| 1 | /* |
| 2 | * Copyright 2007 Bobby Bingham |
| 3 | * Copyright 2012 Robert Nagy <ronag89 gmail com> |
| 4 | * Copyright 2012 Anton Khirnov <anton khirnov net> |
| 5 | * |
| 6 | * This file is part of FFmpeg. |
| 7 | * |
| 8 | * FFmpeg is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU Lesser General Public |
| 10 | * License as published by the Free Software Foundation; either |
| 11 | * version 2.1 of the License, or (at your option) any later version. |
| 12 | * |
| 13 | * FFmpeg is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | * Lesser General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU Lesser General Public |
| 19 | * License along with FFmpeg; if not, write to the Free Software |
| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 21 | */ |
| 22 | |
| 23 | /** |
| 24 | * @file |
| 25 | * a filter enforcing given constant framerate |
| 26 | */ |
| 27 | |
| 28 | #include <float.h> |
| 29 | #include <stdint.h> |
| 30 | |
| 31 | #include "libavutil/common.h" |
| 32 | #include "libavutil/fifo.h" |
| 33 | #include "libavutil/mathematics.h" |
| 34 | #include "libavutil/opt.h" |
| 35 | #include "libavutil/parseutils.h" |
| 36 | |
| 37 | #include "avfilter.h" |
| 38 | #include "internal.h" |
| 39 | #include "video.h" |
| 40 | |
| 41 | typedef struct FPSContext { |
| 42 | const AVClass *class; |
| 43 | |
| 44 | AVFifoBuffer *fifo; ///< store frames until we get two successive timestamps |
| 45 | |
| 46 | /* timestamps in input timebase */ |
| 47 | int64_t first_pts; ///< pts of the first frame that arrived on this filter |
| 48 | |
| 49 | double start_time; ///< pts, in seconds, of the expected first frame |
| 50 | |
| 51 | AVRational framerate; ///< target framerate |
| 52 | int rounding; ///< AVRounding method for timestamps |
| 53 | |
| 54 | /* statistics */ |
| 55 | int frames_in; ///< number of frames on input |
| 56 | int frames_out; ///< number of frames on output |
| 57 | int dup; ///< number of frames duplicated |
| 58 | int drop; ///< number of framed dropped |
| 59 | } FPSContext; |
| 60 | |
| 61 | #define OFFSET(x) offsetof(FPSContext, x) |
| 62 | #define V AV_OPT_FLAG_VIDEO_PARAM |
| 63 | #define F AV_OPT_FLAG_FILTERING_PARAM |
| 64 | static const AVOption fps_options[] = { |
| 65 | { "fps", "A string describing desired output framerate", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, { .str = "25" }, .flags = V|F }, |
| 66 | { "start_time", "Assume the first PTS should be this value.", OFFSET(start_time), AV_OPT_TYPE_DOUBLE, { .dbl = DBL_MAX}, -DBL_MAX, DBL_MAX, V }, |
| 67 | { "round", "set rounding method for timestamps", OFFSET(rounding), AV_OPT_TYPE_INT, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" }, |
| 68 | { "zero", "round towards 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_ZERO }, 0, 5, V|F, "round" }, |
| 69 | { "inf", "round away from 0", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_INF }, 0, 5, V|F, "round" }, |
| 70 | { "down", "round towards -infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_DOWN }, 0, 5, V|F, "round" }, |
| 71 | { "up", "round towards +infty", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_UP }, 0, 5, V|F, "round" }, |
| 72 | { "near", "round to nearest", OFFSET(rounding), AV_OPT_TYPE_CONST, { .i64 = AV_ROUND_NEAR_INF }, 0, 5, V|F, "round" }, |
| 73 | { NULL } |
| 74 | }; |
| 75 | |
| 76 | AVFILTER_DEFINE_CLASS(fps); |
| 77 | |
| 78 | static av_cold int init(AVFilterContext *ctx) |
| 79 | { |
| 80 | FPSContext *s = ctx->priv; |
| 81 | |
| 82 | if (!(s->fifo = av_fifo_alloc_array(2, sizeof(AVFrame*)))) |
| 83 | return AVERROR(ENOMEM); |
| 84 | |
| 85 | s->first_pts = AV_NOPTS_VALUE; |
| 86 | |
| 87 | av_log(ctx, AV_LOG_VERBOSE, "fps=%d/%d\n", s->framerate.num, s->framerate.den); |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static void flush_fifo(AVFifoBuffer *fifo) |
| 92 | { |
| 93 | while (av_fifo_size(fifo)) { |
| 94 | AVFrame *tmp; |
| 95 | av_fifo_generic_read(fifo, &tmp, sizeof(tmp), NULL); |
| 96 | av_frame_free(&tmp); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | static av_cold void uninit(AVFilterContext *ctx) |
| 101 | { |
| 102 | FPSContext *s = ctx->priv; |
| 103 | if (s->fifo) { |
| 104 | s->drop += av_fifo_size(s->fifo) / sizeof(AVFrame*); |
| 105 | flush_fifo(s->fifo); |
| 106 | av_fifo_freep(&s->fifo); |
| 107 | } |
| 108 | |
| 109 | av_log(ctx, AV_LOG_VERBOSE, "%d frames in, %d frames out; %d frames dropped, " |
| 110 | "%d frames duplicated.\n", s->frames_in, s->frames_out, s->drop, s->dup); |
| 111 | } |
| 112 | |
| 113 | static int config_props(AVFilterLink* link) |
| 114 | { |
| 115 | FPSContext *s = link->src->priv; |
| 116 | |
| 117 | link->time_base = av_inv_q(s->framerate); |
| 118 | link->frame_rate= s->framerate; |
| 119 | link->w = link->src->inputs[0]->w; |
| 120 | link->h = link->src->inputs[0]->h; |
| 121 | |
| 122 | return 0; |
| 123 | } |
| 124 | |
| 125 | static int request_frame(AVFilterLink *outlink) |
| 126 | { |
| 127 | AVFilterContext *ctx = outlink->src; |
| 128 | FPSContext *s = ctx->priv; |
| 129 | int frames_out = s->frames_out; |
| 130 | int ret = 0; |
| 131 | |
| 132 | while (ret >= 0 && s->frames_out == frames_out) |
| 133 | ret = ff_request_frame(ctx->inputs[0]); |
| 134 | |
| 135 | /* flush the fifo */ |
| 136 | if (ret == AVERROR_EOF && av_fifo_size(s->fifo)) { |
| 137 | int i; |
| 138 | for (i = 0; av_fifo_size(s->fifo); i++) { |
| 139 | AVFrame *buf; |
| 140 | |
| 141 | av_fifo_generic_read(s->fifo, &buf, sizeof(buf), NULL); |
| 142 | buf->pts = av_rescale_q(s->first_pts, ctx->inputs[0]->time_base, |
| 143 | outlink->time_base) + s->frames_out; |
| 144 | |
| 145 | if ((ret = ff_filter_frame(outlink, buf)) < 0) |
| 146 | return ret; |
| 147 | |
| 148 | s->frames_out++; |
| 149 | } |
| 150 | return 0; |
| 151 | } |
| 152 | |
| 153 | return ret; |
| 154 | } |
| 155 | |
| 156 | static int write_to_fifo(AVFifoBuffer *fifo, AVFrame *buf) |
| 157 | { |
| 158 | int ret; |
| 159 | |
| 160 | if (!av_fifo_space(fifo) && |
| 161 | (ret = av_fifo_realloc2(fifo, 2*av_fifo_size(fifo)))) { |
| 162 | av_frame_free(&buf); |
| 163 | return ret; |
| 164 | } |
| 165 | |
| 166 | av_fifo_generic_write(fifo, &buf, sizeof(buf), NULL); |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 170 | static int filter_frame(AVFilterLink *inlink, AVFrame *buf) |
| 171 | { |
| 172 | AVFilterContext *ctx = inlink->dst; |
| 173 | FPSContext *s = ctx->priv; |
| 174 | AVFilterLink *outlink = ctx->outputs[0]; |
| 175 | int64_t delta; |
| 176 | int i, ret; |
| 177 | |
| 178 | s->frames_in++; |
| 179 | /* discard frames until we get the first timestamp */ |
| 180 | if (s->first_pts == AV_NOPTS_VALUE) { |
| 181 | if (buf->pts != AV_NOPTS_VALUE) { |
| 182 | ret = write_to_fifo(s->fifo, buf); |
| 183 | if (ret < 0) |
| 184 | return ret; |
| 185 | |
| 186 | if (s->start_time != DBL_MAX && s->start_time != AV_NOPTS_VALUE) { |
| 187 | double first_pts = s->start_time * AV_TIME_BASE; |
| 188 | first_pts = FFMIN(FFMAX(first_pts, INT64_MIN), INT64_MAX); |
| 189 | s->first_pts = av_rescale_q(first_pts, AV_TIME_BASE_Q, |
| 190 | inlink->time_base); |
| 191 | av_log(ctx, AV_LOG_VERBOSE, "Set first pts to (in:%"PRId64" out:%"PRId64")\n", |
| 192 | s->first_pts, av_rescale_q(first_pts, AV_TIME_BASE_Q, |
| 193 | outlink->time_base)); |
| 194 | } else { |
| 195 | s->first_pts = buf->pts; |
| 196 | } |
| 197 | } else { |
| 198 | av_log(ctx, AV_LOG_WARNING, "Discarding initial frame(s) with no " |
| 199 | "timestamp.\n"); |
| 200 | av_frame_free(&buf); |
| 201 | s->drop++; |
| 202 | } |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | /* now wait for the next timestamp */ |
| 207 | if (buf->pts == AV_NOPTS_VALUE || av_fifo_size(s->fifo) <= 0) { |
| 208 | return write_to_fifo(s->fifo, buf); |
| 209 | } |
| 210 | |
| 211 | /* number of output frames */ |
| 212 | delta = av_rescale_q_rnd(buf->pts - s->first_pts, inlink->time_base, |
| 213 | outlink->time_base, s->rounding) - s->frames_out ; |
| 214 | |
| 215 | if (delta < 1) { |
| 216 | /* drop the frame and everything buffered except the first */ |
| 217 | AVFrame *tmp; |
| 218 | int drop = av_fifo_size(s->fifo)/sizeof(AVFrame*); |
| 219 | |
| 220 | av_log(ctx, AV_LOG_DEBUG, "Dropping %d frame(s).\n", drop); |
| 221 | s->drop += drop; |
| 222 | |
| 223 | av_fifo_generic_read(s->fifo, &tmp, sizeof(tmp), NULL); |
| 224 | flush_fifo(s->fifo); |
| 225 | ret = write_to_fifo(s->fifo, tmp); |
| 226 | |
| 227 | av_frame_free(&buf); |
| 228 | return ret; |
| 229 | } |
| 230 | |
| 231 | /* can output >= 1 frames */ |
| 232 | for (i = 0; i < delta; i++) { |
| 233 | AVFrame *buf_out; |
| 234 | av_fifo_generic_read(s->fifo, &buf_out, sizeof(buf_out), NULL); |
| 235 | |
| 236 | /* duplicate the frame if needed */ |
| 237 | if (!av_fifo_size(s->fifo) && i < delta - 1) { |
| 238 | AVFrame *dup = av_frame_clone(buf_out); |
| 239 | |
| 240 | av_log(ctx, AV_LOG_DEBUG, "Duplicating frame.\n"); |
| 241 | if (dup) |
| 242 | ret = write_to_fifo(s->fifo, dup); |
| 243 | else |
| 244 | ret = AVERROR(ENOMEM); |
| 245 | |
| 246 | if (ret < 0) { |
| 247 | av_frame_free(&buf_out); |
| 248 | av_frame_free(&buf); |
| 249 | return ret; |
| 250 | } |
| 251 | |
| 252 | s->dup++; |
| 253 | } |
| 254 | |
| 255 | buf_out->pts = av_rescale_q(s->first_pts, inlink->time_base, |
| 256 | outlink->time_base) + s->frames_out; |
| 257 | |
| 258 | if ((ret = ff_filter_frame(outlink, buf_out)) < 0) { |
| 259 | av_frame_free(&buf); |
| 260 | return ret; |
| 261 | } |
| 262 | |
| 263 | s->frames_out++; |
| 264 | } |
| 265 | flush_fifo(s->fifo); |
| 266 | |
| 267 | ret = write_to_fifo(s->fifo, buf); |
| 268 | |
| 269 | return ret; |
| 270 | } |
| 271 | |
| 272 | static const AVFilterPad avfilter_vf_fps_inputs[] = { |
| 273 | { |
| 274 | .name = "default", |
| 275 | .type = AVMEDIA_TYPE_VIDEO, |
| 276 | .filter_frame = filter_frame, |
| 277 | }, |
| 278 | { NULL } |
| 279 | }; |
| 280 | |
| 281 | static const AVFilterPad avfilter_vf_fps_outputs[] = { |
| 282 | { |
| 283 | .name = "default", |
| 284 | .type = AVMEDIA_TYPE_VIDEO, |
| 285 | .request_frame = request_frame, |
| 286 | .config_props = config_props |
| 287 | }, |
| 288 | { NULL } |
| 289 | }; |
| 290 | |
| 291 | AVFilter ff_vf_fps = { |
| 292 | .name = "fps", |
| 293 | .description = NULL_IF_CONFIG_SMALL("Force constant framerate."), |
| 294 | .init = init, |
| 295 | .uninit = uninit, |
| 296 | .priv_size = sizeof(FPSContext), |
| 297 | .priv_class = &fps_class, |
| 298 | .inputs = avfilter_vf_fps_inputs, |
| 299 | .outputs = avfilter_vf_fps_outputs, |
| 300 | }; |