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Refactor standard macroblock decoder.
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@bsmiles32
bsmiles32 committed Dec 1, 2013
1 parent 7f34cc8 commit 8979df7
Showing 1 changed file with 28 additions and 35 deletions.
63 changes: 28 additions & 35 deletions src/jpeg.c
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Expand Up @@ -33,7 +33,7 @@
#define SUBBLOCK_SIZE 64

typedef void (*tile_line_emitter_t)(const int16_t *y, const int16_t *u, uint32_t address);
typedef void (*std_macroblock_decoder_t)(int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE]);
typedef void (*subblock_transform_t)(int16_t* dst, const int16_t* src);

/* rdram operations */
// FIXME: these functions deserve their own module
Expand All @@ -43,7 +43,10 @@ static uint32_t rdram_read_u32(uint32_t address);
static void rdram_write_many_u32(const uint32_t *src, uint32_t address, unsigned int count);

/* standard jpeg ucode decoder */
static void jpeg_decode_std(const char * const version, const std_macroblock_decoder_t decode_mb, const tile_line_emitter_t emit_line);
static void jpeg_decode_std(const char * const version,
const subblock_transform_t transform_luma,
const subblock_transform_t transform_chroma,
const tile_line_emitter_t emit_line);

/* helper functions */
static uint8_t clamp_u8(int16_t x);
Expand All @@ -60,9 +63,11 @@ static void EmitYUVTileLine(const int16_t *y, const int16_t *u, uint32_t address
static void EmitRGBATileLine(const int16_t *y, const int16_t *u, uint32_t address);

/* macroblocks operations */
static void DecodeMacroblock1(int16_t *macroblock, int32_t *y_dc, int32_t *u_dc, int32_t *v_dc, const int16_t *qtable);
static void DecodeMacroblock2(int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE]);
static void DecodeMacroblock3(int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE]);
static void decode_macroblock_ob(int16_t *macroblock, int32_t *y_dc, int32_t *u_dc, int32_t *v_dc, const int16_t *qtable);
static void decode_macroblock_std(
const subblock_transform_t transform_luma,
const subblock_transform_t transform_chroma,
int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE]);
static void EmitTilesMode0(const tile_line_emitter_t emit_line, const int16_t *macroblock, uint32_t address);
static void EmitTilesMode2(const tile_line_emitter_t emit_line, const int16_t *macroblock, uint32_t address);

Expand Down Expand Up @@ -145,7 +150,7 @@ static const float IDCT_K[10] =
**************************************************************************/
void jpeg_decode_PS0()
{
jpeg_decode_std("PS0", DecodeMacroblock3, EmitYUVTileLine);
jpeg_decode_std("PS0", RescaleYSubBlock, RescaleUVSubBlock, EmitYUVTileLine);
}

/***************************************************************************
Expand All @@ -154,7 +159,7 @@ void jpeg_decode_PS0()
**************************************************************************/
void jpeg_decode_PS()
{
jpeg_decode_std("PS", DecodeMacroblock2, EmitRGBATileLine);
jpeg_decode_std("PS", NULL, NULL, EmitRGBATileLine);
}

/***************************************************************************
Expand Down Expand Up @@ -197,7 +202,7 @@ void jpeg_decode_OB()
int16_t macroblock[6*SUBBLOCK_SIZE];

rdram_read_many_u16((uint16_t*)macroblock, address, 6*SUBBLOCK_SIZE);
DecodeMacroblock1(macroblock, &y_dc, &u_dc, &v_dc, (qscale != 0) ? qtable : NULL);
decode_macroblock_ob(macroblock, &y_dc, &u_dc, &v_dc, (qscale != 0) ? qtable : NULL);
EmitTilesMode2(EmitYUVTileLine, macroblock, address);

address += (2*6*SUBBLOCK_SIZE);
Expand All @@ -206,7 +211,10 @@ void jpeg_decode_OB()


/* local functions */
static void jpeg_decode_std(const char * const version, const std_macroblock_decoder_t decode_mb, const tile_line_emitter_t emit_line)
static void jpeg_decode_std(const char * const version,
const subblock_transform_t transform_luma,
const subblock_transform_t transform_chroma,
const tile_line_emitter_t emit_line)
{
int16_t qtables[3][SUBBLOCK_SIZE];
unsigned int mb;
Expand Down Expand Up @@ -259,7 +267,8 @@ static void jpeg_decode_std(const char * const version, const std_macroblock_dec
for (mb = 0; mb < macroblock_count; ++mb)
{
rdram_read_many_u16((uint16_t*)macroblock, address, macroblock_size);
decode_mb(macroblock, subblock_count, (const int16_t (*)[SUBBLOCK_SIZE])qtables);
decode_macroblock_std(transform_luma, transform_chroma,
macroblock, subblock_count, (const int16_t (*)[SUBBLOCK_SIZE])qtables);

if (mode == 0)
{
Expand Down Expand Up @@ -399,7 +408,7 @@ static void EmitTilesMode2(const tile_line_emitter_t emit_line, const int16_t *m
}
}

static void DecodeMacroblock1(int16_t *macroblock, int32_t *y_dc, int32_t *u_dc, int32_t *v_dc, const int16_t *qtable)
static void decode_macroblock_ob(int16_t *macroblock, int32_t *y_dc, int32_t *u_dc, int32_t *v_dc, const int16_t *qtable)
{
int sb;

Expand All @@ -426,28 +435,10 @@ static void DecodeMacroblock1(int16_t *macroblock, int32_t *y_dc, int32_t *u_dc,
}
}

static void DecodeMacroblock2(int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE])
{
unsigned int sb;
unsigned int q = 0;

for (sb = 0; sb < subblock_count; ++sb)
{
int16_t tmp_sb[SUBBLOCK_SIZE];
const int isChromaSubBlock = (subblock_count - sb <= 2);

if (isChromaSubBlock) { ++q; }

MultSubBlocks(macroblock, macroblock, qtables[q], 4);
ZigZagSubBlock(tmp_sb, macroblock);
InverseDCTSubBlock(macroblock, tmp_sb);

macroblock += SUBBLOCK_SIZE;
}

}

static void DecodeMacroblock3(int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE])
static void decode_macroblock_std(
const subblock_transform_t transform_luma,
const subblock_transform_t transform_chroma,
int16_t *macroblock, unsigned int subblock_count, const int16_t qtables[3][SUBBLOCK_SIZE])
{
unsigned int sb;
unsigned int q = 0;
Expand All @@ -465,11 +456,13 @@ static void DecodeMacroblock3(int16_t *macroblock, unsigned int subblock_count,

if (isChromaSubBlock)
{
RescaleUVSubBlock(macroblock, macroblock);
if (transform_chroma != NULL)
transform_chroma(macroblock, macroblock);
}
else
{
RescaleYSubBlock(macroblock, macroblock);
if (transform_luma != NULL)
transform_luma(macroblock, macroblock);
}

macroblock += SUBBLOCK_SIZE;
Expand Down

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