+
+void vp9_rc_update_framerate(VP9_COMP *cpi) {
+ const VP9_COMMON *const cm = &cpi->common;
+ const VP9_CONFIG *const oxcf = &cpi->oxcf;
+ RATE_CONTROL *const rc = &cpi->rc;
+ int vbr_max_bits;
+
+ rc->av_per_frame_bandwidth = (int)(oxcf->target_bandwidth / oxcf->framerate);
+ rc->min_frame_bandwidth = (int)(rc->av_per_frame_bandwidth *
+ oxcf->two_pass_vbrmin_section / 100);
+
+ rc->min_frame_bandwidth = MAX(rc->min_frame_bandwidth, FRAME_OVERHEAD_BITS);
+
+ // A maximum bitrate for a frame is defined.
+ // The baseline for this aligns with HW implementations that
+ // can support decode of 1080P content up to a bitrate of MAX_MB_RATE bits
+ // per 16x16 MB (averaged over a frame). However this limit is extended if
+ // a very high rate is given on the command line or the the rate cannnot
+ // be acheived because of a user specificed max q (e.g. when the user
+ // specifies lossless encode.
+ vbr_max_bits = (int)(((int64_t)rc->av_per_frame_bandwidth *
+ oxcf->two_pass_vbrmax_section) / 100);
+ rc->max_frame_bandwidth = MAX(MAX((cm->MBs * MAX_MB_RATE), MAXRATE_1080P),
+ vbr_max_bits);
+
+ // Set Maximum gf/arf interval
+ rc->max_gf_interval = 16;
+
+ // Extended interval for genuinely static scenes
+ rc->static_scene_max_gf_interval = cpi->key_frame_frequency >> 1;
+
+ // Special conditions when alt ref frame enabled in lagged compress mode
+ if (oxcf->play_alternate && oxcf->lag_in_frames) {
+ if (rc->max_gf_interval > oxcf->lag_in_frames - 1)
+ rc->max_gf_interval = oxcf->lag_in_frames - 1;
+
+ if (rc->static_scene_max_gf_interval > oxcf->lag_in_frames - 1)
+ rc->static_scene_max_gf_interval = oxcf->lag_in_frames - 1;
+ }
+
+ if (rc->max_gf_interval > rc->static_scene_max_gf_interval)
+ rc->max_gf_interval = rc->static_scene_max_gf_interval;
+}