commit f7e7cf637e1b457d56b3aaf4d05c928ef9acff17
author Louis Li <Ching-shih.Li@amd.com> Tue Mar 31 10:20:21 2020 +0800
committer Marge Bot <eric+marge@anholt.net> Mon Aug 10 01:39:18 2020 +0000
tree 62a9abd140cb084316013bbf41ff119e0c51cc46
parent 4975b3ec551d81460f07d0fe6a645c1e1f1548f1

radeon/radeon_vce: fix out of target bitrate in CBR mode (H.264)

StoneyRidge may not comply to required target bitrate
when generating H.264 stream in CBR mode.

Signed-off-by: Louis Li <Ching-shih.Li@amd.com>
Reviewed-by: Leo Liu <leo.liu@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4384>

src/gallium/drivers/radeon/radeon_vce_52.c

diff --git a/src/gallium/drivers/radeon/radeon_vce_52.c b/src/gallium/drivers/radeon/radeon_vce_52.c
index 141032d..dd2ffbb 100644
--- a/src/gallium/drivers/radeon/radeon_vce_52.c
+++ b/src/gallium/drivers/radeon/radeon_vce_52.c
@@ -47,7 +47,17 @@
    enc->enc_pic.rc.frame_rate_num = pic->rate_ctrl.frame_rate_num;
    enc->enc_pic.rc.frame_rate_den = pic->rate_ctrl.frame_rate_den;
    enc->enc_pic.rc.max_qp = 51;
-   enc->enc_pic.rc.vbv_buffer_size = pic->rate_ctrl.vbv_buffer_size;
+
+   /* For CBR mode, to guarantee bitrate of generated stream complies with
+    * target bitrate (e.g. no over +/-10%), vbv_buffer_size should be same
+    * as target bitrate.
+    */
+   if (enc->enc_pic.rc.rc_method == PIPE_H264_ENC_RATE_CONTROL_METHOD_CONSTANT) {
+           enc->enc_pic.rc.vbv_buffer_size = pic->rate_ctrl.target_bitrate;
+   } else {
+           enc->enc_pic.rc.vbv_buffer_size = pic->rate_ctrl.vbv_buffer_size;
+   }
+
    enc->enc_pic.rc.vbv_buf_lv = pic->rate_ctrl.vbv_buf_lv;
    enc->enc_pic.rc.fill_data_enable = pic->rate_ctrl.fill_data_enable;
    enc->enc_pic.rc.enforce_hrd = pic->rate_ctrl.enforce_hrd;