FFmpeg
vf_phase.c
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1 /*
2  * Copyright (c) 2004 Ville Saari
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 General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 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
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License along
17  * 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 "libavutil/avassert.h"
22 #include "libavutil/imgutils.h"
23 #include "libavutil/pixdesc.h"
24 #include "libavutil/opt.h"
25 #include "avfilter.h"
26 #include "formats.h"
27 #include "internal.h"
28 #include "video.h"
29 
30 enum PhaseMode {
40 };
41 
42 typedef struct PhaseContext {
43  const AVClass *class;
44  int mode; ///<PhaseMode
45  AVFrame *frame; /* previous frame */
46  int nb_planes;
47  int planeheight[4];
48  int linesize[4];
49 } PhaseContext;
50 
51 #define OFFSET(x) offsetof(PhaseContext, x)
52 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
53 #define CONST(name, help, val, unit) { name, help, 0, AV_OPT_TYPE_CONST, {.i64=val}, 0, 0, FLAGS, unit }
54 
55 static const AVOption phase_options[] = {
56  { "mode", "set phase mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=AUTO_ANALYZE}, PROGRESSIVE, AUTO_ANALYZE, FLAGS, "mode" },
57  CONST("p", "progressive", PROGRESSIVE, "mode"),
58  CONST("t", "top first", TOP_FIRST, "mode"),
59  CONST("b", "bottom first", BOTTOM_FIRST, "mode"),
60  CONST("T", "top first analyze", TOP_FIRST_ANALYZE, "mode"),
61  CONST("B", "bottom first analyze", BOTTOM_FIRST_ANALYZE, "mode"),
62  CONST("u", "analyze", ANALYZE, "mode"),
63  CONST("U", "full analyze", FULL_ANALYZE, "mode"),
64  CONST("a", "auto", AUTO, "mode"),
65  CONST("A", "auto analyze", AUTO_ANALYZE, "mode"),
66  { NULL }
67 };
68 
70 
72 {
73  static const enum AVPixelFormat pix_fmts[] = {
78  };
79 
80  AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
81  if (!fmts_list)
82  return AVERROR(ENOMEM);
83  return ff_set_common_formats(ctx, fmts_list);
84 }
85 
87 {
88  PhaseContext *s = inlink->dst->priv;
90  int ret;
91 
92  if ((ret = av_image_fill_linesizes(s->linesize, inlink->format, inlink->w)) < 0)
93  return ret;
94 
95  s->planeheight[1] = s->planeheight[2] = AV_CEIL_RSHIFT(inlink->h, desc->log2_chroma_h);
96  s->planeheight[0] = s->planeheight[3] = inlink->h;
97 
99 
100  return 0;
101 }
102 
103 /*
104  * This macro interpolates the value of both fields at a point halfway
105  * between lines and takes the squared difference. In field resolution
106  * the point is a quarter pixel below a line in one field and a quarter
107  * pixel above a line in other.
108  *
109  * (The result is actually multiplied by 25)
110  */
111 #define DIFF(a, as, b, bs) ((t) = ((*(a) - (b)[bs]) << 2) + (a)[(as) << 1] - (b)[-(bs)], (t) * (t))
112 
113 /*
114  * Find which field combination has the smallest average squared difference
115  * between the fields.
116  */
117 static enum PhaseMode analyze_plane(void *ctx, enum PhaseMode mode, AVFrame *old, AVFrame *new)
118 {
119  double bdiff, tdiff, pdiff;
120 
121  if (mode == AUTO) {
122  mode = new->interlaced_frame ? new->top_field_first ?
124  } else if (mode == AUTO_ANALYZE) {
125  mode = new->interlaced_frame ? new->top_field_first ?
127  }
128 
129  if (mode <= BOTTOM_FIRST) {
130  bdiff = pdiff = tdiff = 65536.0;
131  } else {
132  const int ns = new->linesize[0];
133  const int os = old->linesize[0];
134  const uint8_t *nptr = new->data[0];
135  const uint8_t *optr = old->data[0];
136  const int h = new->height;
137  const int w = new->width;
138  int bdif, tdif, pdif;
139  double scale;
140 
141  int top = 0, t;
142  const uint8_t *rend, *end = nptr + (h - 2) * ns;
143 
144  bdiff = pdiff = tdiff = 0.0;
145 
146  nptr += ns;
147  optr += os;
148  while (nptr < end) {
149  pdif = tdif = bdif = 0;
150 
151  switch (mode) {
152  case TOP_FIRST_ANALYZE:
153  if (top) {
154  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
155  pdif += DIFF(nptr, ns, nptr, ns);
156  tdif += DIFF(nptr, ns, optr, os);
157  }
158  } else {
159  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
160  pdif += DIFF(nptr, ns, nptr, ns);
161  tdif += DIFF(optr, os, nptr, ns);
162  }
163  }
164  break;
166  if (top) {
167  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
168  pdif += DIFF(nptr, ns, nptr, ns);
169  bdif += DIFF(optr, os, nptr, ns);
170  }
171  } else {
172  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
173  pdif += DIFF(nptr, ns, nptr, ns);
174  bdif += DIFF(nptr, ns, optr, os);
175  }
176  }
177  break;
178  case ANALYZE:
179  if (top) {
180  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
181  tdif += DIFF(nptr, ns, optr, os);
182  bdif += DIFF(optr, os, nptr, ns);
183  }
184  } else {
185  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
186  bdif += DIFF(nptr, ns, optr, os);
187  tdif += DIFF(optr, os, nptr, ns);
188  }
189  }
190  break;
191  case FULL_ANALYZE:
192  if (top) {
193  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
194  pdif += DIFF(nptr, ns, nptr, ns);
195  tdif += DIFF(nptr, ns, optr, os);
196  bdif += DIFF(optr, os, nptr, ns);
197  }
198  } else {
199  for (rend = nptr + w; nptr < rend; nptr++, optr++) {
200  pdif += DIFF(nptr, ns, nptr, ns);
201  bdif += DIFF(nptr, ns, optr, os);
202  tdif += DIFF(optr, os, nptr, ns);
203  }
204  }
205  break;
206  default:
207  av_assert0(0);
208  }
209 
210  pdiff += (double)pdif;
211  tdiff += (double)tdif;
212  bdiff += (double)bdif;
213  nptr += ns - w;
214  optr += os - w;
215  top ^= 1;
216  }
217 
218  scale = 1.0 / (w * (h - 3)) / 25.0;
219  pdiff *= scale;
220  tdiff *= scale;
221  bdiff *= scale;
222 
223  if (mode == TOP_FIRST_ANALYZE) {
224  bdiff = 65536.0;
225  } else if (mode == BOTTOM_FIRST_ANALYZE) {
226  tdiff = 65536.0;
227  } else if (mode == ANALYZE) {
228  pdiff = 65536.0;
229  }
230 
231  if (bdiff < pdiff && bdiff < tdiff) {
232  mode = BOTTOM_FIRST;
233  } else if (tdiff < pdiff && tdiff < bdiff) {
234  mode = TOP_FIRST;
235  } else {
236  mode = PROGRESSIVE;
237  }
238  }
239 
240  av_log(ctx, AV_LOG_DEBUG, "mode=%c tdiff=%f bdiff=%f pdiff=%f\n",
241  mode == BOTTOM_FIRST ? 'b' : mode == TOP_FIRST ? 't' : 'p',
242  tdiff, bdiff, pdiff);
243  return mode;
244 }
245 
247 {
248  AVFilterContext *ctx = inlink->dst;
249  AVFilterLink *outlink = ctx->outputs[0];
250  PhaseContext *s = ctx->priv;
251  enum PhaseMode mode;
252  int plane, top, y;
253  AVFrame *out;
254 
255  if (ctx->is_disabled) {
256  av_frame_free(&s->frame);
257  /* we keep a reference to the previous frame so the filter can start
258  * being useful as soon as it's not disabled, avoiding the 1-frame
259  * delay. */
260  s->frame = av_frame_clone(in);
261  return ff_filter_frame(outlink, in);
262  }
263 
264  out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
265  if (!out) {
266  av_frame_free(&in);
267  return AVERROR(ENOMEM);
268  }
269  av_frame_copy_props(out, in);
270 
271  if (!s->frame) {
272  s->frame = in;
273  mode = PROGRESSIVE;
274  } else {
275  mode = analyze_plane(ctx, s->mode, s->frame, in);
276  }
277 
278  for (plane = 0; plane < s->nb_planes; plane++) {
279  const uint8_t *buf = s->frame->data[plane];
280  const uint8_t *from = in->data[plane];
281  uint8_t *to = out->data[plane];
282 
283  for (y = 0, top = 1; y < s->planeheight[plane]; y++, top ^= 1) {
284  memcpy(to, mode == (top ? BOTTOM_FIRST : TOP_FIRST) ? buf : from, s->linesize[plane]);
285 
286  buf += s->frame->linesize[plane];
287  from += in->linesize[plane];
288  to += out->linesize[plane];
289  }
290  }
291 
292  if (in != s->frame)
293  av_frame_free(&s->frame);
294  s->frame = in;
295  return ff_filter_frame(outlink, out);
296 }
297 
299 {
300  PhaseContext *s = ctx->priv;
301 
302  av_frame_free(&s->frame);
303 }
304 
305 static const AVFilterPad phase_inputs[] = {
306  {
307  .name = "default",
308  .type = AVMEDIA_TYPE_VIDEO,
309  .filter_frame = filter_frame,
310  .config_props = config_input,
311  },
312  { NULL }
313 };
314 
315 static const AVFilterPad phase_outputs[] = {
316  {
317  .name = "default",
318  .type = AVMEDIA_TYPE_VIDEO,
319  },
320  { NULL }
321 };
322 
324  .name = "phase",
325  .description = NULL_IF_CONFIG_SMALL("Phase shift fields."),
326  .priv_size = sizeof(PhaseContext),
327  .priv_class = &phase_class,
328  .uninit = uninit,
330  .inputs = phase_inputs,
331  .outputs = phase_outputs,
333 };
int plane
Definition: avisynth_c.h:384
#define NULL
Definition: coverity.c:32
const AVPixFmtDescriptor * av_pix_fmt_desc_get(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2522
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
static const AVOption phase_options[]
Definition: vf_phase.c:55
AVOption.
Definition: opt.h:246
planar YUV 4:4:4, 24bpp, (1 Cr & Cb sample per 1x1 Y samples)
Definition: pixfmt.h:71
misc image utilities
int av_pix_fmt_count_planes(enum AVPixelFormat pix_fmt)
Definition: pixdesc.c:2562
Main libavfilter public API header.
const char * desc
Definition: nvenc.c:68
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:168
static int query_formats(AVFilterContext *ctx)
Definition: vf_phase.c:71
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
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
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
static const AVFilterPad phase_inputs[]
Definition: vf_phase.c:305
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1093
planar YUV 4:2:0, 20bpp, (1 Cr & Cb sample per 2x2 Y & A samples)
Definition: pixfmt.h:101
uint8_t
#define av_cold
Definition: attributes.h:82
AVOptions.
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
static const AVFilterPad phase_outputs[]
Definition: vf_phase.c:315
AVFilter ff_vf_phase
Definition: vf_phase.c:323
const char * from
Definition: jacosubdec.c:65
#define OFFSET(x)
Definition: vf_phase.c:51
planar YUV 4:4:0 full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV440P and setting color_range...
Definition: pixfmt.h:100
planar YUV 4:2:2, 16bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV422P and setting col...
Definition: pixfmt.h:79
#define av_log(a,...)
const char * to
Definition: webvttdec.c:34
A filter pad used for either input or output.
Definition: internal.h:54
planar YUV 4:2:2 24bpp, (1 Cr & Cb sample per 2x1 Y & A samples)
Definition: pixfmt.h:176
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:569
static int config_input(AVFilterLink *inlink)
Definition: vf_phase.c:86
uint8_t log2_chroma_h
Amount to shift the luma height right to find the chroma height.
Definition: pixdesc.h:101
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
void * priv
private data for use by the filter
Definition: avfilter.h:353
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
Definition: vf_phase.c:38
simple assert() macros that are a bit more flexible than ISO C assert().
#define FLAGS
Definition: vf_phase.c:52
PhaseMode
Definition: vf_phase.c:30
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
AVFILTER_DEFINE_CLASS(phase)
planar YUV 4:2:0, 12bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV420P and setting col...
Definition: pixfmt.h:78
uint8_t w
Definition: llviddspenc.c:38
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
AVFrame * av_frame_clone(const AVFrame *src)
Create a new frame that references the same data as src.
Definition: frame.c:540
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
int linesize[4]
Definition: vf_phase.c:48
planar YUV 4:4:4 32bpp, (1 Cr & Cb sample per 1x1 Y & A samples)
Definition: pixfmt.h:177
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_phase.c:246
Descriptor that unambiguously describes how the bits of a pixel are stored in the up to 4 data planes...
Definition: pixdesc.h:81
AVFrame * frame
Definition: vf_phase.c:45
#define CONST(name, help, val, unit)
Definition: vf_phase.c:53
void * buf
Definition: avisynth_c.h:766
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
uint8_t pi<< 24) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8, uint8_t,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16, int16_t,(*(const int16_t *) pi >> 8)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16, int16_t,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32, int32_t,(*(const int32_t *) pi >> 24)+0x80) CONV_FUNC_GROUP(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32, int32_t,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, float, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, float, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, float, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, double, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, double, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC_GROUP(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, double, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31))))#define SET_CONV_FUNC_GROUP(ofmt, ifmt) static void set_generic_function(AudioConvert *ac){}void ff_audio_convert_free(AudioConvert **ac){if(!*ac) return;ff_dither_free(&(*ac) ->dc);av_freep(ac);}AudioConvert *ff_audio_convert_alloc(AVAudioResampleContext *avr, enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, int sample_rate, int apply_map){AudioConvert *ac;int in_planar, out_planar;ac=av_mallocz(sizeof(*ac));if(!ac) return NULL;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);return NULL;}return ac;}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;}else if(in_planar) ac->func_type=CONV_FUNC_TYPE_INTERLEAVE;else ac->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);return ac;}int ff_audio_convert(AudioConvert *ac, AudioData *out, AudioData *in){int use_generic=1;int len=in->nb_samples;int p;if(ac->dc){av_log(ac->avr, AV_LOG_TRACE,"%d samples - audio_convert: %s to %s (dithered)\n", len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt));return ff_convert_dither(ac-> in
planar YUV 4:1:0, 9bpp, (1 Cr & Cb sample per 4x4 Y samples)
Definition: pixfmt.h:72
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
int av_image_fill_linesizes(int linesizes[4], enum AVPixelFormat pix_fmt, int width)
Fill plane linesizes for an image with pixel format pix_fmt and width width.
Definition: imgutils.c:89
int mode
PhaseMode.
Definition: vf_phase.c:44
#define DIFF(a, as, b, bs)
Definition: vf_phase.c:111
const char * name
Filter name.
Definition: avfilter.h:148
#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:133
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:275
#define flags(name, subs,...)
Definition: cbs_av1.c:561
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
int nb_planes
Definition: vf_phase.c:46
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
int planeheight[4]
Definition: vf_phase.c:47
#define ns(max_value, name, subs,...)
Definition: cbs_av1.c:682
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
Y , 8bpp.
Definition: pixfmt.h:74
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:215
static enum PhaseMode analyze_plane(void *ctx, enum PhaseMode mode, AVFrame *old, AVFrame *new)
Definition: vf_phase.c:117
planar YUV 4:4:4, 24bpp, full scale (JPEG), deprecated in favor of AV_PIX_FMT_YUV444P and setting col...
Definition: pixfmt.h:80
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples)
Definition: pixfmt.h:73
A list of supported formats for one end of a filter link.
Definition: formats.h:64
planar YUV 4:1:1, 12bpp, (1 Cr & Cb sample per 4x1 Y samples) full scale (JPEG), deprecated in favor ...
Definition: pixfmt.h:258
An instance of a filter.
Definition: avfilter.h:338
FILE * out
Definition: movenc.c:54
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_phase.c:298
planar YUV 4:4:0 (1 Cr & Cb sample per 1x2 Y samples)
Definition: pixfmt.h:99
internal API functions
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
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
mode
Use these values in ebur128_init (or&#39;ed).
Definition: ebur128.h:83
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:654
#define AV_CEIL_RSHIFT(a, b)
Definition: common.h:58