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/encoder.h

@@ -26,6 +26,7 @@ public:
   virtual int encode_frame(VisionBuf* buf, VisionIpcBufExtra *extra) = 0;
   virtual void encoder_open() = 0;
   virtual void encoder_close() = 0;
+  virtual void set_bitrate(int bitrate) = 0;
 
   void publisher_publish(int segment_num, uint32_t idx, VisionIpcBufExtra &extra, unsigned int flags, kj::ArrayPtr<capnp::byte> header, kj::ArrayPtr<capnp::byte> dat);
 

system/loggerd/encoder/ffmpeg_encoder.cc

@@ -72,6 +72,10 @@ void FfmpegEncoder::encoder_close() {
   is_open = false;
 }
 
+void FfmpegEncoder::set_bitrate(int bitrate) {
+  LOGE("adaptive bitrate is not supported for ffmpeg encoder %s", encoder_info.publish_name);
+}
+
 int FfmpegEncoder::encode_frame(VisionBuf* buf, VisionIpcBufExtra *extra) {
   assert(buf->width == this->in_width);
   assert(buf->height == this->in_height);

system/loggerd/encoder/ffmpeg_encoder.h

@@ -21,6 +21,7 @@ public:
   int encode_frame(VisionBuf* buf, VisionIpcBufExtra *extra);
   void encoder_open();
   void encoder_close();
+  void set_bitrate(int bitrate);
 
 private:
   int segment_num = -1;

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;

system/loggerd/encoder/v4l_encoder.h

@@ -13,6 +13,7 @@ public:
   int encode_frame(VisionBuf* buf, VisionIpcBufExtra *extra);
   void encoder_open();
   void encoder_close();
+  void set_bitrate(int bitrate);
 
 private:
   int fd;
@@ -20,6 +21,8 @@ private:
   bool is_open = false;
   int segment_num = -1;
   int counter = 0;
+  int current_bitrate = -1;
+  bool adaptive_bitrate;
 
   SafeQueue<VisionIpcBufExtra> extras;