Function jpeg_decode_OB

Source/Core/JpegTask.cpp:199–232

* JPEG decoding ucode found in Ogre Battle and Bottom of the 9th. **************************************************************************/

 * JPEG decoding ucode found in Ogre Battle and Bottom of the 9th.
 **************************************************************************/
void jpeg_decode_OB(OSTask *task)
{
    s16 qtable[SUBBLOCK_SIZE] {};
    u32 mb {};

    s32 y_dc {}, u_dc {}, v_dc {};

	u32  address  {(u32)task->t.data_ptr};
	const u32 macroblock_count {task->t.data_size};
	const u32  qscale   {task->t.yield_data_size};

    if (task->t.yield_data_size != 0 )
    {
        if (task->t.yield_data_size > 0)
        {
            ScaleSubBlock(qtable, DEFAULT_QTABLE, qscale);
        }
        else
        {
            RShiftSubBlock(qtable, DEFAULT_QTABLE, -qscale);
        }
    }

    for (mb = 0; mb < macroblock_count; ++mb)
    {
        s16 macroblock[6*SUBBLOCK_SIZE];

        rdram_read_many_u16((u16*)macroblock, address, 6*SUBBLOCK_SIZE);
        DecodeMacroblock1(macroblock, &y_dc, &u_dc, &v_dc, (qscale != 0) ? qtable : nullptr);
        EmitTilesMode2(EmitYUVTileLine, macroblock, address);

        address += (2*6*SUBBLOCK_SIZE);
    }
}

static u8 clamp_u8(s16 x)
{