FFmpeg
vf_random.c
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1 /*
2  * Copyright (c) 2015 Paul B Mahol
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 "libavutil/lfg.h"
22 #include "libavutil/opt.h"
23 #include "libavutil/random_seed.h"
24 #include "avfilter.h"
25 #include "formats.h"
26 #include "internal.h"
27 #include "video.h"
28 
29 #define MAX_FRAMES 512
30 
31 typedef struct RandomContext {
32  const AVClass *class;
33 
35  int nb_frames;
36  int64_t random_seed;
39  int64_t pts[MAX_FRAMES];
40  int flush_idx;
42 
43 #define OFFSET(x) offsetof(RandomContext, x)
44 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
45 
46 static const AVOption random_options[] = {
47  { "frames", "set number of frames in cache", OFFSET(nb_frames), AV_OPT_TYPE_INT, {.i64=30}, 2, MAX_FRAMES, FLAGS },
48  { "seed", "set the seed", OFFSET(random_seed), AV_OPT_TYPE_INT64, {.i64=-1}, -1, UINT32_MAX, FLAGS },
49  { NULL }
50 };
51 
52 AVFILTER_DEFINE_CLASS(random);
53 
55 {
56  RandomContext *s = ctx->priv;
57  uint32_t seed;
58 
59  if (s->random_seed < 0)
61  seed = s->random_seed;
62  av_lfg_init(&s->lfg, seed);
63 
64  return 0;
65 }
66 
68 {
69  AVFilterContext *ctx = inlink->dst;
70  RandomContext *s = ctx->priv;
71  AVFilterLink *outlink = ctx->outputs[0];
72  AVFrame *out;
73  int idx;
74 
75  if (s->nb_frames_filled < s->nb_frames) {
76  s->frames[s->nb_frames_filled] = in;
77  s->pts[s->nb_frames_filled++] = in->pts;
78  return 0;
79  }
80 
81  idx = av_lfg_get(&s->lfg) % s->nb_frames;
82 
83  out = s->frames[idx];
84  out->pts = s->pts[0];
85  memmove(&s->pts[0], &s->pts[1], (s->nb_frames - 1) * sizeof(s->pts[0]));
86  s->frames[idx] = in;
87  s->pts[s->nb_frames - 1] = in->pts;
88 
89  return ff_filter_frame(outlink, out);
90 }
91 
92 static int request_frame(AVFilterLink *outlink)
93 {
94  AVFilterContext *ctx = outlink->src;
95  RandomContext *s = ctx->priv;
96  int ret;
97 
98  ret = ff_request_frame(ctx->inputs[0]);
99 
100 next:
101  if (ret == AVERROR_EOF && !ctx->is_disabled && s->nb_frames > 0) {
102  AVFrame *out = s->frames[s->nb_frames - 1];
103  if (!out) {
104  s->nb_frames--;
105  goto next;
106  }
107  out->pts = s->pts[s->flush_idx++];
108  ret = ff_filter_frame(outlink, out);
109  s->frames[s->nb_frames - 1] = NULL;
110  s->nb_frames--;
111  }
112 
113  return ret;
114 }
115 
117 {
118  RandomContext *s = ctx->priv;
119 
120  for (int i = 0; i < s->nb_frames; i++)
121  av_frame_free(&s->frames[i]);
122 }
123 
124 static const AVFilterPad random_inputs[] = {
125  {
126  .name = "default",
127  .type = AVMEDIA_TYPE_VIDEO,
128  .filter_frame = filter_frame,
129  },
130  { NULL }
131 };
132 
133 static const AVFilterPad random_outputs[] = {
134  {
135  .name = "default",
136  .type = AVMEDIA_TYPE_VIDEO,
137  .request_frame = request_frame,
138  },
139  { NULL }
140 };
141 
143  .name = "random",
144  .description = NULL_IF_CONFIG_SMALL("Return random frames."),
145  .priv_size = sizeof(RandomContext),
146  .priv_class = &random_class,
147  .init = init,
148  .uninit = uninit,
149  .inputs = random_inputs,
150  .outputs = random_outputs,
151 };
Definition: lfg.h:27
#define NULL
Definition: coverity.c:32
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
int64_t random_seed
Definition: vf_random.c:36
AVOption.
Definition: opt.h:246
Main libavfilter public API header.
static const AVOption random_options[]
Definition: vf_random.c:46
AVFrame * frames[MAX_FRAMES]
Definition: vf_random.c:38
#define OFFSET(x)
Definition: vf_random.c:43
int64_t pts[MAX_FRAMES]
Definition: vf_random.c:39
int is_disabled
the enabled state from the last expression evaluation
Definition: avfilter.h:385
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:346
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1093
#define av_cold
Definition: attributes.h:82
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:388
#define AVERROR_EOF
End of file.
Definition: error.h:55
A filter pad used for either input or output.
Definition: internal.h:54
AVFILTER_DEFINE_CLASS(random)
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
static int request_frame(AVFilterLink *outlink)
Definition: vf_random.c:92
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 FLAGS
Definition: vf_random.c:44
AVFilter ff_vf_random
Definition: vf_random.c:142
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
int nb_frames_filled
Definition: vf_random.c:37
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: vf_random.c:67
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
static unsigned int seed
Definition: videogen.c:78
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:47
#define MAX_FRAMES
Definition: vf_random.c:29
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
Describe the class of an AVClass context structure.
Definition: log.h:67
Filter definition.
Definition: avfilter.h:144
static av_cold int init(AVFilterContext *ctx)
Definition: vf_random.c:54
const char * name
Filter name.
Definition: avfilter.h:148
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:350
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
static av_cold void uninit(AVFilterContext *ctx)
Definition: vf_random.c:116
An instance of a filter.
Definition: avfilter.h:338
FILE * out
Definition: movenc.c:54
uint32_t av_get_random_seed(void)
Get a seed to use in conjunction with random functions.
Definition: random_seed.c:120
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:407
internal API functions
static const AVFilterPad random_outputs[]
Definition: vf_random.c:133
static const AVFilterPad random_inputs[]
Definition: vf_random.c:124