最简单的视频编码器：libvpx（编码YUV为VP8）

标签：libvpx   vp8   vp9   视频   编解码   

流程图

源代码

/**
 * 最简单的基于VPX的视频编码器
 * Simplest VPX Encoder
 *
 * 雷霄骅 Lei Xiaohua
 * leixiaohua1020@126.com
 * 中国传媒大学/数字电视技术
 * Communication University of China / Digital TV Technology
 * http://blog.csdn.net/leixiaohua1020
 *
 * 本程序精简了libvpx中的一个示例代码。
 * 可以YUV格式的像素数据编码为VPx(VP8/VP9)码流，是最简单的
 * 基于libvpx的视频编码器
 * 需要注意的是，编码输出的封装格式是IVF
 *
 * This example modified from an example from vpx project.
 * It encode YUV data to VPX(VP8/VP9) bitstream.
 * It‘s the simplest encoder example based on libvpx.
 */
#include <stdio.h>
#include <stdlib.h>
 
 
#define VPX_CODEC_DISABLE_COMPAT 1
 
#include "vpx/vpx_encoder.h"
#include "vpx/vp8cx.h"
 
#define interface (&vpx_codec_vp8_cx_algo)
 
#define fourcc    0x30385056
 
#define IVF_FILE_HDR_SZ  (32)
#define IVF_FRAME_HDR_SZ (12)
 
static void mem_put_le16(char *mem, unsigned int val) {
    mem[0] = val;
    mem[1] = val>>8;
}
 
static void mem_put_le32(char *mem, unsigned int val) {
    mem[0] = val;
    mem[1] = val>>8;
    mem[2] = val>>16;
    mem[3] = val>>24;
}
 
 
static void write_ivf_file_header(FILE *outfile,
                                  const vpx_codec_enc_cfg_t *cfg,
                                  int frame_cnt) {
    char header[32];
 
    if(cfg->g_pass != VPX_RC_ONE_PASS && cfg->g_pass != VPX_RC_LAST_PASS)
        return;
    header[0] = ‘D‘;
    header[1] = ‘K‘;
    header[2] = ‘I‘;
    header[3] = ‘F‘;
    mem_put_le16(header+4,  0);                   /* version */
    mem_put_le16(header+6,  32);                  /* headersize */
    mem_put_le32(header+8,  fourcc);              /* headersize */
    mem_put_le16(header+12, cfg->g_w);            /* width */
    mem_put_le16(header+14, cfg->g_h);            /* height */
    mem_put_le32(header+16, cfg->g_timebase.den); /* rate */
    mem_put_le32(header+20, cfg->g_timebase.num); /* scale */
    mem_put_le32(header+24, frame_cnt);           /* length */
    mem_put_le32(header+28, 0);                   /* unused */
 
    fwrite(header, 1, 32, outfile);
}
 
 
static void write_ivf_frame_header(FILE *outfile,
                                   const vpx_codec_cx_pkt_t *pkt)
{
    char             header[12];
    vpx_codec_pts_t  pts;
 
    if(pkt->kind != VPX_CODEC_CX_FRAME_PKT)
        return;
 
    pts = pkt->data.frame.pts;
    mem_put_le32(header, pkt->data.frame.sz);
    mem_put_le32(header+4, pts&0xFFFFFFFF);
    mem_put_le32(header+8, pts >> 32);
 
    fwrite(header, 1, 12, outfile);
}
 
int main(int argc, char **argv) {
 
    FILE *infile, *outfile;
    vpx_codec_ctx_t codec;
    vpx_codec_enc_cfg_t cfg;
    int frame_cnt = 0;
    unsigned char file_hdr[IVF_FILE_HDR_SZ];
    unsigned char frame_hdr[IVF_FRAME_HDR_SZ];
    vpx_image_t raw;
    vpx_codec_err_t ret;
    int width,height;
         int y_size;
    int frame_avail;
    int got_data;
    int flags = 0;
 
    width = 640;
    height = 360;
 
         /* Open input file for this encoding pass */
         infile = fopen("../cuc_ieschool_640x360_yuv420p.yuv", "rb");
         outfile = fopen("cuc_ieschool.ivf", "wb");
 
         if(infile==NULL||outfile==NULL){
                   printf("Error open files.\n");
                   return -1;
         }
 
         if(!vpx_img_alloc(&raw, VPX_IMG_FMT_I420, width, height, 1)){
        printf("Fail to allocate image\n");
                   return -1;
         }
 
    printf("Using %s\n",vpx_codec_iface_name(interface));
 
    /* Populate encoder configuration */
    ret = vpx_codec_enc_config_default(interface, &cfg, 0);
    if(ret) {
        printf("Failed to get config: %s\n", vpx_codec_err_to_string(ret));
        return -1;                                                 
    }
 
    /* Update the default configuration with our settings */
    cfg.rc_target_bitrate =800;
    cfg.g_w = width;                                                          
    cfg.g_h = height;                                                        
 
    write_ivf_file_header(outfile, &cfg, 0);
 
    /* Initialize codec */                                               
    if(vpx_codec_enc_init(&codec, interface, &cfg, 0)){
        printf("Failed to initialize encoder\n");
                   return -1;
         }
 
    frame_avail = 1;
    got_data = 0;
 
         y_size=cfg.g_w*cfg.g_h;
 
    while(frame_avail || got_data) {
        vpx_codec_iter_t iter = NULL;
        const vpx_codec_cx_pkt_t *pkt;
                  
                   if(fread(raw.planes[0], 1, y_size*3/2, infile)!=y_size*3/2){
                            frame_avail=0;
                   }
 
                   if(frame_avail){
                            ret=vpx_codec_encode(&codec,&raw,frame_cnt,1,flags,VPX_DL_REALTIME);
                   }else{
                            ret=vpx_codec_encode(&codec,NULL,frame_cnt,1,flags,VPX_DL_REALTIME);
                   }
 
                   if(ret){
            printf("Failed to encode frame\n");
                            return -1;
                   }
        got_data = 0;
        while( (pkt = vpx_codec_get_cx_data(&codec, &iter)) ) {
            got_data = 1;
            switch(pkt->kind) {
            case VPX_CODEC_CX_FRAME_PKT:
                write_ivf_frame_header(outfile, pkt);
                fwrite(pkt->data.frame.buf, 1, pkt->data.frame.sz,outfile);
                break;
            default:
                break;
            }
        }
                   printf("Succeed encode frame: %5d\n",frame_cnt);
        frame_cnt++;
    }
 
    fclose(infile);
 
    vpx_codec_destroy(&codec);
 
    /* Try to rewrite the file header with the actual frame count */
    if(!fseek(outfile, 0, SEEK_SET))
        write_ivf_file_header(outfile, &cfg, frame_cnt-1);
 
    fclose(outfile);
 
    return 0;
}

运行结果

程序的输入为一个YUV文件（已经测试过YUV420P格式）。

输出为IVF封装格式的VP8码流文件。

VP8码流文件的信息如下所示。

下载

最简单的视频编码器：libvpx（编码YUV为VP8）

标签：libvpx   vp8   vp9   视频   编解码   

原文地址：http://blog.csdn.net/leixiaohua1020/article/details/42079217