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00028 #include "avfilter.h"
00029 #include "libavutil/eval.h"
00030 #include "libavutil/avstring.h"
00031 #include "libavutil/pixdesc.h"
00032 #include "libavutil/imgutils.h"
00033 #include "libavutil/mathematics.h"
00034 #include "internal.h"
00035
00036 static const char *var_names[] = {
00037 "E",
00038 "PHI",
00039 "PI",
00040 "main_w", "W",
00041 "main_h", "H",
00042 "overlay_w", "w",
00043 "overlay_h", "h",
00044 NULL
00045 };
00046
00047 enum var_name {
00048 VAR_E,
00049 VAR_PHI,
00050 VAR_PI,
00051 VAR_MAIN_W, VAR_MW,
00052 VAR_MAIN_H, VAR_MH,
00053 VAR_OVERLAY_W, VAR_OW,
00054 VAR_OVERLAY_H, VAR_OH,
00055 VAR_VARS_NB
00056 };
00057
00058 #define MAIN 0
00059 #define OVERLAY 1
00060
00061 typedef struct {
00062 int x, y;
00063
00064 AVFilterBufferRef *overpicref;
00065
00066 int max_plane_step[4];
00067 int hsub, vsub;
00068
00069 char x_expr[256], y_expr[256];
00070 } OverlayContext;
00071
00072 static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
00073 {
00074 OverlayContext *over = ctx->priv;
00075
00076 av_strlcpy(over->x_expr, "0", sizeof(over->x_expr));
00077 av_strlcpy(over->y_expr, "0", sizeof(over->y_expr));
00078
00079 if (args)
00080 sscanf(args, "%255[^:]:%255[^:]", over->x_expr, over->y_expr);
00081
00082 return 0;
00083 }
00084
00085 static av_cold void uninit(AVFilterContext *ctx)
00086 {
00087 OverlayContext *over = ctx->priv;
00088
00089 if (over->overpicref)
00090 avfilter_unref_buffer(over->overpicref);
00091 }
00092
00093 static int query_formats(AVFilterContext *ctx)
00094 {
00095 const enum PixelFormat inout_pix_fmts[] = { PIX_FMT_YUV420P, PIX_FMT_NONE };
00096 const enum PixelFormat blend_pix_fmts[] = { PIX_FMT_YUVA420P, PIX_FMT_NONE };
00097 AVFilterFormats *inout_formats = avfilter_make_format_list(inout_pix_fmts);
00098 AVFilterFormats *blend_formats = avfilter_make_format_list(blend_pix_fmts);
00099
00100 avfilter_formats_ref(inout_formats, &ctx->inputs [MAIN ]->out_formats);
00101 avfilter_formats_ref(blend_formats, &ctx->inputs [OVERLAY]->out_formats);
00102 avfilter_formats_ref(inout_formats, &ctx->outputs[MAIN ]->in_formats );
00103
00104 return 0;
00105 }
00106
00107 static int config_input_main(AVFilterLink *inlink)
00108 {
00109 OverlayContext *over = inlink->dst->priv;
00110 const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
00111
00112 av_image_fill_max_pixsteps(over->max_plane_step, NULL, pix_desc);
00113 over->hsub = pix_desc->log2_chroma_w;
00114 over->vsub = pix_desc->log2_chroma_h;
00115
00116 return 0;
00117 }
00118
00119 static int config_input_overlay(AVFilterLink *inlink)
00120 {
00121 AVFilterContext *ctx = inlink->dst;
00122 OverlayContext *over = inlink->dst->priv;
00123 char *expr;
00124 double var_values[VAR_VARS_NB], res;
00125 int ret;
00126
00127
00128
00129 var_values[VAR_E ] = M_E;
00130 var_values[VAR_PHI] = M_PHI;
00131 var_values[VAR_PI ] = M_PI;
00132
00133 var_values[VAR_MAIN_W ] = var_values[VAR_MW] = ctx->inputs[MAIN ]->w;
00134 var_values[VAR_MAIN_H ] = var_values[VAR_MH] = ctx->inputs[MAIN ]->h;
00135 var_values[VAR_OVERLAY_W] = var_values[VAR_OW] = ctx->inputs[OVERLAY]->w;
00136 var_values[VAR_OVERLAY_H] = var_values[VAR_OH] = ctx->inputs[OVERLAY]->h;
00137
00138 if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values,
00139 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
00140 goto fail;
00141 over->x = res;
00142 if ((ret = av_expr_parse_and_eval(&res, (expr = over->y_expr), var_names, var_values,
00143 NULL, NULL, NULL, NULL, NULL, 0, ctx)))
00144 goto fail;
00145 over->y = res;
00146
00147 if ((ret = av_expr_parse_and_eval(&res, (expr = over->x_expr), var_names, var_values,
00148 NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
00149 goto fail;
00150 over->x = res;
00151
00152 av_log(ctx, AV_LOG_INFO,
00153 "main w:%d h:%d fmt:%s overlay x:%d y:%d w:%d h:%d fmt:%s\n",
00154 ctx->inputs[MAIN]->w, ctx->inputs[MAIN]->h,
00155 av_pix_fmt_descriptors[ctx->inputs[MAIN]->format].name,
00156 over->x, over->y,
00157 ctx->inputs[OVERLAY]->w, ctx->inputs[OVERLAY]->h,
00158 av_pix_fmt_descriptors[ctx->inputs[OVERLAY]->format].name);
00159
00160 if (over->x < 0 || over->y < 0 ||
00161 over->x + var_values[VAR_OVERLAY_W] > var_values[VAR_MAIN_W] ||
00162 over->y + var_values[VAR_OVERLAY_H] > var_values[VAR_MAIN_H]) {
00163 av_log(ctx, AV_LOG_ERROR,
00164 "Overlay area (%d,%d)<->(%d,%d) not within the main area (0,0)<->(%d,%d) or zero-sized\n",
00165 over->x, over->y,
00166 (int)(over->x + var_values[VAR_OVERLAY_W]),
00167 (int)(over->y + var_values[VAR_OVERLAY_H]),
00168 (int)var_values[VAR_MAIN_W], (int)var_values[VAR_MAIN_H]);
00169 return AVERROR(EINVAL);
00170 }
00171 return 0;
00172
00173 fail:
00174 av_log(NULL, AV_LOG_ERROR,
00175 "Error when evaluating the expression '%s'\n", expr);
00176 return ret;
00177 }
00178
00179 static int config_output(AVFilterLink *outlink)
00180 {
00181 AVFilterContext *ctx = outlink->src;
00182 int exact;
00183
00184 AVRational tb1 = ctx->inputs[MAIN ]->time_base;
00185 AVRational tb2 = ctx->inputs[OVERLAY]->time_base;
00186 AVRational *tb = &ctx->outputs[0]->time_base;
00187 exact = av_reduce(&tb->num, &tb->den,
00188 av_gcd((int64_t)tb1.num * tb2.den,
00189 (int64_t)tb2.num * tb1.den),
00190 (int64_t)tb1.den * tb2.den, INT_MAX);
00191 av_log(ctx, AV_LOG_INFO,
00192 "main_tb:%d/%d overlay_tb:%d/%d -> tb:%d/%d exact:%d\n",
00193 tb1.num, tb1.den, tb2.num, tb2.den, tb->num, tb->den, exact);
00194 if (!exact)
00195 av_log(ctx, AV_LOG_WARNING,
00196 "Timestamp conversion inexact, timestamp information loss may occurr\n");
00197
00198 outlink->w = ctx->inputs[MAIN]->w;
00199 outlink->h = ctx->inputs[MAIN]->h;
00200
00201 return 0;
00202 }
00203
00204 static AVFilterBufferRef *get_video_buffer(AVFilterLink *link, int perms, int w, int h)
00205 {
00206 return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
00207 }
00208
00209 static void start_frame(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
00210 {
00211 AVFilterBufferRef *outpicref = avfilter_ref_buffer(inpicref, ~0);
00212 AVFilterContext *ctx = inlink->dst;
00213 OverlayContext *over = ctx->priv;
00214
00215 inlink->dst->outputs[0]->out_buf = outpicref;
00216 outpicref->pts = av_rescale_q(outpicref->pts, ctx->inputs[MAIN]->time_base,
00217 ctx->outputs[0]->time_base);
00218
00219 if (!over->overpicref || over->overpicref->pts < outpicref->pts) {
00220 AVFilterBufferRef *old = over->overpicref;
00221 over->overpicref = NULL;
00222 avfilter_request_frame(ctx->inputs[OVERLAY]);
00223 if (over->overpicref) {
00224 if (old)
00225 avfilter_unref_buffer(old);
00226 } else
00227 over->overpicref = old;
00228 }
00229
00230 avfilter_start_frame(inlink->dst->outputs[0], outpicref);
00231 }
00232
00233 static void start_frame_overlay(AVFilterLink *inlink, AVFilterBufferRef *inpicref)
00234 {
00235 AVFilterContext *ctx = inlink->dst;
00236 OverlayContext *over = ctx->priv;
00237
00238 over->overpicref = inpicref;
00239 over->overpicref->pts = av_rescale_q(inpicref->pts, ctx->inputs[OVERLAY]->time_base,
00240 ctx->outputs[0]->time_base);
00241 }
00242
00243 static void blend_slice(AVFilterContext *ctx,
00244 AVFilterBufferRef *dst, AVFilterBufferRef *src,
00245 int x, int y, int w, int h,
00246 int slice_y, int slice_w, int slice_h)
00247 {
00248 OverlayContext *over = ctx->priv;
00249 int i, j, k;
00250 int width, height;
00251 int overlay_end_y = y+h;
00252 int slice_end_y = slice_y+slice_h;
00253 int end_y, start_y;
00254
00255 width = FFMIN(slice_w - x, w);
00256 end_y = FFMIN(slice_end_y, overlay_end_y);
00257 start_y = FFMAX(y, slice_y);
00258 height = end_y - start_y;
00259
00260 if (dst->format == PIX_FMT_BGR24 || dst->format == PIX_FMT_RGB24) {
00261 uint8_t *dp = dst->data[0] + x * 3 + start_y * dst->linesize[0];
00262 uint8_t *sp = src->data[0];
00263 int b = dst->format == PIX_FMT_BGR24 ? 2 : 0;
00264 int r = dst->format == PIX_FMT_BGR24 ? 0 : 2;
00265 if (slice_y > y)
00266 sp += (slice_y - y) * src->linesize[0];
00267 for (i = 0; i < height; i++) {
00268 uint8_t *d = dp, *s = sp;
00269 for (j = 0; j < width; j++) {
00270 d[r] = (d[r] * (0xff - s[3]) + s[0] * s[3] + 128) >> 8;
00271 d[1] = (d[1] * (0xff - s[3]) + s[1] * s[3] + 128) >> 8;
00272 d[b] = (d[b] * (0xff - s[3]) + s[2] * s[3] + 128) >> 8;
00273 d += 3;
00274 s += 4;
00275 }
00276 dp += dst->linesize[0];
00277 sp += src->linesize[0];
00278 }
00279 } else {
00280 for (i = 0; i < 3; i++) {
00281 int hsub = i ? over->hsub : 0;
00282 int vsub = i ? over->vsub : 0;
00283 uint8_t *dp = dst->data[i] + (x >> hsub) +
00284 (start_y >> vsub) * dst->linesize[i];
00285 uint8_t *sp = src->data[i];
00286 uint8_t *ap = src->data[3];
00287 int wp = FFALIGN(width, 1<<hsub) >> hsub;
00288 int hp = FFALIGN(height, 1<<vsub) >> vsub;
00289 if (slice_y > y) {
00290 sp += ((slice_y - y) >> vsub) * src->linesize[i];
00291 ap += (slice_y - y) * src->linesize[3];
00292 }
00293 for (j = 0; j < hp; j++) {
00294 uint8_t *d = dp, *s = sp, *a = ap;
00295 for (k = 0; k < wp; k++) {
00296
00297 int alpha_v, alpha_h, alpha;
00298 if (hsub && vsub && j+1 < hp && k+1 < wp) {
00299 alpha = (a[0] + a[src->linesize[3]] +
00300 a[1] + a[src->linesize[3]+1]) >> 2;
00301 } else if (hsub || vsub) {
00302 alpha_h = hsub && k+1 < wp ?
00303 (a[0] + a[1]) >> 1 : a[0];
00304 alpha_v = vsub && j+1 < hp ?
00305 (a[0] + a[src->linesize[3]]) >> 1 : a[0];
00306 alpha = (alpha_v + alpha_h) >> 1;
00307 } else
00308 alpha = a[0];
00309 *d = (*d * (0xff - alpha) + *s++ * alpha + 128) >> 8;
00310 d++;
00311 a += 1 << hsub;
00312 }
00313 dp += dst->linesize[i];
00314 sp += src->linesize[i];
00315 ap += (1 << vsub) * src->linesize[3];
00316 }
00317 }
00318 }
00319 }
00320
00321 static void draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir)
00322 {
00323 AVFilterContext *ctx = inlink->dst;
00324 AVFilterLink *outlink = ctx->outputs[0];
00325 AVFilterBufferRef *outpicref = outlink->out_buf;
00326 OverlayContext *over = ctx->priv;
00327
00328 if (over->overpicref &&
00329 !(over->x >= outpicref->video->w || over->y >= outpicref->video->h ||
00330 y+h < over->y || y >= over->y + over->overpicref->video->h)) {
00331 blend_slice(ctx, outpicref, over->overpicref, over->x, over->y,
00332 over->overpicref->video->w, over->overpicref->video->h,
00333 y, outpicref->video->w, h);
00334 }
00335 avfilter_draw_slice(outlink, y, h, slice_dir);
00336 }
00337
00338 static void end_frame(AVFilterLink *inlink)
00339 {
00340 avfilter_end_frame(inlink->dst->outputs[0]);
00341 avfilter_unref_buffer(inlink->cur_buf);
00342 }
00343
00344 static void null_draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { }
00345
00346 static void null_end_frame(AVFilterLink *inlink) { }
00347
00348 AVFilter avfilter_vf_overlay = {
00349 .name = "overlay",
00350 .description = NULL_IF_CONFIG_SMALL("Overlay a video source on top of the input."),
00351
00352 .init = init,
00353 .uninit = uninit,
00354
00355 .priv_size = sizeof(OverlayContext),
00356
00357 .query_formats = query_formats,
00358
00359 .inputs = (AVFilterPad[]) {{ .name = "main",
00360 .type = AVMEDIA_TYPE_VIDEO,
00361 .start_frame = start_frame,
00362 .get_video_buffer= get_video_buffer,
00363 .config_props = config_input_main,
00364 .draw_slice = draw_slice,
00365 .end_frame = end_frame,
00366 .min_perms = AV_PERM_READ,
00367 .rej_perms = AV_PERM_REUSE2|AV_PERM_PRESERVE, },
00368 { .name = "overlay",
00369 .type = AVMEDIA_TYPE_VIDEO,
00370 .start_frame = start_frame_overlay,
00371 .config_props = config_input_overlay,
00372 .draw_slice = null_draw_slice,
00373 .end_frame = null_end_frame,
00374 .min_perms = AV_PERM_READ,
00375 .rej_perms = AV_PERM_REUSE2, },
00376 { .name = NULL}},
00377 .outputs = (AVFilterPad[]) {{ .name = "default",
00378 .type = AVMEDIA_TYPE_VIDEO,
00379 .config_props = config_output, },
00380 { .name = NULL}},
00381 };