如何直接使用 ffmpeg 将 H264 原始 ZF7B44CFFAFD5C52223D5498196C8A2E7BZ 写入 mp4

Question

I want to wrap the H264 Nalus(x264 encoded) into mp4 using ffmpeg(SDK 2.1), but the output mp4 file could not play. I don't know how to set the pts and dts. Here's my code, using the code from Raw H264 frames in mpegts container using libavcodec and muxing.c from www.ffmpeg.org. My H264 stream has no B-Frame, every nalu starts with 00 00 00 01,the stream begins with sps pps then the h264 data.

#include "stdafx.h"
#include <stdlib.h>
#include <stdio.h>
#include "Stream2Mp4.h"

#include <libavutil/opt.h>
#include <libavutil/mathematics.h>
#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>
#include <libswresample/swresample.h>
#include <libswresample/swresample.h>

#define STREAM_FRAME_RATE 25
#define STREAM_PIX_FMT    AV_PIX_FMT_YUV420P /* default pix_fmt */

static int ptsInc = 0;
static int vi = -1;
static int waitkey = 1;

// < 0 = error
// 0 = I-Frame
// 1 = P-Frame
// 2 = B-Frame
// 3 = S-Frame
int getVopType( const void *p, int len )
{   
if ( !p || 6 >= len )
    return -1;

unsigned char *b = (unsigned char*)p;

// Verify NAL marker
if ( b[ 0 ] || b[ 1 ] || 0x01 != b[ 2 ] )
{   b++;
if ( b[ 0 ] || b[ 1 ] || 0x01 != b[ 2 ] )
    return -1;
} // end if

b += 3;

// Verify VOP id
if ( 0xb6 == *b )
{   b++;
return ( *b & 0xc0 ) >> 6;
} // end if

switch( *b )
{   case 0x65 : return 0;
case 0x61 : return 1;
case 0x01 : return 2;
} // end switch

return -1;
}

int get_nal_type( void *p, int len )
{
if ( !p || 5 >= len )
    return -1;

unsigned char *b = (unsigned char*)p;

// Verify NAL marker
if ( b[ 0 ] || b[ 1 ] || 0x01 != b[ 2 ] )
{   b++;
if ( b[ 0 ] || b[ 1 ] || 0x01 != b[ 2 ] )
    return -1;
} // end if

b += 3;

return *b;
}


/* 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:
    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:
    c->codec_id = codec_id;
    c->bit_rate = 90000;
    c->width = 480;
    c->height = 354;
    c->time_base.den = 15;
    c->time_base.num = 1;
    c->gop_size = 12;
    c->pix_fmt = STREAM_PIX_FMT;
    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(AVFormatContext *&m_pOc, void *p, int len)
{
int ret; 
const char* pszFileName = "output002.mp4";
AVOutputFormat *fmt;
AVCodec *video_codec;
AVStream *m_pVideoSt;

if (0x67 != get_nal_type(p, len))
{
    printf("can not detect nal type");
    return -1;
}
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)
{
    m_pVideoSt = add_stream(m_pOc, &video_codec, fmt->video_codec);
}

if (m_pVideoSt)
{
    open_video(m_pOc, video_codec, m_pVideoSt); 
}

av_dump_format(m_pOc, 0, pszFileName, 1);

/* 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': %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*/


void WriteVideo(AVFormatContext *&m_pOc,void* data, int nLen)
{
int ret;

if ( 0 > vi )
{
    printf("vi less than 0");
    //return -1;
}
AVStream *pst = m_pOc->streams[ vi ];

// Init packet
AVPacket pkt;

AVCodecContext *c = pst->codec;

av_init_packet( &pkt );
pkt.flags |= ( 0 >= getVopType( data, nLen ) ) ? 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.dts = (ptsInc++) * (90000/STREAM_FRAME_RATE);

ret = av_interleaved_write_frame( m_pOc, &pkt );
if (ret < 0)
{
    printf("cannot write frame");
}


}

void CloseMp4(AVFormatContext *&m_pOc)
{
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;
}

}

could anybody help me? Thank you very much!

Answer 1

you can try this.

if(pkt.pts != AV_NOPTS_VALUE)
{
    pkt.pts = av_rescale_q_rnd(ptsInc++, c->time_base, pst->time_base, 
        (AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
}

Answer 2

What is weird that you seem to ignore the sps/pps data which informs the decoder. you only verify that you have an sps in your CreateMp4. I think the decoder actually needs those.