FFmpeg学习：复用器的使用（录制摄像头和麦克风数据，输出mkv文件）
介绍
本文在上一篇复用器的使用基础上，将输入文件改为摄像头和麦克风
- 目前只是单线程
代码如下：
点击查看代码
#include <iostream>
#define __STDC_CONSTANT_MACROS //它允许C++程序使用C99标准中指定的 stdint.h 宏，而这些宏不在C++标准中。
//诸如 UINT8_MAX ， INT64_MIN 和 INT32_C () 之类的宏可能已在C++应用程序中以其他方式定义
extern "C" {
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/mathematics.h"
#include "libavutil/pixdesc.h"
#include "libavutil/imgutils.h"
#include "libavutil/dict.h"
#include "libavutil/parseutils.h"
#include "libavutil/samplefmt.h"
#include "libavutil/avassert.h"
#include "libavutil/time.h"
#include "libavformat/avformat.h"
#include "libavdevice/avdevice.h"
#include "libswscale/swscale.h"
#include "libavutil/opt.h"
#include "libavcodec/avfft.h"
#include "libswresample/swresample.h"
#define SDL_MAIN_HANDLED
#include "SDL.h"
#include "SDL_main.h"
#include "SDL_video.h"
#include "SDL_thread.h"
#if CONFIG_AVFILTER
# include "libavfilter/avfilter.h"
# include "libavfilter/buffersink.h"
# include "libavfilter/buffersrc.h"
#endif
}
#include <string>
int main()
{
AVOutputFormat* OFormat = NULL;
AVFormatContext* pvFormatCtx = NULL;//保存视频数据
AVFormatContext* paFormatCtx = NULL;//保存音频数据
AVFormatContext* poFormatCtx = NULL;//输出数据上下文
int videoindex = -1, audioindex = -1;
int videoindex_out = -1, audioindex_out = -1;
int64_t frame_index = 0;
int64_t cur_pts_v = 0, cur_pts_a = 0;
const char* out_filename = "shuchu.mkv";//输出文件 "rtp://127.0.0.1:1234";//
const char* audio_filename = "audio.mp3";//输出文件
const char* video_filename = "video.h264";//输出文件
AVPacket* pkt;
int ret, i;
pvFormatCtx = avformat_alloc_context();
paFormatCtx = avformat_alloc_context();
//poFormatCtx = avformat_alloc_context();
//设备初始化
avdevice_register_all();
//网络初始化
avformat_network_init();
//打开摄像头——视频流
AVInputFormat* ifmt = av_find_input_format("dshow");
AVDictionary* opt_v = NULL;
av_dict_set(&opt_v, "rtbufsize", "100*1280*720", 0);//设置循环缓冲区大小
av_dict_set(&opt_v, "video_size", "1280x720", 0);
av_dict_set(&opt_v, "framerate", "30", 0);
av_dict_set(&opt_v, "vcodec", "libx264", 0);//指定视频编码格式
av_dict_set(&opt_v, "reuse", "1", 0);
if (avformat_open_input(&pvFormatCtx, "video=Integrated Camera", ifmt, &opt_v) != 0) {
// if (avformat_open_input(&pvFormatCtx, video_filename, NULL, NULL) != 0) {
printf("Couldn't open video input stream.\n");
return -1;
}
if (avformat_find_stream_info(pvFormatCtx, NULL) < 0)
{
printf("Couldn't find stream information.\n");
return -1;
}
//打开麦克风——音频流
AVDictionary* opt_a = NULL;
av_dict_set(&opt_a, "acodec", "libfdk_aac",0);//指定音频编码格式
//av_dict_set(&opt_v, "rtbufsize", "30*16*44100", 0);//设置循环缓冲区大小
const char* audio_name = u8"audio=麦克风阵列 (英特尔® 智音技术)";//u8"audio=麦克风 (2- Realtek(R) Audio)";
if (avformat_open_input(&paFormatCtx, audio_name, ifmt, &opt_a) != 0) {
// if (avformat_open_input(&paFormatCtx, audio_filename, NULL, NULL) != 0) {
printf("Couldn't open audio input stream.\n");
return -1;
}
if (avformat_find_stream_info(paFormatCtx, NULL) < 0)
{
printf("Couldn't find stream information.\n");
return -1;
}
//开始输出 rtp_mpegts(rtp支持的格式) mpegts(UDP支持的格式) flv(rtmp支持的格式)
avformat_alloc_output_context2(&poFormatCtx, NULL, "rtp_mpegts", out_filename);//初始化输出文件
if (!poFormatCtx) {
printf("Could not create output context\n");
return -1;
}
OFormat = poFormatCtx->oformat;
//给输出添加视频流
for (i = 0; i < pvFormatCtx->nb_streams; i++) {
//Create output AVStream according to input AVStream
if (pvFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
/*
* 步骤：
* 1、首先根据视频流创建新的输出流（要添加初始化编码器）
* 2、将原视频流的编码器上下文 复制 给输出流
*/
AVStream* in_stream = pvFormatCtx->streams[i];
AVCodec* in_codec = avcodec_find_decoder(in_stream->codecpar->codec_id);
AVStream* out_stream = avformat_new_stream(poFormatCtx, in_codec);
videoindex = i;
if (!out_stream) {
printf("Failed allocating output stream\n");
return -1;
}
videoindex_out = out_stream->index;
//Copy the settings of AVCodecContext
AVCodecContext* codec_ctx = avcodec_alloc_context3(in_codec);
ret = avcodec_parameters_to_context(codec_ctx,in_stream->codecpar);
if (ret < 0) {
printf("Failed to copy in_stream codecpar to codec context\n");
return -1;
}
codec_ctx->codec_tag = 0;
if (poFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
codec_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
ret = avcodec_parameters_from_context(out_stream->codecpar, codec_ctx);
if (ret < 0) {
printf("Failed to copy codec context to out_stream codecpar context\n");
return -1;
}
}
}
//给输出添加音频流
for (i = 0; i < paFormatCtx->nb_streams; i++) {
//Create output AVStream according to input AVStream
if (paFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
AVStream* in_stream = paFormatCtx->streams[i];
AVCodec* in_codec = avcodec_find_decoder(in_stream->codecpar->codec_id);
AVStream* out_stream = avformat_new_stream(poFormatCtx, in_codec);
audioindex = i;
if (!out_stream) {
printf("Failed allocating output stream\n");
return -1;
}
//av_copy_packet();
audioindex_out = out_stream->index;
//Copy the settings of AVCodecContext
AVCodecContext* codec_ctx = avcodec_alloc_context3(in_codec);
ret = avcodec_parameters_to_context(codec_ctx, in_stream->codecpar);
if (ret < 0) {
printf("Failed to copy in_stream codecpar to codec context\n");
return -1;
}
codec_ctx->codec_tag = 0;
if (poFormatCtx->oformat->flags & AVFMT_GLOBALHEADER)
codec_ctx->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
ret = avcodec_parameters_from_context(out_stream->codecpar, codec_ctx);
if (ret < 0) {
printf("Failed to copy codec context to out_stream codecpar context\n");
return -1;
}
}
}
printf("==========Output Information==========\n");
av_dump_format(poFormatCtx, 0, out_filename, 1);
printf("======================================\n");
//Open output file
if (!(OFormat->flags & AVFMT_NOFILE)) {
AVDictionary* dic = NULL;
//av_dict_set(&dic, "vcodec", "copy", 0);//指定视频编码格式
//av_dict_set(&dic, "pkt_size", "1316", 0); //Maximum UDP packet size
//av_dict_set(&dic, "fifo_size", "18800", 0);
//av_dict_set(&dic, "buffer_size", "1000000", 0);
//av_dict_set(&dic, "bitrate", "11000000", 0);
//av_dict_set(&dic, "buffer_size", "1000000", 0);//1316
//av_dict_set(&dic, "reuse", "1", 0);
if (avio_open2(&poFormatCtx->pb, out_filename, AVIO_FLAG_WRITE, NULL, &dic) < 0) {
printf("Could not open url '%s'", out_filename);
return -1;
}
}
//配置参数
//av_opt_set(poFormatCtx->priv_data, "muxrate", "11000000", 0);
//av_opt_set(poFormatCtx->priv_data, "MpegTSWrite", "1", 0);
//av_opt_set(poFormatCtx->priv_data, "pes_payload_size", "300", 0);
//Write file header
if (avformat_write_header(poFormatCtx, NULL) < 0) {
printf("Error occurred when opening output file\n");
return -1;
}
//开始写文件
int64_t last_pts = -1;
//start_time = av_gettime();
AVPacket* pkta=NULL, * pktv=nullptr;
while (1) {
if (pktv == NULL) {
pktv = av_packet_alloc();
if (av_read_frame(pvFormatCtx, pktv) >= 0) {
if (pktv->pts == AV_NOPTS_VALUE) {
//Write PTS
AVRational time_base1 = pvFormatCtx->streams[videoindex]->time_base;
//Duration between 2 frames (us)
int64_t calc_duration = (double)AV_TIME_BASE / av_q2d(pvFormatCtx->streams[videoindex]->r_frame_rate);
//Parameters
//pkt->pts = (double)(frame_index * calc_duration) / (double)(av_q2d(time_base1) * AV_TIME_BASE);
pktv->pts = (double)((cur_pts_v+1) * calc_duration) / (double)(av_q2d(time_base1) * AV_TIME_BASE);
pktv->dts = pktv->pts;
pktv->duration = (double)calc_duration / (double)(av_q2d(time_base1) * AV_TIME_BASE);
}
cur_pts_v = pktv->pts;
}
else {
av_packet_free(&pktv);
break;
}
}
if (pkta == NULL) {
pkta = av_packet_alloc();
if (av_read_frame(paFormatCtx, pkta) >= 0) {
cur_pts_a = pkta->pts;
}
else {
av_packet_free(&pkt);
break;
}
}
AVFormatContext* ifmt_ctx;
int stream_index = 0;
AVStream* in_stream, * out_stream;
if (av_compare_ts(cur_pts_v, pvFormatCtx->streams[videoindex]->time_base, cur_pts_a, paFormatCtx->streams[audioindex]->time_base) <= 0) {
ifmt_ctx = pvFormatCtx;
stream_index = videoindex_out;
in_stream = ifmt_ctx->streams[pktv->stream_index];
out_stream = poFormatCtx->streams[stream_index];
av_packet_rescale_ts(pktv,in_stream->time_base,out_stream->time_base);
//
if (last_pts >= pktv->pts) {
pktv->pts = last_pts + 1;
pktv->dts = last_pts + 1;
}
last_pts = pktv->pts;
pktv->pos = -1;
pktv->stream_index = stream_index;
printf("frame_index: %lld Packet. in_video_pts: %lld Packet. size:%5d. pts:%lld\n", frame_index,cur_pts_v, pktv->size, pktv->pts);
//Write
if (av_interleaved_write_frame(poFormatCtx, pktv) < 0) {
printf("Error muxing packet\n");
break;
}
av_packet_free(&pktv);
frame_index++;
}
else {
ifmt_ctx = paFormatCtx;
stream_index = audioindex_out;
in_stream = ifmt_ctx->streams[pkta->stream_index];
out_stream = poFormatCtx->streams[stream_index];
av_packet_rescale_ts(pkta, in_stream->time_base, out_stream->time_base);
if (last_pts >= pkta->pts) {
pkta->pts = last_pts + 1;
pkta->dts = last_pts + 1;
}
last_pts = pkta->pts;
pkta->pos = -1;
pkta->stream_index = stream_index;
printf("frame_index: %lld Packet. in_audio_pts: %lld Packet. size:%5d. pts:%lld\n", frame_index, cur_pts_a, pkta->size, pkta->pts);
//Write
if (av_interleaved_write_frame(poFormatCtx, pkta) < 0) {
printf("Error muxing packet\n");
break;
}
av_packet_free(&pkta);
frame_index++;
}
if (frame_index > 300) {
break;
}
}
//av_packet_free(&pkt);
//Write file trailer
av_write_trailer(poFormatCtx);
avformat_close_input(&pvFormatCtx);
avformat_close_input(&paFormatCtx);
/* close output */
if (poFormatCtx && !(OFormat->flags & AVFMT_NOFILE))
avio_close(poFormatCtx->pb);
avformat_free_context(poFormatCtx);
if (ret < 0 && ret != AVERROR_EOF) {
printf("Error occurred.\n");
return -1;
}
return 0;
}
存在问题
已解决问题
【问题一：avformat_write_header时报错】
Could not find tag for codec pcm_s16le in stream #1, codec not currently supported in container
解决方法：将输出的文件格式由mp4改为mkv；
【问题二：时间戳对不上】
自带播放器解码有问题，推荐使用 VLC。
