本文共 10276 字，大约阅读时间需要 34 分钟。
x264官网：
libx264编译:
首先直接调用libx264完成编码（YUV编码为H.264）
主要函数详解：
x264_param_default()：设置参数集结构体x264_param_t的缺省值。
x264_picture_alloc()：为图像结构体x264_picture_t分配内存。
x264_encoder_open()：打开编码器。
x264_encoder_encode()：编码一帧图像。
x264_encoder_close()：关闭编码器。
x264_picture_clean()：释放x264_picture_alloc()申请的资源。
存储数据的结构体如下所示。
x264_picture_t：存储压缩编码前的像素数据。
x264_nal_t：存储压缩编码后的码流数据。
话不多说，上代码：
#include #include #include "stdint.h"#if defined ( __cplusplus)extern "C"{#include "x264.h"};#else#include "x264.h"#endifint main(int argc, char** argv){ int ret; int y_size; int i,j; //FILE* fp_src = fopen("../cuc_ieschool_640x360_yuv444p.yuv", "rb"); FILE* fp_src = fopen("../cuc_ieschool_640x360_yuv420p.yuv", "rb"); FILE* fp_dst = fopen("cuc_ieschool.h264", "wb"); //Encode 50 frame //if set 0, encode all frame int frame_num = 50; int csp=X264_CSP_I420; int width=640,height=360; 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); pParam->i_width = width; pParam->i_height = height; /* //Param pParam->i_log_level = X264_LOG_DEBUG; pParam->i_threads = X264_SYNC_LOOKAHEAD_AUTO; pParam->i_frame_total = 0; pParam->i_keyint_max = 10; 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_fps_den = 1; pParam->i_fps_num = 25; pParam->i_timebase_den = pParam->i_fps_num; pParam->i_timebase_num = pParam->i_fps_den; */ pParam->i_csp=csp; x264_param_apply_profile(pParam, x264_profile_names[5]); 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_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 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_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;}
功能强大的FFmpeg整合了很多编码器， 不仅可以编码H.264的视频，而且可以编码MPEG4/MPEG2/VP8等等各种FFmpeg支持的视频。当然编码的流程是相同的，只是需要设置不同的编码参数而已。FFmpeg也调用libx264完成编码 H.264的工作。
主要函数详解：
av_register_all()：注册FFmpeg所有编解码器。
avformat_alloc_output_context2()：初始化输出码流的AVFormatContext。
avio_open()：打开输出文件。
av_new_stream()：创建输出码流的AVStream。
avcodec_find_encoder()：查找编码器。
avcodec_open2()：打开编码器。
avformat_write_header()：写文件头（对于某些没有文件头的封装格式，不需要此函数。比如说MPEG2TS）。
avcodec_encode_video2()：编码一帧视频。即将AVFrame（存储YUV像素数据）编码为AVPacket（存储H.264等格式的码流数据）。
av_write_frame()：将编码后的视频码流写入文件。
flush_encoder()：输入的像素数据读取完成后调用此函数。用于输出编码器中剩余的AVPacket。
av_write_trailer()：写文件尾（对于某些没有文件头的封装格式，不需要此函数。比如说MPEG2TS）。
代码：
#include #define __STDC_CONSTANT_MACROS#ifdef _WIN32//Windowsextern "C"{#include "libavutil/opt.h"#include "libavcodec/avcodec.h"#include "libavformat/avformat.h"};#else//Linux...#ifdef __cplusplusextern "C"{#endif#include #include #include #ifdef __cplusplus};#endif#endifint flush_encoder(AVFormatContext *fmt_ctx,unsigned int stream_index){ int ret; int got_frame; AVPacket enc_pkt; if (!(fmt_ctx->streams[stream_index]->codec->codec->capabilities & CODEC_CAP_DELAY)) return 0; while (1) { enc_pkt.data = NULL; enc_pkt.size = 0; av_init_packet(&enc_pkt); ret = avcodec_encode_video2 (fmt_ctx->streams[stream_index]->codec, &enc_pkt, NULL, &got_frame); av_frame_free(NULL); if (ret < 0) break; if (!got_frame){ ret=0; break; } printf("Flush Encoder: Succeed to encode 1 frame!\tsize:%5d\n",enc_pkt.size); /* mux encoded frame */ ret = av_write_frame(fmt_ctx, &enc_pkt); if (ret < 0) break; } return ret;}int main(int argc, char* argv[]){ AVFormatContext* pFormatCtx; AVOutputFormat* fmt; AVStream* video_st; AVCodecContext* pCodecCtx; AVCodec* pCodec; AVPacket pkt; uint8_t* picture_buf; AVFrame* pFrame; int picture_size; int y_size; int framecnt=0; //FILE *in_file = fopen("src01_480x272.yuv", "rb"); //Input raw YUV data FILE *in_file = fopen("../cuc_ieschool_640x360_yuv420p.yuv", "rb"); //Input raw YUV data int in_w=640,in_h=360; //Input data's width and height int framenum=100; //Frames to encode //const char* out_file = "src01.h264"; //Output Filepath //const char* out_file = "src01.ts"; //const char* out_file = "src01.hevc"; const char* out_file = "ds.h264"; av_register_all(); //Method1. pFormatCtx = avformat_alloc_context(); //Guess Format fmt = av_guess_format(NULL, out_file, NULL); pFormatCtx->oformat = fmt; //Method 2. //avformat_alloc_output_context2(&pFormatCtx, NULL, NULL, out_file); //fmt = pFormatCtx->oformat; //Open output URL if (avio_open(&pFormatCtx->pb,out_file, AVIO_FLAG_READ_WRITE) < 0){ printf("Failed to open output file! \n"); return -1; } video_st = avformat_new_stream(pFormatCtx, 0); video_st->time_base.num = 1; video_st->time_base.den = 25; if (video_st==NULL){ return -1; } //Param that must set pCodecCtx = video_st->codec; //pCodecCtx->codec_id =AV_CODEC_ID_HEVC; pCodecCtx->codec_id = fmt->video_codec; pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO; pCodecCtx->pix_fmt = PIX_FMT_YUV420P; pCodecCtx->width = in_w; pCodecCtx->height = in_h; pCodecCtx->time_base.num = 1; pCodecCtx->time_base.den = 25; pCodecCtx->bit_rate = 400000; pCodecCtx->gop_size=250; //H264 //pCodecCtx->me_range = 16; //pCodecCtx->max_qdiff = 4; //pCodecCtx->qcompress = 0.6; pCodecCtx->qmin = 10; pCodecCtx->qmax = 51; //Optional Param pCodecCtx->max_b_frames=3; // Set Option AVDictionary *param = 0; //H.264 if(pCodecCtx->codec_id == AV_CODEC_ID_H264) { av_dict_set(¶m, "preset", "slow", 0); av_dict_set(¶m, "tune", "zerolatency", 0); //av_dict_set(¶m, "profile", "main", 0); } //H.265 if(pCodecCtx->codec_id == AV_CODEC_ID_H265){ av_dict_set(¶m, "preset", "ultrafast", 0); av_dict_set(¶m, "tune", "zero-latency", 0); } //Show some Information av_dump_format(pFormatCtx, 0, out_file, 1); pCodec = avcodec_find_encoder(pCodecCtx->codec_id); if (!pCodec){ printf("Can not find encoder! \n"); return -1; } if (avcodec_open2(pCodecCtx, pCodec,¶m) < 0){ printf("Failed to open encoder! \n"); return -1; } pFrame = av_frame_alloc(); picture_size = avpicture_get_size(pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); picture_buf = (uint8_t *)av_malloc(picture_size); avpicture_fill((AVPicture *)pFrame, picture_buf, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height); //Write File Header avformat_write_header(pFormatCtx,NULL); av_new_packet(&pkt,picture_size); y_size = pCodecCtx->width * pCodecCtx->height; for (int i=0; i data[0] = picture_buf; // Y pFrame->data[1] = picture_buf+ y_size; // U pFrame->data[2] = picture_buf+ y_size*5/4; // V //PTS pFrame->pts=i; int got_picture=0; //Encode int ret = avcodec_encode_video2(pCodecCtx, &pkt,pFrame, &got_picture); if(ret < 0){ printf("Failed to encode! \n"); return -1; } if (got_picture==1){ printf("Succeed to encode frame: %5d\tsize:%5d\n",framecnt,pkt.size); framecnt++; pkt.stream_index = video_st->index; ret = av_write_frame(pFormatCtx, &pkt); av_free_packet(&pkt); } } //Flush Encoder int ret = flush_encoder(pFormatCtx,0); if (ret < 0) { printf("Flushing encoder failed\n"); return -1; } //Write file trailer av_write_trailer(pFormatCtx); //Clean if (video_st){ avcodec_close(video_st->codec); av_free(pFrame); av_free(picture_buf); } avio_close(pFormatCtx->pb); avformat_free_context(pFormatCtx); fclose(in_file); return 0;}
Reference:
转载地址：http://unqqf.baihongyu.com/