hw encoder: set_bitrate and apply_bitrate based on Param (#38095)

* initial codex

* remove ISP delay from encode ms

* try something simpler

* not allowing increase bug

* decrease bitrate increase rate

* upsample only on consecutive good checks

* rearrange

* clean

* Revert frame timing processing time change

* clean

* remove bitrate option and just do it on --stream

* make set_bitrate a lot more simple

* clean default impl

* further cleaning

* struct for bitrate to pass ci

* refactor a bit

* add comment

* small clean

* add init()

* increase bitrate

* update ffmpeg message

* remove unnecessary include

* modify set_bitrate

* change to Param

* remove getInt helper; add back in diff pr

* reword unclear error message

* move webrtcd change to new branch

system/loggerd/encoder/v4l_encoder.cc

@@ -155,6 +155,8 @@ V4LEncoder::V4LEncoder(const EncoderInfo &encoder_info, int in_width, int in_hei
   assert(strcmp((const char *)cap.card, "msm_vidc_venc") == 0);
 
   EncoderSettings encoder_settings = encoder_info.get_settings(in_width);
+  current_bitrate = encoder_settings.bitrate;
+  adaptive_bitrate = encoder_info.adaptive_bitrate;
   bool is_h265 = encoder_settings.encode_type == cereal::EncodeIndex::Type::FULL_H_E_V_C;
 
   struct v4l2_format fmt_out = {
@@ -304,6 +306,25 @@ void V4LEncoder::encoder_close() {
   this->is_open = false;
 }
 
+void V4LEncoder::set_bitrate(int bitrate) {
+  if (!adaptive_bitrate || bitrate == current_bitrate) return;
+  if (bitrate <= 0) {
+    LOGE("invalid livestream encoder bitrate %d", bitrate);
+    return;
+  }
+
+  struct v4l2_control ctrl = {
+    .id = V4L2_CID_MPEG_VIDEO_BITRATE,
+    .value = bitrate,
+  };
+
+  if (util::safe_ioctl(fd, VIDIOC_S_CTRL, &ctrl) == -1) {
+    LOGE("failed to update %s bitrate to %d", encoder_info.publish_name, bitrate);
+    return;
+  }
+  current_bitrate = bitrate;
+}
+
 V4LEncoder::~V4LEncoder() {
   encoder_close();
   v4l2_buf_type buf_type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE;