From df2dce9dd7f57cb1c9e225c30a86d14f0f26ab70 Mon Sep 17 00:00:00 2001
From: xufulong <839789740@qq.com>
Date: Thu, 16 Apr 2020 00:10:51 +0800
Subject: [PATCH] translate VideoStream.cpp into English

translate VideoStream.cpp into English
---
 Live/src/main/cpp/VideoStream.cpp | 59 ++++++++++++++-----------------
 1 file changed, 27 insertions(+), 32 deletions(-)

diff --git a/Live/src/main/cpp/VideoStream.cpp b/Live/src/main/cpp/VideoStream.cpp
index a6431d1..2033c5e 100644
--- a/Live/src/main/cpp/VideoStream.cpp
+++ b/Live/src/main/cpp/VideoStream.cpp
@@ -38,42 +38,41 @@ void VideoStream::setVideoEncInfo(int width, int height, int fps, int bitrate) {
         DELETE(pic_in);
     }
 
-    //打开x264编码器
-    //x264编码器的属性
+    //setting x264 params
     x264_param_t param;
     x264_param_default_preset(&param, "ultrafast", "zerolatency");
     param.i_level_idc = 32;
-    //输入数据格式
+    //input format
     param.i_csp = X264_CSP_I420;
     param.i_width = width;
     param.i_height = height;
-    //无b帧
+    //no B frame
     param.i_bframe = 0;
-    //参数i_rc_method表示码率控制，CQP(恒定质量)，CRF(恒定码率)，ABR(平均码率)
+    //i_rc_method:bitrate control, CQP(constant quality), CRF(constant bitrate), ABR(average bitrate)
     param.rc.i_rc_method = X264_RC_ABR;
-    //码率(比特率,单位Kbps)
+    //bitrate(Kbps)
     param.rc.i_bitrate = bitrate / 1000;
-    //瞬时最大码率
+    //max bitrate
     param.rc.i_vbv_max_bitrate = bitrate / 1000 * 1.2;
-    //设置了i_vbv_max_bitrate必须设置此参数，码率控制区大小,单位kbps
+    //unit:kbps
     param.rc.i_vbv_buffer_size = bitrate / 1000;
 
-    //帧率
+    //frame rate
     param.i_fps_num = fps;
     param.i_fps_den = 1;
     param.i_timebase_den = param.i_fps_num;
     param.i_timebase_num = param.i_fps_den;
-    //用fps而不是时间戳来计算帧间距离
+    //using fps
     param.b_vfr_input = 0;
-    //帧距离(关键帧)  2s一个关键帧
+    //key frame interval(GOP)
     param.i_keyint_max = fps * 2;
-    //设置是让每个关键帧(I帧)都附带sps/pps
+    //each key frame attaches sps/pps
     param.b_repeat_headers = 1;
-    //多线程
+    //thread number
     param.i_threads = 1;
 
     x264_param_apply_profile(&param, "baseline");
-    //打开编码器
+    //open encoder
     videoCodec = x264_encoder_open(&param);
     pic_in = new x264_picture_t;
     x264_picture_alloc(pic_in, X264_CSP_I420, width, height);
@@ -86,10 +85,10 @@ void VideoStream::setVideoCallback(VideoCallback videoCallback) {
 
 void VideoStream::encodeData(int8_t *data) {
     pthread_mutex_lock(&mutex);
-    //y数据
+    //y
     memcpy(pic_in->img.plane[0], data, ySize);
     for (int i = 0; i < uvSize; ++i) {
-        //u数据
+        //uv
         *(pic_in->img.plane[1] + i) = *(data + ySize + i * 2 + 1);
         *(pic_in->img.plane[2] + i) = *(data + ySize + i * 2);
     }
@@ -120,10 +119,9 @@ void VideoStream::encodeData(int8_t *data) {
 void VideoStream::encodeDataNew(int8_t *y_plane, int8_t *u_plane, int8_t *v_plane) {
     pthread_mutex_lock(&mutex);
 
-    //直接拷贝
     memcpy(pic_in->img.plane[0], y_plane, (size_t) ySize);
-    memcpy(pic_in->img.plane[1], u_plane, (size_t) ySize/4);
-    memcpy(pic_in->img.plane[2], v_plane, (size_t) ySize/4);
+    memcpy(pic_in->img.plane[1], u_plane, (size_t) ySize / 4);
+    memcpy(pic_in->img.plane[2], v_plane, (size_t) ySize / 4);
 
     x264_nal_t *pp_nal;
     int pi_nal;
@@ -153,17 +151,16 @@ void VideoStream::sendSpsPps(uint8_t *sps, uint8_t *pps, int sps_len, int pps_le
     RTMPPacket *packet = new RTMPPacket;
     RTMPPacket_Alloc(packet, bodySize);
     int i = 0;
-    //固定头
+    //start code
     packet->m_body[i++] = 0x17;
-    //类型
+    //type
     packet->m_body[i++] = 0x00;
     packet->m_body[i++] = 0x00;
     packet->m_body[i++] = 0x00;
     packet->m_body[i++] = 0x00;
 
-    //版本
+    //version
     packet->m_body[i++] = 0x01;
-    //编码规格
     packet->m_body[i++] = sps[1];
     packet->m_body[i++] = sps[2];
     packet->m_body[i++] = sps[3];
@@ -171,7 +168,7 @@ void VideoStream::sendSpsPps(uint8_t *sps, uint8_t *pps, int sps_len, int pps_le
 
     //sps
     packet->m_body[i++] = 0xE1;
-    //sps长度
+    //sps len
     packet->m_body[i++] = (sps_len >> 8) & 0xff;
     packet->m_body[i++] = sps_len & 0xff;
     memcpy(&packet->m_body[i], sps, sps_len);
@@ -183,13 +180,12 @@ void VideoStream::sendSpsPps(uint8_t *sps, uint8_t *pps, int sps_len, int pps_le
     packet->m_body[i++] = (pps_len) & 0xff;
     memcpy(&packet->m_body[i], pps, pps_len);
 
-    //视频
+    //video
     packet->m_packetType = RTMP_PACKET_TYPE_VIDEO;
     packet->m_nBodySize = bodySize;
     packet->m_nChannel = 10;
-    //sps pps没有时间戳
+    //sps and pps no timestamp
     packet->m_nTimeStamp = 0;
-    //不使用绝对时间
     packet->m_hasAbsTimestamp = 0;
     packet->m_headerType = RTMP_PACKET_SIZE_MEDIUM;
 
@@ -206,23 +202,22 @@ void VideoStream::sendFrame(int type, uint8_t *payload, int i_payload) {
     }
     int bodySize = 9 + i_payload;
     RTMPPacket *packet = new RTMPPacket;
-    //
     RTMPPacket_Alloc(packet, bodySize);
 
     packet->m_body[0] = 0x27;
-    if(type == NAL_SLICE_IDR){
+    if (type == NAL_SLICE_IDR) {
         packet->m_body[0] = 0x17;
         if (DEBUG) {
             LOGI("IDR key frame");
         }
     }
-    //类型
+    //packet type
     packet->m_body[1] = 0x01;
-    //时间戳
+    //timestamp
     packet->m_body[2] = 0x00;
     packet->m_body[3] = 0x00;
     packet->m_body[4] = 0x00;
-    //数据长度 int 4个字节
+    //packet len
     packet->m_body[5] = (i_payload >> 24) & 0xff;
     packet->m_body[6] = (i_payload >> 16) & 0xff;
     packet->m_body[7] = (i_payload >> 8) & 0xff;