val = enc->width;
val = enc->width && enc->pix_fmt != PIX_FMT_NONE;
static int has_codec_parameters(AVCodecContext *enc){    int val;    switch(enc->codec_type) {    case CODEC_TYPE_AUDIO:        val = enc->sample_rate;        break;    case CODEC_TYPE_VIDEO:        val = enc->width;        break;    default:        val = 1;        break;    }    return (val != 0);}