ref: 8064583d2621a159b01508c1fd0017c4e7887938
dir: /examples/vp8_set_maps.txt/
@TEMPLATE encoder_tmpl.c VP8 Set Active and ROI Maps =========================== ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION This is an example demonstrating how to control the VP8 encoder's ROI and Active maps. ROI (Reigon of Interest) maps are a way for the application to assign each macroblock in the image to a region, and then set quantizer and filtering parameters on that image. Active maps are a way for the application to specify on a macroblock-by-macroblock basis whether there is any activity in that macroblock. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ INTRODUCTION Configuration ------------- An ROI map is set on frame 22. If the width of the image in macroblocks is evenly divisble by 4, then the output will appear to have distinct columns, where the quantizer, loopfilter, and static threshold differ from column to column. An active map is set on frame 33. If the width of the image in macroblocks is evenly divisble by 4, then the output will appear to have distinct columns, where one column will have motion and the next will not. The active map is cleared on frame 44. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PER_FRAME_CFG if(frame_cnt + 1 == 22) { vpx_roi_map_t roi; int i; roi.rows = cfg.g_h/16; roi.cols = cfg.g_w/16; roi.delta_q[0] = 0; roi.delta_q[1] = -2; roi.delta_q[2] = -4; roi.delta_q[3] = -6; roi.delta_lf[0] = 0; roi.delta_lf[1] = 1; roi.delta_lf[2] = 2; roi.delta_lf[3] = 3; roi.static_threshold[0] = 1500; roi.static_threshold[1] = 1000; roi.static_threshold[2] = 500; roi.static_threshold[3] = 0; /* generate an ROI map for example */ roi.roi_map = malloc(roi.rows * roi.cols); for(i=0;i<roi.rows*roi.cols;i++) roi.roi_map[i] = i & 3; if(vpx_codec_control(&codec, VP8E_SET_ROI_MAP, &roi)) die_codec(&codec, "Failed to set ROI map"); free(roi.roi_map); } else if(frame_cnt + 1 == 33) { vpx_active_map_t active; int i; active.rows = cfg.g_h/16; active.cols = cfg.g_w/16; /* generate active map for example */ active.active_map = malloc(active.rows * active.cols); for(i=0;i<active.rows*active.cols;i++) active.active_map[i] = i & 1; if(vpx_codec_control(&codec, VP8E_SET_ACTIVEMAP, &active)) die_codec(&codec, "Failed to set active map"); free(active.active_map); } else if(frame_cnt + 1 == 44) { vpx_active_map_t active; active.rows = cfg.g_h/16; active.cols = cfg.g_w/16; /* pass in null map to disable active_map*/ active.active_map = NULL; if(vpx_codec_control(&codec, VP8E_SET_ACTIVEMAP, &active)) die_codec(&codec, "Failed to set active map"); } ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PER_FRAME_CFG Observing The Effects --------------------- Use the `simple_decoder` example to decode this sample, and observe the change in the image at frames 22, 33, and 44.