V2.0.4 支持读取编码配置文件，用于改变编码配置

 #include "AVTranscoder.h"
 #include "tools.h"
+#include "ConfigFile.h"
+
+extern CConfigFile _codec_config;
 
 #ifndef max
 #define max(a,b)            (((a) > (b)) ? (a) : (b))
@@ -227,9 +230,8 @@ int CAVTranscoder::open_output_file(const char *filename)
 				return AVERROR_INVALIDDATA;
 			}
 
-			/* In this example, we transcode to same properties (picture size,
-			* sample rate etc.). These properties can be changed for output
-			* streams easily using filters */
+			printf("\n video parameters:");
+
 				enc_ctx->height = _nOutputHeight;
 				enc_ctx->width = _nOutputWidth;
 				enc_ctx->sample_aspect_ratio.den = 1;
@@ -238,21 +240,58 @@ int CAVTranscoder::open_output_file(const char *filename)
 				enc_ctx->pix_fmt = AV_PIX_FMT_YUV420P;
 				/* video time_base can be set to whatever is handy and supported by encoder */
 				enc_ctx->time_base.num = 1;
-				enc_ctx->time_base.den = 20;
-				enc_ctx->gop_size = 20;
+				enc_ctx->time_base.den = _codec_config.get_int("fps", 20);
+				printf("\n fps: %d", enc_ctx->time_base.den);
+				enc_ctx->gop_size = _codec_config.get_int("gop_size", enc_ctx->time_base.den);
+				printf("\n gop_size: %d", enc_ctx->gop_size);
 				
-				enc_ctx->me_range = 16;
-				enc_ctx->max_qdiff = 4;
-				enc_ctx->qmin = 10;
-				enc_ctx->qmax = 30;
-				enc_ctx->qcompress = 0.6f;
+				enc_ctx->me_range = _codec_config.get_int("me_range", 16);
+				printf("\n me_range: %d", enc_ctx->me_range);
+				enc_ctx->max_qdiff = _codec_config.get_int("max_qdiff", 4);
+				printf("\n max_qdiff: %d", enc_ctx->max_qdiff);
+				enc_ctx->qmin = _codec_config.get_int("qmin", 10);
+				printf("\n qmin: %d", enc_ctx->qmin);
+				enc_ctx->qmax = _codec_config.get_int("qmax", 30);
+				printf("\n qmax: %d", enc_ctx->qmax);
+
+				enc_ctx->qcompress = _codec_config.get_float("qcompress", 0.6f);
+				printf("\n qcompress: %.2f", enc_ctx->qcompress);
 				
-				enc_ctx->framerate.den = 20;
+				enc_ctx->framerate.den = enc_ctx->time_base.den;
 				enc_ctx->framerate.num = 1;
-				enc_ctx->max_b_frames = 0;
+				enc_ctx->max_b_frames = _codec_config.get_int("max_b_frames", 0);
+				printf("\n max_b_frames: %d", enc_ctx->max_b_frames);
+
+				enc_ctx->bit_rate = _codec_config.get_int("bit_rate", 256000);
+				printf("\n bit_rate: %d", enc_ctx->bit_rate);
+				enc_ctx->rc_max_rate = _codec_config.get_int("rc_max_rate", 0);
+				printf("\n rc_max_rate: %d", enc_ctx->rc_max_rate);
+				enc_ctx->rc_min_rate = _codec_config.get_int("rc_min_rate", 0);
+				printf("\n rc_min_rate: %d", enc_ctx->rc_min_rate);
+				enc_ctx->rc_buffer_size = _codec_config.get_int("rc_buffer_size", enc_ctx->rc_max_rate);
+				printf("\n rc_buffer_size: %d", enc_ctx->rc_buffer_size);
 
 				AVDictionary * d = NULL;
-				av_dict_set(&d, "preset", "ultrafast", 0);
+				std::string preset = _codec_config.get_string("preset", "ultrafast");
+				if (preset != "none") {
+					printf("\n preset: %s", preset.c_str());
+					av_dict_set(&d, "preset", preset.c_str(), 0);
+				}
+
+				std::string tune = _codec_config.get_string("tune", "none");
+				if (tune != "none") {
+					printf("\n tune: %s", tune.c_str());
+					av_dict_set(&d, "tune", tune.c_str(), 0);
+				}
+
+				std::string profile = _codec_config.get_string("profile", "none");
+				if (profile != "none") {
+					printf("\n profile: %s", profile.c_str());
+					av_dict_set(&d, "profile", profile.c_str(), 0);
+				}
+
+				printf("\n-----------------------------------");
+
 				/* Third parameter can be used to pass settings to encoder */
 				ret = avcodec_open2(enc_ctx, encoder, &d);
 				if (ret < 0) {
@@ -261,20 +300,24 @@ int CAVTranscoder::open_output_file(const char *filename)
 				}
 			}
 			else {
+				printf("\n audio parameters:");
 				encoder = avcodec_find_encoder(AV_CODEC_ID_AAC);;
 				if (!encoder) {
 					av_log(NULL, AV_LOG_FATAL, "Necessary encoder not found\n");
 					return AVERROR_INVALIDDATA;
 				}
-				enc_ctx->sample_rate = 48000;
+				enc_ctx->sample_rate = _codec_config.get_int("a_sample_rate", 48000);
+				printf("\n sample_rate: %d", enc_ctx->sample_rate);
 				enc_ctx->channel_layout = AV_CH_LAYOUT_MONO;
 				enc_ctx->channels = av_get_channel_layout_nb_channels(AV_CH_LAYOUT_MONO);
 				/* take first format from list of supported formats */
 				enc_ctx->sample_fmt = PCM_FORMAT_FOR_AAC_ENCODE; //AV_SAMPLE_FMT_FLTP;
 				enc_ctx->time_base.num = 1;
 				enc_ctx->time_base.den = enc_ctx->sample_rate;
-				enc_ctx->bit_rate = 64000;
+				printf("\n bit_rate: %d", enc_ctx->bit_rate);
+				enc_ctx->bit_rate = _codec_config.get_int("a_bit_rate", 64000);
 				/* Third parameter can be used to pass settings to encoder */
+				printf("\n-----------------------------------");
 				ret = avcodec_open2(enc_ctx, encoder, NULL);
 				if (ret < 0) {
 					av_log(NULL, AV_LOG_ERROR, "Cannot open audio encoder for stream #%u\n", i);

+#include "ConfigFile.h"
+#include <iostream>
+#include <fstream>
+using namespace std;
+
+CConfigFile::CConfigFile()
+{
+}
+
+
+CConfigFile::~CConfigFile()
+{
+}
+
+std::string& trim(std::string &s)
+{
+	if (s.empty())
+	{
+		return s;
+	}
+
+	s.erase(0, s.find_first_not_of(" "));
+	s.erase(s.find_last_not_of(" ") + 1);
+	return s;
+}
+
+int CConfigFile::load(const char * filename)
+{
+	ifstream fin(filename);
+	if (!fin) {
+		return -1;
+	}
+
+	const int  LINE_LENGTH = 1000;
+	char  str[LINE_LENGTH];
+	while (fin.getline(str, LINE_LENGTH))
+	{
+		char * p = str;
+		while (*p == 0x20 || *p == 0x9){
+			p++;//bypass space and tab
+		}
+		if (*p == ';' || *p == '#'){
+			continue;//bypass the comment line
+		}
+
+		std::string linestr = p;
+
+		string::size_type position = linestr.find('=');
+		if (position != linestr.npos) {
+			string item = linestr.substr(0, position);
+			int value_len = linestr.length() - position;
+			if (value_len > 0) {
+				string value = linestr.substr(position + 1, value_len);
+				trim(item);
+				trim(value);
+				_configs[item] = value;
+			}
+		}
+	}
+	return 0;
+}
+
+std::string CConfigFile::lookup(const char * item)
+{
+	map<string, string>::iterator it = _configs.find(item);
+	if (it != _configs.end()) {
+		return (*it).second;
+	}
+	return "";
+}
+
+int CConfigFile::get_int(const char * item, int def)
+{
+	std::string value = lookup(item);
+	if (value.length() > 0) {
+		return atoi(value.c_str());
+	}
+	else
+	{
+		return def;
+	}
+}
+
+float CConfigFile::get_float(const char * item, float def)
+{
+	std::string value = lookup(item);
+	if (value.length() > 0) {
+		return atof(value.c_str());
+	}
+	else
+	{
+		return def;
+	}
+}
+
+std::string CConfigFile::get_string(const char * item, const char * def)
+{
+	std::string value = lookup(item);
+	if (value.length() > 0) {
+		return value;
+	}
+	else
+	{
+		return def;
+	}
+}

+#pragma once
+#include <string>
+#include <map>
+
+class CConfigFile
+{
+public:
+	CConfigFile();
+	~CConfigFile();
+	int load(const char * filename);
+	std::string lookup(const char  *item);
+	int get_int(const char * item, int def);
+	float get_float(const char * item, float def);
+	std::string get_string(const char * item, const char * def);
+protected:
+	std::map<std::string, std::string> _configs;
+};
+

@@ -3,7 +3,7 @@
 读入合屏信息文件，合成画中画视频。
 
 使用方法：
-merge_pip merge_info.txt [-t {0,1,2}]
+merge_pip merge_info.txt [-t {0,1,2}] [-c codec.cfg]
 其中merge_info.txt为合屏信息文件，格式如下：
 
 teacher:
@@ -31,6 +31,22 @@ student:下面是学生的录像信息文件，一个文件名一行
 2 为使用一对多布局
 如果不加-t,则为程序自动选择合屏布局
 
+-c 为可选参数，后面为编码配置文件名。缺省的编码配置文件名为merge_pip_codec.cfg。在windows系统里，与merge_av.exe放在同一目录。在linux下，放在HOME目录下的merge_av目录。
+merge_pip_codec.cfg主要编码参数：
+#帧率
+ fps = 20 
+#关键帧间隔，默认与fps一致，即每秒一个关键帧
+ gop_size = 20
+#视频码率
+ bit_rate = 256000
+;视频预设值编码参数: ultrafast、superfast、veryfast、faster、fast、medium、slow、slower、veryslow、placebo
+ preset = ultrafast 
+#音频采样率
+ a_sample_rate = 48000
+ #音频码率
+ a_bit_rate = 64000
+
+
 合屏后生成完成信息文件，文件名为"m_" + 输入文件名" + ".txt"，合成的mp4文件名为"m_" + 输入文件名" + ".mp4"
 如merge_pip 1.txt
 生成的完成信息文件是m_1.txt，m_1.txt只有一行，记录输出的mp4文件名（m_1.mp4)、参与合成m_1.mp4的第一个媒体文件名（用于帮助确认m_1.mp4的开始时间）及mp4的时长。下面是一个实际的m_1.txt内容：
@@ -49,4 +65,7 @@ V2.0.3
 1.没有老师，但是有两个学生时，默认使用一对多布局
 2.一对一时，老师和学生的视频尺寸不同时，合成的视频高度取老师视频高度加上学生视频高度（之前版本假定老师和学生视频大小一致，使用的是最大高度的二倍）
 3.一对多时，支持学生的视频尺寸不一致的情况（之前版本假定只有一种视频尺寸，其它尺寸视为异常）
-4.一对多时，最多只在老师视频下部排4个学生，多于4个学生的情况，扩大合成视频的高度，把学生视频排列在老师视频下方，保证老师视频部分最多只有一排学生视频，避免老师视频被过度遮挡
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+4.一对多时，最多只在老师视频下部排4个学生，多于4个学生的情况，扩大合成视频的高度，把学生视频排列在老师视频下方，保证老师视频部分最多只有一排学生视频，避免老师视频被过度遮挡
+
+V2.0.4
+1.支持读取编码配置文件，用于改变编码配置
\ No newline at end of file

@@ -9,6 +9,7 @@
 #include <deque>
 #include "tools.h"
 #include "AVTranscoder.h"
+#include "ConfigFile.h"
 
 bool only_print = false;
 bool keep_tmp_files = false;
@@ -50,11 +51,11 @@ void run_shell_cmd(const char * cmd)
 	}
 }
 
+
+char exe_path[1024] = { 0 };
 #ifdef WIN32
 #include <Windows.h>
 
-char exe_path[MAX_PATH] = { 0 };
-
 int GetExePath()
 {
 	char path_buffer[MAX_PATH] = "";
@@ -70,15 +71,37 @@ int GetExePath()
 	strcat(exe_path, dir);
 	return 0;
 }
+#else
+int GetExePath()
+{
+	char path[1024];
+	int cnt = readlink("/proc/self/exe", path, 1024);
+	if (cnt < 0 || cnt >= 1024)
+	{
+		return -1;
+	}
+	
+	for (int i = cnt; i >= 0; --i)
+	{
+		if (path[i] == '/')
+		{
+			path[i + 1] = '\0';
+			break;
+		}
+	}
+	strcpy(exe_path, path);
+	return 0;
+}
 #endif
 
 char cfg_path[1024];
 
 void get_config_path(){
-#ifdef WIN32
+
 	GetExePath();
 	strcpy(cfg_path, exe_path);
-#else
+
+#if 0
 	strcpy(cfg_path, getenv("HOME"));
 	strcat(cfg_path, "/merge_av/");
 #endif
@@ -957,6 +980,10 @@ int readfile(const char * filename, media_role role)
 
 vector<string> all_input_files_for_pip;
 
+CConfigFile _codec_config;
+
+char user_codec_cfg[1024] = { 0 };
+
 void load_codec_param()
 {
 	strcpy(acodec_param, default_acodec_param);
@@ -968,43 +995,19 @@ void load_codec_param()
 	char cfgfile[1024];
 
 	strcpy(cfgfile, cfg_path);
-	strcat(cfgfile, "merge_pip.cfg");
 
-	ifstream fin(cfgfile);
-	if (!fin) {
-		return;
-	}
-	const int  LINE_LENGTH = 1000;
-	char  str[LINE_LENGTH];
-	str[0] = 0;
-	if (fin.getline(str, LINE_LENGTH))
-	{
-		printf("\nload video codec from %s: %s\n", cfgfile, str);
-		strcpy(vcodec_param, str);
-	}
-	str[0] = 0;
-	if (fin.getline(str, LINE_LENGTH))
-	{
-		printf("load audio codec from %s: %s\n", cfgfile, str);
-		strcpy(acodec_param, str);
+	if (user_codec_cfg[0]) {
+		strcat(cfgfile, user_codec_cfg);
 	}
-	str[0] = 0;
-	if (fin.getline(str, LINE_LENGTH))
-	{
-		printf("load av codec from %s: %s\n", cfgfile, str);
-		strcpy(av_codec_param, str);
+	else {
+		strcat(cfgfile, "merge_pip_codec.cfg");
 	}
-	str[0] = 0;
-	if (fin.getline(str, LINE_LENGTH))
-	{
-		printf("load pip codec from %s: %s\n", cfgfile, str);
-		strcpy(pip_param, str);
+
+	if (_codec_config.load(cfgfile) < 0) {
+		printf("open codec config file fail: %s", cfgfile);
 	}
-	str[0] = 0;
-	if (fin.getline(str, LINE_LENGTH))
-	{
-		printf("load pip1 codec from %s: %s\n", cfgfile, str);
-		strcpy(pip1_param, str);
+	else {
+		printf("open codec config file success: %s", cfgfile);
 	}
 }
 
@@ -1198,17 +1201,13 @@ int process_av_files(char * record_info, int piptype)
 int main(int argc, char * argv[])
 {
 	if (argc < 2) {
-		printf("   merge_pip 2.0.3\n");
+		printf("   merge_pip 2.0.4\n");
 		printf("   merge video files to one pip video according to record info file,\nusage:");
-		printf("\n   %s record_info_filename [-t {0,1,2}]", argv[0]);
+		printf("\n   %s record_info_filename [-t {0,1,2}]  [-c codec.cfg]", argv[0]);
 		printf("\n\n");
 		return -1;
 	}
 
-	//get_config_path();
-
-	//load_codec_param();
-
 	int piptype = 0;
 	for (int i = 2; i < argc; i++){
 		if (!strcmp(argv[i], "-t")){
@@ -1219,7 +1218,20 @@ int main(int argc, char * argv[])
 			}
 			piptype = atoi(argv[i]);
 		}
+		else if (!strcmp(argv[i], "-c")){
+			i++;
+			if (i > argc) {
+				printf("error,should have codec config file name after -c");
+				return -2;
+			}
+			strcpy(user_codec_cfg,argv[i]);
+		}
 	}
 
+
+	get_config_path();
+
+	load_codec_param();
+
 	return process_av_files(argv[1], piptype);
 }

@@ -86,6 +86,7 @@
   <ItemGroup>
     <ClCompile Include="AudioDecoder.cpp" />
     <ClCompile Include="AVDecoder.cpp" />
+    <ClCompile Include="ConfigFile.cpp" />
     <ClCompile Include="merge_pip.cpp" />
     <ClCompile Include="tools.cpp" />
     <ClCompile Include="VideoDecoder.cpp" />
@@ -94,6 +95,7 @@
   <ItemGroup>
     <ClInclude Include="AudioDecoder.h" />
     <ClInclude Include="AVDecoder.h" />
+    <ClInclude Include="ConfigFile.h" />
     <ClInclude Include="media_info.h" />
     <ClInclude Include="tools.h" />
     <ClInclude Include="VideoDecoder.h" />

@@ -36,6 +36,9 @@
     <ClCompile Include="merge_pip.cpp">
       <Filter>源文件</Filter>
     </ClCompile>
+    <ClCompile Include="ConfigFile.cpp">
+      <Filter>源文件</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="VideoDecoder.h">
@@ -56,5 +59,8 @@
     <ClInclude Include="tools.h">
       <Filter>头文件</Filter>
     </ClInclude>
+    <ClInclude Include="ConfigFile.h">
+      <Filter>头文件</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
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