Compared to dualinput, this API can handle more than two inputs and can generate frames synchronized to any or all input streams.
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| 1 | /* | ||
| 2 | * Copyright (c) 2013 Nicolas George | ||
| 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 License | ||
| 8 | * 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 | ||
| 14 | * GNU Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public License | ||
| 17 | * along with FFmpeg; if not, write to the Free Software Foundation, Inc., | ||
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | #include "libavutil/avassert.h" | ||
| 22 | #include "avfilter.h" | ||
| 23 | #include "bufferqueue.h" | ||
| 24 | #include "framesync.h" | ||
| 25 | #include "internal.h" | ||
| 26 | |||
| 27 | #define OFFSET(member) offsetof(FFFrameSync, member) | ||
| 28 | |||
| 29 | static const char *framesync_name(void *ptr) | ||
| 30 | { | ||
| 31 | return "framesync"; | ||
| 32 | } | ||
| 33 | |||
| 34 | static const AVClass framesync_class = { | ||
| 35 | .version = LIBAVUTIL_VERSION_INT, | ||
| 36 | .class_name = "framesync", | ||
| 37 | .item_name = framesync_name, | ||
| 38 | .category = AV_CLASS_CATEGORY_FILTER, | ||
| 39 | .option = NULL, | ||
| 40 | .parent_log_context_offset = OFFSET(parent), | ||
| 41 | }; | ||
| 42 | |||
| 43 | enum { | ||
| 44 | STATE_BOF, | ||
| 45 | STATE_RUN, | ||
| 46 | STATE_EOF, | ||
| 47 | }; | ||
| 48 | |||
| 49 | void ff_framesync_init(FFFrameSync *fs, void *parent, unsigned nb_in) | ||
| 50 | { | ||
| 51 | fs->class = &framesync_class; | ||
| 52 | fs->parent = parent; | ||
| 53 | fs->nb_in = nb_in; | ||
| 54 | } | ||
| 55 | |||
| 56 | static void framesync_sync_level_update(FFFrameSync *fs) | ||
| 57 | { | ||
| 58 | unsigned i, level = 0; | ||
| 59 | |||
| 60 | for (i = 0; i < fs->nb_in; i++) | ||
| 61 | if (fs->in[i].state != STATE_EOF) | ||
| 62 | level = FFMAX(level, fs->in[i].sync); | ||
| 63 | av_assert0(level <= fs->sync_level); | ||
| 64 | if (level < fs->sync_level) | ||
| 65 | av_log(fs, AV_LOG_VERBOSE, "Sync level %u\n", level); | ||
| 66 | if (level) | ||
| 67 | fs->sync_level = level; | ||
| 68 | else | ||
| 69 | fs->eof = 1; | ||
| 70 | } | ||
| 71 | |||
| 72 | int ff_framesync_configure(FFFrameSync *fs) | ||
| 73 | { | ||
| 74 | unsigned i; | ||
| 75 | int64_t gcd, lcm; | ||
| 76 | |||
| 77 | if (!fs->time_base.num) { | ||
| 78 | for (i = 0; i < fs->nb_in; i++) { | ||
| 79 | if (fs->in[i].sync) { | ||
| 80 | if (fs->time_base.num) { | ||
| 81 | gcd = av_gcd(fs->time_base.den, fs->in[i].time_base.den); | ||
| 82 | lcm = (fs->time_base.den / gcd) * fs->in[i].time_base.den; | ||
| 83 | if (lcm < AV_TIME_BASE / 2) { | ||
| 84 | fs->time_base.den = lcm; | ||
| 85 | fs->time_base.num = av_gcd(fs->time_base.num, | ||
| 86 | fs->in[i].time_base.num); | ||
| 87 | } else { | ||
| 88 | fs->time_base.num = 1; | ||
| 89 | fs->time_base.den = AV_TIME_BASE; | ||
| 90 | break; | ||
| 91 | } | ||
| 92 | } else { | ||
| 93 | fs->time_base = fs->in[i].time_base; | ||
| 94 | } | ||
| 95 | } | ||
| 96 | } | ||
| 97 | if (!fs->time_base.num) { | ||
| 98 | av_log(fs, AV_LOG_ERROR, "Impossible to set time base\n"); | ||
| 99 | return AVERROR(EINVAL); | ||
| 100 | } | ||
| 101 | av_log(fs, AV_LOG_VERBOSE, "Selected %d/%d time base\n", | ||
| 102 | fs->time_base.num, fs->time_base.den); | ||
| 103 | } | ||
| 104 | |||
| 105 | for (i = 0; i < fs->nb_in; i++) | ||
| 106 | fs->in[i].pts = fs->in[i].pts_next = AV_NOPTS_VALUE; | ||
| 107 | fs->sync_level = UINT_MAX; | ||
| 108 | framesync_sync_level_update(fs); | ||
| 109 | |||
| 110 | return 0; | ||
| 111 | } | ||
| 112 | |||
| 113 | static void framesync_advance(FFFrameSync *fs) | ||
| 114 | { | ||
| 115 | int latest; | ||
| 116 | unsigned i; | ||
| 117 | int64_t pts; | ||
| 118 | |||
| 119 | if (fs->eof) | ||
| 120 | return; | ||
| 121 | while (!fs->frame_ready) { | ||
| 122 | latest = -1; | ||
| 123 | for (i = 0; i < fs->nb_in; i++) { | ||
| 124 | if (!fs->in[i].have_next) { | ||
| 125 | if (latest < 0 || fs->in[i].pts < fs->in[latest].pts) | ||
| 126 | latest = i; | ||
| 127 | } | ||
| 128 | } | ||
| 129 | if (latest >= 0) { | ||
| 130 | fs->in_request = latest; | ||
| 131 | break; | ||
| 132 | } | ||
| 133 | |||
| 134 | pts = fs->in[0].pts_next; | ||
| 135 | for (i = 1; i < fs->nb_in; i++) | ||
| 136 | if (fs->in[i].pts_next < pts) | ||
| 137 | pts = fs->in[i].pts_next; | ||
| 138 | if (pts == INT64_MAX) { | ||
| 139 | fs->eof = 1; | ||
| 140 | break; | ||
| 141 | } | ||
| 142 | for (i = 0; i < fs->nb_in; i++) { | ||
| 143 | if (fs->in[i].pts_next == pts || | ||
| 144 | (fs->in[i].before == EXT_INFINITY && | ||
| 145 | fs->in[i].state == STATE_BOF)) { | ||
| 146 | av_frame_free(&fs->in[i].frame); | ||
| 147 | fs->in[i].frame = fs->in[i].frame_next; | ||
| 148 | fs->in[i].pts = fs->in[i].pts_next; | ||
| 149 | fs->in[i].frame_next = NULL; | ||
| 150 | fs->in[i].pts_next = AV_NOPTS_VALUE; | ||
| 151 | fs->in[i].have_next = 0; | ||
| 152 | fs->in[i].state = fs->in[i].frame ? STATE_RUN : STATE_EOF; | ||
| 153 | if (fs->in[i].sync == fs->sync_level && fs->in[i].frame) | ||
| 154 | fs->frame_ready = 1; | ||
| 155 | if (fs->in[i].state == STATE_EOF && | ||
| 156 | fs->in[i].after == EXT_STOP) | ||
| 157 | fs->eof = 1; | ||
| 158 | } | ||
| 159 | } | ||
| 160 | if (fs->eof) | ||
| 161 | fs->frame_ready = 0; | ||
| 162 | if (fs->frame_ready) | ||
| 163 | for (i = 0; i < fs->nb_in; i++) | ||
| 164 | if ((fs->in[i].state == STATE_BOF && | ||
| 165 | fs->in[i].before == EXT_STOP)) | ||
| 166 | fs->frame_ready = 0; | ||
| 167 | fs->pts = pts; | ||
| 168 | } | ||
| 169 | } | ||
| 170 | |||
| 171 | static int64_t framesync_pts_extrapolate(FFFrameSync *fs, unsigned in, | ||
| 172 | int64_t pts) | ||
| 173 | { | ||
| 174 | /* Possible enhancement: use the link's frame rate */ | ||
| 175 | return pts + 1; | ||
| 176 | } | ||
| 177 | |||
| 178 | static void framesync_inject_frame(FFFrameSync *fs, unsigned in, AVFrame *frame) | ||
| 179 | { | ||
| 180 | int64_t pts; | ||
| 181 | |||
| 182 | av_assert0(!fs->in[in].have_next); | ||
| 183 | if (frame) { | ||
| 184 | pts = av_rescale_q(frame->pts, fs->in[in].time_base, fs->time_base); | ||
| 185 | frame->pts = pts; | ||
| 186 | } else { | ||
| 187 | pts = fs->in[in].state != STATE_RUN || fs->in[in].after == EXT_INFINITY | ||
| 188 | ? INT64_MAX : framesync_pts_extrapolate(fs, in, fs->in[in].pts); | ||
| 189 | fs->in[in].sync = 0; | ||
| 190 | framesync_sync_level_update(fs); | ||
| 191 | } | ||
| 192 | fs->in[in].frame_next = frame; | ||
| 193 | fs->in[in].pts_next = pts; | ||
| 194 | fs->in[in].have_next = 1; | ||
| 195 | } | ||
| 196 | |||
| 197 | int ff_framesync_add_frame(FFFrameSync *fs, unsigned in, AVFrame *frame) | ||
| 198 | { | ||
| 199 | av_assert1(in < fs->nb_in); | ||
| 200 | if (!fs->in[in].have_next) | ||
| 201 | framesync_inject_frame(fs, in, frame); | ||
| 202 | else | ||
| 203 | ff_bufqueue_add(fs, &fs->in[in].queue, frame); | ||
| 204 | return 0; | ||
| 205 | } | ||
| 206 | |||
| 207 | void ff_framesync_next(FFFrameSync *fs) | ||
| 208 | { | ||
| 209 | unsigned i; | ||
| 210 | |||
| 211 | av_assert0(!fs->frame_ready); | ||
| 212 | for (i = 0; i < fs->nb_in; i++) | ||
| 213 | if (!fs->in[i].have_next && fs->in[i].queue.available) | ||
| 214 | framesync_inject_frame(fs, i, ff_bufqueue_get(&fs->in[i].queue)); | ||
| 215 | fs->frame_ready = 0; | ||
| 216 | framesync_advance(fs); | ||
| 217 | } | ||
| 218 | |||
| 219 | void ff_framesync_drop(FFFrameSync *fs) | ||
| 220 | { | ||
| 221 | fs->frame_ready = 0; | ||
| 222 | } | ||
| 223 | |||
| 224 | int ff_framesync_get_frame(FFFrameSync *fs, unsigned in, AVFrame **rframe, | ||
| 225 | unsigned get) | ||
| 226 | { | ||
| 227 | AVFrame *frame; | ||
| 228 | unsigned need_copy = 0, i; | ||
| 229 | int64_t pts_next; | ||
| 230 | int ret; | ||
| 231 | |||
| 232 | if (!fs->in[in].frame) { | ||
| 233 | *rframe = NULL; | ||
| 234 | return 0; | ||
| 235 | } | ||
| 236 | frame = fs->in[in].frame; | ||
| 237 | if (get) { | ||
| 238 | /* Find out if we need to copy the frame: is there another sync | ||
| 239 | stream, and do we know if its current frame will outlast this one? */ | ||
| 240 | pts_next = fs->in[in].have_next ? fs->in[in].pts_next : INT64_MAX; | ||
| 241 | for (i = 0; i < fs->nb_in && !need_copy; i++) | ||
| 242 | if (i != in && fs->in[i].sync && | ||
| 243 | (!fs->in[i].have_next || fs->in[i].pts_next < pts_next)) | ||
| 244 | need_copy = 1; | ||
| 245 | if (need_copy) { | ||
| 246 | if (!(frame = av_frame_clone(frame))) | ||
| 247 | return AVERROR(ENOMEM); | ||
| 248 | if ((ret = av_frame_make_writable(frame)) < 0) { | ||
| 249 | av_frame_free(&frame); | ||
| 250 | return ret; | ||
| 251 | } | ||
| 252 | } else { | ||
| 253 | fs->in[in].frame = NULL; | ||
| 254 | } | ||
| 255 | fs->frame_ready = 0; | ||
| 256 | } | ||
| 257 | *rframe = frame; | ||
| 258 | return 0; | ||
| 259 | } | ||
| 260 | |||
| 261 | void ff_framesync_uninit(FFFrameSync *fs) | ||
| 262 | { | ||
| 263 | unsigned i; | ||
| 264 | |||
| 265 | for (i = 0; i < fs->nb_in; i++) { | ||
| 266 | av_frame_free(&fs->in[i].frame); | ||
| 267 | av_frame_free(&fs->in[i].frame_next); | ||
| 268 | ff_bufqueue_discard_all(&fs->in[i].queue); | ||
| 269 | } | ||
| 270 | } | ||
| 271 | |||
| 272 | int ff_framesync_process_frame(FFFrameSync *fs, unsigned all) | ||
| 273 | { | ||
| 274 | int ret, count = 0; | ||
| 275 | |||
| 276 | av_assert0(fs->on_event); | ||
| 277 | while (1) { | ||
| 278 | ff_framesync_next(fs); | ||
| 279 | if (fs->eof || !fs->frame_ready) | ||
| 280 | break; | ||
| 281 | if ((ret = fs->on_event(fs)) < 0) | ||
| 282 | return ret; | ||
| 283 | ff_framesync_drop(fs); | ||
| 284 | count++; | ||
| 285 | if (!all) | ||
| 286 | break; | ||
| 287 | } | ||
| 288 | if (!count && fs->eof) | ||
| 289 | return AVERROR_EOF; | ||
| 290 | return count; | ||
| 291 | } | ||
| 292 | |||
| 293 | int ff_framesync_filter_frame(FFFrameSync *fs, AVFilterLink *inlink, | ||
| 294 | AVFrame *in) | ||
| 295 | { | ||
| 296 | int ret; | ||
| 297 | |||
| 298 | if ((ret = ff_framesync_process_frame(fs, 1)) < 0) | ||
| 299 | return ret; | ||
| 300 | if ((ret = ff_framesync_add_frame(fs, FF_INLINK_IDX(inlink), in)) < 0) | ||
| 301 | return ret; | ||
| 302 | if ((ret = ff_framesync_process_frame(fs, 0)) < 0) | ||
| 303 | return ret; | ||
| 304 | return 0; | ||
| 305 | } | ||
| 306 | |||
| 307 | int ff_framesync_request_frame(FFFrameSync *fs, AVFilterLink *outlink) | ||
| 308 | { | ||
| 309 | AVFilterContext *ctx = outlink->src; | ||
| 310 | int input, ret; | ||
| 311 | |||
| 312 | if ((ret = ff_framesync_process_frame(fs, 0)) < 0) | ||
| 313 | return ret; | ||
| 314 | if (ret > 0) | ||
| 315 | return 0; | ||
| 316 | if (fs->eof) | ||
| 317 | return AVERROR_EOF; | ||
| 318 | outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP; | ||
| 319 | input = fs->in_request; | ||
| 320 | ret = ff_request_frame(ctx->inputs[input]); | ||
| 321 | if (ret == AVERROR_EOF) { | ||
| 322 | if ((ret = ff_framesync_add_frame(fs, input, NULL)) < 0) | ||
| 323 | return ret; | ||
| 324 | if ((ret = ff_framesync_process_frame(fs, 0)) < 0) | ||
| 325 | return ret; | ||
| 326 | ret = 0; | ||
| 327 | } | ||
| 328 | return ret; | ||
| 329 | } | ||