編譯環境:ubuntu12.04
目標平臺:ARM Cortex A9
交叉編譯器:arm-none-linux-gnueabi-gcc 4.4.1
一、移植x264庫到ARM板,請看上一篇博文移植x264編碼庫
二、測試:
調用x264庫將YUV碼流文件編碼壓縮成H.264視頻文件,代碼如下(該代碼來自雷神博文最簡單的視頻編碼器:基於libx264(編碼YUV爲H.264),並參考博友文章通過V4L2採集yuv數據,並用x264壓縮數據成H264格式的文件修改添加支持YUV422格式編碼):
流程圖中主要的函數如下所示。
x264_param_default():設置參數集結構體x264_param_t的缺省值。
x264_picture_alloc():爲圖像結構體x264_picture_t分配內存。
x264_encoder_open():打開編碼器。
x264_encoder_encode():編碼一幀圖像。
x264_encoder_close():關閉編碼器。
x264_picture_clean():釋放x264_picture_alloc()申請的資源。
存儲數據的結構體如下所示。
x264_picture_t:存儲壓縮編碼前的像素數據。
x264_nal_t:存儲壓縮編碼後的碼流數據。
此外流程圖中還包括一個「flush_encoder」模塊,該模塊使用的函數和編碼模塊是一樣的。唯一的不同在於不再輸入視頻像素數據。它的作用在於輸出編碼器中剩餘的碼流數據。
H264Encoder *pEn = (H264Encoder *) AllocBuffer(sizeof(H264Encoder)); pEn->param = (x264_param_t *) AllocBuffer(sizeof(x264_param_t)); x264_param_default(pEn->param); //set default param /*設置profile屬性*/ //x264_profile_names數組定義如下:static const char * const x264_profile_names[] = //{ "baseline", "main", "high", "high10", "high422", "high444", 0 }; x264_param_apply_profile(pEn->param,x264_profile_names[0]); pEn->param->i_csp = X264_CSP_I420;// 設置幀數據格式爲420 pEn->param->i_width = m_nPicW; // 設置幀寬度 pEn->param->i_height = m_nPicH; // 設置幀高度 pEn->param->rc.i_lookahead = 0; pEn->param->i_fps_num = m_nFps; // 設置幀率(分子) pEn->param->i_fps_den = 1; // 設置幀率時間1s(分母) pEn->param->rc.i_bitrate = m_nBitrate; // 設置碼率 pEn->param->rc.i_vbv_max_bitrate = pCodecParam->encoder.iMaxBitrate; // 設置平均碼率模式下,最大瞬時碼率 pEn->param->i_keyint_max = m_nFps * 2; // 設置GOP最大長度 pEn->param->i_keyint_min = m_nFps * 2; // 設置GOP最小長度 pEn->param->pf_log = x264_log; // 設置打印日誌回調 pEn->param->p_log_private = NULL; pEn->param->i_log_level = X264_LOG_WARNING; pEn->param->b_vfr_input = 0; // 1:使用timebase和時間戳做碼率控制 0:只使用fps做碼率控制 pEn->param->i_timebase_num = 1; // timebase(分子) pEn->param->i_timebase_den = 1000; // timebase(分母) pEn->param->b_repeat_headers = 0; // 1:在每個關鍵幀前面放sps和pps pEn->param->i_threads = 1; // 並行編碼多個幀線程數 pEn->param->rc.i_rc_method = X264_RC_ABR; // 碼率控制方法,CQP(恆定質量),CRF(恆定碼率),ABR(平均碼率) pEn->param->rc.i_vbv_buffer_size = pCodecParam->encoder.iMaxBitrate; //碼率控制緩衝區的大小,單位kbit,默認0 pEn->handle = x264_encoder_open(pEn->param); // 創建一個新的編碼器句柄
編碼實現:
/** * 最簡單的基於X264的視頻編碼器 * Simplest X264 Encoder * jiangyu * * 本程序可以YUV格式的像素數據編碼爲H.264碼流,是最簡單的 * 基於libx264的視頻編碼器 * * This software encode YUV data to H.264 bitstream. * It's the simplest encoder example based on libx264. */ #include <stdio.h> #include <stdlib.h> #include "stdint.h" #if defined ( __cplusplus) extern "C" { #include "x264.h" }; #else #include "x264.h" #endif int width=640; int height=480; int csp=X264_CSP_I420; int main(int argc, char** argv) { int ret; int y_size; int i,j; FILE* fp_src = fopen("./yuv420p_640x480.yuv", "rb"); FILE* fp_dst = fopen("output.h264", "wb"); //Encode frame number //if set 0, encode all frame int frame_num=0; int iNal = 0; x264_nal_t* pNals = NULL; x264_t* pHandle = NULL; x264_picture_t* pPic_in = (x264_picture_t*)malloc(sizeof(x264_picture_t)); x264_picture_t* pPic_out = (x264_picture_t*)malloc(sizeof(x264_picture_t)); x264_param_t* pParam = (x264_param_t*)malloc(sizeof(x264_param_t)); //Check if(fp_src==NULL||fp_dst==NULL){ printf("Error open files.\n"); return -1; } x264_param_default(pParam); //給參數結構體賦默認值 x264_param_default_preset(pParam, "fast" , "zerolatency" ); //設置preset和tune //修改部分參數 pParam->i_csp=csp; pParam->i_width = width; // 寬度 pParam->i_height = height; // 高度 pParam->i_fps_num = 25; // 設置幀率(分子) pParam->i_fps_den = 1; // 設置幀率時間1s(分母) pParam->i_threads = X264_SYNC_LOOKAHEAD_AUTO; pParam->i_keyint_max = 10; //在此間隔設置IDR關鍵幀 pParam->rc.i_bitrate = 1200; // 設置碼率,在ABR(平均碼率)模式下才生效,且必須在設置ABR前先設置bitrate pParam->rc.i_rc_method = X264_RC_ABR; // 碼率控制方法,CQP(恆定質量),CRF(恆定碼率,缺省值23),ABR(平均碼率) /* //Param pParam->i_log_level = X264_LOG_DEBUG; pParam->i_frame_total = 0; pParam->i_bframe = 5; pParam->b_open_gop = 0; pParam->i_bframe_pyramid = 0; pParam->rc.i_qp_constant=0; pParam->rc.i_qp_max=0; pParam->rc.i_qp_min=0; pParam->i_bframe_adaptive = X264_B_ADAPT_TRELLIS; pParam->i_timebase_den = pParam->i_fps_num; pParam->i_timebase_num = pParam->i_fps_den; */ //set profile x264_param_apply_profile(pParam, "baseline"); //open encoder pHandle = x264_encoder_open(pParam); x264_picture_init(pPic_out); x264_picture_alloc(pPic_in, csp, pParam->i_width, pParam->i_height); //ret = x264_encoder_headers(pHandle, &pNals, &iNal); y_size = pParam->i_width * pParam->i_height; //detect frame number if(frame_num==0){ fseek(fp_src,0,SEEK_END); switch(csp){ case X264_CSP_I444:frame_num=ftell(fp_src)/(y_size*3);break; case X264_CSP_I422:frame_num=ftell(fp_src)/(y_size*2);break; case X264_CSP_I420:frame_num=ftell(fp_src)/(y_size*3/2);break; default:printf("Colorspace Not Support.\n");return -1; } fseek(fp_src,0,SEEK_SET); } //Loop to Encode for( i=0;i<frame_num;i++){ switch(csp){ case X264_CSP_I444:{ fread(pPic_in->img.plane[0],y_size,1,fp_src); //Y fread(pPic_in->img.plane[1],y_size,1,fp_src); //U fread(pPic_in->img.plane[2],y_size,1,fp_src); //V break;} case X264_CSP_I422:{ int index = 0; int y_i=0,u_i=0,v_i=0; for(index = 0 ; index < y_size*2 ;){ fread(&pPic_in->img.plane[0][y_i++],1,1,fp_src); //Y index++; fread(&pPic_in->img.plane[1][u_i++],1,1,fp_src); //U index++; fread(&pPic_in->img.plane[0][y_i++],1,1,fp_src); //Y index++; fread(&pPic_in->img.plane[2][v_i++],1,1,fp_src); //V index++; }break;} case X264_CSP_I420:{ fread(pPic_in->img.plane[0],y_size,1,fp_src); //Y fread(pPic_in->img.plane[1],y_size/4,1,fp_src); //U fread(pPic_in->img.plane[2],y_size/4,1,fp_src); //V break;} default:{ printf("Colorspace Not Support.\n"); return -1;} } pPic_in->i_pts = i; ret = x264_encoder_encode(pHandle, &pNals, &iNal, pPic_in, pPic_out); if (ret< 0){ printf("Error.\n"); return -1; } printf("Succeed encode frame: %5d\n",i); for ( j = 0; j < iNal; ++j){ fwrite(pNals[j].p_payload, 1, pNals[j].i_payload, fp_dst); } } i=0; //flush encoder while(1){ ret = x264_encoder_encode(pHandle, &pNals, &iNal, NULL, pPic_out); if(ret==0){ break; } printf("Flush 1 frame.\n"); for (j = 0; j < iNal; ++j){ fwrite(pNals[j].p_payload, 1, pNals[j].i_payload, fp_dst); } i++; } x264_picture_clean(pPic_in); x264_encoder_close(pHandle); pHandle = NULL; free(pPic_in); free(pPic_out); free(pParam); fclose(fp_src); fclose(fp_dst); return 0; }
PC端ubuntu下交叉編譯:
arm-none-linux-gnueabi-gcc x264_coder.c -o x264_coder -L/home/jiangyu/software/x264/x264-snapshot-20181014-2245/_install/lib/ -I/home/jiangyu/software/x264/x264-snapshot-20181014-2245/_install/include/ -lx264
生成可執行文件x264_coder,拷貝至目標板進行編碼測試:
目標板上執行:./x264_coder
生成output_image.h264視頻文件,利用VLC播放器可打開觀看
編碼前文件大小out_image.yuv 58.5M
編碼壓縮後文件大小out_image.h264 360KB
至此本節完成。