Function msmpeg4_decode_picture_header

libavcodec/msmpeg4.c:1382–1546

}

int msmpeg4_decode_picture_header(MpegEncContext * s)
{
    int code;

#if 0
{
int i;
for(i=0; i<s->gb.size_in_bits; i++)
    av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
//    get_bits1(&s->gb);
av_log(s->avctx, AV_LOG_DEBUG, "END\n");
return -1;
}
#endif

    if(s->msmpeg4_version==1){
        int start_code;
        start_code = (get_bits(&s->gb, 16)<<16) | get_bits(&s->gb, 16);
        if(start_code!=0x00000100){
            av_log(s->avctx, AV_LOG_ERROR, "invalid startcode\n");
            return -1;
        }

        skip_bits(&s->gb, 5); // frame number */
    }

    s->pict_type = get_bits(&s->gb, 2) + 1;
    if (s->pict_type != FF_I_TYPE &&
        s->pict_type != FF_P_TYPE){
        av_log(s->avctx, AV_LOG_ERROR, "invalid picture type\n");
        return -1;
    }
#if 0
{
    static int had_i=0;
    if(s->pict_type == FF_I_TYPE) had_i=1;
    if(!had_i) return -1;
}
#endif
    s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
    if(s->qscale==0){
        av_log(s->avctx, AV_LOG_ERROR, "invalid qscale\n");
        return -1;
    }

    if (s->pict_type == FF_I_TYPE) {
        code = get_bits(&s->gb, 5);
        if(s->msmpeg4_version==1){
            if(code==0 || code>s->mb_height){
                av_log(s->avctx, AV_LOG_ERROR, "invalid slice height %d\n", code);
                return -1;
            }

            s->slice_height = code;
        }else{
            /* 0x17: one slice, 0x18: two slices, ... */
            if (code < 0x17){
                av_log(s->avctx, AV_LOG_ERROR, "error, slice code was %X\n", code);