#include"ffmpeg_mp4.h"
int ptsInc = 0;
int waitkey = 1;;
int STREAM_FRAME_RATE = 25;
AVFormatContext* m_pOc;
int vi;
bool isIdrFrame2(uint8_t* buf, int len){
switch (buf[0] & 0x1f){
case 7: // SPS
return true;
case 8: // PPS
return true;
case 5:
return true;
case 1:
return false;
default:
return false;
break;
}
return false;
}
bool isIdrFrame1(uint8_t* buf, int size){
//主要是解析idr前面的sps pps
// static bool found = false;
// if(found){ return true;}
int last = 0;
for (int i = 2; i <= size; ++i){
if (i == size) {
if (last) {
bool ret = isIdrFrame2(buf+last ,i - last);
if (ret) {
//found = true;
return true;
}
}
} else if (buf[i - 2]== 0x00 && buf[i - 1]== 0x00 && buf[i] == 0x01) {
if (last) {
int size = i - last - 3;
if (buf[i - 3]) ++size;
bool ret = isIdrFrame2(buf+last ,size);
if (ret) {
//found = true;
return true;
}
}
last = i + 1;
}
}
return false;
}
/* Add an output stream */
AVStream *add_stream(AVFormatContext *oc, AVCodec **codec, enum AVCodecID codec_id)
{
AVCodecContext *c;
AVStream *st;
/* find the encoder */
*codec = avcodec_find_encoder(codec_id);
if (!*codec)
{
printf("could not find encoder for '%s' \n", avcodec_get_name(codec_id));
exit(1);
}
st = avformat_new_stream(oc, *codec);
if (!st)
{
printf("could not allocate stream \n");
exit(1);
}
st->id = oc->nb_streams-1;
c = st->codec;
vi = st->index;
switch ((*codec)->type)
{
case AVMEDIA_TYPE_AUDIO:
printf("AVMEDIA_TYPE_AUDIO\n");
c->sample_fmt = (*codec)->sample_fmts ? (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
c->bit_rate = 64000;
c->sample_rate = 44100;
c->channels = 2;
break;
case AVMEDIA_TYPE_VIDEO:
printf("AVMEDIA_TYPE_VIDEO\n");
c->codec_id = AV_CODEC_ID_H264;
c->bit_rate = 0;
c->width = 1080;
c->height = 720;
c->time_base.den = 50;
c->time_base.num = 1;
c->gop_size = 1;
c->pix_fmt = AV_PIX_FMT_YUV420P;
if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO)
{
c->max_b_frames = 2;
}
if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO)
{
c->mb_decision = 2;
}
break;
default:
break;
}
if (oc->oformat->flags & AVFMT_GLOBALHEADER)
{
c->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
return st;
}
void open_video(AVFormatContext *oc, AVCodec *codec, AVStream *st)
{
int ret;
AVCodecContext *c = st->codec;
/* open the codec */
ret = avcodec_open2(c, codec, NULL);
if (ret < 0)
{
printf("could not open video codec");
//exit(1);
}
}
int CreateMp4(const char* filename)
{
int ret; // 成功返回0，失败返回1
const char* pszFileName =filename;
AVOutputFormat *fmt;
AVCodec *video_codec;
AVStream *m_pVideoSt;
av_register_all();
avformat_alloc_output_context2(&m_pOc, NULL, NULL, pszFileName);
if (!m_pOc)
{
printf("Could not deduce output format from file extension: using MPEG. \n");
avformat_alloc_output_context2(&m_pOc, NULL, "mpeg", pszFileName);
}
if (!m_pOc)
{
return 1;
}
fmt = m_pOc->oformat;
if (fmt->video_codec != AV_CODEC_ID_NONE)
{
printf("1111111111111111add_stream\n");
m_pVideoSt = add_stream(m_pOc, &video_codec, fmt->video_codec);
}
if (m_pVideoSt)
{
printf("1111111111111111open_video\n");
open_video(m_pOc, video_codec, m_pVideoSt);
}
printf("==========Output Information==========\n");
av_dump_format(m_pOc, 0, pszFileName, 1);
printf("======================================\n");
/* open the output file, if needed */
if (!(fmt->flags & AVFMT_NOFILE))
{
ret = avio_open(&m_pOc->pb, pszFileName, AVIO_FLAG_WRITE);
if (ret < 0)
{
printf("could not open %s\n", pszFileName);
return 1;
}
}
/* Write the stream header, if any */
ret = avformat_write_header(m_pOc, NULL);
if (ret < 0)
{
printf("Error occurred when opening output file");
return 1;
}
}
/* write h264 data to mp4 file
* 创建mp4文件返回2；写入数据帧返回0 */
void WriteVideo(void* data, int nLen)
{
int ret;
if ( 0 > vi )
{
printf("vi less than 0\n");
//return -1;
}
AVStream *pst = m_pOc->streams[ vi ];
//printf("vi=====%d\n",vi);
// Init packet
AVPacket pkt;
// 我的添加，为了计算pts
AVCodecContext *c = pst->codec;
av_init_packet( &pkt );
int isI = isIdrFrame1( (uint8_t*)data, nLen );
printf("isIFrame is %d\n",isI);
pkt.flags |= isI ? AV_PKT_FLAG_KEY : 0;
pkt.stream_index = pst->index;
pkt.data = (uint8_t*)data;
pkt.size = nLen;
// Wait for key frame
if ( waitkey ){
if ( 0 == ( pkt.flags & AV_PKT_FLAG_KEY ) ){
return ;
}
else
waitkey = 0;
}
pkt.pts = (ptsInc++) * (90000/STREAM_FRAME_RATE);
pkt.pts = av_rescale_q((ptsInc++)*2, pst->codec->time_base,pst->time_base);
//pkt.dts = (ptsInc++) * (90000/STREAM_FRAME_RATE);
// pkt.pts=av_rescale_q_rnd(pkt.pts, pst->time_base,pst->time_base,(AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.dts=av_rescale_q_rnd(pkt.dts, pst->time_base,pst->time_base,(AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
pkt.duration = av_rescale_q(pkt.duration,pst->time_base, pst->time_base);
pkt.pos = -1;
printf("pkt.size=%d\n",pkt.size);
ret = av_interleaved_write_frame( m_pOc, &pkt );
if (ret < 0)
{
printf("cannot write frame");
}
}
void CloseMp4()
{
waitkey = -1;
vi = -1;
if (m_pOc)
av_write_trailer(m_pOc);
if (m_pOc && !(m_pOc->oformat->flags & AVFMT_NOFILE))
avio_close(m_pOc->pb);
if (m_pOc)
{
avformat_free_context(m_pOc);
m_pOc = NULL;
}
}
