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00026 #include "libavutil/eval.h"
00027 #include "libavutil/fifo.h"
00028 #include "libavutil/mathematics.h"
00029 #include "avfilter.h"
00030
00031 static const char *var_names[] = {
00032 "E",
00033 "PHI",
00034 "PI",
00035
00036 "TB",
00037
00038 "pts",
00039 "start_pts",
00040 "prev_pts",
00041 "prev_selected_pts",
00042
00043 "t",
00044 "start_t",
00045 "prev_t",
00046 "prev_selected_t",
00047
00048 "pict_type",
00049 "I",
00050 "P",
00051 "B",
00052 "S",
00053 "SI",
00054 "SP",
00055 "BI",
00056
00057 "interlace_type",
00058 "PROGRESSIVE",
00059 "TOPFIRST",
00060 "BOTTOMFIRST",
00061
00062 "n",
00063 "selected_n",
00064 "prev_selected_n",
00065
00066 "key",
00067 "pos",
00068
00069 NULL
00070 };
00071
00072 enum var_name {
00073 VAR_E,
00074 VAR_PHI,
00075 VAR_PI,
00076
00077 VAR_TB,
00078
00079 VAR_PTS,
00080 VAR_START_PTS,
00081 VAR_PREV_PTS,
00082 VAR_PREV_SELECTED_PTS,
00083
00084 VAR_T,
00085 VAR_START_T,
00086 VAR_PREV_T,
00087 VAR_PREV_SELECTED_T,
00088
00089 VAR_PICT_TYPE,
00090 VAR_PICT_TYPE_I,
00091 VAR_PICT_TYPE_P,
00092 VAR_PICT_TYPE_B,
00093 VAR_PICT_TYPE_S,
00094 VAR_PICT_TYPE_SI,
00095 VAR_PICT_TYPE_SP,
00096 VAR_PICT_TYPE_BI,
00097
00098 VAR_INTERLACE_TYPE,
00099 VAR_INTERLACE_TYPE_P,
00100 VAR_INTERLACE_TYPE_T,
00101 VAR_INTERLACE_TYPE_B,
00102
00103 VAR_N,
00104 VAR_SELECTED_N,
00105 VAR_PREV_SELECTED_N,
00106
00107 VAR_KEY,
00108 VAR_POS,
00109
00110 VAR_VARS_NB
00111 };
00112
00113 #define FIFO_SIZE 8
00114
00115 typedef struct {
00116 AVExpr *expr;
00117 double var_values[VAR_VARS_NB];
00118 double select;
00119 int cache_frames;
00120 AVFifoBuffer *pending_frames;
00121 } SelectContext;
00122
00123 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
00124 {
00125 SelectContext *select = ctx->priv;
00126 int ret;
00127
00128 if ((ret = av_expr_parse(&select->expr, args ? args : "1",
00129 var_names, NULL, NULL, NULL, NULL, 0, ctx)) < 0) {
00130 av_log(ctx, AV_LOG_ERROR, "Error while parsing expression '%s'\n", args);
00131 return ret;
00132 }
00133
00134 select->pending_frames = av_fifo_alloc(FIFO_SIZE*sizeof(AVFilterBufferRef*));
00135 if (!select->pending_frames) {
00136 av_log(ctx, AV_LOG_ERROR, "Failed to allocate pending frames buffer.\n");
00137 return AVERROR(ENOMEM);
00138 }
00139 return 0;
00140 }
00141
00142 #define INTERLACE_TYPE_P 0
00143 #define INTERLACE_TYPE_T 1
00144 #define INTERLACE_TYPE_B 2
00145
00146 static int config_input(AVFilterLink *inlink)
00147 {
00148 SelectContext *select = inlink->dst->priv;
00149
00150 select->var_values[VAR_E] = M_E;
00151 select->var_values[VAR_PHI] = M_PHI;
00152 select->var_values[VAR_PI] = M_PI;
00153
00154 select->var_values[VAR_N] = 0.0;
00155 select->var_values[VAR_SELECTED_N] = 0.0;
00156
00157 select->var_values[VAR_TB] = av_q2d(inlink->time_base);
00158
00159 select->var_values[VAR_PREV_PTS] = NAN;
00160 select->var_values[VAR_PREV_SELECTED_PTS] = NAN;
00161 select->var_values[VAR_PREV_SELECTED_T] = NAN;
00162 select->var_values[VAR_START_PTS] = NAN;
00163 select->var_values[VAR_START_T] = NAN;
00164
00165 select->var_values[VAR_PICT_TYPE_I] = AV_PICTURE_TYPE_I;
00166 select->var_values[VAR_PICT_TYPE_P] = AV_PICTURE_TYPE_P;
00167 select->var_values[VAR_PICT_TYPE_B] = AV_PICTURE_TYPE_B;
00168 select->var_values[VAR_PICT_TYPE_SI] = AV_PICTURE_TYPE_SI;
00169 select->var_values[VAR_PICT_TYPE_SP] = AV_PICTURE_TYPE_SP;
00170
00171 select->var_values[VAR_INTERLACE_TYPE_P] = INTERLACE_TYPE_P;
00172 select->var_values[VAR_INTERLACE_TYPE_T] = INTERLACE_TYPE_T;
00173 select->var_values[VAR_INTERLACE_TYPE_B] = INTERLACE_TYPE_B;;
00174
00175 return 0;
00176 }
00177
00178 #define D2TS(d) (isnan(d) ? AV_NOPTS_VALUE : (int64_t)(d))
00179 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
00180
00181 static int select_frame(AVFilterContext *ctx, AVFilterBufferRef *picref)
00182 {
00183 SelectContext *select = ctx->priv;
00184 AVFilterLink *inlink = ctx->inputs[0];
00185 double res;
00186
00187 if (isnan(select->var_values[VAR_START_PTS]))
00188 select->var_values[VAR_START_PTS] = TS2D(picref->pts);
00189 if (isnan(select->var_values[VAR_START_T]))
00190 select->var_values[VAR_START_T] = TS2D(picref->pts) * av_q2d(inlink->time_base);
00191
00192 select->var_values[VAR_PTS] = TS2D(picref->pts);
00193 select->var_values[VAR_T ] = TS2D(picref->pts) * av_q2d(inlink->time_base);
00194 select->var_values[VAR_POS] = picref->pos == -1 ? NAN : picref->pos;
00195 select->var_values[VAR_PREV_PTS] = TS2D(picref ->pts);
00196
00197 select->var_values[VAR_INTERLACE_TYPE] =
00198 !picref->video->interlaced ? INTERLACE_TYPE_P :
00199 picref->video->top_field_first ? INTERLACE_TYPE_T : INTERLACE_TYPE_B;
00200 select->var_values[VAR_PICT_TYPE] = picref->video->pict_type;
00201
00202 res = av_expr_eval(select->expr, select->var_values, NULL);
00203 av_log(inlink->dst, AV_LOG_DEBUG,
00204 "n:%d pts:%d t:%f pos:%d interlace_type:%c key:%d pict_type:%c "
00205 "-> select:%f\n",
00206 (int)select->var_values[VAR_N],
00207 (int)select->var_values[VAR_PTS],
00208 select->var_values[VAR_T],
00209 (int)select->var_values[VAR_POS],
00210 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_P ? 'P' :
00211 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_T ? 'T' :
00212 select->var_values[VAR_INTERLACE_TYPE] == INTERLACE_TYPE_B ? 'B' : '?',
00213 (int)select->var_values[VAR_KEY],
00214 av_get_picture_type_char(select->var_values[VAR_PICT_TYPE]),
00215 res);
00216
00217 select->var_values[VAR_N] += 1.0;
00218
00219 if (res) {
00220 select->var_values[VAR_PREV_SELECTED_N] = select->var_values[VAR_N];
00221 select->var_values[VAR_PREV_SELECTED_PTS] = select->var_values[VAR_PTS];
00222 select->var_values[VAR_PREV_SELECTED_T] = select->var_values[VAR_T];
00223 select->var_values[VAR_SELECTED_N] += 1.0;
00224 }
00225 return res;
00226 }
00227
00228 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref)
00229 {
00230 SelectContext *select = inlink->dst->priv;
00231
00232 select->select = select_frame(inlink->dst, picref);
00233 if (select->select) {
00234
00235 if (select->cache_frames) {
00236 if (!av_fifo_space(select->pending_frames))
00237 av_log(inlink->dst, AV_LOG_ERROR,
00238 "Buffering limit reached, cannot cache more frames\n");
00239 else
00240 av_fifo_generic_write(select->pending_frames, &picref,
00241 sizeof(picref), NULL);
00242 return;
00243 }
00244 avfilter_start_frame(inlink->dst->outputs[0], avfilter_ref_buffer(picref, ~0));
00245 }
00246 }
00247
00248 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
00249 {
00250 SelectContext *select = inlink->dst->priv;
00251
00252 if (select->select && !select->cache_frames)
00253 avfilter_draw_slice(inlink->dst->outputs[0], y, h, slice_dir);
00254 }
00255
00256 static void end_frame(AVFilterLink *inlink)
00257 {
00258 SelectContext *select = inlink->dst->priv;
00259 AVFilterBufferRef *picref = inlink->cur_buf;
00260
00261 if (select->select) {
00262 if (select->cache_frames)
00263 return;
00264 avfilter_end_frame(inlink->dst->outputs[0]);
00265 }
00266 avfilter_unref_buffer(picref);
00267 }
00268
00269 static int request_frame(AVFilterLink *outlink)
00270 {
00271 AVFilterContext *ctx = outlink->src;
00272 SelectContext *select = ctx->priv;
00273 AVFilterLink *inlink = outlink->src->inputs[0];
00274 select->select = 0;
00275
00276 if (av_fifo_size(select->pending_frames)) {
00277 AVFilterBufferRef *picref;
00278 av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL);
00279 avfilter_start_frame(outlink, avfilter_ref_buffer(picref, ~0));
00280 avfilter_draw_slice(outlink, 0, outlink->h, 1);
00281 avfilter_end_frame(outlink);
00282 avfilter_unref_buffer(picref);
00283 return 0;
00284 }
00285
00286 while (!select->select) {
00287 int ret = avfilter_request_frame(inlink);
00288 if (ret < 0)
00289 return ret;
00290 }
00291
00292 return 0;
00293 }
00294
00295 static int poll_frame(AVFilterLink *outlink)
00296 {
00297 SelectContext *select = outlink->src->priv;
00298 AVFilterLink *inlink = outlink->src->inputs[0];
00299 int count, ret;
00300
00301 if (!av_fifo_size(select->pending_frames)) {
00302 if ((count = avfilter_poll_frame(inlink)) <= 0)
00303 return count;
00304
00305 select->cache_frames = 1;
00306 while (count-- && av_fifo_space(select->pending_frames)) {
00307 ret = avfilter_request_frame(inlink);
00308 if (ret < 0)
00309 break;
00310 }
00311 select->cache_frames = 0;
00312 }
00313
00314 return av_fifo_size(select->pending_frames)/sizeof(AVFilterBufferRef *);
00315 }
00316
00317 static av_cold void uninit(AVFilterContext *ctx)
00318 {
00319 SelectContext *select = ctx->priv;
00320 AVFilterBufferRef *picref;
00321
00322 av_expr_free(select->expr);
00323 select->expr = NULL;
00324
00325 while (select->pending_frames &&
00326 av_fifo_generic_read(select->pending_frames, &picref, sizeof(picref), NULL) == sizeof(picref))
00327 avfilter_unref_buffer(picref);
00328 av_fifo_free(select->pending_frames);
00329 select->pending_frames = NULL;
00330 }
00331
00332 AVFilter avfilter_vf_select = {
00333 .name = "select",
00334 .description = NULL_IF_CONFIG_SMALL("Select frames to pass in output."),
00335 .init = init,
00336 .uninit = uninit,
00337
00338 .priv_size = sizeof(SelectContext),
00339
00340 .inputs = (AVFilterPad[]) {{ .name = "default",
00341 .type = AVMEDIA_TYPE_VIDEO,
00342 .get_video_buffer = avfilter_null_get_video_buffer,
00343 .config_props = config_input,
00344 .start_frame = start_frame,
00345 .draw_slice = draw_slice,
00346 .end_frame = end_frame },
00347 { .name = NULL }},
00348 .outputs = (AVFilterPad[]) {{ .name = "default",
00349 .type = AVMEDIA_TYPE_VIDEO,
00350 .poll_frame = poll_frame,
00351 .request_frame = request_frame, },
00352 { .name = NULL}},
00353 };