codec = avcodec_find_encoder_by_name(CODEC_NAME);
if (!codec) {
    cerr << "Codec " << codec_name << " not foundn";
    exit(1);
}

c = avcodec_alloc_context3(codec);
if (!c) {
    cerr << "Could not allocate video codec contextn";
    exit(1);
}

pkt = av_packet_alloc();
if (!pkt)
    exit(1);

/* put sample parameters */
c->bit_rate = 400000;
/* resolution must be a multiple of two */
c->width = PIC_HEIGHT;
c->height = PIC_WIDTH;
/* frames per second */
c->time_base = (AVRational){1, FPS};
c->framerate = (AVRational){FPS, 1};
c->gop_size = 10;
c->max_b_frames = 1;
c->pix_fmt = AV_PIX_FMT_YUV420P;
c->rtp_payload_size = 30000;
if (codec->id == AV_CODEC_ID_H264)
    av_opt_set(c->priv_data, "preset", "fast", 0);
av_opt_set_int(c->priv_data, "slice-max-size", 30000, 0);
/* open it */
ret = avcodec_open2(c, codec, NULL);
if (ret < 0) {
    cerr << "Could not open codecn";
    exit(1);
}

void DeviceSource::deliverFrame() {
    if (!isCurrentlyAwaitingData()) return; // we're not ready for the data yet

    u_int8_t* newFrameDataStart = (u_int8_t*) pkt->data;
    unsigned newFrameSize = pkt->size; //%%% TO BE WRITTEN %%%
    // Deliver the data here:
    if (newFrameSize > fMaxSize) { // Condition becomes true many times
        fFrameSize = fMaxSize;
        fNumTruncatedBytes = newFrameSize - fMaxSize;
    } else {
        fFrameSize = newFrameSize;
    }
    gettimeofday(&fPresentationTime, NULL); // If you have a more accurate time - e.g., from an encoder - then use that instead.
    // If the device is *not* a 'live source' (e.g., it comes instead from a file or buffer), then set "fDurationInMicroseconds" here.
    memmove(fTo, newFrameDataStart, fFrameSize);
}