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up to 20% faster multi-threaded decoding

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Mostly visible for large images.
Reconstruction+filtering is now done in parallel to bitstream-parsing.

Change-Id: I4cc4483d803b255f4d97a2fcd9158b1c291dd900
This commit is contained in:
skal 2013-10-15 00:25:21 +02:00
parent 38efdc2e9c
commit 0532149c8a
4 changed files with 49 additions and 33 deletions
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57
src/dec/frame.c
View File

@ -21,6 +21,9 @@ extern "C" {
#define ALIGN_MASK (32 - 1)
static void ReconstructRow(const VP8Decoder* const dec,
const VP8ThreadContext* ctx); // TODO(skal): remove
//------------------------------------------------------------------------------
// Filtering
@ -41,9 +44,10 @@ static WEBP_INLINE int hev_thresh_from_level(int level, int keyframe) {
static void DoFilter(const VP8Decoder* const dec, int mb_x, int mb_y) {
const VP8ThreadContext* const ctx = &dec->thread_ctx_;
const int cache_id = ctx->id_;
const int y_bps = dec->cache_y_stride_;
VP8FInfo* const f_info = ctx->f_info_ + mb_x;
uint8_t* const y_dst = dec->cache_y_ + ctx->id_ * 16 * y_bps + mb_x * 16;
uint8_t* const y_dst = dec->cache_y_ + cache_id * 16 * y_bps + mb_x * 16;
const int level = f_info->f_level_;
const int ilevel = f_info->f_ilevel_;
const int limit = 2 * level + ilevel;
@ -65,8 +69,8 @@ static void DoFilter(const VP8Decoder* const dec, int mb_x, int mb_y) {
}
} else { // complex
const int uv_bps = dec->cache_uv_stride_;
uint8_t* const u_dst = dec->cache_u_ + ctx->id_ * 8 * uv_bps + mb_x * 8;
uint8_t* const v_dst = dec->cache_v_ + ctx->id_ * 8 * uv_bps + mb_x * 8;
uint8_t* const u_dst = dec->cache_u_ + cache_id * 8 * uv_bps + mb_x * 8;
uint8_t* const v_dst = dec->cache_v_ + cache_id * 8 * uv_bps + mb_x * 8;
const int hev_thresh =
hev_thresh_from_level(level, dec->frm_hdr_.key_frame_);
if (mb_x > 0) {
@ -164,25 +168,29 @@ static void PrecomputeFilterStrengths(VP8Decoder* const dec) {
static int FinishRow(VP8Decoder* const dec, VP8Io* const io) {
int ok = 1;
const VP8ThreadContext* const ctx = &dec->thread_ctx_;
const int cache_id = ctx->id_;
const int extra_y_rows = kFilterExtraRows[dec->filter_type_];
const int ysize = extra_y_rows * dec->cache_y_stride_;
const int uvsize = (extra_y_rows / 2) * dec->cache_uv_stride_;
const int y_offset = ctx->id_ * 16 * dec->cache_y_stride_;
const int uv_offset = ctx->id_ * 8 * dec->cache_uv_stride_;
const int y_offset = cache_id * 16 * dec->cache_y_stride_;
const int uv_offset = cache_id * 8 * dec->cache_uv_stride_;
uint8_t* const ydst = dec->cache_y_ - ysize + y_offset;
uint8_t* const udst = dec->cache_u_ - uvsize + uv_offset;
uint8_t* const vdst = dec->cache_v_ - uvsize + uv_offset;
const int first_row = (ctx->mb_y_ == 0);
const int last_row = (ctx->mb_y_ >= dec->br_mb_y_ - 1);
int y_start = MACROBLOCK_VPOS(ctx->mb_y_);
int y_end = MACROBLOCK_VPOS(ctx->mb_y_ + 1);
const int mb_y = ctx->mb_y_;
const int is_first_row = (mb_y == 0);
const int is_last_row = (mb_y >= dec->br_mb_y_ - 1);
ReconstructRow(dec, ctx);
if (ctx->filter_row_) {
FilterRow(dec);
}
if (io->put != NULL) {
if (!first_row) {
int y_start = MACROBLOCK_VPOS(mb_y);
int y_end = MACROBLOCK_VPOS(mb_y + 1);
if (!is_first_row) {
y_start -= extra_y_rows;
io->y = ydst;
io->u = udst;
@ -193,7 +201,7 @@ static int FinishRow(VP8Decoder* const dec, VP8Io* const io) {
io->v = dec->cache_v_ + uv_offset;
}
if (!last_row) {
if (!is_last_row) {
y_end -= extra_y_rows;
}
if (y_end > io->crop_bottom) {
@ -234,8 +242,8 @@ static int FinishRow(VP8Decoder* const dec, VP8Io* const io) {
}
}
// rotate top samples if needed
if (ctx->id_ + 1 == dec->num_caches_) {
if (!last_row) {
if (cache_id + 1 == dec->num_caches_) {
if (!is_last_row) {
memcpy(dec->cache_y_ - ysize, ydst + 16 * dec->cache_y_stride_, ysize);
memcpy(dec->cache_u_ - uvsize, udst + 8 * dec->cache_uv_stride_, uvsize);
memcpy(dec->cache_v_ - uvsize, vdst + 8 * dec->cache_uv_stride_, uvsize);
@ -270,6 +278,11 @@ int VP8ProcessRow(VP8Decoder* const dec, VP8Io* const io) {
ctx->id_ = dec->cache_id_;
ctx->mb_y_ = dec->mb_y_;
ctx->filter_row_ = filter_row;
{
VP8MBData* const tmp = ctx->mb_data_;
ctx->mb_data_ = dec->mb_data_;
dec->mb_data_ = tmp;
}
if (filter_row) { // just swap filter info
VP8FInfo* const tmp = ctx->f_info_;
ctx->f_info_ = dec->f_info_;
@ -419,7 +432,8 @@ static int AllocateMemory(VP8Decoder* const dec) {
mb_w * (dec->use_threads_ ? 2 : 1) * sizeof(VP8FInfo)
: 0;
const size_t yuv_size = YUV_SIZE * sizeof(*dec->yuv_b_);
const size_t mb_data_size = mb_w * sizeof(*dec->mb_data_);
const size_t mb_data_size =
(dec->use_threads_ ? 2 : 1) * mb_w * sizeof(*dec->mb_data_);
const size_t cache_height = (16 * num_caches
+ kFilterExtraRows[dec->filter_type_]) * 3 / 2;
const size_t cache_size = top_size * cache_height;
@ -472,6 +486,10 @@ static int AllocateMemory(VP8Decoder* const dec) {
mem += yuv_size;
dec->mb_data_ = (VP8MBData*)mem;
dec->thread_ctx_.mb_data_ = (VP8MBData*)mem;
if (dec->use_threads_) {
dec->thread_ctx_.mb_data_ += mb_w;
}
mem += mb_data_size;
dec->cache_y_stride_ = 16 * mb_w;
@ -576,14 +594,17 @@ static void DoUVTransform(uint32_t bits, const int16_t* const src,
}
}
void VP8ReconstructBlocks(const VP8Decoder* const dec, int mb_y) {
static void ReconstructRow(const VP8Decoder* const dec,
const VP8ThreadContext* ctx) {
int j;
int mb_x;
const int mb_y = ctx->mb_y_;
const int cache_id = ctx->id_;
uint8_t* const y_dst = dec->yuv_b_ + Y_OFF;
uint8_t* const u_dst = dec->yuv_b_ + U_OFF;
uint8_t* const v_dst = dec->yuv_b_ + V_OFF;
for (mb_x = 0; mb_x < dec->mb_w_; ++mb_x) {
const VP8MBData* const block = dec->mb_data_ + mb_x;
const VP8MBData* const block = ctx->mb_data_ + mb_x;
// Rotate in the left samples from previously decoded block. We move four
// pixels at a time for alignment reason, and because of in-loop filter.
@ -676,8 +697,8 @@ void VP8ReconstructBlocks(const VP8Decoder* const dec, int mb_y) {
}
// Transfer reconstructed samples from yuv_b_ cache to final destination.
{
const int y_offset = dec->cache_id_ * 16 * dec->cache_y_stride_;
const int uv_offset = dec->cache_id_ * 8 * dec->cache_uv_stride_;
const int y_offset = cache_id * 16 * dec->cache_y_stride_;
const int uv_offset = cache_id * 8 * dec->cache_uv_stride_;
uint8_t* const y_out = dec->cache_y_ + mb_x * 16 + y_offset;
uint8_t* const u_out = dec->cache_u_ + mb_x * 8 + uv_offset;
uint8_t* const v_out = dec->cache_v_ + mb_x * 8 + uv_offset;

4
src/dec/idec.c
View File

@ -472,9 +472,7 @@ static VP8StatusCode DecodeRemaining(WebPIDecoder* const idec) {
}
VP8InitScanline(dec); // Prepare for next scanline
// Reconstruct the samples.
VP8ReconstructBlocks(dec, dec->mb_y_);
// Filter and emit the row.
// Reconstruct, filter and emit the row.
if (!VP8ProcessRow(dec, io)) {
return IDecError(idec, VP8_STATUS_USER_ABORT);
}

4
src/dec/vp8.c
View File

@ -657,9 +657,7 @@ static int ParseFrame(VP8Decoder* const dec, VP8Io* io) {
}
VP8InitScanline(dec); // Prepare for next scanline
// Reconstruct the samples.
VP8ReconstructBlocks(dec, dec->mb_y_);
// Filter and emit the row.
// Reconstruct, filter and emit the row.
if (!VP8ProcessRow(dec, io)) {
return VP8SetError(dec, VP8_STATUS_USER_ABORT, "Output aborted.");
}

17
src/dec/vp8i.h
View File

@ -197,11 +197,12 @@ typedef struct {
// Persistent information needed by the parallel processing
typedef struct {
int id_; // cache row to process (in [0..2])
int mb_y_; // macroblock position of the row
int filter_row_; // true if row-filtering is needed
VP8FInfo* f_info_; // filter strengths
VP8Io io_; // copy of the VP8Io to pass to put()
int id_; // cache row to process (in [0..2])
int mb_y_; // macroblock position of the row
int filter_row_; // true if row-filtering is needed
VP8FInfo* f_info_; // filter strengths (swapped with dec->f_info_)
VP8MBData* mb_data_; // reconstruction data (swapped with dec->mb_data_)
VP8Io io_; // copy of the VP8Io to pass to put()
} VP8ThreadContext;
// Saved top samples, per macroblock. Fits into a cache-line.
@ -287,8 +288,8 @@ struct VP8Decoder {
size_t mem_size_;
// Per macroblock non-persistent infos.
int mb_x_, mb_y_; // current position, in macroblock units
VP8MBData* mb_data_; // reconstruction data
int mb_x_, mb_y_; // current position, in macroblock units
VP8MBData* mb_data_; // parsed reconstruction data
// Filtering side-info
int filter_type_; // 0=off, 1=simple, 2=complex
@ -324,8 +325,6 @@ void VP8ParseQuant(VP8Decoder* const dec);
// in frame.c
int VP8InitFrame(VP8Decoder* const dec, VP8Io* io);
// Reconstruct a full row of blocks (prediction + residual adding)
void VP8ReconstructBlocks(const VP8Decoder* const dec, int mb_y);
// Call io->setup() and finish setting up scan parameters.
// After this call returns, one must always call VP8ExitCritical() with the
// same parameters. Both functions should be used in pair. Returns VP8_STATUS_OK