static void qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
                              int stride, int width, int height,
                              int delta, const uint8_t *ctable,
                              uint8_t *refdata)
{
    int i, j;
    int code;
    int filled = 0;
    int orig_height;

    /* copy prev frame */
    for(i = 0; i < height; i++)
        memcpy(refdata + (i * width), dst + (i * stride), width);

    orig_height = height;
    height--;
    dst = dst + height * stride;

    while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
        code = bytestream2_get_byte(&qctx->buffer);

        if(delta) {
            /* motion compensation */
            while((code & 0xF0) == 0xF0) {
                if(delta == 1) {
                    int me_idx;
                    int me_w, me_h, me_x, me_y;
                    uint8_t *me_plane;
                    int corr, val;

                    /* get block size by index */
                    me_idx = code & 0xF;
                    me_w = qpeg_table_w[me_idx];
                    me_h = qpeg_table_h[me_idx];

                    /* extract motion vector */
                    corr = bytestream2_get_byte(&qctx->buffer);

                    val = corr >> 4;
                    if(val > 7)
                        val -= 16;
                    me_x = val;

                    val = corr & 0xF;
                    if(val > 7)
                        val -= 16;
                    me_y = val;

                    /* check motion vector */
                    if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
                       (height - me_y - me_h < 0) || (height - me_y >= orig_height) ||
                       (filled + me_w > width) || (height - me_h < 0))
                        av_log(qctx->avctx, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
                               me_x, me_y, me_w, me_h, filled, height);
                    else {
                        /* do motion compensation */
                        me_plane = refdata + (filled + me_x) + (height - me_y) * width;
                        for(j = 0; j < me_h; j++) {
                            for(i = 0; i < me_w; i++)
                                dst[filled + i - (j * stride)] = me_plane[i - (j * width)];
                        }
                    }
                }
                code = bytestream2_get_byte(&qctx->buffer);
            }
        }

        if(code == 0xE0) /* end-of-picture code */
            break;
        if(code > 0xE0) { /* run code: 0xE1..0xFF */
            int p;

            code &= 0x1F;
            p = bytestream2_get_byte(&qctx->buffer);
            for(i = 0; i <= code; i++) {
                dst[filled++] = p;
                if(filled >= width) {
                    filled = 0;
                    dst -= stride;
                    height--;
                    if (height < 0)
                        break;
                }
            }
        } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
            code &= 0x1F;

            for(i = 0; i <= code; i++) {
                dst[filled++] = bytestream2_get_byte(&qctx->buffer);
                if(filled >= width) {
                    filled = 0;
                    dst -= stride;
                    height--;
                    if (height < 0)
                        break;
                }
            }
        } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
            int skip;

            code &= 0x3F;
            /* codes 0x80 and 0x81 are actually escape codes,
               skip value minus constant is in the next byte */
            if(!code)
                skip = bytestream2_get_byte(&qctx->buffer) +  64;
            else if(code == 1)
                skip = bytestream2_get_byte(&qctx->buffer) + 320;
            else
                skip = code;
            filled += skip;
            while( filled >= width) {
                filled -= width;
                dst -= stride;
                height--;
                if(height < 0)
                    break;
            }
        } else {
            /* zero code treated as one-pixel skip */
            if(code) {
                dst[filled++] = ctable[code & 0x7F];
            }
            else
                filled++;
            if(filled >= width) {
                filled = 0;
                dst -= stride;
                height--;
            }
        }
    }
}