.h:94
packed ARGB 8:8:8:8, 32bpp, ARGBARGB...
Definition: pixfmt.h:92
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
uint8_t nb_components
The number of components each pixel has, (1-4)
Definition: pixdesc.h:83
#define FFMIN(a, b)
Definition: common.h:96
uint8_t blackpt[4]
Definition: vf_normalize.c:87
AVFormatContext * ctx
Definition: movenc.c:48
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_normalize.c:323
#define s(width, name)
Definition: cbs_vp9.c:257
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_normalize.c:313
packed RGB 8:8:8, 24bpp, BGRBGR...
Definition: pixfmt.h:69
#define OFFSET(x)
Definition: vf_normalize.c:107
static int config_input(AVFilterLink *inlink)
Definition: vf_normalize.c:282
#define FLAGS
Definition: vf_normalize.c:108
int av_frame_is_writable(AVFrame *frame)
Check if the frame data is writable.
Definition: frame.c:594
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:257
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(constuint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(constint16_t *) pi >>8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(constint16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(constint32_t *) pi >>24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(constint32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(constfloat *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(constfloat *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(constfloat *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(constdouble *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(constdouble *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(constdouble *) pi *(1U<< 31))))#defineSET_CONV_FUNC_GROUP(ofmt, ifmt) staticvoidset_generic_function(AudioConvert *ac){}voidff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enumAVSampleFormatout_fmt, enumAVSampleFormatin_fmt, intchannels, intsample_rate, intapply_map){AudioConvert *ac;intin_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) returnNULL;ac->avr=avr;ac->out_fmt=out_fmt;ac->in_fmt=in_fmt;ac->channels=channels;ac->apply_map=apply_map;if(avr->dither_method!=AV_RESAMPLE_DITHER_NONE &&av_get_packed_sample_fmt(out_fmt)==AV_SAMPLE_FMT_S16 &&av_get_bytes_per_sample(in_fmt)>2){ac->dc=ff_dither_alloc(avr, out_fmt, in_fmt, channels, sample_rate, apply_map);if(!ac->dc){av_free(ac);returnNULL;}returnac;}in_planar=ff_sample_fmt_is_planar(in_fmt, channels);out_planar=ff_sample_fmt_is_planar(out_fmt, channels);if(in_planar==out_planar){ac->func_type=CONV_FUNC_TYPE_FLAT;ac->planes=in_planar?ac->channels:1;}elseif(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;elseac->func_type=CONV_FUNC_TYPE_DEINTERLEAVE;set_generic_function(ac);if(ARCH_AARCH64) ff_audio_convert_init_aarch64(ac);if(ARCH_ARM) ff_audio_convert_init_arm(ac);if(ARCH_X86) ff_audio_convert_init_x86(ac);returnac;}intff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){intuse_generic=1;intlen=in->nb_samples;intp;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%dsamples-audio_convert:%sto%s(dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));returnff_convert_dither(ac-> in
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
packed BGR 8:8:8, 32bpp, BGRXBGRX... X=unused/undefined
Definition: pixfmt.h:240
static void normalize(NormalizeContext *s, AVFrame *in, AVFrame *out)
Definition: vf_normalize.c:124
const char * name
Filter name.
Definition: avfilter.h:148
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
int offset
Number of elements before the component of the first pixel.
Definition: pixdesc.h:47
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:240
if(ret< 0)
Definition: vf_mcdeint.c:279
static double c[64]
struct NormalizeContext::@228 min[3]
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:338
int height
Definition: frame.h:284
FILE * out
Definition: movenc.c:54
#define av_freep(p)
formats
Definition: signature.h:48
internal API functions
packed RGB 8:8:8, 32bpp, XRGBXRGB... X=unused/undefined
Definition: pixfmt.h:237
float min
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
for(j=16;j >0;--j)
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:654
#define FFMAX3(a, b, c)
Definition: common.h:95