Stuff

AVFormatContext* openMFile(const char* pFileName, AVStream** ppVideoStream, AVStream** ppAudioStream
                                                   , int nWidth, int nHeight, int nFps
                                                   , int nEncType, int nBitrate, int nSampleRate, int nSampleType, int nChannels)
{
        if(!pFileName) return NULL;

        AVOutputFormat* pAVFmt;
        AVFormatContext* pAVContext;

        AVStream* pAudioStream;
        AVStream* pVideoStream;
        
        pAVFmt = av_guess_format(NULL, pFileName, NULL);
        if (!pAVFmt) {
                printf("Could not deduce output format from file extension: using MPEG.\n");
                pAVFmt = av_guess_format("mpeg", NULL, NULL);
        }
        if (!pAVFmt) {
                fprintf(stderr, "Could not find suitable output format\n");
                return NULL;
        }
        pAVFmt->video_codec = CODEC_ID_MJPEG;
        if(nEncType == 0)
                pAVFmt->audio_codec = CODEC_ID_PCM_MULAW;
        else
                pAVFmt->audio_codec = CODEC_ID_AAC;

        pAVContext = avformat_alloc_context();
    if (!pAVContext) {
        fprintf(stderr, "Memory error\n");
        return NULL;
    }
    pAVContext->oformat = pAVFmt;
    snprintf(pAVContext->filename, sizeof(pAVContext->filename), "%s", pFileName);

        pAudioStream = NULL;
        pVideoStream = NULL;
    if (pAVFmt->video_codec != CODEC_ID_NONE) {
        pVideoStream = addVideoStream(pAVContext, nWidth, nHeight, nFps);
    }
        if (pAVFmt->audio_codec != CODEC_ID_NONE) {
                pAudioStream = addAudioStream(pAVContext, nBitrate, nSampleRate, nSampleType, nChannels);
        }
//      av_dump_format(pAVContext, 0, pFileName, 1);

    if (!(pAVFmt->flags & AVFMT_NOFILE)) {
        if (avio_open(&pAVContext->pb, pFileName, AVIO_FLAG_WRITE) < 0) {
            fprintf(stderr, "Could not open '%s'\n", pFileName);
            syslog(LOG_NOTICE, "Failed to open %s\n", pFileName);
            return NULL;
        }
    }

    avformat_write_header(pAVContext, NULL);
        *ppVideoStream = pVideoStream;
        *ppAudioStream = pAudioStream;

        return pAVContext;
}

AVStream* addVideoStream(AVFormatContext* pAVContext, int nWidth, int nHeight, int nFps)
{
    if(!pAVContext) return -1;

    AVCodecContext* pCodecContext = NULL;
    AVStream* pAVStream = NULL;
    AVCodec* codec;

//  printf("addVideoStream:%d!!!\n", nFps);

    pAVStream = av_new_stream(pAVContext, 0);
    if (!pAVStream) {
        fprintf(stderr, "Could not alloc stream\n");
        NULL;
    }

    pCodecContext = pAVStream->codec;
    pCodecContext->codec_id = pAVContext->oformat->video_codec;
    pCodecContext->codec_type = AVMEDIA_TYPE_VIDEO;

    pCodecContext->bit_rate = 400000;

    pCodecContext->width  = nWidth;
    pCodecContext->height = nHeight;

    pCodecContext->time_base.den = nFps;
    pCodecContext->time_base.num = 1;
    pCodecContext->gop_size = 12;                   /* emit one intra frame every twelve frames at most */
    pCodecContext->pix_fmt = PIX_FMT_YUVJ422P;
    if (pCodecContext->codec_id == CODEC_ID_MPEG2VIDEO) {
        pCodecContext->max_b_frames = 2;
    }
    if (pCodecContext->codec_id == CODEC_ID_MPEG1VIDEO) {
        pCodecContext->mb_decision=2;
    }
    if(pAVContext->oformat->flags & AVFMT_GLOBALHEADER)
        pCodecContext->flags |= CODEC_FLAG_GLOBAL_HEADER;

    pCodecContext = pAVStream->codec;
//  codec = avcodec_find_encoder(pCodecContext->codec_id);
//  if (!codec) {
//  //  fprintf(stderr, "codec not found\n");
//  //  return NULL;
//  }
//  if (avcodec_open(pCodecContext, codec) < 0) {
//  //  fprintf(stderr, "could not open codec\n");
//  //  return NULL;
//  }

    return pAVStream;
}